阅读说明：本技术 线控转向装置 (Steer-by-wire apparatus ) 是由 洪承奎 于 2020-02-17 设计创作，主要内容包括：根据本发明的实施例,当驾驶员向转向轴施加大于反作用力马达的反作用扭矩的转向扭矩时,转向轴被机械地阻止而不再旋转,因此可以改善驾驶员的转向感受。(According to the embodiment of the invention, when the driver applies the steering torque larger than the reaction torque of the reaction force motor to the steering shaft, the steering shaft is mechanically stopped from rotating any more, and thus the steering feeling of the driver can be improved.)

1. A steer-by-wire apparatus comprising:

a steering shaft connected to one end of the torsion bar and having a first gear part formed on an outer circumferential surface thereof;

a first rotor rotatably coupled in the housing to be connected with the motor, connected with the other end of the torsion bar, and having a hollow receiving part at one side thereof, the hollow receiving part extending axially and having a second gear part formed on an inner circumferential surface thereof;

a second rotor having a third gear part on an outer circumferential surface thereof, the third gear part being engaged with the first gear part and the second gear part between the first gear part and the second gear part; and

a stopper provided with the second rotor and limiting a range of a rotation angle of the second rotor when the second rotor rotates between the first gear part and the second gear part.

2. The steer-by-wire apparatus of claim 1, wherein the stopper has a support member projecting radially outward from the second rotor.

3. The steer-by-wire apparatus according to claim 2, wherein either one of the stopper or the second rotor has a projection projecting axially, and the other has an insertion portion corresponding to the projection, and wherein the stopper and the second rotor are coupled to each other when the projection is inserted into the insertion portion.

4. The steer-by-wire apparatus according to claim 2, wherein the stopper is provided on an axial one-side surface of the second rotor.

5. The steer-by-wire apparatus according to claim 4, wherein the support member is supported on an outer circumferential surface of the steering shaft to restrict a rotation angle of the second rotor.

6. The steer-by-wire apparatus according to claim 4, wherein the support member is supported on an outer circumferential surface of the steering shaft or an inner circumferential surface of the housing to restrict a rotation angle of the second rotor.

7. The steer-by-wire apparatus according to claim 4, wherein the steering shaft is formed with a first step part in that an outer circumferential surface of one side in an axial direction thereof is recessed from the first gear part.

8. The steer-by-wire apparatus according to claim 7, wherein a second step part facing the first step part protrudes radially from an inner circumferential surface of the housing, and wherein the support part is supported on the second step part to restrict a rotation angle of the second rotor.

9. The steer-by-wire apparatus according to claim 7, wherein the receiving member is formed with an extension extending from a position where the second gear member is formed to an axial side of the receiving member, and wherein the extension is supported on an inner circumferential surface of the extension to restrict a rotation angle of the second rotor.

10. The steer-by-wire apparatus of claim 4, wherein the support member comprises a first support member and a second support member.

11. The steer-by-wire apparatus according to claim 10, wherein the first support member and the second support member are disposed to be symmetrical to each other with respect to a line connecting a center of the second rotor and a center of the steering shaft.

12. The steer-by-wire apparatus according to claim 2, wherein the stopper is provided at the other axial side surface of the second rotor.

13. The steer-by-wire apparatus according to claim 12, wherein the support member is supported on an outer circumferential surface of the steering shaft or an inner circumferential surface of the receiving member to restrict a rotation angle of the second rotor.

14. The steer-by-wire apparatus according to claim 12, wherein the steering shaft is formed with a recessed portion as an outer circumferential surface of the other side in the axial direction thereof is recessed from the first gear member.

15. The steer-by-wire apparatus according to claim 14, wherein the support member is supported on an inner circumferential surface of the receiving member to restrict a rotation angle of the second rotor.

16. The steer-by-wire apparatus of claim 12, wherein the support member comprises a first support member and a second support member.

17. The steer-by-wire apparatus according to claim 16, wherein the first support member and the second support member are disposed to be symmetrical to each other with respect to a line connecting a center of the second rotor and a center of the steering shaft.

18. The steer-by-wire apparatus according to claim 1, wherein the first rotor has a projection projecting axially on the other side thereof.

