Power transmission device

Abstract

This disclosure relates to a power transmission device including a constant velocity joint and a hub. The power transmission device includes a hub, an outer race, a first inner race, a second inner race, a shaft, a rod, and an elastomer. The first inner race is coupled to the outer race to form a first constant velocity joint, the second inner race is coupled to the outer race to form a second constant velocity joint, the shaft is connected to the first inner race to transmit rotation to the first inner race, the rod is connected to the second inner race and the hub to receive rotation from the second inner race and transmit the rotation to the hub, and the elastomer is configured to elastically support the rod or the shaft relative to the outer race.

Description

Technical Field

[0001] This disclosure relates to a power transmission device including a constant velocity universal joint and a wheel hub. Background Technology

[0002] Vehicles such as purpose-built vehicles (PBVs) have a limited maximum articulation angle of approximately 54 degrees due to interference between the outer seat ring and the axle, resulting in a limited turning radius. In particular, the electrification and enlargement of PBVs are increasing wheelbase dimensions, requiring even larger turning radii. However, conventional power transmission systems, consisting of constant velocity joints and wheel hubs connected to each other, and possessing the aforementioned limited maximum articulation angle, make it difficult to perform U-turns or park PBVs.

[0003] The information disclosed in this background section is intended to enhance the understanding of the background technology of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0004] One aspect of this disclosure is to provide a power transmission device capable of reducing the turning radius by increasing the turning radius of the wheels.

[0005] A power transmission device according to an embodiment of the present disclosure includes a hub, an outer race, a first inner race, a second inner race, a shaft, a rod, and an elastomer. The first inner race is coupled to the outer race to form a first constant velocity universal joint, and the second inner race is coupled to the outer race to form a second constant velocity universal joint. The shaft is connected to the first inner race to transmit rotation to the first inner race. The rod is connected to the second inner race and the hub to receive rotation from the second inner race and transmit the rotation to the hub. The elastomer is configured to elastically support the rod or the shaft relative to the outer race.

[0006] The power transmission device may further include a support plate fixed to the outer race, wherein the elastomer can elastically support the rod or the shaft relative to the support plate.

[0007] The elastic body can be a helical spring.

[0008] The power transmission device may further include a fixing part, which is fixed to the outer bearing ring, wherein the elastic body may be fixed to the fixing part to elastically support the rod or the shaft.

[0009] Elastomers can be made of rubber or plastic.

[0010] Each of the first and second constant velocity joints can be implemented as a fixed ball type constant velocity joint or a sliding ball type constant velocity joint.

[0011] One of the first and second constant velocity universal joints can be implemented as a fixed ball type constant velocity universal joint, and the other can be implemented as a sliding ball type constant velocity universal joint.

[0012] The first and second constant velocity universal joints can have different sizes. Attached Figure Description

[0013] The accompanying drawings, which are incorporated in this specification, illustrate exemplary embodiments, and the detailed description, which is used in conjunction with the exemplary embodiments below, further illustrates the technical concepts of this disclosure, and this disclosure should not be construed as being limited to what is shown in these drawings. In the drawings: Figure 1 This is a cross-sectional view of a power transmission device according to an embodiment of the present disclosure; Figure 2 This is a perspective view of the outer race of a power transmission device according to an embodiment of the present disclosure; Figure 3 It is along Figure 2 A cross-sectional view taken from line AA; Figure 4 This is a perspective view of the rod of a power transmission device according to an embodiment of the present disclosure; Figure 5 This is a view showing the support plate and the elastomer of the power transmission device according to an embodiment of the present disclosure; Figure 6 This is a cross-sectional view of a power transmission device according to another embodiment of the present disclosure; Figure 7 This is a cross-sectional view of a power transmission device according to yet another embodiment of the present disclosure; and Figure 8 This is a view showing the elastic body of a power transmission device according to an embodiment of the present disclosure. Detailed Implementation

[0014] The embodiments of this disclosure are provided to illustrate the disclosure more fully to those skilled in the art. These embodiments can be modified in various other forms, and the scope of this disclosure is not limited to them. The embodiments are provided to make this disclosure more faithful and complete, and to fully convey the concept of this disclosure to those skilled in the art.

[0015] Exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings, enabling those skilled in the art to readily practice the present disclosure.

[0016] Reference Figure 1The power transmission device 10 may include a constant velocity joint 11 and a hub 12. The hub 12 may be rotatably supported by a rolling bearing 13. The rolling bearing 13 may include an inner ring 15, an outer ring 16, and bearing balls 17 disposed between the inner ring 15 and the outer ring 16. The rolling bearing 13 may also include a retainer 48 and a seal 49. The hub 12 may include a radially outwardly extending flange 18, and power may be transmitted via bolts 19 connected to the flange 18. The power transmission device 10 may transmit rotational power transmitted via the shaft 20 to the bolts 19 via the constant velocity joint 11 and the hub 12.

