JP4817686B2 - Drive shaft speed reducer - Google Patents

Description

  The present invention relates to a drive shaft reduction device that transmits rotation of a drive shaft to a driven body via a planetary gear mechanism.

  As a conventional drive shaft reduction gear provided with a planetary gear mechanism, a structure of an independent suspension axle described in Patent Document 1 has been proposed. The structure of the independent suspension axle described in Patent Document 1 has a cross-sectional configuration as shown in FIG. As shown in FIG. 6, in the axle housing 41 that is independently suspended by a vehicle body frame (not shown), a drive shaft 43 having one end connected to the universal joint 42 is supported at two points by a roller bearing 44 and a cylindrical bush 45. ing.

  A sun gear shaft 47 having a sun gear 46 is fixed to the end of the drive shaft 43. A planetary gear 50 is engaged with the sun gear 46, and the planetary gear 50 is supported by a planetary gear shaft 52 supported by a carrier 51. The planetary gear 50 meshes with a ring gear 53 fixed to the axle housing 41.

  A ring gear hub 53a extending in the radial direction is attached to the ring gear 53, and a shaft portion 53b extending in the axial direction is formed on the link gear hub 53a. The shaft portion 53b is fixed to the outer peripheral portion of the axle housing 41 by spline coupling. The carrier 51 is coupled to a wheel hub 54 that is rotatably mounted on the axle housing 41.

  The shaft portion 53 b of the ring gear 53 is spline-coupled to the outer peripheral portion of the shaft portion of the axle housing 41 and is attached to the axle housing 41 so as not to rotate. The movement of the ring gear 53 in the axial direction is restricted by a locking piece 56 attached to the end of the axle housing 41. One bearing 55 b that supports the wheel hub 54 is disposed on the outer peripheral portion of the shaft portion 53 b of the ring gear 53.

  The wheel hub 54 is supported by a pair of bearings 55a and 55b respectively disposed on the outer peripheral portion of the axle housing 41 and the outer peripheral portion of the shaft portion 53b. A wheel (not shown) can be attached to the wheel hub 54. The rotation of the drive shaft 43 is decelerated by the planetary gear mechanism and transmitted as the rotation of the wheel hub 54, so that the wheel mounted on the wheel hub 54 can be decelerated and rotated.

Since the drive shaft 43 is supported at two points by the roller bearing 44 and the cylindrical bush 45, the sun gear shaft 47 is not affected even if a radial force is applied to the universal joint 42. ing. The sun gear shaft 47 is spline-engaged with the drive shaft 43 via a cylindrical joint 48. For this reason, the sun gear 46 is arranged in a floating state, and the tooth contact with the planetary gear 50 is kept good.
JP-A-8-40095

  In the structure of the independent suspension axle as described in Patent Document 1, since the bearing 55b is disposed on the outer peripheral portion of the shaft portion 53b, the wheel hub 54 is disposed between the axle housing 41 and the wheel hub 54. The bearing 55b to be supported and the shaft portion 53b of the ring gear 53 are arranged. For this reason, when the bearing 55b is deformed by receiving a load from the wheel hub 54, the spline coupling portion between the shaft portion 53b and the axle housing 41 receives the deformation load.

  When a deformation load is applied to the spline coupling portion between the shaft portion 53b and the axle housing 41, a minute slip due to relative repetition occurs between the two surfaces in contact with the spline coupling portion. The minute slip causes wear between the two surfaces. That is, the phenomenon of wear due to minute slip and fretting are likely to occur. Due to the occurrence of fretting, there is a problem that durability at the spline portion is lowered.

  Further, since the wheel hub 54 is supported on the outer peripheral portion of the shaft portion 53b of the ring gear 53 via the bearing 55b, there is a problem that the outer peripheral diameter of the wheel hub 54 is increased. Further, since the locking piece 56 that restricts the axial movement of the ring gear 53 is disposed in the space between the end of the axle housing 41 and the sun gear 46, the thickness of the locking piece 56 is increased. It was difficult to obtain sufficient strength, and it was difficult to ensure sufficient strength as the locking piece 56.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a highly durable drive shaft speed reducer with the object of solving the above problems.

