阅读说明：本技术 用于球形组件的设备和方法 (Apparatus and method for spherical assembly ) 是由 埃萨姆·阿卜杜勒拉赫曼·阿马尔 于 2020-05-13 设计创作，主要内容包括：提供了推进设备和对应的方法。该设备在球形组件内采用可以在球形组件内旋转的重物。作用于重物上的重力导致重力的力矩被施加到球形组件,这可以导致对球形组件的推进。球形组件还可以包括一个或更多个马达,用于使重物在球形组件内旋转。在一些实施方案中,重物包括磁芯和导体。该设备可以包括提供磁通的磁绕组,重物可以旋转经过该磁通。该设备还可以向导体提供电流。当带有磁芯的重物旋转经过磁通时,该设备向导体施加电流。因此,磁力被施加到重物,这可以推进球形组件。(A propulsion device and corresponding method are provided. The apparatus employs a weight within a spherical assembly that can rotate within the spherical assembly. Gravity acting on the weight causes a moment of gravity to be applied to the spherical assembly, which may result in propulsion of the spherical assembly. The spherical assembly may further include one or more motors for rotating the weight within the spherical assembly. In some embodiments, the weight includes a magnetic core and a conductor. The apparatus may include a magnetic winding providing a magnetic flux through which the weight may rotate. The device may also provide current to the conductor. The apparatus applies a current to the conductor as the weight with the magnetic core rotates through the magnetic flux. Thus, a magnetic force is applied to the weight, which may propel the spherical assembly.)

1. A spherical assembly, comprising:

a spherical shell;

a first motor connected to a first weight and the spherical housing;

a second motor connected to a second weight and the spherical housing;

a third motor connected to a third weight and the spherical housing; and

a controller operably coupled to the first motor, the second motor, and the third motor, and configured to:

causing the first motor to rotate the first weight in a first direction at a first rotational speed based on a rotational speed of the spherical assembly;

causing the second motor to rotate the second weight in a second direction at a second rotational speed based on the rotational speed of the spherical assembly; and

rotating the third weight in the second direction at the second rotational speed with the third motor;

causing the first motor to change the first rotational speed of the first weight relative to the second rotational speeds of the second and third weights to change a direction of travel of the ball assembly.

2. The ball assembly of claim 1, wherein the first weight weighs about twice the weight of each of the second and third weights.

3. The spherical assembly of claim 2, wherein the controller is configured to rotate the first weight to counteract a centrifugal force on the spherical assembly caused by rotation of at least the second and third weights.

4. The ball assembly according to claim 1, wherein the controller is configured to cause the first rotational speed of the first motor and the second rotational speeds of the second and third motors to be the rotational speeds of the ball assembly.

5. The ball assembly of claim 1, wherein the controller is configured to cause the first motor to rotate the first weight such that the first weight provides a maximum gravitational moment about a point along a central axis of the ball assembly.

6. The ball assembly of claim 5, wherein the controller is configured to cause the second motor to rotate the second weight such that the second weight provides a maximum gravitational moment about the point along the central axis of the ball assembly while the controller causes the first motor to rotate the first weight to provide a maximum gravitational moment about the central axis of the ball assembly.

7. The ball assembly of claim 1, wherein the controller is configured to cause: the first motor changing the first rotational speed of the first weight to the rotational speed of the spherical assembly; and

the second motor changes the second rotational speed of the second weight to the rotational speed of the spherical assembly.

8. The spherical assembly of claim 1, wherein the controller is configured to cause the first and second motors to rotate the first and second weights such that a center of gravity of the first weight and a center of gravity of the second weight are maintained in a half of the spherical housing.

9. The ball assembly according to claim 1, wherein at least one of the first weight and the second weight is coupled to a current conductor, wherein the controller is configured to pass current through the current conductor based on the rotational speed of the ball assembly.

10. A spherical assembly, comprising:

a spherical inner component surrounding:

a first motor connected to a first weight;

a second motor connected to a second weight; and

a controller operably coupled to the first motor and to the second motor and configured to:

causing the first motor to rotate the first weight in a first direction at a first rotational speed of rotational speeds based on the spherical inner assembly;

causing the second motor to rotate the second weight in a second direction at a second rotational speed based on the rotational speed of the spherical inner assembly; and

changing the first rotational speed of the first motor in association with the second rotational speed of the second motor to change a direction of travel of the spherical assembly; and

a spherical outer component surrounding:

the spherical inner component; and

a friction reducer configured to minimize friction between the spherical inner component and the spherical outer component.

11. The spherical assembly of claim 10, further comprising a first magnetic winding partially attached to the spherical outer assembly and a second magnetic winding partially attached to the spherical inner assembly.

12. The spherical assembly of claim 11, wherein a polarity of the first magnetic winding is opposite a polarity of the second magnetic winding, and wherein at least one of the first and second weights is coupled to a magnetic core and a current carrying conductor.

13. The spherical assembly of claim 10, wherein the friction reducer comprises at least one ball bearing.

14. The ball assembly of claim 10, the first weight weighing at least twice as much as each of the second and third weights.

15. The spherical assembly of claim 10, further comprising at least one motion detector in communication with the controller and configured to detect a rotational speed of the spherical inner assembly.

16. A method of propelling a spherical assembly, comprising:

rotating a first weight in a first direction at a first rotational speed by a first motor based on the rotational speed of the spherical assembly; and

rotating a second weight in a second direction at a second rotational speed by a second motor based on the rotational speed of the spherical assembly; and

changing the first rotational speed of the first motor in association with the second rotational speed of the second motor to change a direction of travel of the spherical assembly.

17. The method of claim 16, further comprising causing the first rotational speed of the first motor and the second rotational speed of the second motor to be the rotational speed of the spherical assembly.

18. The method of claim 16, further comprising:

causing the first motor to rotate the first weight to counteract centrifugal forces acting on the spherical assembly caused by rotation of at least the second and third weights.

19. The method of claim 16, further comprising rotating a third weight in the second direction at the second rotational speed with a third motor.

20. The ball assembly of claim 10, further comprising a third motor, wherein the controller is configured to rotate the third weight in the second direction at the second rotational speed.

FIELD

The present disclosure relates generally to propulsion (propulsion), and more particularly, to vehicle drive systems and corresponding methods of propulsion.

Background

Today's transportation vehicles include vehicle drive systems that are typically driven by an internal combustion engine, an electric motor, or in some cases a mixture of both, which provides the motive force for vehicle propulsion. These vehicles are also equipped with a steering mechanism and a gearbox that is controlled manually or automatically. These steering mechanisms allow for control of vehicle direction of travel, while the gearbox facilitates vehicle torque and speed. However, in order to change the direction of travel, the vehicle requires a circular area in which to perform a turn, also referred to as a turning radius.

To propel in a given direction, today's vehicles rely on a horizontal reaction friction between the vehicle's tires and the running surface (e.g., the road surface). The friction force is a vertical force at the point of contact between the tires of the vehicle and the running surface based on the coefficient of friction and the weight of the vehicle. Thus, the tire provides a horizontal force that is a reaction force of the equal horizontal force in the opposite direction due to friction. If the friction is low, slippage will occur between the tire and the running surface, which may occur on icy or muddy surfaces, where the coefficient of friction between the vehicle's tire and the icy or muddy surface may be less than the coefficient of friction between the vehicle's tire on a dry surface. When slippage occurs, the vehicle not only fails to propel as expected, but the vehicle also loses control over its direction of travel and also loses energy due to the slippage rather than using that energy for propulsion. There is therefore an opportunity to improve the vehicle drive systems of today.

SUMMARY

Briefly, the apparatus uses a weight within a spherical assembly, whereby the spherical assembly rotates the weight to propel the spherical assembly using gravity and the centrifugal force created by the rotating weight. For example, the apparatus may employ appropriately shaped weights within the spherical assembly, whereby the spherical assembly rotates the weights so that the center of gravity of the weights is continuously maintained in the front half of the spherical assembly regardless of its rotation, while the spherical assembly is propelled using the moment due to the gravitational forces acting on the weights and the centrifugal forces generated by the rotating weights.

In some embodiments, the spherical assembly includes a spherical housing, two motors (such as electric motors), two weights, and a controller (such as a processor). A first motor is connected to the first weight and the spherical housing, and a second motor is connected to the second weight and the spherical housing. For example, the motors may be connected to the spherical housing at positions opposite to each other along a centerline of the spherical housing. In some examples, the two weights are equally heavy.

A controller is operably coupled to the first motor and to the second motor such that the controller can control each of the motors (e.g., control the direction and speed of rotation of the motors). The controller is configured to cause the first motor to rotate the first weight in a particular direction at a rotational speed (e.g., a rotational rate), which may be based on a rotational (e.g., rolling) speed of the spherical assembly. For example, assuming that the spherical assembly rotates at a given rotational speed, the controller activates the first motor such that the first motor rotates the first weight at the same rotational speed as the rotational speed of the spherical assembly. As another example, the controller may cause the first motor to rotate the first weight at a rotational speed that is slower or greater than the rotational speed of the spherical assembly. Similarly, the controller is configured to cause the second motor to rotate the second weight in a particular direction at a rotational speed, which may also be based on the rotational speed of the spherical assembly. For example, the controller may be configured to cause the rotational speed of the first motor and the rotational speed of the second motor to be the rotational speed of the spherical assembly. In this way, the controller may maintain the center of gravity of the first and second weights in the half of the spherical assembly (e.g., in the front half of the spherical assembly, or in the half closest to the direction of travel of the spherical assembly) as the spherical assembly rotates.

