Travel device for dump truck

Abstract

To easily realize a reliable fixing structure for a shaft bearing with respect to a spindle while securing arrangement spaces for peripheral components of the shaft bearing.SOLUTION: In a travel device 11 for a dump track 1, a bearing retainer 42 provided on an inner peripheral surface side of a spindle 12 is fitted on an inner peripheral surface of the spindle 12 and is disposed on one side in an axial direction, with a gap G from a female spline portion 12G of the spindle 12 and from a second carrier 39. The bearing retainer 42 is supported on the inner peripheral surface of the spindle 12 by a support member 50.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a traveling device for a dump truck. [Background technology]

[0002] In the running gear of a large transport vehicle, for example a dump truck, a spindle serving as a rotating support shaft and an electric motor are fixed to a vehicle body frame. The output shaft of the electric motor is connected to a reduction gear via a shaft. The reduction gear rotates a wheel supported by the spindle via a bearing, and transmits power to the tire. An axial intermediate portion of the shaft is supported by a shaft bearing provided on the inner peripheral surface side of the spindle. The spindle is manufactured from cast steel, and a bearing retainer supporting the outer ring of the shaft bearing is often cast integrally with the spindle.

[0003] Dump trucks that are mainly used in mines and the like and weigh more than 100 tons have large vessels for transporting cargo such as excavated ore. The weight of the cargo and the vehicle body of the vessel are supported on the ground by the tires, so a large load acts on the wheels and spindles that support the tires. In order to support this large load, it is desirable to use a forged spindle, which can be made stronger than a cast spindle.

[0004] Another reason for forging the spindle is the limitations on the tire size that can be used. There is an upper limit to the tire diameter of dump truck tires available on the market, so models with heavy vehicle weights can be made larger by increasing the tire width. Therefore, the spindle diameter cannot be made larger, and the axial length of the spindle increases, so the bending load acting on the spindle becomes particularly large. Therefore, the heavier the vehicle model, the greater the need for a high-strength spindle.

[0005] Dump trucks accelerate the vehicle body, including the load, by the tractive force output by the traveling gear, and give the vehicle speed. Therefore, if the spindle, which is one of the parts that supports the load of the vehicle body weight, is made stronger, it is expected that the load capacity can be increased for the same tractive force and required vehicle speed. In other words, a forged spindle, which is stronger than a cast spindle, leads to improved work efficiency by increasing the load capacity, and is also a means of responding to customer needs.

[0006] By the way, when forging a large spindle used in a dump truck, in the case of die forging, an even larger forging die and hammer are required, which is not realistic. Although it is possible to manufacture it in the case of free forging in which a core bar is used to secure the inner diameter hole, it is impossible to create fine irregularities in free forging, so in order to create the protrusions, all parts other than the necessary protrusions are cut. With this method, the yield rate drops significantly when forging a large spindle, and a huge number of processing steps are required. Therefore, it is necessary to forge a large spindle with a structure that has as few irregularities as possible. Therefore, it is very difficult to manufacture a bearing retainer that holds the shaft bearing that supports the shaft on the inner peripheral surface of the spindle by protruding it in a convex shape.

[0007] On the other hand, if the shaft bearing is not fixed to the inner peripheral surface of the spindle, the vibration of the shaft it supports cannot be suppressed, leading to damage to the shaft, and the shaft bearing itself will also vibrate, leading to damage.

[0008] Considering these circumstances, a structure that uses a spline portion formed on the inner peripheral surface of the spindle to fix components of the reducer has been proposed as one structure for reliably fixing a shaft bearing to the inner peripheral surface of the spindle. For example, Patent Document 1 discloses a structure in which the spline portion is extended in the axial direction of the spindle, a bearing retainer that holds the shaft bearing is fixed by a spline connection, and the axial direction is fixed by a snap ring. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2020-75635 A Summary of the Invention [Problem to be solved by the invention]

[0010] However, in the structure disclosed in Patent Document 1, the spline portion formed on the inner surface of the spindle needs to be extended to the vicinity of the shaft bearing, which requires deep and long spline processing on the inner surface of the spindle, increasing the labor required for spline processing.

[0011] Furthermore, when heat treatment is performed to improve the durability of the spline portion, the spline portion will be deformed due to distortion caused by the heat treatment, which may make it difficult to maintain the assembly precision of the traveling device.

[0012] Furthermore, since the bearing retainer is splined to the spindle, a spline portion of sufficient width is required on the outer circumferential surface of the bearing retainer, which increases the volume and weight of the bearing retainer itself. Therefore, it is highly likely that it will be difficult to secure sufficient space around the bearing retainer, i.e., around the shaft bearing, for arranging peripheral components such as components that provide a fault detection function or a lubrication function.