[0017] The constant velocity joint 11 can be configured with an outer race 21 and two inner races 22 and 23, which combine to perform two independent hinges. That is, the constant velocity joint 11 can be constructed to achieve two constant velocity joints while sharing a single outer race 21. Therefore, the constant velocity joint 11 can have a maximum hinge angle corresponding to the sum of the two hinge angles. This can significantly increase the resulting maximum hinge angle, thereby leading to an increase in the maximum steering angle. The constant velocity joint 11 can be implemented as a fixed ball type joint, wherein the constant velocity joint is hinged in an axially fixed position, or as a sliding ball type joint, wherein the constant velocity joint is hinged while sliding axially along the track groove of the outer race 21.

[0018] Reference Figures 1 to 3 The outer race 21 may have multiple first outer ball grooves 25 and multiple second outer ball grooves 26, which are formed longitudinally on the inner circumferential surfaces of both sides of the outer race 21. The first outer ball grooves 25 may mate with a first inner ball groove 27, which is formed on the right side of the inner race (i.e., Figure 1 The outer peripheral surface of the first inner race 22) and the second outer ball groove 26 can mate with the second inner ball groove 28, the second inner ball groove 28 being formed on the left side of the inner race (i.e., Figure 1 The outer peripheral surface of the second inner race 23 is used for the outer race 21. A first ball retainer 31 can be arranged between the inner peripheral surface on the right side of the outer race 21 and the first inner race 22, and a second ball retainer 32 can be arranged between the inner peripheral surface on the left side of the outer race 21 and the second inner race 23. The first ball retainer 31 and the second ball retainer 32 can each have windows configured to receive balls 33 and 34, respectively. The balls 33 and 34 can be accommodated in the space formed by the first outer ball groove 25 and the first inner ball groove 27, and in the space formed by the second outer ball groove 26 and the second inner ball groove 28, respectively, with the balls 33 and 34 positioned within the windows formed in the first ball retainer 31 and the second ball retainer 32. This allows for two constant velocity universal joint structures sharing the outer race 21.

[0019] Reference Figure 2 and Figure 3 The outer bearing ring 21 may have a recess 38 at its center in the longitudinal direction. The recess 38 is an inwardly recessed portion, and the first outer ball groove 25 and the second outer ball groove 26 may be arranged on both sides of the recess 38 in a separated state.

[0020] Shaft 20 is configured to receive power from a vehicle's power source (e.g., a transmission or motor) and is fastened to a first inner race 22. Shaft 20 can be connected to the first inner race 22 via a spline connection, whereby rotation of shaft 20 can be transmitted to the first inner race 22. Rotation of the first inner race 22 can be transmitted to the outer race 21 via balls 33, and rotation of the outer race 21 can be transmitted to the first inner race 23 via balls 34.

[0021] Reference Figure 4 The rod 41 may be provided with two spline structures 42 and 43, which can be splined to the second inner race 23 and the hub 12 respectively. The rod 41 can be splined to the second inner race 23 via the spline structure 42 provided at one end, so that the rotation of the second inner race 23 can be transmitted to the rod 41. The rod 41 can be splined to the hub 12 via the other spline structure 43, so that the rotation of the rod 41 can be transmitted to the hub 12. One end of the rod 41 may be exposed outside the hub 12, where the wheel nut 44 can be connected to fix the rod 41 and the hub 12.

[0022] Sheaths 45 and 46 are configured to seal the grease filling the outer race 21 and can be fastened between one end of the outer race 21 and the shaft 20 and between the other end of the outer race 21 and the rod 41, respectively.

[0023] In embodiments of this disclosure, the hinge between the outer race 21 and the shaft 20 and the hinge between the outer race 21 and the rod 41 can be performed independently, and the constant velocity universal joint 11 can have a maximum hinge angle corresponding to the sum of the two hinge angles.

[0024] The rod 41 can be elastically supported relative to the outer race 21 by the elastic body 51. (See reference...) Figure 1 and Figure 5The support plate 52 can be fixed to the inner surface of the outer race 21, and the elastic body 51 can elastically support the rod 41 relative to the support plate 52. The elastic body 51 can be a helical spring and can be arranged in a compressed state to support the rod 41 in a direction away from the support plate 52. In this case, the elastic body support portion 53 can be formed to protrude from the support plate 52 toward the rod 41. Therefore, the rod 41 can be elastically supported relative to the outer race 21 by the elastic body 51. Therefore, during hinge, the hinge between the outer race 21 and the rod 41 can be limited by the elastic force of the elastic body 51, thereby enabling the hinge between the outer race 21 and the shaft 20, and then enabling the hinge between the outer race 21 and the rod 41. During reset, the hinge between the outer race 21 and the rod 41 can be reset, and the hinge between the outer race 21 and the shaft 20 can also be reset. As described above, when hinge and reset are performed sequentially, deviation of the outer race (a state where the position of the outer race cannot be controlled) can be prevented.

