阅读说明：本技术 可时限地差动的末级齿轮装置 (Final stage gear device capable of time-limited differential motion ) 是由 广田功 日向野升 远藤学 大桥和弘 沼部俊吾 于 2019-04-17 设计创作，主要内容包括：本发明的将驱动轴与第一车轴及第二车轴驱动地结合的齿轮装置具备：壳体,其与所述驱动轴齿轮结合并绕轴旋转；轮毂,其能够与所述第一车轴结合；离合器部件,其与所述壳体卡合且以能够脱离啮合的方式与所述轮毂啮合；施力单元,其将所述离合器部件保持在与所述轮毂啮合的位置；以及差动齿轮组,其将所述壳体与第一车轴及第二车轴进行齿轮结合,并由所述离合器部件将所述第一车轴与所述第二车轴之间的差动锁定。(The gear device for drivingly coupling a drive shaft to a first axle and a second axle according to the present invention includes: a housing coupled with the driving shaft gear and rotating around a shaft; a hub engageable with the first axle; a clutch member engaged with the housing and engaged with the hub so as to be disengageably engaged therewith; an urging unit that holds the clutch member at a position of engagement with the hub; and a differential gear set that gear-couples the housing to the first and second axles, and differentially locks the first and second axles by the clutch member.)

1. A gear device that drivingly couples a drive shaft to a first axle and a second axle, the gear device comprising:

a housing coupled with the driving shaft gear and rotating around a shaft;

a hub engageable with the first axle;

a clutch member engaged with the housing and engaged with the hub so as to be disengageably engaged therewith;

an urging unit that holds the clutch member at a position of engagement with the hub; and

and a differential gear set that gear-couples the housing to the first and second axles and locks a differential between the first and second axles by the clutch member.

2. The gear arrangement according to claim 1,

further provided with: and an actuator that operates only when electric power is input and drives the clutch member in a direction of disengaging from the hub.

3. The gear arrangement according to claim 1,

the urging unit includes a first spring that urges the clutch member toward the hub.

4. The gear arrangement according to claim 3,

further provided with: and a second spring that biases the clutch member in a direction of separating from the hub.

5. The gear device according to claim 1, further comprising:

a flange fixed to the clutch member and led out of the housing; and the number of the first and second groups,

a detection device that detects an axial position of the flange.

Technical Field

The following disclosure relates to a gear device for driving a pair of drive wheels at the same rotational speed in a vehicle, and capable of allowing a differential motion between the two drive wheels only under certain conditions.

Background

When the automobile turns, the left and right drive wheels draw arcs of different lengths, and therefore, a difference in rotation speed must be allowed between the drive wheels. In order to transmit torque to a drive wheel while allowing the speed difference, an automobile mainly running on a paved road generally uses a final drive including a differential. In order to transmit torque to the remaining drive wheels even when one of the drive wheels temporarily loses traction, a device for limiting the differential motion of the differential (so-called limit differential) or a device for locking the differential motion (locking or locking differential) may be included. Patent document 1 discloses a related art.

Automobiles called All Terrain Vehicles (ATVs) are used mainly for the purpose of driving on bad roads such as dirt roads. In this automobile, one or both of the wheels frequently lose traction during running. The allowance of the differential operation adversely interferes with the transmission of torque, and the idling operation and the differential operation restriction are frequently repeated, which imposes a significant burden on the engine and the transmission system. Therefore, in many cases, the ATV directly couples the left and right axles without using a differential. In a bad road, the drive wheels can easily slip, and therefore the difference in the rotation speed absorbs the slip of the drive wheels.

Documents of the prior art

Patent document

Patent document 1: U.S. patent application publication 2018/0195596A1

Disclosure of Invention

Even ATVs sometimes travel on paved roads, lawns, etc. with very limited opportunities, such as unloading to trailers, entering and exiting garages. If there is no difference, the tire is damaged on the paved road, and if it is on the lawn, the lawn is damaged. On the other hand, it is not reasonable to continuously suffer from the above-mentioned adverse effects due to very limited opportunities, and it is necessary to continuously input external energy such as electric power to the device for differential locking, thereby impairing the energy conversion efficiency. The apparatus disclosed below is completed in consideration of this problem.