In order to achieve the above object, according to the first aspect of the present invention, a driven body rotatably supported by a drive shaft housing via a bearing, and the rotation through the drive shaft housing are transmitted to the driven body. A sun gear in the planetary gear mechanism, comprising: a drive shaft; and a planetary gear mechanism that is disposed between the drive shaft and the driven body and decelerates the rotation of the drive shaft and transmits the rotation to the driven body. Is supported by the drive shaft so as to be integrally rotatable, a carrier that supports the planetary gear in the planetary gear mechanism is supported by the driven body so as to be integrally rotatable, and the ring gear in the planetary gear mechanism is non-rotatable. Supported by a drive shaft housing, the ring gear includes a ring gear hub extending in a radial direction from the ring gear and a shaft portion extending in the axial direction from the ring gear hub. In the dynamic shaft speed reducer, the shaft portion of the ring gear is non-rotatably supported by the inner peripheral surface of the shaft portion of the drive shaft housing, is attached to the drive shaft housing, and holds the bearing in the axial direction. has a bearing holder, a movement to the axial direction of the ring gear, and a locking means for restricting between the bearing holder,
The locking means comprises the split ring that can be hooked to the bearing holder and divided into a plurality of circumferential directions, and the fixing means that fixes the ring gear hub to the split ring. It has a feature.

The main feature of the second invention is that the configuration of the split ring in the first invention is specified.

  In the present invention, the bearing that supports the driven body can be disposed in the drive shaft housing, and the shaft portion of the ring gear cannot be rotated on the inner peripheral surface side of the drive shaft housing without supporting the bearing. It is supported. For this reason, even if the bearing receives a load from the driven body, the load can be supported by the drive shaft housing.

  Therefore, it is possible to prevent a deformation load from acting between the shaft portion of the ring gear and the inner peripheral surface side of the drive shaft housing due to the load from the driven body. That is, it is possible to prevent fretting between the shaft portion of the ring gear and the inner peripheral surface side of the drive shaft housing. Thereby, durability at the joint portion between the shaft portion of the ring gear and the inner peripheral surface side of the drive shaft housing can be improved.

  Further, the rotational force of the ring gear is not transmitted to the bearing holder that holds the bearing in the axial direction. For this reason, the bearing holder is not loosened by the rotational force of the ring gear. Furthermore, since the ring gear hub is supported by the inner peripheral surface of the drive shaft housing, the outer dimension in the radial direction and the length in the axial direction of the drive shaft reduction device can be reduced. As a result, the drive shaft speed reducer can be made compact.

  Embodiments of a drive shaft reduction device according to the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a drive shaft speed reducing device according to the present invention. FIG. 2 shows an enlarged view of the main part of the P part in FIG. FIG. 3 shows the configuration of the split ring of the drive shaft speed reducing device according to the present invention.

  In the following description, an independent suspension axle device will be described as an example of the drive shaft reduction device. In the independent suspension axle device, an axle housing is used as a drive shaft housing, and a wheel hub is used as a driven body. In addition to the independent suspension axle device, a transmission device and the like can be applied to the drive shaft speed reduction device of the present invention. For this reason, the configuration of the drive shaft speed reduction device of the present invention is not limited to the configuration described below, and various modifications are possible.

  As shown in FIG. 1, the drive shaft reduction gear 1 includes a two-stage reduction planetary gear device. The drive shaft speed reducing device 1 can be configured to include a single-stage decelerating planetary gear unit or a multi-stage decelerating planetary gear unit.

  A drive shaft 2 branched by a differential gear or the like is disposed in the axle housing 20 as a drive shaft housing. A two-stage planetary gear unit 38 is disposed between the drive shaft 2 and the wheel hub 11.

  The planetary gear device 38 includes a first sun gear 3 provided at the tip of the drive shaft 2, a first ring gear 5 that is non-rotatably supported by the spline coupling portion 16 between the axle housing 20, the first sun gear 3, The first stage gear shift is performed by the first planetary gear 4 disposed between the first ring gear 5 and the first ring gear 5. The rotation of the first carrier 6 that supports the first planetary gear 4 is transmitted to the second sun gear 7 disposed on the front side of the drive shaft 2.

  The planetary gear device 38 is disposed between the second sun gear 7, the second ring gear 9 that is non-rotatably supported by the first ring gear 5 and the spline coupling portion 17, and the second sun gear 7 and the second ring gear 9. The second planetary gear 8 provided and the second carrier 10 that supports the second planetary gear 8 and is coupled to the wheel hub 11 perform the second speed change. The second carrier 10 is integrally coupled to the wheel hub 11 via the ring 12.