[0025] Figure 6 This is a cross-sectional view of a power transmission device according to another embodiment of the present disclosure. Besides the elastic body 61 elastically supporting the shaft 20 instead of the rod 41, Figure 6 The embodiments shown are the same as those described above. (Refer to...) Figure 6 The support plate 62 can be fixed to the outer race 21, and the elastomer 61 can elastically support the shaft 20 relative to the support plate 62. In this case, the elastomer support portion 63 can be formed to protrude from the support plate 62 toward the shaft 20. Therefore, the hinge and reset can be performed in the reverse order of the above embodiment.

[0026] In another embodiment of this disclosure, a constant velocity universal joint can be achieved by combining a fixed ball joint and a sliding ball joint. In yet another embodiment, a constant velocity universal joint can be achieved by combining two universal joints of different sizes.

[0027] Figure 7 and Figure 8 A power transmission device according to yet another embodiment of the present disclosure is shown. Figure 7 This is a cross-sectional view of a power transmission device according to yet another embodiment of the present disclosure, and Figure 8 This is a view illustrating the elastic body of a power transmission device according to an embodiment of the present disclosure. (Refer to...) Figure 7 and Figure 8 The elastomer 71 can be implemented using an elastic material such as rubber or plastic, and the elastomer 71 can be fixed to an annular fixing portion 72, which is press-fitted to the outer race 21. The elastomer 71 can protrude toward the shaft 20 to elastically support the shaft 20 relative to the fixing portion 72. Therefore, the shaft 20 can be elastically supported relative to the outer race 21. Although Figure 7 and Figure 8The illustration shows the case where the elastomer 71 protrudes toward the shaft 20 to elastically support the shaft 20, but the elastomer can also protrude toward the rod 41 to elastically support the rod 41.

[0028] The first and second constant velocity universal joints can have different dimensions. For example, the outer race 21 can be configured to have different dimensions on the left and right sides of the recess 38. In this configuration, the hinge angle between the outer race 21 and the shaft 20, and the hinge angle between the outer race 21 and the rod 41, can be different from each other, thereby allowing the steering angle to vary according to design specifications.

[0029] According to embodiments of this disclosure, a constant velocity universal joint can perform two independent hinges while sharing a single outer race, thereby increasing the maximum hinge angle obtained. Furthermore, the shaft or rod can be elastically supported relative to the outer race, allowing for sequential hinge and reset, and thus preventing misalignment of the outer race.

[0030] The above are merely embodiments for implementing this disclosure. This disclosure is not limited to the above embodiments, and those skilled in the art will recognize the technical spirit of this disclosure, and various modifications can be made without departing from the spirit of this disclosure as claimed in the appended claims.

Claims

1. A power transmission device, characterized in that, include: Wheel hub; Outer seat ring; A first inner race, which is combined with the outer race to form a first constant velocity universal joint; The second inner race, which is combined with the outer race to form a second constant velocity universal joint; A shaft connected to the first inner race so as to transmit rotation to the first inner race; A rod, the rod being connected to the second inner race and the hub, for receiving rotation from the second inner race and transmitting the rotation to the hub; and An elastomer configured to elastically support the rod or shaft relative to the outer race.

2. The power transmission device according to claim 1, characterized in that, The power transmission device further includes: Support plate, the support plate being fixed to the outer bearing ring, wherein The elastomer elastically supports the rod or the shaft relative to the support plate.

3. The power transmission device according to claim 2, characterized in that, The elastic body is a helical spring.

4. The power transmission device according to claim 1, characterized in that, The power transmission device further includes: The fixing part is fixed to the outer bearing ring, wherein The elastomer is fixed to the fixing part to elastically support the rod or the shaft.

5. The power transmission device according to claim 4, characterized in that, The elastomer is made of rubber or plastic.

6. The power transmission device as described in claim 1, characterized in that, Each of the first constant velocity joint and the second constant velocity joint is implemented as a fixed ball type constant velocity joint or a sliding ball type constant velocity joint.

7. The power transmission device as described in claim 6, characterized in that, One of the first and second constant velocity universal joints is implemented as a fixed ball type constant velocity universal joint, and The other is implemented as a sliding ball type constant velocity universal joint.

8. The power transmission device according to claim 6, characterized in that, The first constant velocity universal joint and the second constant velocity universal joint have different dimensions.

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