According to one aspect, a gear device for drivingly coupling a drive axle to a first axle and a second axle comprises: a housing coupled with the driving shaft gear and rotating around a shaft; a hub engageable with the first axle; a clutch member engaged with the housing and engaged with the hub so as to be disengageably engaged therewith; an urging unit that holds the clutch member at a position of engagement with the hub; and a differential gear set that gear-couples the housing to the first and second axles, and that locks a differential between the first and second axles by the clutch member.

Drawings

Fig. 1 is a front sectional view of a gear device according to an embodiment.

Fig. 2 is a front sectional view of a gear device according to another embodiment.

Fig. 3 is a partial front sectional view of the gear device of fig. 1, in which the vicinity of the clutch and the actuator is enlarged.

Fig. 4 is a partial front sectional view of a modification.

Fig. 5 is a partial front sectional view of another modification.

Fig. 6 is a partial front sectional view of a further modification.

Fig. 7 is a partial front sectional view of a gear device of an example of combination with a switch.

Fig. 8 is a circumferential cross-sectional view of the gear device mainly showing a relationship between the clutch member and the through hole of the housing.

Detailed Description

Several exemplary embodiments are described below in conjunction with the appended drawings. In the following description and claims, unless otherwise specified, the shaft means a rotation shaft of an axle and generally coincides with a rotation shaft of a gear device. The axial direction is a direction parallel thereto, the radial direction is a direction perpendicular thereto, and the circumferential direction is a direction around the axis.

Referring mainly to fig. 1, the gear device according to the present embodiment can be used as a final drive that can transmit torque from a drive shaft to a pair of axles and can perform differential motion only with a limited time, and is particularly applicable to an ATV. The gear device is provided with: a housing 1 rotating around an axis C; locking the differential gear set 3 in a steady state; a clutch 5 for locking the differential; an actuator 7 for driving the clutch 5 to unlock; and a crown gear 9 for coupling with the drive shaft gear.

The housing 1 is substantially cylindrical about the axis C, and may be a single member (one-piece type) in its entirety. In this case, the housing 1 has an opening of a corresponding size, for example, in the circumferential surface, in order to facilitate the fitting of the components inside. Alternatively, as shown in fig. 2, the case 1 may be divided into a main body 1A and a lid 1B (two-piece type). In this form, the interior of the main body 1A is open to the outside before the lid body 1B is fixed, and therefore an opening for introducing an internal component is not required. Of course, the number of the cells may be 3 or more.

A ring gear 9 is fixed to, for example, the outer periphery of the housing 1, and is coupled to the drive shaft gear. The case 1 may integrally have a portion protruding in a flange shape so as to be positioned in contact with the ring gear 9. As shown in fig. 1, the portions may be joined to each other by a weld metal that is melted into a weld portion 11 that is a gap between the portions and the ring gear 9. The welded part 11 may have a groove for facilitating welding. In order to facilitate welding, as shown in fig. 1, the welded portion 11 may be exposed in the axial direction at one end of the housing 1, or may be directed outward in the radial direction.

Alternatively, as shown in fig. 2, the housing 1 and the ring gear 9 may be fixed by fastening with bolts 11B. In this case, the body 1A and the lid 1B may be provided with corresponding flanges 1AF, 1BF, and the bolts 11B may be fastened to fix the ring gear 9 together therewith. Alternatively, another fixing means independent of the bolt 11B may be used for fixing the main body 1A and the lid 1B.

The housing 1 rotates about the axis C upon receiving a torque from the drive shaft via the ring gear 9. In order to enable smooth rotation, for example, the housing 1 is rotatably supported near both ends thereof by ball bearings or roller bearings 13A, 13B, respectively. The bearing may be fitted to a boss portion projecting in the axial direction from the housing 1, but instead of or in addition to this, a bearing 13C fitted to the outer periphery of the housing 1 may be used as shown in fig. 5. For positioning the bearing 13C, for example, a pin or a ring 85 fitted, engaged, press-fitted, or joined to the outer periphery of the housing 1 can be used.

The differential gear set 3 is supported by the case 1, and is coupled to the side gears 31A and 31B that are coupled to the axles, respectively, to thereby mediate transmission of torque from the case 1 to the side gears 31A and 31B. Since the clutch 5 is locked at the time of stabilization, the differential gear set 3 rotates both axles at the same rotational speed, but allows the differential motion between the side gears 31A, 31B at the time of unlocking. Fig. 1 and 2 illustrate a bevel gear type differential gear set 3, but other forms are of course possible.