[0013] In view of the above circumstances, an object of the present invention is to easily realize a structure for reliably fixing a shaft bearing to a spindle while ensuring space for arranging peripheral components of the shaft bearing. [Means for solving the problem]

[0014] In order to solve the above-mentioned problems, a traveling device for a dump truck of the present invention includes a cylindrical spindle having one axial side attached to a vehicle body and having a spline portion formed on an inner peripheral surface of the other axial side of the spindle, a wheel located on the other side of the spindle and provided on an outer peripheral surface side of the spindle, on which a tire is mounted, a wheel bearing provided between the spindle and the wheel and supporting the wheel rotatably with respect to the spindle, a rotation source provided on the one side of the spindle and having an output shaft inserted on the inner peripheral surface side of the spindle, a shaft having one end located on the inner peripheral surface side of the spindle and connected to the output shaft of the rotation source and the other end protruding from the other side of the spindle, and a wheel bearing located on the other side of the spindle and provided between the shaft and the wheel. a planetary gear reduction gear having a plurality of planetary gears rotatably supported by a carrier splined to the spline portion of the spindle, and a shaft bearing located on the inner surface side of the spindle, positioned on the one side of the carrier, and configured to rotatably support the shaft relative to the spindle, wherein a bearing retainer made of a separate member from the spindle and holding the shaft bearing is provided on the inner surface side of the spindle, the bearing retainer being fitted to the inner surface of the spindle, being disposed at a distance from each of the spline portion and the carrier of the spindle on the one side, and being supported by the inner surface of the spindle by a support member. Effect of the Invention

[0015] According to the present invention, it is possible to easily realize a structure for reliably fixing a shaft bearing to a high-strength spindle while ensuring space for arranging peripheral parts of the shaft bearing. [Brief description of the drawings]

[0016] [Figure 1] Side view of a dump truck. [Diagram 2] FIG. 2 is a rear view of the dump truck shown in FIG. 1. [Diagram 3] FIG. 3 is a cross-sectional view of the rear wheel side traveling device shown in FIG. 2 . [Figure 4] FIG. 4 is a detailed view of the wet brake device and its surroundings in the traveling device shown in FIG. 3. [Diagram 5] FIG. 4 is a detailed view of the vicinity of a bearing retainer in the traveling device shown in FIG. 3. [Figure 6] FIG. 11 is a detailed view of the vicinity of a bearing retainer in a traveling device according to a second embodiment. [Figure 7] FIG. 11 is a detailed view of the vicinity of a bearing retainer in a traveling device according to a third embodiment. [Figure 8] FIG. 13 is a detailed view of the vicinity of a bearing retainer in the traveling device according to the fourth embodiment. [Figure 9] FIG. 9 is a diagram showing the arrangement structure of the oil supply pipe shown in FIG. 8 . [Figure 10] FIG. 10 is a diagram showing a source of lubricating oil for the oil supply pipe shown in FIG. 9 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Components with the same reference numerals in each embodiment have similar components in each embodiment unless otherwise specified, and the description thereof will be omitted.

[0018] [First embodiment] 1 to 5, a traveling device 11 of a dump truck 1 according to a first embodiment will be described. Fig. 1 is a side view of the dump truck 1. Fig. 2 is a rear view of the dump truck 1 shown in Fig. 1.

[0019] In this embodiment, a mining dump truck used in mines or the like will be described as an example of the dump truck 1. The dump truck 1 has a vehicle body 2 having a sturdy frame structure. Left and right front wheels 3 are rotatably provided at the front of the vehicle body 2, and left and right rear wheels 4 are rotatably provided at the rear of the vehicle body 2 (only the left front wheel 3 and the left rear wheel 4 are shown in FIG. 1). The left and right front wheels 3 constitute steering wheels that are steered by the driver of the dump truck 1. A front wheel suspension 3A consisting of a hydraulic shock absorber or the like is provided between the vehicle body 2 and the left and right front wheels 3.

[0020] The left and right rear wheels 4 constitute driving wheels of the dump truck 1. The left and right rear wheels 4 are rotationally driven by a traveling device 11 described below. As shown in Fig. 2, the rear wheels 4 are made of dual-wheel tires and include axially inner and outer tires 4A and wheels 15 on which the tires 4A are mounted. Between the vehicle body 2 and the left and right rear wheels 4, rear-wheel suspensions 4B consisting of hydraulic shock absorbers or the like are provided.

[0021] The vessel (cargo platform) 5 is mounted on the vehicle body 2 so that it can be raised and lowered. The vessel 5 is formed as a large container with a total length of 10 to 13 m (meters) in order to carry a large amount of heavy cargo such as crushed stone. The rear bottom of the vessel 5 is connected to the rear end of the vehicle body 2 via a connecting pin 6 or the like so that it can be raised and lowered (tilted). A eaves portion 5A that covers a cab 7 (described below) from above is integrally provided on the front upper portion of the vessel 5.

