JP5764157B2 - Axle device for work vehicle and work vehicle - Google Patents

Description

  The present invention relates to a work vehicle axle device and a work vehicle.

  A work vehicle such as a wheel loader or a backhoe loader includes an axle device. The axle device is a device for transmitting driving force from the engine to the tire. For example, as disclosed in Patent Document 1, the axle device includes an axle shaft, an axle housing, and a planetary gear mechanism. The axle housing houses the axle shaft. The planetary gear mechanism is disposed on the side of the axle shaft. The axle housing is supported by the wheel hub via a bearing. The ring gear of the planetary gear mechanism is supported on the axle housing via a ring gear hub. The ring gear hub is connected to the axle housing. A fixing member is attached to the end of the axle housing in the axial direction. The movement of the ring gear hub and the wheel hub is restricted by the fixing member. Thereby, a wheel is hold | maintained at an axle housing.

JP 2007-120649 A

  In order to improve the holding force of the wheel to the axle housing, it is preferable that the fixing member is firmly fixed to the axle housing. For this purpose, the holding force of the wheel can be improved by enlarging the fixing member and increasing the fixing force of the fixing member. However, in this case, there is a problem that the axle device is enlarged. Further, the holding force of the wheel can be improved by adding a fixing member different from the fixing member. However, in this case, a structure for attaching an additional fixing member is required, and there is a problem that the structure of the axle device is complicated. Or the space for arrange | positioning an additional fixing member is needed, and an axle apparatus may enlarge.

  An object of the present invention is to improve the wheel holding force with a simple structure in an axle device, and to prevent the axle device from being enlarged.

  An axle device for a work vehicle according to an aspect of the present invention includes an axle shaft, an axle housing, a planetary gear mechanism, a wheel hub, a carrier, a wheel, a first bearing, a ring gear hub, A fixing member and a second fixing member are provided. The axle housing houses the axle shaft. The planetary gear mechanism is disposed outside the axle housing in the axial direction. The planetary gear mechanism has a sun gear, a planetary gear, and a ring gear. The sun gear is fixed to the axle shaft. The planetary gear meshes with the sun gear. The ring gear meshes with the planetary gear. The wheel hub is disposed outward of the axle housing in the radial direction. The carrier rotatably supports the planetary gear. The carrier is disposed outside the wheel hub in the axial direction. The carrier houses the planetary gear mechanism. The wheel houses a wheel hub and a carrier. The wheel is attached to the wheel hub and the carrier. The first bearing is disposed between the inner peripheral surface of the wheel hub and the outer peripheral surface of the axle housing. The ring gear hub is disposed outside the first bearing in the axial direction and outside the axle housing in the radial direction. The ring gear hub is connected to the ring gear. The first fixing member is disposed outside the ring gear hub in the axial direction. The first fixing member is fixed to the axle housing. The second fixing member is disposed outward of the first bearing in the axial direction and outward of the axle housing in the radial direction. The outer peripheral surface of the axle housing has a first outer peripheral surface, a second outer peripheral surface, and a stepped portion. The first outer peripheral surface supports the first bearing. The second outer peripheral surface has an outer diameter that is smaller than the outer diameter of the first outer peripheral surface. The step portion is located between the first outer peripheral surface and the second outer peripheral surface. The axle housing has a spline and a relief groove. The spline is provided on the second outer peripheral surface. The escape groove is disposed between the spline and the step portion on the second outer peripheral surface. The ring gear hub is connected to the axle housing via a spline. The second fixing member is fitted in the escape groove. The outer peripheral surface of the second fixing member is located outward from the inner peripheral surface of the first bearing in the radial direction.