In some examples, the controller causes the first motor to rotate the first weight in one direction and the second motor to rotate the second weight in the same or another direction. For example, the controller may cause the first motor to rotate the first weight in a clockwise direction and cause the second motor to rotate the second weight in a counterclockwise direction.

In some examples, the controller is configured to cause the first motor to change the rotational speed of the first weight from the current rotational speed to the current rotational speed of the spherical assembly. The processor may also cause the second motor to change the rotational speed of the second weight from the current rotational speed to the rotational speed of the spherical assembly. For example, the processor may cause the first motor and the second motor to cause the centers of gravity of the two counter-rotating weights to coincide in one half of the spherical assembly, which may be the rotating front half of the spherical assembly within a 360 degree horizontal plane of the spherical assembly. The first motor and the second motor may rotate in opposite directions.

In some examples, the controller is configured to cause the first motor to change the rotational speed of the first weight in association with the rotational speed of the second weight to change the direction of travel of the ball assembly. For example, the controller may be configured to cause the first motor to instantaneously change the rotation speed of the first weight in association with the opposite rotation speed of the second weight to horizontally shift a position where the centers of gravity of the two weights coincide. This results in a change in the direction of travel of the spherical assembly. As another example, assuming that the first and second motors rotate the first and second weights, respectively, at the same rotational speed (e.g., the controller causes the first and second motors to rotate at the same rotational speed), the controller may slow or speed up the first motor such that the rotational speed of the first weight is different from the rotational speed of the second weight. Similarly, the controller may slow or speed up the second motor so that the rotational speed of the second weight is different from the rotational speed of the first weight.

In some embodiments, the controller is configured to cause the first motor to rotate the first weight such that the first weight provides a maximum gravitational moment about a point along the central axis (i.e., the vertical radial centerline) of the spherical assembly. For example, assuming the spherical assembly is not rotating (e.g., is at rest), the center of gravity of the spherical assembly is along the central axis of the spherical assembly. The controller may rotate the first weight such that the center of gravity of the spherical assembly moves away from the central axis of the spherical assembly, thereby causing the spherical assembly to rotate.

In some embodiments, the controller is configured to cause the first and second motors to rotate the first and second weights, respectively, at opposite but equal speeds. The rotational speed of the weight may be equal to the rotational speed of the spherical assembly. The centers of gravity of the two weights may coincide at a particular position on an imaginary plane defined by the geometric vertical centerline of the spherical assembly and the direction of travel of the spherical assembly. In some examples, the controller is configured to cause the two motors to momentarily and equally slow or speed up their rotational speeds equal to but opposite to the rotational speed of the spherical assembly. The controller may also control the duration (e.g., length of time) of the momentary slowing or speeding of the rotation of the weight. By slowing down or speeding up the rotation speed of the weights, the centers of gravity of the two weights can coincide at a new position on the imaginary plane. The new position may be in the front or back half of the spherical assembly. For example, by having the center of gravity of the two weights coincide at the location of the rear half of the spherical assembly, the rotation of the spherical assembly may be slowed or stopped.

In some examples, the controller is configured to cause the second motor to rotate the second weight such that the second weight provides a maximum gravitational moment about a point along the central axis of the spherical assembly while the controller causes the first motor to rotate the first weight to provide a maximum gravitational moment about the central axis of the spherical assembly. As an example, assuming that the ball assembly rotates at a rotational speed, the controller may cause the first and second motors to rotate the first and second weights in opposite directions at the same rotational speed as the rotational speed of the ball assembly. In this example, the processor rotates the weights such that each time the spherical assembly rotates, the weights provide the maximum possible moment of gravity on the weights about the central axis of the spherical assembly twice.

In some embodiments, the planar surface of the first weight forms an angle greater than 0 degrees (e.g., 1 degree) with respect to the central axis of the spherical assembly. In some examples, the planar surface of the second weight forms an angle greater than 0 degrees with respect to the central axis of the spherical assembly. For example, the weights may be configured such that the sides of each weight face the center of the spherical assembly at the same angle. In some examples, the planar surfaces of the first and second weights form an angle of 0 degrees with respect to the central axis of the spherical assembly.

In some embodiments, the spherical component comprises a spherical inner component and a spherical outer component. The spherical inner assembly encloses a first motor connected to the first weight and a second motor connected to the second weight. The spherical inner assembly also encloses a controller operably coupled to the first motor and to the second motor. The controller may be configured to cause the first motor to rotate the first weight in one direction at a rotational speed that is based on a rotational speed of the spherical inner assembly. The controller may be further configured to cause the second motor to rotate the second motor in the same or a different direction at a rotational speed based on the rotational speed of the spherical inner assembly. For example, the controller may cause the first and second motors to rotate the first and second weights, respectively, at the same rotational speed but in opposite directions. As another example, the controller may cause the first and second motors to rotate the first and second weights, respectively, at a rotational speed of the spherical inner assembly.

In some examples, the spherical assembly may use electricity (e.g., via one or more electric motors) to rotate weights within the spherical assembly. In some embodiments, the weight may include a radial magnetic core and a cross current carrying conductor through which the device may provide current. The current carrying conductor may be embedded in the weight. For example, the device may provide radial magnetic flux through a radial magnetic core such that when the weight is rotated through the magnetic flux, a magnetic force is applied to the weight. The force may be perpendicular to the direction of the radial flux and the direction of the current flow. Magnetic forces may be used to propel the spherical assembly. For example, the magnetic force may increase the rotational speed of the spherical inner member. In some examples, the direction of current flow through the conductor may be reversed, which may result in a force being generated in the opposite direction. This force may cause the rotational speed of the ball assembly to decrease (e.g., slow down). Thus, the magnetic force generated may add to or counteract the gravitational force acting on the weight. The controller may control the current in the conductor to help speed up or slow down the spherical inner component. The controller may also adjust the rotational speed of the weight to match the new speed of the spherical inner assembly.

In some examples, the controller may adjust the rotational speed of the weight to match the rotational speed of the spherical inner assembly. In some examples, current is generated in the conductor as the weight rotates through the generated magnetic flux. The controller may direct the generated current to charge a battery positioned within the assembly.

In this way, the spherical assembly may operate without the internal combustion engine or independently of the internal combustion engine. The spherical assembly may also operate without or independently of a conventional gearbox and steering mechanism. In some examples, a vehicle (such as an automobile, truck, semi-truck, amphibious vehicle, or any other suitable vehicle) is propelled using one or more spherical components. For example, one or more of the spherical assemblies may be wirelessly controlled by the controller. Other uses will also be envisioned as would be recognized by those skilled in the art having the benefit of this disclosure.

In some examples, the spherical component further includes a first radial magnetic winding attached to the spherical outer component and a second magnetic winding attached to the spherical inner component. The first magnetic winding and the second magnetic winding may have opposite polarities, thereby generating a magnetic field between the spherical outer component and the spherical inner component. For example, the magnetic winding may provide a magnetic field from the spherical outer component to the spherical inner component or from the spherical inner component to the spherical outer component, thereby creating a magnetic flux between the spherical outer component and the spherical inner component in a given direction. In some examples, the magnetic windings may instead be rare earth permanent magnets.

In some examples, the vehicle includes one or more spherical assemblies, wherein each spherical assembly is surrounded by a spherical shell. The spherical shell may enclose more than half of the spherical assembly. The spherical shell may include magnetic windings with a polarity similar to the polarity of the magnetic windings located in the spherical outer component. In this way, the magnetic forces induced by the respective magnetic windings will oppose each other to provide magnetic levitation between the spherical shell and the spherical outer assembly.

In some examples, the spherical outer component surrounds the spherical inner component. The spherical inner component may also enclose a friction reducer configured to minimize friction between the spherical inner component and the spherical outer component. For example, the friction reducer may be a lubricant, such as oil, a mechanical device (such as a ball bearing), any combination of these, or any other known method of reducing friction. In one example, the friction reducer includes at least one ball bearing located in an oil flow path between the spherical inner component and the spherical outer component. In some examples, the spherical outer assembly includes an inner shell and an outer shell, wherein the inner shell is in contact with the friction reducer.

In some examples, the spherical assembly includes one or more motion detectors. A motion detector may be used to detect the rotational speed of the spherical inner component. A motion detector may also be used to detect the rotational speed of the spherical outer component. Any given motion detector may be in communication with the controller, whereby the controller may detect the rotational speed provided by the motion detector. For example, the controller may be electrically coupled to the motion detector, thereby allowing wired communication, or may communicate wirelessly with the motion detector.

In some examples, at least one motion detector is in communication with the controller and configured to detect a rotational speed of the spherical inner component. Based on the detected rotational speed of the spherical inner component, the controller may determine at what rotational speed (e.g., rate) to rotate the first motor and the second motor as described above. In some examples, the motion detector may be coupled to the spherical outer assembly such that detection of the rotational speed of the spherical inner assembly is relative to the rotational speed of the spherical outer assembly. In some examples, the rotational speed of the spherical inner assembly may be detected by the controller by monitoring the period of current drawn by the motors as they rotate their respective weights. For example, the controller may access a table stored in memory, such as a look-up table, that translates current consumption into motor workload. Based on the amount of current drawn, the controller may determine the workload of the respective motor. The controller may then employ one or more functions, such as a logarithmic function, to determine the rotational speed of the spherical inner member.