Referring primarily to fig. 3 in conjunction with fig. 1, the clutch 5 is formed of dog teeth (ドッグ )53 and dog teeth 55 engraved on the clutch member 51 for engagement therewith. Instead of the mutually engaging pawl teeth, a key, a spline, an engaging structure such as a projection, or other restricting means may be used.

The pawl teeth 53 or other engaging structure are engraved on a hub coupled to one axle, such as the side gear 31A. Such a configuration is advantageous in that the structure of the apparatus can be simplified, or the hub may be a hub member independent from the side gear 31A. The hub member is engaged or coupled with the side gear 31A or the axle to restrict the differential motion, or may be integrated.

The clutch member 51 is movable in the axial direction from an engaged position shown by a solid line to a disengaged position shown by a two-dot chain line in the drawing. In the steady state, the clutch member 51 is held at the engaged position by an urging means described later, and the differential gear set 3 is locked, thereby locking the differential between the two axles.

The clutch member 51 is disc-shaped about the axis C, and has one surface provided with pawl teeth 55 and one or more legs projecting from the opposite surface thereof at equal intervals in the circumferential direction. On the other hand, the housing 1 has a through hole 15 corresponding thereto. The legs of the clutch member 51 face the actuator 7 through the through holes 15, respectively.

The actuator 7 can be, for example, an electromagnetic actuator that is operated by input of electric power. As an example thereof, as described below, the plunger 75 is driven by the electrically excited solenoid 71. The clutch member 51 moves forward and backward in accordance with the axial forward and backward movement of the plunger 75. Alternatively, the solenoid 71 itself may advance and retract, and the clutch member 51 may advance and retract.

The solenoid 71 preferably includes a core 73 for guiding magnetic flux. The core 73 abuts on one end of the housing 1, but rotates relative to the housing 1 because it is locked to the carrier together with the solenoid 71. As shown in fig. 3 and 5, magnetic core 73 may slide in contact with an end surface of case 1, and in this case, the end surface of case 1 may be used as a part of magnetic core 73. Alternatively, as shown in fig. 4, the core 73 may be provided with an extension portion 73E extending toward the boss portion of the housing 1, and positioned by the extension portion 73E so as to be separated from the end surface of the housing 1. According to the configurations shown in fig. 3 and 5, although friction that cannot be ignored is generated between the magnetic core 73 and the housing 1 due to the reaction force of the driving plunger 75 and the magnetic flux leaking into the housing 1, the friction is further reduced in the configuration shown in fig. 4, and the energy loss due to the leakage of the magnetic flux also becomes smaller.

The plunger 75 is disposed so as to abut against the leg of the clutch member 51. For example, the core 73 may have a gap for jumping magnetic flux, and the plunger 75 may be disposed along the gap. The plunger 75 may be slidably fitted to, for example, a boss portion of the housing 1. Normally, the plunger 75 rotates together with the housing 1, and therefore rotates relatively to the magnetic core 73.

The plunger 75 may be formed of an outer ring 77 and an inner ring 79 which are integrated with each other by press fitting or the like. The outer ring 77 facing the magnetic core 73 may be made of a magnetic material such as carbon steel for guiding magnetic flux, and the inner ring 79 may be made of a non-magnetic material for preventing leakage of magnetic flux.

When no electric power is supplied, that is, when the electric power is not excited, the plunger 75 abuts against the clutch member 51, and this position is defined as an engagement position. To assist in holding the clutch member 51 in the engaged position, a biasing means, an example of which is a spring 83, can be utilized.

As shown in fig. 3, for example, the ring 81 may be engaged with a boss portion of the housing 1 in advance, and the spring 83 may be elastically interposed between the ring 81 and the plunger 75. Alternatively, as shown in fig. 5, the ring 81 may be fitted, press-fitted or joined to the boss portion. Alternatively, as shown in fig. 4, the spring 83 may be interposed between the core 73 or the extension 73E thereof and the plunger 75. Still alternatively, the spring 83 may be interposed between the inner surface of the housing 1 and the clutch member 51, for example.

As shown in fig. 5, the reaction force of the spring 83 may be supported only by the ring 81, but as shown in fig. 3 and 4, the bearing 13A may be brought into contact with the ring 81 or the extension portion 73E in order to also load the bearing 13A. Alternatively, as shown in fig. 6, only the bearing 13A may be used for load. The spring 83 may directly abut against the clutch member 51 to press the clutch member.