  In this work vehicle axle device, movement of the ring gear hub and the first bearing in the axial direction is restricted by the first fixing member. Further, the movement of the first bearing in the axial direction is restricted by the second fixing member. Therefore, the holding force of the wheel can be improved by the first fixing member and the second fixing member. Moreover, since it is not necessary to enlarge the first fixing member, it is possible to prevent the axle device from being enlarged. Further, the second fixing member is fitted in the escape groove. The relief groove is a configuration that is required when processing to form a spline on the outer peripheral surface of the axle housing. Therefore, the second fixing member can be attached using the escape groove without adding a complicated structure for attaching the second fixing member. Thereby, the holding force of a wheel can be improved with a simple structure.

  Preferably, the outer end portion in the axial direction of the inner peripheral surface of the first bearing has a shape in which the inner diameter increases in a direction approaching the second fixing member. In this case, when the first bearing moves outward in the axial direction, the first bearing rides on the second fixing member. When the first bearing rides on the second fixing member, the outer peripheral surface of the first bearing is pressed against the inner peripheral surface of the wheel hub. As a result, the holding force of the wheel hub can be increased.

  Preferably, the first bearing has an outer ring, an inner ring, and a rolling element. The rolling element has a truncated cone shape disposed between the outer ring and the inner ring. The ring gear hub is in contact with the inner ring. In this case, when the first bearing moves outward in the axial direction, the inner ring of the first bearing rides on the second fixing member. When the inner ring of the first bearing rides on the second fixing member, the outer peripheral surface of the outer ring of the first bearing is pressed against the inner peripheral surface of the wheel hub. Thereby, the holding force of the wheel can be further increased.

  Preferably, the axle device of the work vehicle further includes a second bearing. The second bearing is disposed inward of the first bearing in the axial direction and between the inner peripheral surface of the wheel hub and the outer peripheral surface of the axle housing. The inner peripheral surface of the wheel hub has a protrusion that is disposed between the first bearing and the second bearing in the axial direction. In this case, the outward movement in the axial direction of the second bearing is restricted by the protrusion. Thereby, the holding force of the wheel can be further increased.

  Preferably, the ring gear hub has a recess. The recess has a shape recessed in the axial direction from the inner end in the axial direction of the ring gear hub. A second fixing member is disposed in the recess. In this case, the second fixing member and the ring gear hub can be arranged more compactly in the axial direction than in the case where the second fixing member is arranged away from the ring gear hub in the axial direction. Thereby, an axle apparatus can be reduced in size.

  A work vehicle according to an aspect of the present invention includes the above-described axle device.

  According to the present invention, the holding force of the wheel can be improved with a simple structure, and an increase in the size of the axle device can be prevented.

The side view of a work vehicle. Sectional drawing of an axle apparatus. The expanded sectional view of an axle apparatus. The expanded sectional view of an axle apparatus.

  Hereinafter, a work vehicle according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the work vehicle 1. In the present embodiment, the work vehicle 1 is a wheel loader. The work vehicle 1 includes a vehicle body 2, a work implement 3, a plurality of tires 4, and a cab 5. The cab 5 is placed on the vehicle body 2. The work machine 3 is attached to the front portion of the vehicle body 2.

  The work machine 3 includes a boom 6, a bucket 7, and hydraulic actuators 8 and 9. The boom 6 is a member for lifting the bucket 7. The boom 6 is attached to the vehicle body 2 so as to be rotatable in the vertical direction. The bucket 7 is attached to the tip of the boom 6 so as to be rotatable in the vertical direction. The hydraulic actuators 8 and 9 have a boom cylinder 8 and a bucket cylinder 9. The boom 6 is rotated up and down by a boom cylinder 8. The bucket 7 is rotated up and down by a bucket cylinder 9. The boom 6 can be mounted with other working tools such as forks instead of the bucket 7.

  The work vehicle 1 includes an engine 11 and a hydraulic pump 12. The engine 11 is, for example, a diesel engine, and the driving force generated by the engine 11 is transmitted to the hydraulic pump 12. The driving force generated by the engine 11 is transmitted to the tire 4 via an axle device described later. The hydraulic pump 12 discharges hydraulic oil when driven by the engine 11. The hydraulic actuators 8 and 9 described above are driven by hydraulic oil discharged from the hydraulic pump 12.