In some examples, at least one motion detector is in communication with the controller and configured to detect a rotational speed of the spherical outer assembly. In this manner, the controller may determine, for example, the "roll" speed of the spherical outer assembly.

In some examples, such as at higher rotational speeds, the rotating weight may induce a multi-directional centrifugal force on the spherical assembly. These centrifugal forces may create off-center reaction forces that create unintended moments that may affect the direction of travel of the spherical assembly. However, the controller may correct for these changes in direction based on the detected rotational speed, as described further above and below.

In some examples, the spherical assembly includes a rotating spherical housing, up to three motors (such as electric motors), three weights, and a controller (such as a processor). A first motor is connected to the first weight and the spherical housing, a second motor is connected to the second weight and the spherical housing, and a third motor is connected to the third weight and the spherical housing. For example, the motor may be connected to the spherical housing at a location along a centerline of the spherical housing. In some examples, the weight of one weight is twice the weight of each of the other two weights. For example, the weight of the lighter weights may be about the same, with the heavier weights weighing about twice the weight of each of the lighter weights. The heavier weights may be caused to rotate in one direction by the motor, while the lighter weights are caused to rotate in the opposite direction by the respective motor. The centers of gravity of the heavier weight and the two lighter weights may be caused by the respective motors to rotate with equal radii in three different equally spaced imaginary parallel planes, which may be perpendicular to the plane of the spherical shell. In this embodiment, as the weights rotate, centrifugal forces acting on the weights may propel the spherical assembly in the direction of travel (e.g., forward). In some examples, the controller rotates the heavier weight to counteract a centrifugal force, e.g., an undesirable centrifugal force, caused by the other two (and lighter) weights on the spherical assembly.

Methods of advancing the spherical assembly are also contemplated. These methods may be implemented, for example, by the spherical assembly described above or any component thereof. A method of advancing (e.g., by a controller) a spherical assembly includes causing a first motor to rotate a first weight in a first direction at a first rotational speed that is based on a rotational (e.g., rolling) speed of the spherical assembly. The method also includes causing a second motor to rotate a second weight in a second direction at a second rotational speed that is based on the rotational speed of the spherical assembly.

In some examples, the method further comprises causing the first rotational speed of the first weight and the second rotational speed of the second weight to be the rotational speed of the spherical assembly.

In some examples, the method includes causing the first motor to rotate the first weight such that the first weight provides a maximum gravitational moment about a point along the central axis of the spherical assembly. The method may further include causing a second motor to rotate a second weight such that the second weight provides a maximum gravitational moment about a point along the central axis of the spherical assembly. In some examples, the controller rotates the motor such that the gravitational moments provided by the first and second weights are simultaneous.

In some examples, the method includes changing a first rotational speed of the first motor in association with a second rotational speed of the second motor to change a direction of travel of the ball assembly.

In some examples, the method includes causing the first motor to rotate the first weight in a first direction at a first rotational speed, causing the second motor to rotate the second weight in a second and opposite direction, and causing the third motor to rotate the third weight in a second and opposite direction based on the rotational (e.g., rolling) speed of the spherical assembly. In some examples, the weight of the first weight is about twice the weight of each of the second and third weights (e.g., the second and third weights are the same weight, and the weight of the first weight is twice the weight of the second or third weight). The method may comprise rotating the first weight such that it counteracts the centrifugal force acting on the spherical assembly caused by the rotation of the second and third weights. Other methods in accordance with the disclosure herein are also contemplated.

Among other advantages, the apparatus and method may provide propulsion without the need for an internal combustion engine, a gearbox, or a conventional steering mechanism. The apparatus and method may also allow for changing the direction of travel without requiring a large turn radius. In some examples, the apparatus and methods provide propulsion for a land vehicle. In this way, the apparatus and method may improve road traction control and reduce road slip. The apparatus and method may also shorten the distance that the vehicle stops. Further, the apparatus may require fewer components than conventional internal combustion engines, and may also provide cost benefits.

In some examples, the apparatus and methods provide controlled centrifugal forces that may enable a land vehicle to overcome vertical terrain or propel a flying land vehicle close to the earth while allowing wireless charging of its battery. For example, one or more spherical components may provide initial propulsion for an aircraft (e.g., a rocket) by providing takeoff power during a takeoff phase. In some examples, one or more spherical assemblies may replace a maglev linear motor that propels a high speed train. This may reduce train operating costs, as the train system tracks required for a magnetic levitation train may be relatively expensive.

Other advantages of the disclosure will be apparent to those skilled in the art to which the disclosure pertains from a perusal of the claims, the appended drawings, and the following detailed description of the embodiments.

Brief Description of Drawings

FIG. 1 illustrates spheres of uniform density to illustrate the concepts of the prior art;

2A-2C illustrate a spherical assembly rotating a weight at a rotational speed of the spherical assembly according to some embodiments of the present disclosure;

3A-3C illustrate a spherical assembly rotating a weight at twice a rotational speed of the spherical assembly according to some embodiments of the present disclosure;

4A-4C illustrate a spherical assembly rotating a weight at a rotational speed three times that of the spherical assembly according to some embodiments of the present disclosure;

5A-5C illustrate a spherical assembly rotating a weight at a rotational speed of half that of the spherical assembly according to some embodiments of the present disclosure;

fig. 6 illustrates a ball assembly system according to some embodiments of the present disclosure;

fig. 7 illustrates an electrified spherical assembly system according to some embodiments of the present disclosure;

fig. 8 illustrates the spherical assembly of fig. 7 including additional outer surfaces, according to some embodiments of the present disclosure;

FIG. 9 illustrates a motion detector that may be used with the ball assembly of FIG. 6 according to some embodiments of the present disclosure;

fig. 10A and 10B illustrate weight configurations that may be used with the ball assembly of fig. 2A-2C, 6, or 7, according to some embodiments of the present disclosure;

11A and 11B illustrate a spherical assembly rotating two weights at a rotational speed of the spherical assembly according to some embodiments of the present disclosure;

12A and 12B illustrate a ball assembly rotating two weights at a rotational speed of the ball assembly according to some embodiments of the present disclosure;

13A, 13B, and 13C illustrate various embodiments of an electrified spherical assembly system with three weights according to some embodiments of the present disclosure;

figures 14A and 14B illustrate various views of a plurality of spherical components employed in a rocket, according to some embodiments of the present disclosure;

14C, 14D, 14E, and 14F illustrate examples of the ball assembly of FIGS. 14A and 14B according to some embodiments of the present disclosure; and

fig. 15 illustrates centrifugal forces acting on a spherical assembly according to some embodiments of the present disclosure.

Detailed Description

While the disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. The objects and advantages of the claimed subject matter will become more apparent from the following detailed description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings. It should be understood, however, that the disclosure is not intended to be limited to the particular forms disclosed. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the appended claims.

FIG. 1 illustrates a sphere 100 having a uniform density 102 in three dimensions identified by plane-1104, plane-2106, and plane-3108. For example, in an x, y, z coordinate system, plane-1104 may represent a plane along the x-direction, plane-3108 may represent a plane along the y-direction, and plane-2106 may represent a plane along the z-direction. The geometric center of sphere 102 is identified by point-1110. When placed on a surface, the sphere 102 will have a single point of contact, i.e., at point-2112. If gravity were the only force applied to the sphere 102, the sphere 102 would be stationary, in a stable equilibrium state. Because sphere 102 has a uniform density, its center of gravity appears along a vertical line that intersects points-2112 and-1110.

However, if a weight is embedded in the sphere 102, the sphere 102 will no longer have a uniform density. Thus, its center of gravity will shift and may lie outside the vertical line intersecting point-2112 and point-1110. For example, the center of gravity may shift to a vertical line that intersects plane-1104 and point-3114. The result is that (assuming no other forces are present) the sphere 102 will rotate (e.g., roll) in the direction of the plane-1104 toward the point-3114. The ball 102 will continue to rotate until a new stable equilibrium state is established. Specifically, when the sphere 102 has stopped rotating, the center of gravity of the sphere 102, identified by point-3114, will be along a vertical line passing through the new point of contact of the sphere 102 along plane-1104.

Fig. 2A-2C illustrate the ball assembly 200 in three views (i.e., a side view in fig. 2A, a top view in fig. 2B, and a schematic view in fig. 2C) as the ball assembly 200 rolls along a plane 295. The ball assembly 200 includes a ball housing 256, a first motor 248, a second motor 250, a first weight 252, and a second weight 254. The first motor 248 is connected to a first weight 252 and a spherical housing 256. Likewise, the second motor 250 is connected to a second weight 254 and a spherical housing 256. The side view in fig. 2A shows the ball assembly 200 from the side as the ball assembly 200 rotates along the plane 295. The top view in fig. 2B shows the ball assembly 200 as the same ball assembly 200 is rotated along plane 295, but from a top view. The schematic view in fig. 2C also shows the ball assembly 200 as the same ball assembly 200 is rotated along the plane 295, but the angle shown at each position shows one face (e.g., the planar side) of the weight.