19. The steer-by-wire apparatus of claim 18, wherein the protrusion has a coupling hole, and wherein a motor shaft of the motor is inserted into the coupling hole to couple the motor and the first rotor.

20. The steer-by-wire apparatus of claim 18, wherein the protrusion is connected to a motor shaft of the motor by a belt.

Technical Field

The present embodiment relates to a steer-by-wire apparatus, and more particularly, to a steer-by-wire apparatus that can provide a good steering feeling by mechanically stopping the rotation of a steering shaft when a driver applies a steering torque to the steering shaft that is greater than a reaction torque of a reaction force motor.

Background

A steer-by-wire apparatus is an electric power steering apparatus that uses electric power to steer a vehicle without any mechanical connection such as a steering column or a universal joint between a steering wheel and a front wheel steering apparatus.

In other words, the driver's manipulation of the steering wheel is converted into an electrical signal, which the electronic control device receives and thus determines the output of the motor. Due to the lack of mechanical connections, steer-by-wire systems reduce the risk of injury to the driver from mechanical components in the event of a collision. Further, the steer-by-wire system can make the vehicle lightweight and remarkably reduce assembly line man-hours by saving components such as hydraulic components and mechanical connections, thereby saving unnecessary energy consumption during steering and thus improving fuel efficiency. In addition, the desired steering performance can be achieved through ECU programming.

However, such a steer-by-wire apparatus lacks a mechanical connection between the steering shaft and the wheels, which may cause the driver's steering wheel to rotate endlessly, resulting in a poor steering feel.

In other words, when the rotation of the wheels reaches the maximum point (when the steering wheel or the wheels are in a full rotation state in a general steering apparatus) or when the wheels may no longer rotate due to a curb, the steering shaft no longer rotates, and therefore, there is an increasing need for the ability to notify the driver of this situation by stopping the steering shaft from further rotating.

Disclosure of Invention

Technical problem

The present embodiment is conceived in the context of the above, and aims to provide a good steering feeling by mechanically preventing the steering shaft from rotating when the driver applies a steering torque to the steering shaft that is larger than the reaction torque of the reaction force motor.

The object of the present embodiment is not limited to the above object, and other objects will be apparent to those skilled in the art from the following detailed description.

Technical scheme

According to the present embodiment, there can be provided a steer-by-wire apparatus including: a steering shaft connected to one end of the torsion bar and having a first gear part formed on an outer circumferential surface thereof; a first rotor rotatably coupled in the housing to be connected with the motor, connected with the other end of the torsion bar, and having a hollow receiving part at one side thereof, the hollow receiving part extending axially and having a second gear part formed on an inner circumferential surface thereof; a second rotor having a third gear part on an outer circumferential surface thereof, the third gear part being engaged with the first gear part and the second gear part between the first gear part and the second gear part; and a stopper provided with the second rotor and limiting a range of a rotation angle of the second rotor when the second rotor rotates between the first gear part and the second gear part.

Advantageous effects

According to the present embodiment, when the driver applies a steering torque to the steering shaft that is larger than the reaction torque of the reaction force motor, it is possible to provide a good steering feeling by mechanically stopping the rotation of the steering shaft.

Drawings

Fig. 1 is an exploded perspective view showing a steer-by-wire apparatus according to the present embodiment;

fig. 2 is a perspective view showing a part of fig. 1;

fig. 3 to 10 are sectional views showing an operation state of the steer-by-wire apparatus according to the present embodiment; and is

Fig. 11 and 12 are perspective views showing a part of the steer-by-wire apparatus according to the present embodiment.

Detailed Description

Hereinafter, embodiments of the present embodiment are described in detail with reference to the accompanying drawings. The same or substantially the same reference numbers will be used throughout the specification and drawings to refer to the same or substantially the same elements. A detailed description of known configurations or functions may be omitted when it is determined that the description thereof may make the subject matter of the present invention unclear.

Indicia such as "first," "second," "a," "B," "a," or "(B)" may be used to describe components of the present disclosure. These labels are provided merely to distinguish one component from another component and the nature of the components is not limited by the order or sequence of the labels. When an element is described as being "connected," "coupled," or "linked" to another element, the element may be directly connected or linked to the other element, however it is also understood that other elements may be "connected," "coupled," or "linked" between the elements.