The spring 83 functions to stably press and hold the clutch member 51 in the engaged position via the plunger 75 or directly. In the case of the structure in which the solenoid 71 advances and retreats, as described above, the spring 83 may be disposed so as to urge the solenoid 71.

Other urging means can be used in addition to or instead of the spring 83. Fig. 8 shows an example of a cam mechanism, in which the side surface of the leg of the clutch member 51 and the side surface of the through hole 15 of the housing 1 are inclined in accordance with each other, thereby constituting a cam mechanism. If the housing 1 performs a rotational movement R_DThe inclined side surfaces abut against each other, and the torque is locally converted into the thrust force F in the axial direction. The clutch member 51 is held in engagement by the thrust force FLocation. Of course, the cam may take other suitable configurations regardless of the combination of the legs and the through holes 15.

When electric power is supplied, magnetic flux generated by the solenoid 71 flows through the core 73, the plunger 75 is attracted by the magnetic flux of the jump gap and retreats in the axial direction, and the clutch member 51 moves to the disengaged position. To assist disengagement of the clutch 5, a spring 57 may also be utilized. As illustrated in fig. 3 to 5, the spring 57 may be elastically interposed between the side gear 31A and the clutch member 51, or may be interposed in other places. Further, the spring 57 may be disposed so as to pull the clutch member 51 toward the housing 1.

Alternatively, a structure in which the clutch member 51 is positively pulled out by the actuator 7 may be employed instead of or in addition to the spring 57. Fig. 6 is an example thereof, and the clutch member 51 may be integrally or separately provided with an extension portion 51E extending further from the leg, and the plunger 75 may be engaged with the vicinity of one end thereof. For engagement, a pin or a ring 87 that is fitted, engaged, press-fitted, or joined to the extension portion 51E can be used. When electric power is input, the plunger 75 is attracted by the magnetic flux of the jump gap and moves in the axial direction, and engages with the extended portion 51E to pull out the clutch member 51, whereby the clutch 5 is disengaged. According to this configuration, the spring 57 can be omitted. The extension 51E can also be used to receive the force of the spring 83.

The above embodiments are examples in which the actuator of the clutch member is driven by an electromagnetic force, but instead of the electromagnetic actuator, a device in which the clutch member is driven by another driving device, for example, a piston is driven by a hydraulic pressure such as a hydraulic pressure may be used. Alternatively, instead of the hydraulic pressure, a device using air pressure may be used, or a gear or a cam mechanism driven by a motor may be used for the actuator 7. In short, as long as electric power is not input to the actuator 7, the clutch 5 remains in the engaged state, the differential motion of the differential gear set 3 is prohibited, and torque is always transmitted to both drive wheels on a bad road. The inhibition of the differential does not consume power and does not impair the energy conversion efficiency. When a differential motion is required in a specific scene such as a paved road or lawn, if electric power is input to the actuator 7 only at this time, the differential motion is allowed between the drive wheels without damaging the tires or the road surface.

Whether the clutch member 51 is in the disengaged position or the engaged position can be determined based on the presence or absence of electric power input to the actuator 7, but in addition to this, the gear device may include a device for detecting the position of the clutch member 51. For example, as shown in fig. 7, the gear device may include a flange 19 that is fixed to the clutch member 51 by a screw or the like and is drawn out of the housing 1. The axial position of the flange 19 can be detected by a mechanical switch, an optical sensor, a non-contact sensor using a change in electrostatic capacitance, an electric field, or a magnetic field, or the like. These detection devices may be attached to the gear device or any part of the vehicle body.

Fig. 7 shows an example of the pull switch 21 fixed to the wall surface 25 of the carrier, in which the tip of the rod 23 has a head 23H that opens like an umbrella, and the edge of the flange 19 is slidably engaged with the head 23H. In the engaged position, the lever 23 is pulled out and the switch is on, but in the disengaged position, the lever 23 is retracted and the switch is off. Of course, the relationship between the position of the lever and the on/off state may be reversed, or a push switch may be used instead of the pull switch. Either one of the springs 57 and 83 may be used in addition to or instead of the spring for biasing the lever.

Although several embodiments have been described, modifications and variations of the embodiments can be made based on the disclosure.