  FIG. 2 is a cross-sectional view of the axle device 13 in the II-II cross-sectional view of FIG. As shown in FIG. 2, the axle device 13 includes an axle shaft 21, an axle housing 22, a planetary gear mechanism 23, a wheel hub 24, a carrier 25, a cover 34, and a wheel 26.

  The axle shaft 21 is disposed such that the central axis of the axle shaft 21 is along the vehicle width direction of the work vehicle 1. The axle shaft 21 is rotationally driven by the driving force from the engine 11. The axle shaft 21 has a universal joint 27. The universal joint 27 is disposed in the main body housing 28. In the present embodiment, the axial direction means a direction parallel to the central axis of the axle shaft 21. Further, the inward in the axial direction means a direction toward the center of the vehicle body 2 in a direction parallel to the central axis of the axle shaft 21. The outward direction in the axial direction means a direction away from the center of the vehicle body 2 in a direction parallel to the central axis of the axle shaft 21. Inward in the radial direction means a direction toward the central axis of the axle shaft 21 in a direction parallel to the radial direction of the axle shaft 21. The outward direction in the radial direction means a direction away from the central axis of the axle shaft 21 in a direction parallel to the radial direction of the axle shaft 21.

  The axle housing 22 accommodates the axle shaft 21. The axle housing 22 is fixed to the main body housing 28. The end of the axle shaft 21 protrudes outward in the axial direction from the end of the axle housing 22.

  The planetary gear mechanism 23 is disposed outward in the axial direction of the axle housing 22. The planetary gear mechanism 23 is connected to the axle shaft 21 and transmits the rotation of the axle shaft 21 to the wheel 26 at a reduced speed. The planetary gear mechanism 23 includes a sun gear 31, a plurality of planetary gears 32, and a ring gear 33.

  The sun gear 31 is disposed concentrically with the axle shaft 21. The sun gear 31 is fixed to the axle shaft 21 and rotates together with the axle shaft 21. The planetary gear 32 is disposed around the sun gear 31 and meshes with the sun gear 31. The planetary gear 32 is disposed so as to be able to revolve around the sun gear 31. The planetary gear 32 is disposed so as to be rotatable about the planetary gear 32 axis.

  The ring gear 33 meshes with the planetary gear 32. The planetary gear 32 is disposed so as to be rotatable with respect to the ring gear 33. The carrier 25 supports the planetary gear 32 in a rotatable manner. The carrier 25 rotates with the revolution of the planetary gear 32. The cover 34 is fixed to the carrier 25.

  The wheel hub 24 is disposed outward in the radial direction of the axle housing 22. The carrier 25 is disposed outward in the axial direction of the wheel hub 24. The carrier 25 accommodates the planetary gear mechanism 23. The wheel 26 accommodates the wheel hub 24 and the carrier 25. The wheel 26 is attached to the wheel hub 24 and the carrier 25 by fixing means such as bolts. The tire 26 described above is attached to the wheel 26.

  FIG. 3 is an enlarged view of a part of FIG. As shown in FIG. 3, the axle device 13 includes a first bearing 35, a second bearing 36, a ring gear hub 37, a first fixing member 38, and a second fixing member 39.

  The first bearing 35 is disposed between the inner peripheral surface of the wheel hub 24 and the outer peripheral surface of the axle housing 22. The second bearing 36 is disposed between the inner peripheral surface of the wheel hub 24 and the outer peripheral surface of the axle housing 22. The first bearing 35 is a so-called tapered roller bearing. The first bearing 35 includes a first outer ring 351, a first inner ring 352, and a first rolling element 353. The first rolling element 353 is disposed between the first outer ring 351 and the first inner ring 352. The first rolling element 353 has a truncated cone shape. The first rolling element 353 is arranged such that the central axis of the first rolling element 353 is inclined outward in the axial direction and outward in the radial direction.