Fig. 1 is an exploded perspective view showing a steer-by-wire apparatus according to the present embodiment. Fig. 2 is a perspective view showing a part of fig. 1. Fig. 3 to 10 are sectional views showing an operation state of the steer-by-wire apparatus according to the present embodiment. Fig. 11 and 12 are perspective views showing a part of the steer-by-wire apparatus according to the present embodiment.

Referring to the drawings, according to the present embodiment, a steer-by-wire apparatus 100 includes: a steering shaft 106 connected to one end of the torsion bar 105 and having a first gear member 121 formed on an outer circumferential surface thereof; a first rotor 102 rotatably coupled within the housing 301 to be connected with the motor 101, connected with the other end of the torsion bar 105, and having a hollow receiving part 112 at one side thereof, the hollow receiving part 112 extending axially and having a second gear part 122 formed on an inner circumferential surface thereof; a second rotor 103 having a third gear part 123 on an outer circumferential surface thereof, the third gear part 123 being engaged with the first and second gear parts 121 and 122 between the first and second gear parts 121 and 122; and a stopper 104 provided together with the second rotor 103 and limiting a range of a rotation angle of the second rotor 103 when the second rotor 103 rotates between the first gear part 121 and the second gear part 122.

The steering shaft 106 is connected to a steering wheel 107 and is rotated by manipulation of a driver. An electronic control unit provided in the vehicle receives sensed data from, for example, a torque sensor or an angle sensor connected to the steering shaft 106, and transmits a signal for steering the wheels, which is generated from the sensed data.

Such sensors may include a motor position sensor for transmitting steering information to the electronic control unit, various radar or camera image sensors, which will not be described in detail hereinafter.

The steering shaft 106 is provided with a reaction force motor. Based on the data sensed from the torque sensor, the electronic control unit operates the reaction force motor to generate a reaction force torque in a direction opposite to the steering torque generated when the driver manipulates the steering wheel 107.

In such a steer-by-wire apparatus, since there is no mechanical connection between the steering shaft 106 and the wheels, the driver can turn the steering wheel 107 indefinitely. Therefore, a mechanical restriction is required to stop rotation at an arbitrary angle.

In other words, when the steering wheel 107 reaches the maximum number of turns or the wheels are stuck at the curb, the steering torque of the driver increases, and the reaction torque of the reaction motor also increases. In order to prevent the steering shaft 106 from further rotating when the reaction force motor reaches its maximum output, the steer-by-wire apparatus 100 according to the present embodiment includes a motor 101, a torsion bar 105, a first rotor 102, a second rotor 103, and a stopper 104.

One end of the torsion bar 105 is coupled with the steering shaft 106, and the other end thereof is coupled with the first rotor 102.

One end of the torsion bar 105 may be inserted and coupled to the steering shaft 106, and the other end of the torsion bar 105 may be inserted into a hole 314 formed in one side of the first rotor 102 and coupled. Although not shown in the drawings, serrations may be formed at the other end of the torsion bar 105 and the hole 314 so that the other end of the torsion bar 105 and the first rotor 102 may be coupled together to be circumferentially fastened.

The first rotor 102 is rotatably coupled inside the housing 301 to be connected with the motor 101, and has a hollow receiving member 112 facing the steering shaft 106 at one axial side thereof. The hollow receiving part 112 extends axially and has a second gear part 122 formed on an inner circumferential surface thereof. As shown, the second gear member 122 may be formed at one end of the receiving member 112. A protrusion 311 is formed at the other side of the first rotor 102 to be coupled to the housing 301 by a bearing 313, which will be described in detail below.

In other words, the torsion bar 105 is located inside the receiving part 112, the torsion bar 105 is inserted into the receiving part 112, and the other end of the torsion bar 105 is coupled to the first rotor 102.

The motor 101 is coupled to the first rotor 102 such that torque from the motor 101 is applied to the first rotor 102. Accordingly, the torsion bar 105 connecting the steering shaft 106 and the first rotor 102 is twisted by the motor 101 and the steering torque of the driver. The detailed coupling structure of the first rotor 102 and the motor 101 will be described hereinafter.