  As the planetary gear mechanism 38, a two-speed planetary gear mechanism is illustrated. However, as the planetary gear mechanism, a multi-speed planetary gear mechanism or a one-speed planetary gear mechanism can be used.

  The wheel hub 11 has wheels mounted on the outer periphery thereof, and is rotatably supported by a pair of bearings 22 disposed between the wheel hub 11 and the axle housing 20. In FIG. 1, only one bearing 22 is shown, and the other bearing is not shown.

  The rotation of the drive shaft 2 is transmitted from the first sun gear 3 to the planetary gear unit 38. Since the first ring gear 5 is fixed by the axle housing 20 so as not to rotate, the first planetary gear 4 rotates and revolves as the first sun gear 3 rotates. The first carrier 6 rotates in a state where the rotation of the drive shaft 2 is decelerated by the revolution of the first planetary gear 4.

  As the first carrier 6 rotates, the second sun gear 7 rotates. Since the second ring gear 9 is fixed to the first ring gear 5 fixed in a non-rotatable manner by the axle housing 20, the second planetary gear 8 rotates and revolves as the second sun gear 7 rotates. The second carrier 10 rotates in a state where the rotation of the second sun gear 7 is further decelerated by the revolution of the second planetary gear 8.

  The rotation of the second carrier 10 is transmitted to the wheel hub 11 through the ring 12 and rotates in a state where the rotation of the drive shaft 2 is decelerated by two steps. The wheel can be rotated by the rotation of the wheel hub 11. As a result, the vehicle travels.

    As shown in FIG. 2, the first ring gear 5 and the ring gear hub 15 are spline-coupled at the spline coupling portion 13. The inner peripheral surface of the end portion of the first ring gear 5 and the outer peripheral surface of the ring gear hub 15 are spline-coupled by a spline coupling portion 16. Due to the spline connection, the ring gear hub 15 is supported by the axle housing 20 so as not to rotate.

  Since the shaft portion of the first ring gear 5 is supported by the inner peripheral surface of the shaft end portion 21 of the axle housing 20, the ring gear hub 15 is mounted after the bearing 22 that supports the wheel hub 11 is assembled to the axle housing 20. Can be assembled to the axle housing 20. For this reason, assembly work becomes easy and the ring gear hub 15 can be easily detached from the axle housing 20 without removing the bearing 22. As a result, it can be easily disassembled during repairs and inspections.

  In the above description, an example in which the ring gear hub 15 and the first ring gear 5 are configured separately has been described, but the ring gear hub 15 and the first ring gear 5 can also be configured as an integral unit.

  The movement of the first ring gear 5 in the axial direction is caused by the contact between the gear end surface 5c of the first ring gear 5 meshing with the first planetary gear 4 and the spline portion of the ring gear hub 15, and the holder ring attached to the first ring gear 5. It is regulated by the contact between 5a and the spline portion of the ring gear hub 15.

  A bearing 22 that supports the wheel hub 11 is attached to the outer peripheral surface of the shaft end portion 21 of the axle housing 20. The bearing 22 is configured as a taper roller bearing, and the inner race of the bearing 22 is fixed by a bearing holder 23 so as not to come out in the axial direction.

  The bearing holder 23 is attached to the shaft end portion 21 of the axle housing 20 with a bolt 36 with a shim 35 interposed therebetween. The pressure applied to the bearing 22 can be adjusted by a shim 35 disposed between the bearing holder 23 and the shaft end portion 21 of the axle housing 20.

  A stepped portion 24 is provided on the outer periphery of the bearing holder 23. The recessed portion 19 of the split ring 18 can be hooked on the stepped portion 24. The split ring 18 is attached to the ring gear hub 15 by bolts 34. As shown in FIG. 3, the split ring 18 has an inward recess 19 formed on the outer periphery thereof. The tip of the concave portion 19 is formed as a hook portion that hooks on the stepped portion 24 of the bearing holder 23.

  As shown in FIG. 2, a latching means for restricting the movement of the ring gear hub 15 in the axial direction is configured by hooking the concave portion 19 of the split ring 18 on the stepped portion 24 of the bearing holder 23. By this locking means, movement of the first ring gear 5 in the axial direction with respect to the axle housing 20 is restricted.