Notably, as with reference to fig. 2A-2C and 3-5, it is assumed that the only forces acting on the spherical assembly 200 include the gravitational forces acting on the weights 252, 254 and the frictional forces in the direction of travel at the point of contact of the spherical assembly 200 with the flat surface 295 (e.g., the spherical assembly rolls on the flat surface 295 in vacuum). Assuming that the rotational speed of the spherical element 200 is constant, the three views of fig. 2A-2C show various points of the spherical element 200 after each eighth rotation along the plane 295. For example, in the side view of fig. 2A, position 202 is the beginning of a full rotation of the ball assembly 200 (and similarly at position 218 of the top view in fig. 2B and position 234 of the schematic view in fig. 2C). Position 204 shows the ball assembly 200 after one-eighth of a rotation (and similarly at position 220 in the top view of fig. 2B and position 236 in the schematic view of fig. 2C); position 206 shows the spherical assembly 200 after two-eighths of a rotation (and similarly at position 222 in the top view of fig. 2B and position 238 in the schematic view of fig. 2C); position 208 shows the spherical assembly 200 after three eighths of a turn (and similarly at position 224 in the top view of fig. 2B and position 240 in the schematic view of fig. 2C); position 210 shows the ball assembly 200 after four-eighths of a revolution (and similarly at position 226 in the top view of fig. 2B and position 242 in the schematic view of fig. 2C); position 212 shows the ball assembly 200 after five eighths of a revolution (and similarly at position 228 in the top view of fig. 2B and position 244 in the schematic view of fig. 2C); position 214 shows the ball assembly 200 after six-eighths of a revolution (and similarly at position 230 in the top view of fig. 2B and position 246 in the schematic view of fig. 2C); and position 216 shows the ball assembly 200 after seven eighths of a turn (and similarly at position 232 in the top view of fig. 2B and position 247 in the schematic view of fig. 2C). The top view of fig. 2B shows the same position of the spherical assembly as the side view of fig. 2A when rotated, but from an angle from above. The schematic view of fig. 2C shows the view if viewed from an angle perpendicular to the plane of the weight at each position.

Furthermore, in fig. 2A-2C and 3-5, the weights 252, 254 are shaped as half circles, with each weight in a separate half of the spherical assembly 200. However, it should be understood that the weights may be other shapes. For example, the weights may be shaped as less than a half circle, shaped as a square, shaped as a sphere, a disk, a spherical wedge, shaped as less than a quarter of a sphere, or any other shape.

In this example, motors 248, 250 rotate weights 252, 254, respectively, at the rotational speed of the spherical assembly. For example, the weights 252 and 254 complete one full revolution within the ball assembly 200, while the ball assembly 200 itself also completes one full revolution. Further, in this example, the motors 248, 250 rotate the weights 252, 254 in opposite directions. At position 202 in the side view of fig. 2A (and similarly at position 218 in the top view of fig. 2B and position 234 in the schematic view of fig. 2C), the weight provides the greatest gravitational moment about a point along the central axis of the ball assembly 200. At this position, the weights 252, 254 are coincident in the front half (i.e., the half closest to the direction of travel) of the spherical assembly 200. This is because, at this point in the rotation process, the weights 252, 254 are aligned along the central horizontal axis of the ball assembly 200 and are farthest from the central axis of the ball assembly 200.

As the ball rotates, the motors 248, 250 rotate the weights 252, 254 at the same rotational speed as the spherical assembly 200. Thus, after half a rotation of the ball-shaped assembly 200, identified by position 210 in side view (and similarly by position 226 in top view and position 242 in schematic view), the weights 252, 254 will again coincide in the front half of the ball-shaped assembly 200, but this time the weight 254 appears on top of the weight 252. However, the weights 252, 254 are again aligned along the central horizontal axis of the ball assembly 200. As such, they provide the greatest gravitational moment about a point along the central axis of the spherical assembly 200. In other words, the gravitational force acting on the weights 252, 254 provides a moment to the ball assembly 200 in the direction of travel of the ball assembly 200. In this way, the ball assembly 200 will continue to rotate in the same direction. As mentioned above, the three different views show the position of the weight in one-eighth rotation increments as the ball assembly rotates along the plane 295.

The direction of travel of the ball assembly 200 can be controlled by rotating the weights 252, 254 at a rotational speed that is greater than or less than the rotational speed of the ball assembly 200. For example, fig. 3A-3C again illustrate the spherical assembly 200 of fig. 2A-2C in three views (i.e., a side view in fig. 3A, a top view in fig. 3B, and a schematic view in fig. 3C) as it rolls along a plane 295. However, in this example, the motors 248, 250 rotate the weights 252, 254, respectively, at twice the rotational speed of the spherical assembly. As with fig. 2, the three different views in this example show the position of the weight in increments of every eighth revolution as the ball assembly rotates along the plane 295. Position 302 in the side view of fig. 3A corresponds to position 318 in the top view of fig. 3B and to position 334 in the schematic view of fig. 3C. Similarly, position 304 in the side view of fig. 3A corresponds to position 320 in the top view of fig. 3B and to position 336 in the schematic view of fig. 3C; position 306 in the side view of FIG. 3A corresponds to position 322 in the top view of FIG. 3B and to position 338 in the schematic view of FIG. 3C; position 308 in the side view of FIG. 3A corresponds to position 324 in the top view of FIG. 3B and to position 340 in the schematic view of FIG. 3C; position 310 in the side view of FIG. 3A corresponds to position 326 in the top view of FIG. 3B and to position 342 in the schematic view of FIG. 3C; position 312 in the side view of FIG. 3A corresponds to position 328 in the top view of FIG. 3B and to position 344 in the schematic view of FIG. 3C; position 314 in the side view of FIG. 3A corresponds to position 330 in the top view of FIG. 3B and to position 346 in the schematic view of FIG. 3C; and position 316 in the side view of fig. 3A corresponds to position 332 in the top view of fig. 3B and to position 348 in the schematic view of fig. 3C. At position 302 in the side view of fig. 3A (and similarly at position 318 in the top view of fig. 3B and position 334 in the schematic view of fig. 3C), the weights 252, 254 provide the greatest gravitational moment about a point along the central axis of the ball assembly 200.

Because the weights 252, 254 rotate at twice the rate of rotation of the ball assembly 200, after one full rotation of the ball assembly 200, the weights will make two full rotations within the ball assembly 200. For example, after a half turn of the ball assembly 200, identified by position 310 in the side view of fig. 3A (and similarly by position 326 in the top view of fig. 3B and position 342 in the schematic view of fig. 3C), the weights 252, 254 have completed one full turn. The weight 254 appears on top of the weight 252 because the ball assembly has completed only a half turn. In this position, the weight provides a gravitational moment about a point along the central axis of the ball assembly 200 that opposes the direction of rotation of the ball assembly 200. For example, in this position, the weight will act to slow or stop the rotation of the ball assembly 200.

Fig. 4A-4C illustrate the ball assembly 200 of fig. 2A-2C again in three views (i.e., a side view in fig. 4A, a top view in fig. 4B, and a schematic view in fig. 4C) as it rolls along a plane 295. However, in this example, motors 248, 250 rotate weights 252, 254, respectively, at three times the rotational speed of the spherical assembly. As with fig. 2A-2C, the three different views in this example also show the position of the weight in increments of every eighth turn as the ball assembly rotates along the plane 295. Position 402 in the side view of fig. 4A corresponds to position 418 in the top view of fig. 4B and to position 434 in the schematic view of fig. 4C. Similarly, position 404 in the side view of fig. 4A corresponds to position 420 in the top view of fig. 4B and to position 436 in the schematic view of fig. 4C; position 406 in the side view of FIG. 4A corresponds to position 422 in the top view of FIG. 4B and to position 438 in the schematic view of FIG. 4C; and position 408 in the side view of fig. 4A corresponds to position 424 in the top view of fig. 4B and to position 440 in the schematic view of fig. 4C. At position 402 in the side view of fig. 4A (and similarly at position 418 in the top view of fig. 4B and position 434 in the schematic view of fig. 4C), the weights 252, 254 provide the greatest gravitational moment about a point along the central axis of the ball assembly 200.

Because the weights 252, 254 rotate at three times the rate of rotation of the ball assembly 200, after one full rotation of the ball assembly 200, the weights will make three full rotations within the ball assembly 200. However, because the weights rotate at three times the rate of rotation of the ball assembly 200, rotation of the weights 252, 254 will cause the ball assembly to slow. For example, after one-eighth and before two-eighths of a rotation of the ball assembly 200, identified by positions 404 and 406 in the side view of fig. 4A (and similarly by positions 420 and 422 in the top view of fig. 4B and positions 436 and 438 in the schematic view of fig. 4C), the weights 252, 254 will be fully coincident (e.g., aligned) in the back half of the rotating ball assembly 200 (e.g., relative to the direction of travel of the ball assembly 200) and will cause the ball assembly 200 to slow. Eventually, the spherical component will change its orientation.

Fig. 5A-5C illustrate the ball assembly 200 of fig. 2A-2C again in three views (i.e., a side view in fig. 5A, a top view in fig. 5B, and a schematic view in fig. 5C) as it rolls along a plane 295. However, in this example, the motors 248, 250 rotate the weights 252, 254, respectively, at half the rotational speed of the spherical assembly. As with fig. 2A-2C, the three different views in this example show the position of the weight in one-eighth rotation increments as the ball assembly rotates along the plane 295. Position 502 in the side view of fig. 5A corresponds to position 518 in the top view of fig. 5B and to position 534 in the schematic view of fig. 5C. Similarly, position 504 in the side view of fig. 5A corresponds to position 520 in the top view of fig. 5B and to position 536 in the schematic view of fig. 5C; position 506 in the side view of FIG. 5A corresponds to position 522 in the top view of FIG. 5B and to position 538 in the schematic view of FIG. 5C; position 508 in the side view of fig. 5A corresponds to position 524 in the top view of fig. 5B and to position 540 in the schematic view of fig. 5C; position 510 in the side view of FIG. 5A corresponds to position 526 in the top view of FIG. 5B and to position 542 in the schematic view of FIG. 5C; position 512 in the side view of FIG. 5A corresponds to position 528 in the top view of FIG. 5B and to position 544 in the schematic view of FIG. 5C; position 514 in the side view of FIG. 5A corresponds to position 530 in the top view of FIG. 5B and to position 546 in the schematic view of FIG. 5C; and position 516 in the side view of fig. 5A corresponds to position 532 in the top view of fig. 5B and to position 548 in the schematic view of fig. 5C. At position 502 in the side view of fig. 5A (and similarly at position 518 in the top view of fig. 5B and position 534 in the schematic view of fig. 5C), the weights 252, 254 provide the greatest gravitational moment about a point along the central axis of the ball assembly 200.