The first gear part 121 is formed on the outer circumferential surface of the steering shaft 106, and the second gear part 122 is formed on the inner circumferential surface of the receiving part 112. A third gear part 123 engaged between the first gear part 121 and the second gear part 122 is formed on an outer circumferential surface of the second rotor 103.

In this case, the second rotor 103 is provided with a stopper 104 for limiting the range of the rotation angle of the second rotor 103. When the reaction force motor reaches the maximum output, the rotation of the second rotor 103 is restricted by the stopper 104, so that the rotation of the steering shaft 106 is stopped by the first to third gear members 121, 122, and 123.

In other words, when the reaction force motor reaches the maximum output, the motor 101 is operated, the torsion bar 105 is twisted, so that a phase difference is generated between the opposite ends, i.e., the steering shaft 106 and the first rotor 102. The second rotor 103 provided between the first gear part 121 formed on the steering shaft 106 and the second gear part 122 formed on the first rotor 102 rotates by the phase difference, and the steering shaft 106 is mechanically stopped from rotating as the rotation of the second rotor 103 is restricted by the stopper 104.

The stopper 104 is provided with a support member 131 protruding radially outward from the second rotor 103, and the support member 131 is supported on, for example, the housing 301 or the receiving member 112 to limit the range of the rotation angle of the second rotor 103. This will be described in detail below.

The drawings show an embodiment in which the support member 131 is provided in an elliptical shape, but are not limited thereto, and the support member 131 may be formed in other shapes.

Described is a process in which the rotation of the second rotor 103 is restricted by the stopper 104 to stop the rotation of the steering shaft 106. First, in a case where the wheels can be freely steered, the steering shaft 106, the first rotor 102, and the second rotor 103 rotate together about the center axis of the steering shaft 106. In this case, since the reaction force motor does not reach the maximum output, the motor 101 is not operated.

In the case where the steering wheel 107 reaches the maximum number of turns or the wheel is stuck at the curb, if the reaction force motor reaches the maximum output by the driver's steering torque, the motor 101 is operated, the stopper 104 is supported by, for example, the housing 301 by the operation of the motor 101 to restrict the rotation of the second rotor 103, and as the rotation of the second rotor 103 is restricted, the rotation of the steering shaft 106 engaged with the second rotor 103 is restricted by the first to third gear members 121, 122 and 123.

Meanwhile, two or more second rotors 103 may be provided, and since each of the second rotors 103 has the stopper 104, the number of stoppers 104 supported by, for example, the housing 301 to prevent the rotation of the steering shaft 106 is increased, so that stability may be enhanced.

In other words, as the number of stoppers 104 supported by, for example, the housing 301 and receiving the driver steering torque increases so that the driver steering torque is distributed, enhanced stability can be achieved.

The drawings show an embodiment in which three second rotors 103 are provided as an example, but not limited thereto, and more second rotors 103 may be provided.

Meanwhile, the stopper 104 may be formed integrally with the second rotor 103 or may be separately manufactured and combined.

Referring to fig. 2, if the stopper 104 and the second rotor 103 are separately manufactured, either the stopper 104 or the second rotor 103 is provided with a protrusion 132 axially protruding, and the other is provided with an insertion portion 133 corresponding to the protrusion 132. When the protrusion 132 is inserted into the insertion portion 133, the stopper 104 and the second rotor 103 may be coupled to each other.

Although the drawings show an embodiment in which the insertion portion 133 is formed in the second rotor 103 and the protrusion 132 is formed in the stopper 104, as described above, the protrusion 132 may be formed in the second rotor 103 and the insertion portion 133 may be formed in the stopper 104.

As shown, serrations may be formed on the outer circumferential surface of the protrusion 132 and the inner circumferential surface of the insertion part 133, and when the second rotor 103 and the stopper 104 are coupled to each other, they are fastened in the circumferential direction.

Meanwhile, as described above, the stopper 104 for preventing the rotation of the second rotor 103 is provided with the support member 131. The support member 131 is formed to protrude radially outward from the second rotor 103.