  The inner peripheral surface of the first bearing 35 has an end 354. The end portion 354 is an end portion on the outer side in the axial direction on the inner peripheral surface of the first bearing 35. The end 354 has a shape in which the inner diameter increases toward the outside in the axial direction. That is, the end portion 354 of the first inner ring 352 has a shape in which the inner diameter increases toward the outside in the axial direction.

  The first bearing 35 and the second bearing 36 are arranged side by side in the axial direction. The second bearing 36 is disposed inward in the axial direction of the first bearing 35. The second bearing 36 is disposed between the inner peripheral surface of the wheel hub 24 and the outer peripheral surface of the axle housing 22.

  The second bearing 36 is a so-called tapered roller bearing. The second bearing 36 includes a second outer ring 361, a second inner ring 362, and a second rolling element 363. The second rolling element 363 is disposed between the second outer ring 361 and the second inner ring 362. The second rolling element 363 has a truncated cone shape. The second rolling elements 363 are arranged such that the central axis is inclined inward in the axial direction and outward in the radial direction.

  The inner peripheral surface of the second bearing 36 has an end 364. The end 364 is an end on the inner side in the axial direction on the inner peripheral surface of the second bearing 36. The end 364 has a shape with an inner diameter that increases inward in the axial direction. That is, the end portion 364 of the second inner ring 362 has a shape in which the inner diameter increases toward the inside in the axial direction.

  The ring gear hub 37 is disposed outward in the axial direction of the first bearing 35. The ring gear hub 37 is disposed outward in the radial direction of the axle housing 22. The ring gear hub 37 is connected to the ring gear 33. The ring gear hub 37 is in contact with the first inner ring 352. Specifically, the ring gear hub 37 is in contact with the outer end surface 355 in the axial direction of the first inner ring 352.

  The outer peripheral surface of the axle housing 22 has a fourth outer peripheral surface 221 and a first outer peripheral surface 222. The fourth outer peripheral surface 221 supports the oil seal 41. The oil seal 41 is disposed between the axle housing 22 and the wheel hub 24. The oil seal 41 seals a gap between the axle housing 22 and the wheel hub 24.

  The first outer peripheral surface 222 supports the first bearing 35 and the second bearing 36. A portion supporting the first bearing 35 and a portion supporting the second bearing 36 on the first outer peripheral surface 222 are connected flatly. The diameter of the first outer peripheral surface 222 is smaller than the diameter of the fourth outer peripheral surface 221. For this reason, a first step 226 is formed between the fourth outer peripheral surface 221 and the first outer peripheral surface 222. The second inner ring 362 of the second bearing 36 is in contact with the first step portion 226.

  Note that the inner peripheral surface of the wheel hub 24 has a protruding portion 241. The protruding portion 241 is disposed outward in the radial direction of the first outer peripheral surface 222. The projecting portion 241 is disposed between the first bearing 35 and the second bearing 36 in the axial direction. The protruding portion 241 is disposed between the first outer ring 351 and the second outer ring 361.

  The outer peripheral surface of the axle housing 22 has a second outer peripheral surface 223 and a second step portion 229. The second outer peripheral surface 223 is disposed outward in the axial direction of the first outer peripheral surface 222. The diameter of the second outer peripheral surface 223 is smaller than the diameter of the first outer peripheral surface 222. The second step portion 229 is located between the first floor circumferential surface 222 and the second outer circumferential surface 223. The second outer peripheral surface 223 has a spline 227 and a relief groove 228.

  The spline 227 extends in the axial direction on the outer peripheral surface of the axle housing 22. The spline 227 is disposed outward in the axial direction of the first outer peripheral surface 222. The escape groove 228 extends in the circumferential direction on the outer peripheral surface of the axle housing 22. The escape groove 228 is disposed between the spline 227 and the second step portion 229 in the axial direction. That is, the escape groove 228 is disposed between the spline 227 and the first bearing 35 in the axial direction.

  The outer peripheral surface of the axle housing 22 has a third outer peripheral surface 224. The third outer peripheral surface 224 is disposed outward in the axial direction of the second outer peripheral surface 223. The diameter of the third outer peripheral surface 224 is smaller than the diameter of the second outer peripheral surface 223. A male screw is provided on the outer peripheral surface of the third outer peripheral surface 224.