[0022] The cab 7 is provided at the front of the vehicle body 2, located below the eaves portion 5A provided on the vessel 5. The cab 7 constitutes a driver's compartment where the driver of the dump truck 1 gets in and out of. Inside the cab 7, a driver's seat, a start switch, an accelerator pedal, a brake pedal, a steering handle, and a number of operating levers (none of which are shown), etc. are provided. The eaves portion 5A of the vessel 5 covers the entire cab 7 from above, thereby protecting the cab 7 from flying stones such as rocks. The eaves portion 5A of the vessel 5 protects the driver in the cab 7 when the dump truck 1 overturns, etc.

[0023] The engine 8 is provided at the front of the vehicle body, located below the cab 7. The engine 8 is, for example, a large diesel engine, and drives an on-board generator, a hydraulic pump (neither of which are shown) that serves as a hydraulic source, and the like. Pressurized oil discharged from the hydraulic pump is supplied to a hoist cylinder 9, a steering cylinder for power steering (not shown), and the like.

[0024] The hoist cylinder 9 is provided between the vehicle body 2 and the vessel 5 so as to be vertically extendable and contractable. The hoist cylinder 9 is located between the front wheels 3 and the rear wheels 4, and is arranged on both the left and right sides (only the left side is shown) of the vehicle body 2. The hoist cylinder 9 extends and contracts vertically as pressure oil is supplied to or discharged from the hydraulic pump, and raises or lowers the vessel 5 around the connecting pin 6.

[0025] The axle housing 10 for the rear wheels 4 is provided on the lower rear side of the vehicle body 2 and constitutes a part of the vehicle body 2. The axle housing 10 is formed as a cylindrical body extending in the left-right direction between the left and right rear wheels 4. The axle housing 10 is attached to the rear side of the vehicle body 2 via a rear-wheel suspension 4B. A spindle 12 is fixed to both ends of the axle housing 10 in the left-right direction.

[0026] FIG. 3 is a cross-sectional view of the traveling device 11 on the rear wheel 4 side shown in FIG.

[0027] The traveling gear 11 is provided on each of the left and right rear wheels 4 of the dump truck 1. As shown in Fig. 3, the traveling gear 11 includes a spindle 12, a wheel 15, wheel bearings 17, 18, an electric motor 21, a shaft 22, a planetary gear reduction device 25, a bearing retainer 42, and a shaft bearing 46.

[0028] The traveling device 11 reduces the rotation speed of the electric motor 21 by a planetary gear reduction device 25, and drives the rear wheels 4, which are the drive wheels of the dump truck 1, with a large rotational torque. Since the traveling devices 11 provided on the left and right rear wheels 4 have the same configuration, the following will describe the traveling device 11 provided on the left rear wheel 4.

[0029] In this embodiment, the axial direction of the spindle 12, the electric motor 21, and the shaft 22, which are arranged coaxially with one another, is also simply referred to as the "axial direction." In this embodiment, one side in the axial direction is the side facing inward of the vehicle body 2 in the left-right direction (the electric motor 21 side), which corresponds to the right side in Fig. 3. In this embodiment, the other side in the axial direction is the side facing outward of the vehicle body 2 in the left-right direction (the opposite side of the electric motor 21, i.e., the planetary gear reduction device 25 side), which corresponds to the left side in Fig. 3.

[0030] The spindle 12 is formed in a cylindrical shape with one axial side attached to the vehicle body 2 and a spline portion (female spline portion 12G) formed on the inner peripheral surface on the other axial side. Specifically, the spindle 12 is provided on the other axial side of the axle housing 10. The spindle 12 is formed in a stepped cylindrical shape extending in the axial direction inside the wheel 15. The spindle 12 is composed of a large diameter cylindrical portion 12A located on one axial side, an intermediate cylindrical portion 12B located in the middle of the axial direction, and a small diameter cylindrical portion 12C located on the other axial side. The large diameter cylindrical portion 12A is formed in a cup shape whose diameter gradually decreases toward the intermediate cylindrical portion 12B. One axial end of the large diameter cylindrical portion 12A is fixed to the edge portion of the axle housing 10 using a plurality of bolts 13. The small diameter cylindrical portion 12C is formed in a cylindrical shape with a smaller diameter than the intermediate cylindrical portion 12B. The small diameter cylindrical portion 12C is arranged on the inner peripheral surface side of a wheel mounting sleeve 16 described later. The small diameter cylindrical portion 12C rotatably supports the wheel mounting case 16 via wheel bearings 17 and 18.