In other words, when the second rotor 103 rotates, the end of the support member 131 draws a circle having a radius larger than the outer circumferential surface of the second rotor 103, and therefore, when the steering shaft 106 rotates rightward or leftward, the support member 131 is supported by, for example, the housing 301 or the receiving member 112, thereby limiting the range of the rotation angle of the second rotor 103.

The stopper 104 may be provided on at least one of a side of the second rotor 103 axially facing the steering shaft 106 or the other side of the second rotor 103 axially facing the motor 101. When the second rotor 103 rotates, the supported position of the support member 131 may vary depending on when the stopper 104 is disposed on one side and when the stopper 104 is disposed on the other side.

In other words, although only either case in which the stopper 104 is provided on one side or the other side of the second rotor 103 in the axial direction is shown in the drawings, the stopper 104 may be provided on both sides.

Further, the range of angles in which the second rotor 103 can be rotated and the position at which the support member 131 is supported may vary depending on the thickness of the support member 131, the inner diameter of the housing 301 or the receiving member 112, and the outer diameter of the steering shaft 106, and may be appropriately selected in consideration of the torsional rigidity of the torsion bar 105, the maximum torsional angle, and the maximum output of the reaction force motor.

If the stopper 104 is provided at one side of the second rotor 103 in the axial direction, the second rotor 103 rotates, and the support member 131 is supported on the outer circumferential surface of the steering shaft 106, thereby restricting the range of the rotational angle of the second rotor 103.

Referring to the first embodiment shown in fig. 3, the second gear part 122 is formed at one end of the receiving part 112 such that the stopper 104 is not caught on the receiving part 112 or the housing 301 when the second rotor 103 rotates, and the support part 131 is supported on the outer circumferential surface of the steering shaft 106 while restricting the rotation of the second rotor 103 when the steering shaft 106 rotates to one side or the opposite side.

Since the support member 131 is supported on the outer circumferential surface of the steering shaft 106 and the rotatable range of the second rotor 103 is restricted by the stopper 104, the rotation of the steering shaft 106 is prevented.

Alternatively, since the support member 131 is supported on the outer circumferential surface of the steering shaft 106 or the inner circumferential surface of the housing 301, the rotational angle range of the second rotor 103 can be restricted.

Referring to the second embodiment shown in fig. 4, the support member 131 is radially extended as compared to the above-described first embodiment, so that when the steering shaft 106 is rotated to one side, the support member 131 is supported on the inner circumferential surface of the housing 301, and when the steering shaft 106 is rotated to the opposite side, the support member 131 is supported on the outer circumferential surface of the steering shaft 106, thereby restricting the rotation of the second rotor 103.

In this case, the rotatable range of the second rotor 103 should be reduced as compared with when the support member 131 is supported only on the outer circumferential surface of the steering shaft 106 as described above.

Alternatively, since the support member 131 is not caught on the outer circumferential surface of the steering shaft 106 but is supported on the inner circumferential surface of the housing 301 or the inner circumferential surface of the receiving member 112, the rotational angle range of the second rotor 103 can be restricted.

In this case, the steering shaft 106 may have a first stepped part 501, and the first stepped part 501 is formed such that an outer circumferential surface of one side in the axial direction thereof is radially recessed from the first gear part 121 to prevent the support part 131 from being caught at the outer circumferential surface of the steering shaft 106 when the second rotor 103 rotates.

In other words, when the stopper 104 rotates together with the second rotor 103, the outer circumferential surface of the steering shaft 106 is radially recessed, thereby avoiding the support member 131 that protrudes radially outward from the second rotor 103 from being supported by the steering shaft 106.

Referring to the third embodiment shown in fig. 5, a second stepped part 502 facing the first stepped part 501 and protruding radially from the inner circumferential surface of the housing 301 may be formed to allow the support part 131 to be supported on the inner circumferential surface of the housing 301 when the rotor 103 rotates.

In other words, when the steering shaft 106 is rotated to one side or the opposite side, the support member 131 may be supported by the second step member 502, thereby restricting the rotation of the second rotor 103.

Referring to the fourth embodiment shown in fig. 6, the receiving part 112 may have an extension 601 extending to an axial side from a position where the second gear part 122 is formed to allow the supporting part 131 to be supported at an inner circumferential surface of the receiving part 112 when the second rotor 103 rotates.