  That is, since the movement of the first ring gear 5 in the axial direction can be restricted by the locking means with the bearing holder 23, the movement of the ring gear in the axial direction is not restricted. The first ring gear 5 can be reliably prevented from coming into contact with the end face of the planetary gear, the end face of the sun gear, or the like.

  In particular, if the end face of the sun gear is in contact with the end face of the ring gear and the movement of the ring gear in the axial direction is restricted, the end face of the sun gear is subjected to all axial loads, which may cause early wear. On the other hand, in the present invention, the first ring gear 5 does not come into contact with the end surface of the first sun gear 3, the risk of early wear of the first sun gear end surface is prevented, and the durability of the first sun gear 3 is improved. be able to.

  As shown in FIG. 3, a plurality of screw holes 33 are provided in the flange portion 31 of the split ring 18. As shown in FIG. 2, the split ring 18 is attached to the flange portion 28 of the ring gear hub 15 by a bolt 34 inserted into a bolt hole 29 formed in the flange portion 28 of the ring gear hub 15.

  As described above, after the bearing holder 23 is attached to the axle housing 20, the divided pieces of the split ring 18 can be sequentially engaged with the bearing holder 23, so that the split ring 18 can be easily assembled. .

  In FIG. 3, the split ring 18 is shown as a ring divided into two on the circumference, but the split ring 18 may be configured as a ring divided into three, four, or more. You can also.

  Thereby, the shaft portion 25 of the first ring gear 5, that is, the shaft portion 25 of the ring gear hub 15 attached to the first ring gear 5 can be supported on the inner peripheral surface of the shaft end portion 21 of the axle housing 20 so as not to rotate. . In addition, the movement of the first ring gear 5 in the axial direction can be restricted by the split ring 18 and the bearing holder 23.

  Further, the bearing 22 for supporting the wheel hub 11 can be supported by the shaft end portion 21 of the axle housing 20. Further, the movement restriction of the bearing 22 in the axial direction can be restricted by the bearing holder 23. With these configurations, the drive shaft speed reducer can be made compact.

  FIG. 4 shows the configuration of another embodiment of the drive shaft speed reducing device according to the present invention. In the second embodiment, the configuration of the locking means is different from the configuration of the locking means in the first embodiment. Other configurations are the same as those in the first embodiment. About the structure similar to Example 1, the description of the member is abbreviate | omitted by using the same member code | symbol as used in Example 1. FIG.

  A stepped portion 27 is formed between the spline coupling portion 16 with the axle housing 20 and the flange portion 28 of the ring gear hub 15A at the outer peripheral portion of the shaft portion 25 of the ring gear hub 15A. The inner end surface of the bearing holder 23 </ b> A can abut on the stepped portion 27. The inner end surface of the bearing holder 23A and the stepped portion 27 formed on the outer peripheral surface of the ring gear hub 15A constitute locking means for restricting movement of the ring gear hub 15A in the axial direction.

  The bolt 36 for attaching the bearing holder 23A to the shaft end portion 21 of the axle housing 20 can be tightened through a tightening hole 26 formed in the flange portion 8 of the ring gear hub 15A.

  The bearing holder 23A is configured as a split type bearing holder divided in the circumferential direction in order to facilitate the assembling work.

  FIG. 5 shows the configuration of another embodiment of the drive shaft speed reducing device according to the present invention. In the third embodiment, as a structure of the locking means, a split-type stopper member 32 is provided to restrict the movement of the ring gear hub 15B in the axial direction. In this respect, the structure is different from the locking means in the second embodiment.

  Other configurations are the same as those in the second embodiment. About the structure similar to Example 1 and Example 2, the description of the member is abbreviate | omitted by using the same member code | symbol as used in Example 1 and Example 2. FIG.

  A stepped portion 27 is formed between the axle housing 20A and the flange portion 28 of the ring gear hub 15B on the outer peripheral surface of the shaft portion 25 of the ring gear hub 15B. The stepped portion 27 comes into contact with a split-type stopper member 32 sandwiched between the bearing holder 23 </ b> B and the end of the axle housing 20.

  In order to fix the split-type stopper member 32 between the axle housing 20 and the bearing holder 23B, stepped grooves 37 are formed in the shaft end portion 21 of the axle housing 20 and the end surface of the bearing holder 23B, respectively.

  The bolt 36 for attaching the bearing holder 23A to the shaft end portion 21 of the axle housing 20 can be tightened through a tightening hole 26 formed in the flange portion 28 of the ring gear hub 15B.