[0031] Here, the spindle 12 is manufactured by, for example, free forging using a core bar, and has a greater strength than a spindle manufactured by casting. On the outer peripheral surface side of the spindle 12, a brake mounting portion 12D located at the boundary between the large diameter cylindrical portion 12A and the intermediate cylindrical portion 12B, and an annular step portion 12E located at the boundary between the intermediate cylindrical portion 12B and the small diameter cylindrical portion 12C are integrally formed. A brake housing 41A, which will be described later, is fixed to the brake mounting portion 12D. A motor mounting seat 12F is formed at one end of the large diameter cylindrical portion 12A in the axial direction. An electric motor 21 is attached to this motor mounting seat 12F.

[0032] The other axial end (tip) of the small diameter cylindrical portion 12C is an open end. A female spline portion 12G is formed on the inner peripheral surface of the other axial end of the small diameter cylindrical portion 12C. A male spline portion 39B of a second carrier 39, which will be described later, is splined to the female spline portion 12G.

[0033] A retainer fitting portion 12H is provided on the inner peripheral surface of the small diameter cylindrical portion 12C adjacent to the female spline portion 12G. A cylindrical outer peripheral surface 42D (see FIG. 5) of the bearing retainer 42 is fitted into this retainer fitting portion 12H, for example, in a loose fit state. Furthermore, fitting holes 51 and 52, which will be described later, are provided in the same phase (same circumferential position) in the retainer fitting portion 12H of the spindle 12 and the cylindrical outer peripheral surface 42D of the bearing retainer 42. A support member 50 is attached to these fitting holes 51 and 52 so that the fitting holes 51 and 52 communicate with each other.

[0034] The wheel 15 is located on the other axial side of the spindle 12 and is provided on the outer circumferential surface side of the spindle 12. A tire 4A of the rear wheel 4 is mounted on the wheel 15. The wheel 15 is generally composed of a cylindrical rim 15A extending in the left-right direction and a wheel mounting case 16 fixed to the inner circumferential surface side of the rim 15A. Two tires 4A are mounted in parallel on the outer circumferential surface side of the rim 15A.

[0035] The wheel mounting cylinder 16 is rotatably provided on the outer peripheral surface side of the spindle 12. A rim 15A of the wheel 15 is detachably attached to the outer peripheral surface side of the wheel mounting cylinder 16 by means of press fitting or the like. The wheel mounting cylinder 16 is formed as a stepped cylindrical body having a hollow cylindrical portion 16A and an extended cylindrical portion 16B. The hollow cylindrical portion 16A is rotatably supported by the spindle 12 (small diameter cylindrical portion 12C) via wheel bearings 17, 18. The extended cylindrical portion 16B extends in the axial direction from the end of the outer peripheral surface side of the hollow cylindrical portion 16A toward an internal gear 36 described later.

[0036] The wheel bearings 17, 18 are provided between the spindle 12 and the wheel 15, and support the wheel 15 rotatably relative to the spindle 12. Specifically, the wheel bearings 17, 18 are provided between the small diameter cylindrical portion 12C of the spindle 12 and the wheel mounting case 16 (hollow cylindrical portion 16A) of the wheel 15. The wheel bearings 17, 18 are formed using, for example, the same tapered roller bearing, and support the wheel 15 rotatably on the outer peripheral surface side of the spindle 12. Here, the outer ring of one wheel bearing 17 is positioned in the axial direction by the hollow cylindrical portion 16A of the wheel mounting case 16. The inner ring of one wheel bearing 17 is positioned in the axial direction by an annular bearing retainer 19 abutting against the stepped portion 12E of the spindle 12. The outer ring of the other wheel bearing 18 is positioned in the axial direction by the hollow cylindrical portion 16A of the wheel mounting case 16. The inner ring of the other wheel bearing 18 is positioned in the axial direction by an annular bearing retainer 20 fixed to the open end of the small diameter cylindrical portion 12C of the spindle 12.

[0037] The electric motor 21 as a rotation source is located inside the axle housing 10 and is provided on one side of the spindle 12 in the axial direction. The output shaft 21B of the electric motor 21 is inserted into the inner peripheral surface side of the spindle 12. A plurality of mounting flanges 21A are provided on the casing of the electric motor 21. These mounting flanges 21A are detachably attached to the motor mounting seat 12F of the spindle 12 using bolts or the like. The electric motor 21 has a rotor (not shown) that rotates in a forward or reverse direction by electric power supplied from a generator (not shown) mounted on the vehicle body 2. The rotation of the rotor is output by the output shaft 21B. The base end of the output shaft 21B is integrally connected to the rotor of the electric motor 21. The tip of the output shaft 21B protrudes to the outside from the casing of the electric motor 21. The shaft 22 is coaxially connected to the tip of the output shaft 21B.