In other words, when the steering shaft 106 is rotated to one side or the opposite side, the support member 131 may be supported on the inner circumferential surface of the extension 601, thereby restricting the rotation of the second rotor 103.

Alternatively, the support member 131 includes the first support member 701 or 1001 and the second support member 701 or 1002, and when the second rotor 103 rotates and the support member 131 is supported on, for example, the housing 301, stability can be ensured.

Referring to the fifth embodiment shown in fig. 7, the first support member 701 and the second support member 701 may be disposed to be symmetrical to each other with respect to a line connecting the center of the second rotor 103 and the steering shaft 106 such that the first support member 701 is supported on the outer circumferential surface of the steering shaft 106 and the second support member 702 is supported on the inner circumferential surface of the housing 301 when the steering shaft 106 is rotated to one side, or the first support member 701 is supported on the inner circumferential surface of the housing 301 or the second support member 702 is supported on the outer circumferential surface of the steering shaft 106 when the steering shaft 106 is rotated to the opposite side, thereby restricting the rotation of the second rotor 103.

In other words, as the number of the support members 131 supported by, for example, the housing 301 and subjected to the driver's steering torque increases, the driver's steering torque is distributed, and thus enhanced stability can be achieved.

Although fig. 7 shows an embodiment in which the first step part 501, the second step part 502, or the extension 601 is not formed, the first step part 501 may be formed to change the rotatable range of the second rotor 103, in which case the angles at which the first support part 701 and the second support part 702 are coupled to the second rotor 103 to be supported at the same time may be changed.

If the stopper 104 is provided at the other side in the axial direction of the second rotor 103, the second rotor 103 is rotated, and the support member 131 is supported on the outer circumferential surface of the steering shaft 106 and the inner circumferential surface of the receiving member 112, thereby restricting the rotational angle of the second rotor 103.

Referring to the sixth embodiment shown in fig. 8, when the second rotor 103 rotates, the support member 131 moves between the outer circumferential surface of the steering shaft 106 and the inner circumferential surface of the receiving member 112, so that when the steering shaft 106 rotates to one side, the support member 131 is supported on the inner circumferential surface of the housing 301, and when rotating to the opposite side, the support member 131 is supported on the outer circumferential surface of the steering shaft 106, thereby restricting the rotation of the second rotor 103.

Alternatively, the steering shaft 106 may have a first recess 901, the first recess 901 being formed as an outer circumferential surface of the other side of the steering shaft 106 in the axial direction, radially recessed from the first gear part 121, to prevent the support part 131 from being caught on the outer circumferential surface of the steering shaft 106 when the second rotor 103 rotates.

In other words, when the stopper 104 rotates together with the second rotor 103, the outer circumferential surface of the steering shaft 106 is radially recessed, thereby avoiding the support member 131, which protrudes radially outward from the second rotor 103, from being supported by the steering shaft 106.

Referring to the seventh embodiment shown in fig. 9, since the recess 901 is formed, the support member 131 is not caught on the outer circumferential surface of the steering shaft 106 but supported only on the inner circumferential surface of the receiving member 112, and when the steering shaft 106 is rotated to one side or the opposite side, the support member 131 may be supported on the inner circumferential surface of the receiving member 112, thereby restricting the rotation of the second rotor 103.

In this case, the rotatable range of the second rotor 103 can be increased as compared with the above-described sixth embodiment.

Referring to the eighth embodiment shown in fig. 10, the support member 131 includes the first support member 1001 and the second support member 1002, and when the second rotor 103 rotates and the support member 131 is supported on, for example, the housing 301, stability can be ensured.

The first support member 1001 and the second support member 1002 may be disposed to be symmetrical to each other with respect to a line connecting the center of the second rotor 103 and the steering shaft 106 such that the first support member 1001 is supported on the outer circumferential surface of the steering shaft 106 and the second support member 1002 is supported on the inner circumferential surface of the housing 301 when the steering shaft 106 is rotated to one side, or the first support member 1001 is supported on the inner circumferential surface of the housing 301 or the second support member 1002 is supported on the outer circumferential surface of the steering shaft 106 when the steering shaft 106 is rotated to the opposite side, thereby restricting the rotation of the second rotor 103.