Because the weights 252, 254 rotate at a rate of rotation that is half that of the ball assembly 200, after one full rotation of the ball assembly 200, the weights will make half of the full rotation within the ball assembly 200. For example, after a quarter turn of the spherical assembly 200, identified by position 508 in the side view of fig. 5A (and similarly by position 524 in the top view of fig. 5B and position 540 in the schematic view of fig. 5C), the weights 252, 254 have completed an eighth turn. At this point, the center of gravity of each weight begins to move into the rear half of the ball assembly 200, creating a moment opposite its direction of travel, thus causing the ball assembly 200 to slow.

Fig. 6 illustrates a ball assembly system 600 that includes a ball well (e.g., a guard) 650 and a ball assembly 601. The ball well 650 may surround at least half of the ball assembly 601. The spherical assembly 601 includes an outer spherical assembly 622 and an inner spherical assembly 652, the outer spherical assembly 622 may contact a surface, such as the ground. The outer spherical assembly 622 includes magnetic windings 606. In this example, the spherical well 650 includes one or more magnetic windings 602. The magnetic windings 602 and 606 may be, for example, radial core windings. In some examples, the magnetic windings 602 are the same polarity as the magnetic windings 606 of the outer spherical component 622. In this way, a magnetic force is applied to the spherical well 650, as the windings will repel each other. In some examples, all (e.g., 4) of the spherical wells of the vehicle include magnetic windings 602. The magnetic windings 602 and 606 are configured to provide a magnetic force to the vehicle such that the magnetic force supports some weight of the vehicle. In some examples, all of the weight of the vehicle is supported via magnetic force (e.g., magnetic levitation).

In some examples, the ball well 650 includes one or more detents 631 to slow or stop rotation of the outer ball assembly 622. The brake 631 can help slow or stop the rotation of the ball assembly 601. In addition, the detent 630 may be located between the inner spherical assembly 652 and the outer spherical assembly 622. The brakes 630, 631 may be of any suitable type, such as electronically controlled mechanical brakes (e.g., electromechanical brakes).

In some examples, the inner spherical housing 652 also contains a rechargeable battery and a controller. The outer spherical component 622 may contain a radial magnetic core and windings 606 that uniformly cover some or all of the outer surface of the outer spherical component 606. The outer spherical assembly 622 may also contain a rechargeable battery and a controller (not shown). The controller may also be connected to one or more motion detectors 634. The motion detector 634 may be of any suitable type, such as a type that may indicate absolute and relative rotational speed.

In some examples, a controller (not shown) may activate the ball assembly 601 by causing the motors 612, 614 to begin rotating their associated weights 618, 620, respectively, at a preset slow speed. The controller may also control and adjust the brake 631 and the brake 630 between the inner and outer spherical assemblies 652, 622 to adjust the rotational speed of the inner assembly to match the preset low speed of the weights 618, 620 detected via the motion detector 634. Upon receiving a wireless signal, e.g., from an operator, regarding a desired direction of travel, the controller may create a momentary difference in the rotational speed of the weights 618, 620. The amount and duration of the speed change may be based on the desired direction of travel. The same polarity magnetic windings 602, 606 in both the outer spherical assembly 622 and the spherical well 650 may be activated by the controller to create a magnetic levitation force on the spherical well 650. The controller may also release the brake 630 between them so that the ball assembly 601 is free to move in the desired direction.

In some examples, the controller is operable to control the speed and direction of the spherical assembly 601 based on wireless input signals from an operator. The weights 618, 620 may be automatically rotated (e.g., in opposite directions) by the controller to change the arm length of the torque applied by gravity acting on the weights 618, 620. The controller can also be operable to adjust the resistance applied by the brake 630. For steady state travel (e.g., to maintain a particular rotational speed of the outer spherical assembly 622 that can contact the ground), the controller of the spherical assembly 601 can automatically and continuously maintain the rotational speed of the weights 618, 620 the same as the rotational speed of the inner spherical assembly 652.

Fig. 7 illustrates a ball assembly system 700 that includes a ball well 650 and a ball assembly 701. The spherical component 701 includes a spherical inner component 704 and a spherical outer component 702. The spherical inner assembly 704 houses the motor 714 and weight 720 in a first (e.g., upper) portion and the motor 712 and weight 718 in a second (e.g., lower) portion. For example, each of the first and second portions of the spherical inner assembly 704 may be a sealed chamber. The motors 712, 714 may be variable speed Direct Current (DC) motors, such as variable speed reversible DC motors or any other suitable motor. Weight 720 includes portions of radial magnetic core 740 and portions of current carrying conductor 724. Weight 718 includes a portion of radial core 742 and a portion of current carrying conductor 722. In this example, weights 718 and 720 are in the shape of quarter hollow spheres, where the respective hollow spheres allow placement of radial cores 740, 742 and current carrying conductors 724, 722.

The spherical component 701 may also include a friction reducer configured to minimize friction between the spherical inner component 704 and the spherical outer component 702. In this example, the friction reducer includes a ball bearing 710. The ball bearings 710 may be held in place by a wire mesh or other suitable material. The friction reducer may also include a flow path for oil such that the ball bearing 710 resides in the flow path for the oil. The oil may act as a lubricant as well as a cooling mechanism. The spherical assembly 701 may also include a friction reducer 770, the friction reducer 770 configured to minimize friction between the spherical inner assembly 704 and the radial magnetic windings 716.

The spherical inner member 704 may also have radial magnetic windings 716 enclosed in each of the first and second portions. Similarly, the spherical outer component 702 may surround the radial magnetic winding 706. These magnetic windings may be, for example, radial core windings. The magnetic windings 706, 716 may have opposite polarities to produce a magnetic field on the current carrying conductors 722 and 724 embedded within the weights 718 and 722.

One or both of the portions of the spherical inner assembly 704 may also include one or more controllers (not shown) operably coupled to one or both of the motors 712, 714. The controller may be, for example, a processor, microprocessor, or microcontroller. The controller may also be implemented as part of or in a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), a digital circuit, or any suitable circuit. The controller may be configured to cause the motors 712, 714 to rotate weights 718, 720, respectively. The controller may be housed in a respective half of the central region 708 of the spherical inner member 704. In some examples, the controller is attached to the weights 720, 718 or embedded within the weights 720, 718.

One or both of the first and second portions of the central region 708 may house a battery (not shown) to power each of the central magnetic winding 716, the motors 712, 714, and/or the controller. The battery may be, for example, a rechargeable battery, such as a wireless rechargeable battery, a conventional battery, a gel-type battery, or any other suitable battery. The batteries may optionally be housed in respective halves of the central region 708 of the spherical assembly 701. In some examples, the battery may be attached to one or more weights 720, 718 or embedded within one or more weights 720, 718.

The controller may be operatively connected to the current carrying conductors 722, 724 and may be configured to control the amount, timing, and direction of current flow through the current carrying conductors 722, 724. In some examples, the controller causes motors 712, 714 to rotate weights 718, 720 in opposite directions, respectively, and cause current to flow through current carrying conductors 722, 724. When the weights 718, 720 are rotated by the magnetic field provided by the radial magnetic windings 706, 716, a magnetic force is applied to the weights 718, 722 due to the current flowing through the current carrying conductors 722, 724. The magnetic force applied to the weights 718, 722 may act in conjunction with or counteract the gravitational force acting on the weights 718, 722. For example, the controller may cause current to flow through the current conductors 722, 724 in a direction such that the magnetic force is in the same direction as the gravitational force acting on the weights 718, 722. As such, the magnetic force will tend to increase the velocity of the spherical inner member 704. Similarly, the controller may cause current to flow through the current conductors 722, 724 in the other direction, such that the magnetic force is in the opposite direction to the gravitational force acting on the weights 718, 722. In this example, the magnetic force will tend to reduce the velocity of the spherical inner member 704.

For example, to increase the rotational speed of the spherical inner member 704, the controller may cause an increase in the current flowing through the current carrying conductors 722, 724 when the weights 718, 720 are coincident in the front half of the spherical member 701. To reduce the rotational speed of the spherical inner member 704, the controller can cause an increase in the current flowing through the current carrying conductors 722, 724 when the weights 718, 720 are overlapped in the back half of the spherical member 701. To reduce the rotational speed of the spherical inner member 704, the controller may instead cause a reduction (e.g., complete elimination) of the current flowing through the current carrying conductors 722, 724 when the weights 718, 720 are coincident in the front half of the spherical member 701.

In some examples, rather than flowing current through the current carrying conductors 722, 724, the controller directs the current generated in the current carrying conductors 722, 784 to charge a battery (such as a battery that powers each of the central magnetic winding 716, motors 712, 714, and/or the controller). For example, as the weights 718, 720 rotate through the magnetic flux generated by the radial magnetic windings 706, 716, current is generated in the current carrying conductors 722, 724. The current may be directed by the controller (e.g., via an electrical switch) to charge the one or more batteries.