[0038] The shaft 22 is connected to the output shaft 21B of the electric motor 21. The shaft 22 is formed of a single rod-shaped body inserted in the axial direction into the inner peripheral surface side of the spindle 12 (the small diameter cylindrical portion 12C). The shaft 22 inputs the rotation of the output shaft 21B of the electric motor 21 to the planetary gear reduction device 25. One axial side (base end side) of the shaft 22 is located on the inner peripheral surface side of the spindle 12 and is connected (spline-coupled) to the output shaft 21B of the electric motor 21. The other axial side (tip side) of the shaft 22 protrudes from the other axial end (open end of the small diameter cylindrical portion 12C) of the spindle 12 toward the planetary gear reduction device 25, and a sun gear 27 described later is attached to the tip. In addition, a bearing attachment portion 22A having a step formed in the axial direction is provided at an intermediate portion of the shaft 22 in the axial direction (see FIG. 5). A shaft bearing 46 is attached to the bearing attachment portion 22A. An axially intermediate portion of the shaft 22 is rotatably supported by a shaft bearing 46 on the spindle 12 (the small diameter cylindrical portion 12C).

[0039] The outer drum 23 and the internal gear 36 form part of the wheel mounting case 16. The outer drum 23 is formed in a stepped cylindrical shape having an annular flange portion 23A. The outer drum 23 sandwiches the internal gear 36 between itself and an end edge portion of an extended cylindrical portion 16B that forms the wheel mounting case 16. A plurality of long bolts 24 inserted into the flange portion 23A of the outer drum 23 and the internal gear 36 are screwed into the end edge portion of the extended cylindrical portion 16B. In this way, the internal gear 36 is fixed between the outer drum 23 and the extended cylindrical portion 16B of the wheel mounting case 16.

[0040] The planetary gear reduction device 25 is located on the other axial side of the spindle 12 and is provided between the wheel mounting case 16 of the wheel 15 and the shaft 22. The planetary gear reduction device 25 has a plurality of planetary gears 37 rotatably supported by a second carrier 39 that is spline-coupled to the female spline portion 12G of the spindle 12, as will be described later.

[0041] The planetary gear reduction device 25 is made up of a first stage first planetary gear reduction mechanism 26 and a second stage second planetary gear reduction mechanism 34. The planetary gear reduction device 25 receives the rotation of the electric motor 21 (output shaft 21B) via the shaft 22, and transmits the rotation of the electric motor 21 to the wheel mounting case 16 after reducing the rotation in two stages. As a result, the wheel 15 is rotated together with the tire 4A of the rear wheel 4 with a large rotational force (torque).

[0042] The first planetary gear reduction mechanism 26 is composed of a sun gear 27 splined to the end of the shaft 22, multiple planetary gears 29 (only one is shown) that mesh with the sun gear 27 and a ring-shaped internal gear 28, and a carrier 31 that rotatably supports the multiple planetary gears 29 via support pins 30.

[0043] The outer peripheral surface side of the carrier 31 is removably fixed via a plurality of bolts 31A to the other axial end face of the outer drum 23 integrated with the wheel mounting case 16. A disk-shaped cover plate 32 is removably attached to the inner peripheral surface side of the carrier 31 using bolts or the like. The cover plate 32 is removed from the carrier 31, for example, when performing maintenance on the meshing portion between the sun gear 27 and the planetary gears 29.

[0044] The ring-shaped internal gear 28 is formed using a ring gear that surrounds the sun gear 27 and the multiple planetary gears 29 from the radial outside. The internal gear 28 is arranged to be rotatable relative to the inner peripheral surface of the outer drum 23 via a radial gap. Internal teeth are formed on the inner peripheral surface of the internal gear 28 over the entire circumference. The multiple planetary gears 29 are constantly meshed with these internal teeth. The rotation of the internal gear 28 is transmitted to a second planetary gear reduction mechanism 34 of the second stage via a coupling 33.

[0045] When the sun gear 27 rotates integrally with the shaft 22 by the electric motor 21, the first planetary gear reduction mechanism 26 converts the rotation of the sun gear 27 into rotation and revolution of the planetary gears 29. The rotation (rotation) of the planetary gears 29 is transmitted to the internal gear 28. The rotation of the internal gear 28 is transmitted to the second-stage second planetary gear reduction mechanism 34 via a coupling 33. Meanwhile, the revolution of the planetary gears 29 becomes the rotation of the carrier 31 and is transmitted to the outer drum 23. In this case, the outer drum 23 is integrated with the wheel mounting case 16 and the internal gear 36. As a result, the revolution of the planetary gears 29 is restricted to rotation synchronous with the internal gear 36.