  The split-type stopper member 32 has a configuration that is divided into two on the circumference like the split ring 18, but may be configured as a ring that is divided into three, four, or more. it can.

  The split type stopper member 32 sandwiched between the axle housing 20 and the bearing holder 23B restricts the axial movement of the ring gear hub 15A relative to the axle housing 20. The bearing holder 23A is configured as a split type bearing holder divided in the circumferential direction in order to facilitate the assembling work.

  Therefore, according to the drive shaft speed reducing device of the present invention, since the bearing 22 is directly supported by the shaft portion of the axle housing 20, even if the bearing 22 receives a load from the wheel hub 11, the same load is applied to the axle housing 20. Can be supported by. For this reason, the spline joint 16 between the ring gear hub 15 and the axle housing 20 does not receive a load from the wheel hub 11. Therefore, fretting is less likely to occur at the spline coupling portion 16 between the ring gear hub 15 and the axle housing 20, and durability at the spline coupling portion 16 can be improved.

  Further, since the rotational force from the first ring gear 5 is not transmitted to the bearing holder 23 that holds the bearing 22 so as not to move in the axial direction, the bearing holder is not loosened by the rotational force of the first ring gear 5. .

  Further, since the ring gear hub 15 is supported by the inner peripheral surface of the shaft portion of the axle housing 20, the axial length and radial diameter of the drive shaft reduction device can be shortened, and the drive shaft reduction device is compact. Can be achieved.

  Furthermore, since the ring gear hub 15 is supported by the inner peripheral surface of the shaft portion of the axle housing 20, the ring gear hub 15 can be assembled to the axle housing 20 after the bearing 22 is assembled to the axle housing 20. This facilitates assembly and shortens the work time required for assembly. In addition, the ring gear hub 15 can be removed from the axle housing 20 without removing the bearing 22, and disassembly during repair and inspection becomes easy.

It is a figure which shows the structure of a drive shaft deceleration device. (Example 1) It is a principal part enlarged view of the P section in FIG. Example 1 It is a perspective view which shows the structure of a division | segmentation ring. Example 1 It is a figure which shows the structure of the other Example of a drive shaft deceleration device. (Example 2) It is a figure which shows the structure of another Example of a drive shaft deceleration device. Example 3 It is a figure which shows the structure of a drive shaft deceleration device. (Conventional example)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive shaft reduction device 2 Drive shaft 3 1st sun gear 4 1st planetary gear 5 1st ring gear 6 1st carrier 7 2nd sun gear 8 2nd planetary gear 9 2nd ring gear 10 2nd carrier 11 Wheel ehub 15 Ring gear hub 18 Split ring 20 Axle housing 23 Bearing holder 24 Step portion 25 Shaft portion 27 Step portion 28 Flange portion 32 Stopper member 38 Planetary gear mechanism 41 Axle housing 43 Drive shaft 46 Sun gear 50 Planet gear 51 Carrier 53 Ring gear 53a Ring gear hub 53b Shaft portion 54 Wheel Hub 56 Locking piece

Claims (2)

A driven body rotatably supported by a drive shaft housing via a bearing, a drive shaft that passes through the drive shaft housing and transmits rotation to the driven body, the drive shaft, and the driven body; A planetary gear mechanism that is disposed between and decelerates the rotation of the drive shaft and transmits it to the driven body,
A sun gear in the planetary gear mechanism is supported by the drive shaft so as to be integrally rotatable, a carrier that supports the planetary gear in the planetary gear mechanism is supported by the driven body so as to be integrally rotatable, and a ring gear in the planetary gear mechanism. Is supported by the drive shaft housing in a non-rotatable manner, and the ring gear includes a ring gear hub extending in a radial direction from the ring gear and a shaft portion extending in the axial direction from the ring gear hub. In the device
The shaft portion of the ring gear is supported non-rotatably by the inner peripheral surface of the shaft portion of the drive shaft housing,
A bearing holder attached to the drive shaft housing and holding the bearing in the axial direction;
Locking means for restricting movement of the ring gear in the axial direction with the bearing holder;
Have
The locking means includes a split ring that can be hooked on the bearing holder and divided into a plurality of circumferential directions, and a fixing means that fixes the ring gear hub to the split ring. Drive shaft speed reducer. 2. The drive shaft reduction device according to claim 1 , wherein the split ring has a recess that engages with an end portion of the bearing holder.

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