The controller may also be connected to one or more brakes 728, 730, 732. The controller can control and adjust the brakes 728, 730 between the spherical inner member 704 and the spherical outer member 702 to adjust the rotational speed of the spherical inner member 704. The detent 732 is located between the ball well 650 and the ball outer assembly 702.

The controller may also be connected to one or more motion detectors (not shown). The motion detector may be any suitable detector, such as a detector that may indicate an absolute or relative rotational speed. In some examples, the controller is configured to pass current through the current carrying conductors 722, 724 based on the rotational speed of the spherical inner component 704. For example, the controller may detect the rotational speed of the spherical inner member 704 via one or more of the motion detectors. Based on the detected rotational speed, the controller may increase or decrease the current flowing through the current carrying conductors 722, 724.

Fig. 8 illustrates the spherical assembly of fig. 7 including an outer surface 804. The outer surface 804 encases (e.g., surrounds) the spherical component 701. The outer surface 804 includes air cooling fins 802 to allow heat dissipation. For example, air cooling fins may provide cooling for the friction reducer of FIG. 7. In some examples, the air cooling fins may be covered with a perforated cover. For example, a perforated sheet metal cover with an outer rubber layer may cover the air cooling fins. The outer rubber layer provides a high coefficient of friction when in contact with the road surface, thereby reducing slip. In some examples, the outer surface encases the spherical component 601 of fig. 6.

Fig. 9 shows an example of a motion detector 900. For example, the motion detector 900 may be used as the motion detector 634 of fig. 6, or as the motion detector in fig. 7. In this example, the motion detector 900 is hexagonal in shape and includes a magnetic core and windings 902. The motion detector may be coded to monitor the rotational speed. For example, the motion detectors 728, 730 may be configured to detect the rotational speed of the spherical inner member 704.

Fig. 10A and 10B illustrate weight configurations that may be used, such as may be used in the ball assembly 601. In the figure, the spherical assembly 601 includes weights 1006, 1002. Each weight 1006, 1002 includes a flat surface that forms the same angle (e.g., an angle greater than 0 degrees) with respect to the central axis 1050 of the spherical assembly 601. In other words, the weights 1006, 1008 comprise planes that are inclined and mirror images with respect to the central axis 1050 of the spherical assembly 601. To initiate rotation (e.g., rolling) of the ball assembly 601 along a surface, one or both of the weights 1006, 1008 may be rotated such that one or both of the weights provides a moment to the ball assembly 601 in a desired direction of travel due to gravity.

For example, in FIG. 10A, assume that the ball assembly 601 is at rest with weight 1002 in the position shown and weight 1006 in position 1004. The weight 1002 has a center of gravity 1008 that is a distance from the central axis 1050, and the weight 1006 has a center of gravity (not shown) that is the same distance from the central axis 1050 (assuming the weights 1002, 1006 have the same shape and density). In this position, the moment of gravity on the weight 1002 about the central axis 1050 is the same as the moment of gravity on the weight 1006 about the same central axis 1050. Because the moments are in opposite directions (e.g., the moment caused by weight 1002 is in a counterclockwise direction and the moment caused by weight 1006 is in a clockwise direction), the ball assembly 601 does not rotate.

However, if the weight 1002 or 1006 rotates, the moment acting on the ball assembly 601 changes. For example, if the weight 1006 is rotated to be at position 1040, as indicated by arrow 1052, the moment of gravity on the weight 1002 about the central axis 1050 will be greater than the moment of gravity on the weight 1006 about the same central axis 1050. This is because the center of gravity 1010 of weight 1040 will be a smaller distance from the central axis 1050 than the center of gravity 1008 of weight 1002 will be from the same central axis 1050. As such, the ball assembly 601 will tend to rotate in the direction indicated by arrow 1012 (e.g., counterclockwise). In this manner, rotation of the ball assembly 601 may be initiated.

Similarly, in fig. 10B, the spherical assembly 601 is assumed to be at rest with the weight 1002 in the position shown and the weight 1006 in position 1024. The weight 1002 has a center of gravity 1028 that is a distance from the central axis 1050 and the weight 1006 has a center of gravity 1030 that is the same distance from the central axis 1050 (assuming the weights 1002, 1006 have the same shape and density). Note, however, that these initial distances are smaller than those in fig. 10A. In this position, the moment of gravity on the weight 1002 about the central axis 1050 is the same as the moment of gravity on the weight 1006 about the same central axis 1050. Because the moments are in opposite directions (e.g., the moment caused by weight 1002 is in a counterclockwise direction and the moment caused by weight 1006 is in a clockwise direction), the ball assembly 601 does not rotate.

However, if the weight 1002 or 1006 rotates, the moment acting on the ball assembly 601 changes. For example, if the weight 1006 is rotated as indicated by arrow 1054 to be in position 1042, the moment of gravity on the weight 1002 about the central axis 1050 will be less than the moment of gravity on the weight 1006 about the same central axis 1050. This is because the center of gravity 1028 of the weight 1008 will be a smaller distance from the central axis 1050 than the center of gravity 1020 of the weight 1002 will be from the same central axis 1050. As such, the ball assembly 601 will tend to rotate in the direction identified by arrow 1032 (e.g., clockwise). In this manner, rotation of the ball assembly 601 may also be initiated.

In some examples, a controller, such as the controller described with reference to fig. 7, causes a motor (such as motors 712, 714) to rotate at least one of the weights 1002, 1006 to initiate rotation of the spherical assembly 601.

Fig. 11A and 11B show, in two views, a side view in fig. 11A and a front view in fig. 11B, various points of the spherical assembly 1101 rolling along a plane after one-eighth rotation of the spherical assembly 1101. These figures identify the center of gravity 1102 of the first weight and the center of gravity 1104 of the second weight. Although not shown, it should be understood that each weight is connected to a motor that is operable to receive input from the controller and rotate the weight within the spherical assembly 1101. In fig. 11A, position 1110 represents the beginning of a full rotation of the spherical assembly 1101 as the spherical assembly 1101 rotates clockwise as indicated by the directional arrow, where position 1130 of fig. 11B illustrates the beginning of this rotation, but from a front view (e.g., as the spherical assembly 1101 rotates toward the reader).

Position 1112 shows ball assembly 1101 after one-eighth of a rotation (and similarly, at position 1132 in the front view of FIG. 11B); position 1114 shows the spherical assembly 1101 after two-eighths of a rotation (and similarly, at position 1134 in the front view of FIG. 11B); position 1116 shows the ball assembly 1101 after three-eighths of a turn (and similarly, at position 1136 of the front view of FIG. 11B); position 1118 shows ball assembly 1101 after four-eighths of a turn of rotation (and similarly, at position 1138 in the front view of FIG. 11B); position 1120 shows the spherical assembly 1101 after five eighths of a turn (and similarly, at position 1140 in the front view of fig. 11B); position 1122 shows ball assembly 1101 after six-eighths of a turn (and similarly, in position 1142 of the front view of fig. 11B); position 1124 shows the ball assembly 1101 after seven eighths of a full rotation (and similarly, at position 1144 of the front view of fig. 11B). The front view of fig. 11B shows the same position as the side view of fig. 11A when the spherical assembly 1101 is rotated, but from a front view.

In both fig. 11A and 11B, at each point, the arrows near the center of gravity 1102 of the first weight and the center of gravity 1104 of the second weight indicate the direction of the centrifugal force generated by each respective weight on the spherical assembly 1101. For example, at location 1110 in the side view of fig. 1A (and similarly, at location 1130 in the front view of fig. 11B), the centrifugal force caused by each rotating weight applies equal but opposite force (assuming the weights rotate at similar rotational speeds; at location 1112 (and similarly, location 1132), the centrifugal force has a vertical component in the same vertical direction, but has a horizontal component in the opposite direction; at location 1114 (and similarly, location 1134), the centrifugal force is in the same direction as the direction of travel of the spherical assembly 1101; at location 1116 (and similarly, location 1136), the centrifugal force has a component in the same direction, and a component in the opposite direction; at location 1118 (and similarly, at location 1138), the centrifugal force is in the opposite direction; at location 1120 (and similarly, at location 1140), the centrifugal force has a component in the same direction and a component in the opposite direction; at location 1122 (and similarly, at position 1142), the centrifugal force is in the same direction. Finally, at location 1124 (and similarly, at location 1144), the centrifugal force has a component in the same direction and a component in the opposite direction. When one or more centrifugal forces caused by the rotating weights are in the direction of travel of the spherical assembly 1101, the centrifugal forces may push the spherical assembly in the direction of travel. In some examples, one or more centrifugal forces induced on the spherical assembly 1101 by the rotating weights may cause a change in the direction of travel of the spherical assembly 1101. In some examples, the controller is configured to cause a change in the direction of travel of the spherical assembly 1101 by changing the speed of rotation of the rotating weight.

Fig. 12A and 12B show each point of the spherical assembly 1201 rolling along a plane after each eighth rotation of the spherical assembly 1201 in two views, i.e., a side view in fig. 12A and a front view in fig. 12B. These figures identify the center of gravity of the first weight 1206, the center of gravity of the second weight 1202, and the center of gravity of the third weight 1204. In some examples, the first weight weighs twice as much as each of the second and third weights. In some examples, the first weight rotates within a cavity of the spherical assembly 1201 between the cavities through which the second and third weights rotate, respectively. Although not shown, it will be appreciated that each weight is connected to a motor operable to receive input from the controller and rotate the weight within the spherical assembly 1201. In fig. 12A, position 1210 represents the beginning of a full rotation of the spherical assembly 1201, corresponding to position 1230 of the front view in fig. 12B.