[0046] The coupling 33 is provided between the first planetary gear reduction mechanism 26 and the second planetary gear reduction mechanism 34, and rotates integrally with the first-stage internal gear 28. The outer circumferential surface side of the coupling 33 is spline-connected to the first-stage internal gear 28. The inner circumferential surface side of the coupling 33 is spline-connected to the second-stage sun gear 35 described below. The coupling 33 transmits the rotation of the first-stage internal gear 28 to the second-stage sun gear 35, and causes the sun gear 35 to rotate integrally with the first-stage internal gear 28.

[0047] The second planetary gear reduction mechanism 34 is composed of a cylindrical sun gear 35 arranged on the outer surface side of the shaft 22, a number of planetary gears 37 (only one is shown) that mesh with the sun gear 35 and a ring-shaped internal gear 36, and a cylindrical second carrier 39 that rotatably supports the number of planetary gears 37 via support pins 38.

[0048] The second stage internal gear 36 is formed using a ring gear that surrounds the sun gear 35 and the multiple planetary gears 37 from the radially outer side. The internal gear 36 is fixed integrally between the wheel mounting case 16 (extended cylindrical portion 16B) and the outer drum 23 using long bolts 24. Internal teeth are formed around the entire inner circumferential surface of the internal gear 36. The multiple planetary gears 37 mesh with these internal teeth.

[0049] A cylindrical protrusion 39A protruding toward the spindle 12 is integrally formed at the center of the second carrier 39. A male spline portion 39B is formed on the outer circumferential surface of one axial side (spindle 12 side) of the cylindrical protrusion 39A. The male spline portion 39B of the second carrier 39 is spline-coupled to the female spline portion 12G of the spindle 12 (small diameter cylinder portion 12C). Therefore, the second carrier 39 is unable to rotate with respect to the spindle 12.

[0050] In the second planetary gear reduction mechanism 34, the cylindrical protrusion 39A of the second carrier 39 is spline-coupled to the small diameter cylinder portion 12C of the spindle 12, thereby restricting the revolution of the planetary gear 37 (the rotation of the second carrier 39). When the sun gear 35 rotates integrally with the coupling 33, the second planetary gear reduction mechanism 34 converts the rotation of the sun gear 35 into the rotation of the planetary gears 37. The rotation of the planetary gears 37 is transmitted to the internal gear 36. The internal gear 36 rotates at a reduced speed. As a result, a high-output rotational torque that has been reduced in two stages by the first planetary gear reduction mechanism 26 and the second planetary gear reduction mechanism 34 is transmitted to the wheel mounting case 16 to which the internal gear 36 is fixed, and the rear wheel 4 is rotated.

[0051] FIG. 4 is a detailed view of the wet brake device 41 and its surroundings in the traveling device 11 shown in FIG.

[0052] The brake hub 40 is attached to the wheel mounting case 16. The brake hub 40 is formed as a cylindrical body extending in the axial direction between the wheel mounting case 16 and the wet brake device 41. The other axial side (the wheel mounting case 16 side) of the brake hub 40 is fixed to the hollow cylindrical portion 16A of the wheel mounting case 16 using bolts 40A. One axial side of the brake hub 40 faces the outer circumferential surface of the intermediate cylindrical portion 12B of the spindle 12 in the radial direction.

[0053] The wet brake device 41 is provided between the spindle 12 and the wheel mounting case 16 via the brake hub 40. The wet brake device 41 is configured by a wet multi-plate hydraulic brake. The wet brake device 41 applies a braking force to the wheel mounting case 16. The wet brake device 41 has a brake housing 41A. The brake housing 41A is attached to the brake mounting portion 12D of the spindle 12. A plurality of non-rotating side brake plates 41B and a plurality of rotating side brake plates 41C are provided inside the brake housing 41A. The plurality of non-rotating side brake plates 41B and the plurality of rotating side brake plates 41C are arranged alternately overlapping in the axial direction. The outer peripheral surface side of the non-rotating side brake plate 41B engages with the brake housing 41A. The inner peripheral surface side of the rotating side brake plate 41C engages with the brake hub 40. A brake movable body 41D is provided within the brake housing 41A. The brake movable body 41D moves axially by brake fluid pressure to bring the non-rotating side brake plate 41B and the rotating side brake plate 41C into frictional contact with each other.

[0054] In the wet brake device 41, brake fluid pressure is supplied to an oil chamber of a brake housing 41A in response to depression of a brake pedal (not shown), thereby moving a brake movable body 41D in the axial direction. The brake movable body 41D brings a plurality of non-rotating side brake plates 41B and a rotating side brake plate 41C into frictional contact. This applies a braking force to the wheel mounting case 16 to which the brake hub 40 is fixed.