  The first fixing member 38 has a nut shape. The first fixing member 38 is disposed outward in the axial direction of the ring gear hub 37. The first fixing member 38 is fixed to the axle housing 22. Specifically, the first fixing member 38 is fixed to the third outer peripheral surface 224. A female screw is provided on the inner peripheral surface of the first fixing member 38. The first fixing member 38 is fixed to the third outer peripheral surface 224 by the male screw of the third outer peripheral surface 224 being screwed into the female screw of the first fixing member 38.

  The ring gear hub 37 has a first recess 371. The first recess 371 has a shape that is recessed in the axial direction from the outer end in the axial direction of the ring gear hub 37. A first fixing member 38 is disposed in the first recess 371. The ring gear hub 37 is sandwiched between the first bearing 35 and the first fixing member 38. Thereby, the movement of the ring gear hub 37 in the axial direction is restricted.

  The second fixing member 39 is, for example, a snap ring. The second fixing member 39 is disposed outward in the axial direction of the first bearing 35. The second fixing member 39 is disposed outward in the radial direction of the axle housing 22. The second fixing member 39 is fitted in the escape groove 228. The outer peripheral surface of the second fixing member 39 is located outward in the radial direction from the inner peripheral surface of the first bearing 35. The ring gear hub 37 has a second recess 372. The second recess 372 has a shape that is recessed in the axial direction from the inner end of the ring gear hub 37 in the axial direction. A second fixing member 39 is disposed in the second recess 372.

  The characteristics of the axle device 13 according to this embodiment are as follows. In the axle device 13, movement of the first bearing 35 and the ring gear hub 37 in the axial direction is restricted by the first fixing member 38. Further, the movement of the first bearing 35 in the axial direction is restricted by the second fixing member 39. Therefore, the holding force of the wheel 26 can be improved by the first fixing member 38 and the second fixing member 39. Moreover, since it is not necessary to enlarge the 1st fixing member 38, the enlargement of the axle apparatus 13 can be prevented. Further, the second fixing member 39 is fitted in the escape groove 228. The escape groove 228 is a configuration that is required when processing for forming the spline 227 on the outer peripheral surface of the axle housing 22 is performed. Therefore, the second fixing member 39 can be attached using the escape groove 228 without adding a complicated structure for attaching the second fixing member 39. Thereby, the holding force of the wheel 26 can be improved with a simple structure.

  The end portion 354 of the inner peripheral surface of the first bearing 35 has a shape in which the inner diameter increases in a direction approaching the second fixing member 39. For this reason, as shown in FIG. 4, when the first bearing 35 moves outward in the axial direction, the first inner ring 352 rides on the second fixing member 39. When the first inner ring 352 rides on the second fixing member 39, the first outer ring 351 is pressed against the inner peripheral surface of the wheel hub 24. Thereby, the holding force of the wheel hub 24 can be increased.

  A protrusion 241 on the inner peripheral surface of the wheel hub 24 is disposed between the first bearing 35 and the second bearing 36 in the axial direction. For this reason, the outward movement in the axial direction of the second bearing 36 is restricted by the protruding portion 241. Thereby, the holding force of the wheel 26 can be further increased.

  A second fixing member 39 is disposed in the second recess 372. For this reason, compared with the case where the 2nd fixing member 39 is arrange | positioned away from the ring gear hub 37 in the axial direction, the 2nd fixing member 39 and the ring gear hub 37 can be arrange | positioned compactly in the axial direction. Thereby, the axle apparatus 13 can be reduced in size.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.

  The present invention is not limited to a wheel loader, and may be applied to an axle device of another type of work vehicle such as a backhoe loader or a dump truck.

  The first fixing member is not limited to the shape described above. For example, the first fixing member may have a plate shape and may be fixed to the axle shaft by a bolt. The second fixing member is not limited to the snap ring, and may have another shape as long as it can be fitted into the escape groove.