Position 1212 shows the spherical assembly 1201 after one-eighth of a rotation (and similarly, at position 1232 in the front view of fig. 12B); position 1214 shows the spherical assembly 1201 after two-eighths of a rotation (and similarly, position 1234 in the front view of fig. 12B); position 1216 shows the spherical assembly 1201 after three-eighths of a turn (and similarly, at position 1236 of the front view of fig. 12B); position 1218 shows the spherical assembly 1201 after four-eighths of a rotation (and similarly, at position 1238 in the front view of fig. 12B); position 1220 shows the ball assembly 1201 after five-eighths of a rotation (and similarly, position 1240 in the front view of FIG. 12B); position 1222 shows the ball assembly 1201 after six eighths of a turn of rotation (and similarly, at position 1242 of the front view of fig. 12B); position 1224 shows the spherical assembly 1201 after seven eighths of a full rotation (and similarly, at position 1244 of the front view of fig. 12B). The front view of fig. 12B shows the same position of the spherical assembly 1201 as the side view of fig. 12A when rotated, but from the front view.

In each position, the arrows near the center of gravity 1206 of the first weight, the center of gravity 1202 of the second weight, and the center of gravity 1204 of the third weight indicate the direction of the centrifugal force induced on spherical assembly 1201 by each respective weight in fig. 12A and 12B. For example, at position 1210 in the side view of fig. 12A (and similarly, position 1230 in the front view of fig. 12B), the centrifugal forces caused by each rotating weight exert equal but opposite forces (assuming the weights rotate at similar rotational speeds). At location 1212 (and similarly, location 1232), the centrifugal force has a vertical component in the same vertical direction, but has a horizontal component in the opposite direction. At position 1214 (and similarly, position 1234), the centrifugal force is in the same direction as the direction of travel of the spherical assembly 1201. At location 1216 (and similarly, location 1236), the centrifugal force has a component in the same direction, and a component in the opposite direction. At location 1218 (and similarly at location 1238), the centrifugal force is in the opposite direction. At position 1220 (similarly, position 1240), the centrifugal force has a component in the same direction, as well as a component in the opposite direction. At position 1222 (and similarly, at position 1242), the centrifugal force is in the same direction. Finally, at location 1224 (and similarly, at location 1244), the centrifugal force has a component in the same direction and a component in the opposite direction.

When one or more centrifugal forces caused by the rotating weights are in the direction of travel of the spherical assembly 1201, the centrifugal forces may push the spherical assembly in the direction of travel. In some examples, one or more centrifugal forces induced on the spherical assembly 1201 by the rotating weight may cause a change in the direction of travel of the spherical assembly 1201. In some examples, the controller is configured to cause a change in the direction of travel of the spherical assembly 1201 by changing the rotational speed of the rotating weight.

In some examples, the controller rotates the first weight to counteract (e.g., eliminate) centrifugal forces caused by the rotation of the second and third weights. For example, the first weight may be rotated to counteract an unexpected change in orientation of the spherical assembly 1201.

Fig. 13A, 13B, and 13C show different configurations of electrified spherical assemblies, each having three weights. For example, fig. 13A shows a spherical assembly 1300 that includes a spherical inner assembly 1313 and a spherical outer assembly 1311. One or more ball bearings 710 and, in some examples, a lubricant (e.g., oil) separate spherical inner component 1313 from spherical outer component 1311. This allows the spherical inner component 1313 to rotate within the spherical outer component 1311 with little friction. The spherical inner assembly 1313 houses a first motor 1312 operable to rotate the first weight 1306, a second motor 1308 operable to rotate the second weight 1302, and a third motor 1310 operable to rotate the third weight 1304. The first weight 1306 rotates within the cavity 1334 of the ball assembly 1300. Second mass 1302 rotates within cavity 1330 of ball assembly 1300 and third mass 1304 rotates within cavity 1320 of ball assembly 1300. In some examples, the weight of the first weight 1306 is twice the weight of each of the second weight 1302 and the third weight 1304.

In this example, cavity 1334 is at a smaller radius from the center of spherical assembly 1300 than the radius at which cavities 1330 and 1332 are located. Further, while cavity 1334 spans the upper and lower halves of ball assembly 1300, cavities 1330 and 1332 each span only half of ball assembly 1300.

The spherical assembly 1300 may also include a ball bearing 710 and, in some examples, a lubricant within the cavity of the rotating weight. For example, ball bearings 720 may separate each of the first weight 1306, second weight 1302, and third weight 1304 from the inner walls of their respective cavities 1334, 1330, 1332. In some examples, a permanent magnet 1320, such as a rare earth permanent magnet, may be used to generate a magnetic field between the spherical outer component 1311 and the spherical inner component 1313. Current carrying conductors (not shown) may be embedded within the first weight 1306, second weight 1302, and third weight 1304 so that when the weights rotate, magnetic forces are applied to the weights as they rotate through the magnetic field. These magnetic forces may increase or decrease the rotational speed of the weight. For example, a controller (not shown) may cause the magnetic field to turn on to increase or decrease the rotational speed of any one of the first weight 1306, the second weight 1302, and the third weight 1304. In this example, the first motor 1312, the second motor 1308, and the third motor 1310 are aligned along a central horizontal axis of the spherical assembly 1350, with the first motor 1312 located between the second motor 1308 and the third motor 1310.

Fig. 13B shows a ball assembly 1350 similar to the ball assembly 1300 of fig. 13A, but with a different weight and cavity configuration. The spherical assembly 1350 includes a spherical inner assembly 1313 and a spherical outer assembly 1311. One or more ball bearings 710 and, in some examples, a lubricant (e.g., oil) separate spherical inner component 1313 from spherical outer component 1311. The spherical inner assembly 1313 houses a first motor 1312 operable to rotate the first weight 1306, a second motor 1308 operable to rotate the second weight 1302, and a third motor 1310 operable to rotate the third weight 1304. The first weight 1306 rotates within the cavity 1334 of the ball assembly 1300. Second mass 1302 rotates within cavity 1330 of ball assembly 1300 and third mass 1304 rotates within cavity 1320 of ball assembly 1300. In some examples, the weight of the first weight 1306 is twice the weight of each of the second weight 1302 and the third weight 1304.

In this example, cavity 1334 has the same radius from the center of spherical assembly 1300 as cavities 1330 and 1332. In some examples, cavities 1334, 1330, and 1332 occupy approximately 1/3 of the interior cavity of ball assembly 1350. In addition, cavity 1334 partially spans the upper and lower halves of spherical assembly 1300. Cavity 1332 spans only the top portion of the ball assembly 1300 and cavity 1334 spans only the bottom portion of the ball assembly 1300. In this example, the first motor 1312, the second motor 1308, and the third motor 1310 are aligned along a central horizontal axis of the spherical assembly 1350, with the first motor 1312 located between the second motor 1308 and the third motor 1310.

Fig. 13C shows a ball assembly 1370 similar to the ball assembly 1300 of fig. 13A, but with a different weight and cavity configuration. The spherical assembly 1350 includes a spherical inner assembly 1313 and a spherical outer assembly 1311. One or more ball bearings 710 and, in some examples, a lubricant (e.g., oil) separate spherical inner component 1313 from spherical outer component 1311. The spherical inner assembly 1313 houses a first motor 1312 operable to rotate the first weight 1306, a second motor 1308 operable to rotate the second weight 1302, and a third motor 1310 operable to rotate the third weight 1304. In this example, the first motor 1312, the second motor 1308, and the third motor 1310 are located near the center of the spherical assembly 1370.

The first weight 1306 rotates within the cavity 1334 of the ball assembly 1300. Second mass 1302 rotates within cavity 1330 of ball assembly 1300 and third mass 1304 rotates within cavity 1320 of ball assembly 1300. However, in this example, the radius of cavity 1334 from the center of spherical assembly 1300 is greater than the radius at which cavities 1330 and 1332 are located. In some examples, the weight of the first weight 1306 is twice the weight of each of the second weight 1302 and the third weight 1304. In some examples, the first motor 1312 may also rotate a weighted weight 1305, which weighted weight 1305 may help stabilize the ball assembly 1370 during rotation.

Figure 14A shows a rocket 1403 employing multiple spherical assemblies 1401. For example, the spherical assembly 1401 may comprise one or more of the spherical assemblies of fig. 13A-13C. The spherical assembly may generate a propulsive force in a vertical direction, as indicated by the directional arrow. Fig. 14B illustrates a top view of the ball assembly 1401 of fig. 14A. The spherical assembly 1401 may be rotated in the opposite direction to counteract or minimize horizontal forces while maximizing vertical forces.

Fig. 14C and 14D show each point of the ball assembly 1401 rolling along a plane after each eighth rotation of the ball assembly 1401 in two views, i.e. a side view in fig. 14C and a front view in fig. 14D. These figures identify the center of gravity 1406 of the first weight, the center of gravity 1402 of the second weight, and the center of gravity 1404 of the third weight. In some examples, the first weight weighs twice as much as each of the second and third weights. In some examples, the first weight rotates within a cavity of the ball assembly 1401 between which the second and third weights rotate, respectively. Although not shown, it should be understood that each weight is connected to a motor that is operable to receive input from a controller and rotate the weight within the spherical assembly 1401. In fig. 14C, position 1410 represents the beginning of a full rotation of the ball assembly 1401 in the direction indicated by the directional arrow, which corresponds to position 1430 of the front view in fig. 14D.