[0055] FIG. 5 is a detailed view of the vicinity of the bearing retainer 42 in the traveling device 11 shown in FIG.

[0056] The bearing retainer 42 is provided on the inner peripheral surface side of the small diameter cylindrical portion 12C that constitutes the spindle 12. The bearing retainer 42 holds the shaft bearing 46 inside the small diameter cylindrical portion 12C that constitutes the spindle 12. The bearing retainer 42 is made of a separate member (a separate body) from the spindle 12. The bearing retainer 42 is formed into a stepped cylindrical shape as a whole. The bearing retainer 42 has a shape that fits into the inner peripheral surface of the small diameter cylindrical portion 12C that constitutes the spindle 12. The bearing retainer 42 is supported by a support member 50 on the inner peripheral surface of the small diameter cylindrical portion 12C that constitutes the spindle 12.

[0057] Specifically, a bearing fitting hole 42B is formed on the inner peripheral surface side of the bearing retainer 42. The bearing fitting hole 42B is a bottomed hole, and a shaft bearing 46 is attached to the bearing retainer 42. A cylindrical outer peripheral surface 42D of the bearing retainer 42 is fitted into the retainer fitting portion 12H of the spindle 12, for example, by a clearance fit, and is positioned and fixed in the radial direction.

[0058] A plurality of fitting holes 51 are formed radially in the retainer fitting portion 12H of the small diameter cylindrical portion 12C constituting the spindle 12. Similarly, a plurality of fitting holes 52 are formed radially in the cylindrical outer circumferential surface 42D of the bearing retainer 42. The fitting holes 51 and the fitting holes 52 are formed in the same phase (at the same circumferential position).

[0059] The support member 50 is inserted into and fixed to the fitting holes 51 and 52 so as to communicate with the fitting holes 51 and 52. The support member 50 is formed of a pin or a bolt. The support member 50 is attached to the fitting holes 51 and 52 by, for example, press fitting or screwing. The bearing retainer 42 is positioned and fixed to the spindle 12 in the axial direction and also in the circumferential direction by the support member 50.

[0060] The sleeve 45 is provided on the bearing mounting portion 22A of the shaft 22. The sleeve 45 has a cylindrical bearing fitting portion 45A, a disk-shaped flange portion 45B having a larger diameter than the bearing fitting portion 45A, and a male thread portion 45C located on the opposite side of the bearing fitting portion 45A from the flange portion 45B. The inner circumferential surface side of the sleeve 45 is press-fitted into the shaft 22, and is integrated with the shaft 22 at a position where it abuts against the bearing mounting portion 22A.

[0061] The shaft bearing 46 is located on one axial side of the second carrier 39 of the planetary gear reduction device 25 and is provided on the inner circumferential surface side of the spindle 12. The shaft bearing 46 is held between a bearing retainer 42 attached to the inner circumferential surface side of the spindle 12 (small diameter cylindrical portion 12C) and a sleeve 45. The shaft bearing 46 supports the shaft 22 rotatably relative to the spindle 12. The shaft bearing 46 supports an axial intermediate portion of the shaft 22 rotatably relative to the small diameter cylindrical portion 12C of the spindle 12.

[0062] The shaft bearing 46 is composed of an inner ring 46A that fits into the bearing fitting portion 45A of the sleeve 45, an outer ring 46B that fits into the bearing fitting hole 42B of the bearing retainer 42, and a number of rolling bodies 46C provided between the inner ring 46A and the outer ring 46B.

[0063] The outer ring 46B of the shaft bearing 46 is fitted into the bearing fitting hole 42B of the bearing retainer 42, and is positioned and fixed in the axial direction by a retaining ring 47. The inner ring 46A of the shaft bearing 46 is fitted into the bearing fitting portion 45A of the sleeve 45, and is positioned and fixed in the axial direction by a spacer 48 that is shrink-fitted into the sleeve 45. As a result, the traveling device 11 can rotatably support the axial intermediate portion of the shaft 22 by the shaft bearing 46, and therefore it is possible to suppress runout at the axial intermediate portion of the long shaft 22.

[0064] The dump truck 1 and its traveling device 11 of this embodiment have the configuration described above, and their operation will be described below.

[0065] First, when the driver in the cab 7 of the dump truck 1 starts the engine 8, the hydraulic pump serving as the hydraulic source is rotated and driven, and power is generated by a generator (neither shown). When the dump truck 1 is traveling, power is supplied from the generator to the electric motor 21, which operates the electric motor 21 to rotate the output shaft 21B, which in turn rotates the shaft 22 connected to the output shaft 21B.