In other words, as described above, as the number of the support members 131 supported by, for example, the housing 301 and receiving the steering torque of the driver increases, the steering torque of the driver is distributed, and thus enhanced stability can be achieved.

Therefore, since the support member 131 is supported on, for example, the housing 301 and the rotational angle range of the second rotor 103 is limited, if the reaction force motor reaches the maximum output, the motor 101 is operated, thereby preventing the rotation of the steering shaft 106.

Meanwhile, as described above, the first rotor 102 is rotatably coupled to the housing 301 and connected to the motor 101. An axially protruding protrusion 311 may be provided at the other side of the first rotor 102, and the first rotor 102 and the case 301 may be coupled together by a bearing 313 coupled to the protrusion 311.

Further, referring to fig. 11, a coupling hole 312 is formed in the protrusion 311, and the motor shaft 111 of the motor 101 is inserted into the coupling hole 312, so that the motor 101 can be coupled with the first rotor 102. The coupling hole 312 and the motor shaft 111 may have serrations so as to allow the first rotor 102 and the motor shaft 111 to be coupled in a circumferential direction to be fastened.

Referring to fig. 12, the protrusion 311 of the motor 101 and the motor shaft 111 may be connected by a belt 1201, and in this case, the diameter of the protrusion 311 may be formed to be larger than that of the motor shaft 111.

In this case, a gear may be formed on the outer circumferential surface of the protrusion 311 and the motor shaft 111 to be connected by the belt 1201.

When the diameter of the protrusion 311 is formed larger than the diameter of the motor shaft 111, the gear ratio between the motor shaft 111 and the first rotor 102 is decreased, and the output of the motor 101 transmitted to the first rotor 102 is increased. Therefore, a motor having a smaller maximum output can be used, thereby reducing the size and weight of the motor 101.

Meanwhile, although not shown in the drawings, a damping member may be provided on the outer circumferential surface of the support part 131. Since the damping member is provided, it is possible to absorb the impact sound generated when the supporting part 131 is supported by, for example, the housing 301.

In other words, when the steering shaft 106 rotates and the support member 131 is supported by, for example, the housing 301, the damping member alleviates the collision, so that the collision sound can be reduced.

With the steer-by-wire apparatus thus shaped, when the driver applies a steering torque to the steering shaft that is greater than the reaction torque of the reaction force motor, it is possible to provide a better steering feeling by mechanically preventing the steering shaft from rotating.

Further, since the protrusion of the first rotor is formed to have a diameter larger than that of the motor shaft of the motor, the gear ratio between the motor and the first rotor is reduced, so that a large torque can be applied to the first rotor despite the reduction in the output of the motor. Therefore, the size and weight of the motor can be reduced.

Although it is described above that all components are combined to operate as one or a combination, embodiments of the present disclosure are not limited thereto. One or more components may be selectively combined and operated as long as they are within the scope of the object of the embodiment.

When an element "comprises," "comprising," or "having" another element, the element can further include but not exclude the other element, and the terms "comprising," "including," and "having" are to be construed as not excluding the possibility of having or adding one or more features, numbers, steps, operations, elements, components, or combinations thereof. Unless defined otherwise, all scientific and technical terms used herein may have the same meaning as commonly understood by one of ordinary skill in the art. It will be further understood that terms, such as those defined in dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The previous description is provided to enable any person skilled in the art to make and use the technical ideas of this disclosure, and is provided in the context of a particular application and its requirements. Various modifications, additions and substitutions to the described embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. The above description and the drawings provide examples of the technical idea of the present disclosure for illustrative purposes only. That is, the disclosed embodiments are intended to illustrate the scope of the technical idea of the present disclosure. Thus, the scope of the present disclosure is not limited to the illustrated embodiments, but is to be accorded the widest scope consistent with the claims. The scope of the present disclosure should be determined by the appended claims, and all technical ideas within the scope of equivalents thereof should be construed as being included in the scope of the present disclosure.

Cross Reference to Related Applications

This application claims priority to korean patent application No. 10-2019-0026702 filed on 8.3.2019 from the korean intellectual property office, the entire contents of which are incorporated herein by reference.