Position 1412 shows the ball assembly 1401 after one-eighth of a rotation (and similarly, at position 1432 of the front view of fig. 14D); position 1414 shows the spherical assembly 1401 after two-eighths of a turn (and similarly, at position 1434 of the front view of fig. 14D); position 1416 shows the ball assembly 1401 after three eighths of a turn (and similarly, at position 1436 of the front view of FIG. 14D); position 1418 shows the ball assembly 1401 after four-eighths of a turn (and similarly, at position 1438 of the front view of FIG. 14D); position 1420 shows ball assembly 1401 after five eighths of a rotation (and similarly, position 1440 of the front view of fig. 14D); position 1422 shows spherical assembly 1401 after six-eighths of a turn (and similarly at position 1442 in the front view of fig. 14D); position 1424 shows spherical assembly 1401 after seven eighths of a turn (and similarly, position 1444 in the front view of fig. 14D). The front view of fig. 14D shows the same position of the spherical assembly 1401 as the side view of fig. 14C when rotated, but from a front view.

In each position, the arrows near the center of gravity 1406 of the first weight, the center of gravity 1402 of the second weight, and the center of gravity 1404 of the third weight indicate the direction of the centrifugal force induced on the spherical assembly 1401 by each respective weight, in fig. 14C and 14D. For example, at location 1410 in the side view of fig. 14C (and similarly, at location 1430 in the front view of fig. 14D), the centrifugal force caused by each rotating weight is applied in the same direction (e.g., upward), assuming the weights are rotating at similar rotational speeds. At position 1412 (similarly, position 1432), the centrifugal force has a vertical component in the same vertical direction, but a horizontal component in the opposite direction. At position 1414 (and similarly at position 1434), the centrifugal force is in the opposite direction. For example, the centrifugal force caused by the rotation of the first weight is opposite to the centrifugal force caused by the rotation of the second and third weights. At location 1416 (and similarly, location 1436), the centrifugal force has a component in the same direction (e.g., vertical) and a component in the opposite direction. At position 1418 (and similarly, position 1438), the centrifugal force is in the same direction. At position 1420 (similarly, position 1440), the centrifugal force has a component in the same direction (e.g., vertical) and a component in the opposite direction. At position 1422 (and similarly at position 1442), the centrifugal force is in the opposite direction. For example, the centrifugal force caused by the rotation of the first weight is opposite to the centrifugal force caused by the rotation of the second and third weights. Finally, at position 1424 (and similarly, position 1444), the centrifugal force has a component in the same direction (e.g., vertical direction), as well as a component in the opposite direction.

Fig. 14E and 14F show in two views, a front view in fig. 14E and a side view in fig. 14F, another spherical assembly 1401 rolling along a plane at each point after each eighth turn of the spherical assembly 1401. Fig. 14F is similar to fig. 14C, except that the ball assembly 1401 is rotated in the opposite direction (e.g., counterclockwise instead of clockwise) as shown by the directional arrow at location 1480. By including a spherical assembly 1401 that rotates in the opposite direction, the vibratory forces generated by the rotating weight can be balanced (e.g., cancelled).

In fig. 14F, position 1480 represents the beginning of a full rotation of the ball assembly 1401 rotated in the direction indicated by the directional arrow, which corresponds to position 1460 of the front view in fig. 14E. Position 1482 shows the ball assembly 1401 after one-eighth of rotation (and similarly, position 1462 in the front view of fig. 14E); position 1484 shows the spherical assembly 1401 after two-eighths of a rotation (and similarly, position 1464 in the front view of FIG. 14E); position 1486 shows the ball assembly 1401 after three-eighths of a rotation (and similarly, at position 1466 of the front view of FIG. 14E); position 1488 shows the ball assembly 1401 after four-eighths of a rotation (and similarly, position 1468 in the front view of fig. 14E); position 1490 shows the ball assembly 1401 after five eighths of a revolution (and similarly, at position 1470 in the front view of FIG. 14E); position 1492 shows the ball assembly 1401 after six eighths of a revolution (and similarly, at position 1472 in the front view of FIG. 14E); and position 1494 shows the ball assembly 1401 after seven eighths of a turn (and similarly, position 1474 in the front view of fig. 14E). The front view of fig. 14E shows the same position of the spherical assembly 1401 as the side view of fig. 14F is rotated, but from a front view.

In each position, the arrows near the center of gravity 1452 of the first weight, the center of gravity 1454 of the second weight, and the center of gravity 1456 of the third weight indicate the direction of the centrifugal force induced on ball assembly 1401 by each respective weight, in fig. 14E and 14F. For example, at location 1480 in the side view of fig. 14F (and similarly, location 1460 in the front view of fig. 14E), the centrifugal force caused by each rotating weight is applied in the same direction (e.g., upward), assuming the weights rotate at similar rotational speeds. At position 1482 (and similarly, position 1462), the centrifugal force has a vertical component in the same vertical direction, but has a horizontal component in the opposite direction. At location 1484 (and similarly, at location 1464), the centrifugal force is in the opposite direction. For example, the centrifugal force caused by the rotation of the first weight is opposite to the centrifugal force caused by the rotation of the second and third weights. At position 1466 (and similarly, position 1486), the centrifugal force has a component in the same direction (e.g., vertical direction) and a component in the opposite direction. At position 1488 (and similarly, position 1468), the centrifugal force is in the same direction (e.g., vertically upward). At position 1490 (and similarly, position 1470), the centrifugal force has a component in the same direction (e.g., vertical direction) and a component in the opposite direction. At position 1492 (and similarly at position 1472), the centrifugal force is in the opposite direction. For example, the centrifugal force caused by the rotation of the first weight is opposite to the centrifugal force caused by the rotation of the second and third weights. Finally, at location 1474 (and similarly, location 1494), the centrifugal force has a component in the same direction (e.g., vertical direction), as well as a component in the opposite direction.

Fig. 15 shows the centrifugal forces acting on the ball assemblies 1501 and 1551. The ball assemblies 1501 and 1551 may be, for example, ball assemblies 1401 each having an outer assembly housing that rotates in opposite directions. For each spherical assembly 1501 and 1551, fig. 15 shows a side view and a top view of the respective point after each eighth rotation as the respective spherical assembly rotates along a plane, as shown at position 1515. In this example, a controller (not shown) causes a motor (not shown) to rotate the first, second, and third weights to eliminate unbalanced vibrations due to, for example, centrifugal forces generated by the rotating weights. Fig. 15 identifies the center of gravity of the first weight 1502, the center of gravity of the second weight 1504, and the center of gravity of the third weight 1506.

Graph 1520 shows the corresponding magnitude (percentage) of centrifugal force experienced by the respective spherical assemblies 1501 and 1551 throughout the rotation. The graph 1520 identifies four curves, namely, a curve 1522, a curve 1524, a curve 1526, and a curve 1528. Curves 1524 and 1526 correspond to the spherical component 1501, and curves 1522 and 1528 correspond to the spherical component 1551. Curves 1526 and 1528 represent the magnitude of centrifugal forces experienced by the respective spherical assemblies 1501, 1551 in a direction perpendicular to their direction of travel and their axis of rotation (e.g., up or down from the plane in which they rotate). Curves 1522 and 1524 represent the magnitude of centrifugal force experienced by the respective spherical assemblies 1551, 1501 in the direction of travel thereof.

Thus, for example, after two-eighths of a revolution, curve 1524 shows that spherical assembly 1501 experiences near 100% centrifugal force along its direction of travel, while spherical assembly 1551 experiences little, if any, centrifugal force, as shown by curve 1522. However, after four-eighths of a revolution, curve 1524 shows that the ball assembly 1501 experiences little, if any, centrifugal force, while the ball assembly 1551 experiences near 100% centrifugal force along its direction of travel, as shown by curve 1522.

Curve 1526 shows that after one eighth and five eighths of a revolution, the spherical assembly 1501 experiences the greatest percentage of centrifugal force in the direction perpendicular to the direction of travel. This is because the centrifugal force generated by the rotating weight has a component in the vertical direction. Curve 1528 shows that after three-eighths and seven-eighths of a revolution, the spherical assembly 1551 experiences a maximum percentage of centrifugal force perpendicular to the direction of travel.

Among other advantages, the apparatus and method may provide propulsion without the need for an internal combustion engine or a gearbox. Furthermore, the device can inherently change its direction of travel to any direction without requiring a large turning radius. The apparatus and method may provide propulsion for any suitable vehicle, such as a land or amphibious vehicle (ampibious vehicle). For example, the apparatus and method may improve road traction control and reduce road slip. The apparatus and method may also reduce vehicle stopping distance. Further, the apparatus may require fewer components than conventional internal combustion engines, and may also provide cost benefits. Other advantages of the disclosure will be apparent to those skilled in the art to which the disclosure pertains from a perusal of the claims, the appended drawings, and the following detailed description of the embodiments.

While preferred embodiments of the present subject matter have been described, it is to be understood that the described embodiments are illustrative only, and that the scope of the present subject matter is to be defined solely by the appended claims when given the broadest range of equivalents, and that numerous variations and modifications will suggest themselves to those skilled in the art in light of this review of the present subject matter.