  The first bearing is not limited to the tapered roller bearing but may be other types of bearings such as a ball bearing or a spherical roller bearing. The second bearing is not limited to the tapered roller bearing, but may be another type of bearing such as a ball bearing or a spherical roller bearing.

  According to the present invention, it is possible to improve the wheel holding force with a simple structure in the axle device, and it is possible to prevent the axle device from being enlarged.

DESCRIPTION OF SYMBOLS 1 Work vehicle 21 Axle shaft 22 Axle housing 23 Planetary gear mechanism 24 Wheel hub 25 Carrier 26 Wheel 35 First bearing 36 Second bearing 37 Ring gear hub 38 First fixing member 39 Second fixing member 227 Spline 228 Escape groove 241 Projection 372 Second recess

Claims (7)

The axle shaft,
An axle housing that houses the axle shaft;
A planetary gear having a sun gear fixed to the axle shaft, a planetary gear meshing with the sun gear, and a ring gear meshing with the planetary gear, and disposed outside the axle housing in the axial direction of the axle shaft. Mechanism,
A wheel hub disposed outside the axle housing in a radial direction of the axle shaft;
A carrier that rotatably supports the planetary gear, is disposed outside the wheel hub in the axial direction, and houses the planetary gear mechanism;
A wheel that houses the wheel hub and the carrier and is attached to the wheel hub and the carrier;
A first bearing disposed between an inner peripheral surface of the wheel hub and an outer peripheral surface of the axle housing;
A ring gear hub that is disposed outside the first bearing in the axial direction and outside the axle housing in the radial direction and coupled to the ring gear;
A first fixing member disposed outside the ring gear hub in the axial direction and fixed to the axle housing;
A second fixing member disposed outside the first bearing in the axial direction and outside the axle housing in the radial direction;
With
The outer peripheral surface of the axle housing includes a first outer peripheral surface supporting the first bearing, a second outer peripheral surface having an outer diameter smaller than an outer diameter of the first outer peripheral surface, the first outer peripheral surface, A step portion positioned between the second outer peripheral surface,
The axle housing has a spline provided on the second outer peripheral surface, and a relief groove disposed between the spline and the step portion on the second outer peripheral surface,
The ring gear hub is connected to the axle housing via the spline;
The second fixing member is fitted in the escape groove,
The escape groove is disposed between the spline and the first bearing in the axial direction, and the outer peripheral surface of the second fixing member is more radially outer than the inner peripheral surface of the first bearing. The first bearing is prevented from coming off with respect to the axle housing.
Axle device for work vehicle. An end on the outer side in the axial direction of the inner peripheral surface of the first bearing has a shape in which an inner diameter increases toward a direction approaching the second fixing member.
The axle device of the work vehicle according to claim 1. The first bearing has an outer ring, an inner ring, and a frustoconical rolling element disposed between the outer ring and the inner ring,
The ring gear hub is in contact with the inner ring;
The work vehicle axle device according to claim 2. A second bearing disposed in the axial direction inside the first bearing and between the inner peripheral surface of the wheel hub and the outer peripheral surface of the axle housing;
The inner peripheral surface of the wheel hub has a protruding portion disposed between the first bearing and the second bearing in the axial direction.
A work vehicle axle device according to any one of claims 1 to 3. The ring gear hub has a recess;
The concave portion has a shape recessed in the axial direction from an inner end of the ring gear hub in the axial direction,
The second fixing member is disposed in the recess.
The work vehicle axle device according to any one of claims 1 to 4. The outer peripheral surface of the axle housing further has a third outer peripheral surface that is arranged outward in the axial direction of the second outer peripheral surface and is provided with a male screw.
The first fixing member is fixed to the axle housing by screwing with a male screw on the third outer peripheral surface.
An axle device for a work vehicle according to any one of claims 1 to 5.   A work vehicle comprising the axle device according to any one of claims 1 to 6.

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