[0066] The rotation of the shaft 22 is transmitted from the sun gear 27 of the first-stage first planetary gear reduction mechanism 26 to the multiple planetary gears 29. The rotation of the multiple planetary gears 29 is transmitted to the sun gear 35 of the second-stage second planetary gear reduction mechanism 34 via the internal gear 28 and the coupling 33. The rotation of the sun gear 35 is transmitted to the multiple planetary gears 37. At this time, the male spline portion 39B of the second carrier 39 supporting the planetary gears 37 is spline-coupled to the female spline portion 12G of the spindle 12 (the small diameter cylindrical portion 12C). Therefore, the rotation of the second carrier 39 (the revolution of the planetary gears 37) is restricted.

[0067] As a result, the planetary gear 37 only rotates around the sun gear 35, and the rotation slowed down by the rotation of the planetary gear 37 is transmitted to the internal gear 36 fixed to the wheel mounting case 16. Therefore, the wheel mounting case 16 rotates with a large rotational torque that has been slowed down in two stages by the first planetary gear reduction mechanism 26 and the second planetary gear reduction mechanism 34. As a result, the left and right rear wheels 4, which are drive wheels, rotate integrally with the wheel mounting case 16, allowing the dump truck 1 to travel.

[0068] The dump truck 1 travels between a loading area where cargo such as crushed stone excavated in a mine is loaded into a vessel 5, and an earth-discharging area where the cargo loaded in the vessel 5 is discharged.

[0069] Incidentally, dump trucks 1 used in mines and the like not only have a heavy vehicle body 2, but also have a heavy load on the vessel 5. Therefore, a heavy load acts on the spindle 12, which supports the rear wheels 4 via the wheels 15, due to the weight of the vehicle body 2 and the weight of the load. In this case, by manufacturing the spindle 12 by forging, the strength of the spindle 12 can be increased compared to the spindle 12 manufactured by casting. However, when the spindle 12 is manufactured by forging, it is difficult to form a mounting flange or the like for mounting the bearing retainer 42 on the inner peripheral surface side of the spindle 12.

[0070] In contrast, in the traveling device 11 of the first embodiment, the bearing retainer 42 provided on the inner peripheral surface side of the spindle 12 is fitted into the inner peripheral surface of the spindle 12 and is disposed at a distance G on one side in the axial direction from each of the female spline portion 12G of the spindle 12 and the second carrier 39. The bearing retainer 42 is positioned and fixed to the inner peripheral surface of the spindle 12 by a support member 50.

[0071] As a result, the traveling device 11 of the first embodiment can reliably fix the bearing retainer 42 to the spindle 12 even when the high-strength spindle 12 is manufactured by forging. The traveling device 11 can rotatably support the axial intermediate portion of the shaft 22 by the shaft bearing 46 held in the bearing retainer 42. Therefore, the traveling device 11 can suppress runout at the axial intermediate portion of the long shaft 22. The traveling device 11 can smoothly transmit the rotation of the electric motor 21 (output shaft 21B) to the planetary gear reduction device 25 via the shaft 22.

[0072] As a result, the traveling device 11 allows the dump truck 1 to travel stably. And, since the traveling device 11 can use the high-strength spindle 12 manufactured by forging, the durability of the traveling device 11 can be improved even if the dump truck 1 is enlarged. In addition, the traveling device 11 can increase the load capacity, and improve the workability when transporting the load.

[0073] Moreover, in the traveling device 11, a gap G is formed between the bearing retainer 42 and the second carrier 39. This allows the traveling device 11 to ensure a space for arranging peripheral components, such as components that provide a fault detection function or a lubrication function, around the bearing retainer 42, i.e., around the shaft bearing 46.

[0074] In this way, the traveling device 11 of the first embodiment can easily realize a structure for reliably fixing the shaft bearing 46 to the high-strength spindle 12 while ensuring space for arranging peripheral parts of the shaft bearing 46.

[0075] In the above embodiment, the case where a forged spindle 12 is used is exemplified. However, the traveling device 11 may have a structure in which, for example, a cast spindle 12 is used and the bearing retainer 42 is attached to the inner peripheral surface of the spindle 12. In this case, since there is no need to provide an attachment flange or the like on the inner peripheral surface of the spindle 12, the shape of the casting die can be simplified and the casting die can be manufactured inexpensively.

[0076] That is, the bearing retainer 42 of this embodiment is manufactured as a separate member from the spindle 12, and is attached to the inner peripheral surface of the spindle 12. As a result, the spindle 12 of this embodiment does not need to be provided with a protrusion, such as a mounting flange, for mounting and supporting the bearing retainer 42 on its inner peripheral surface. Therefore, the traveling device 11 of this embodiment makes it possible to individually prepare the bearing retainer 42 in accordance with the requirements of the dump truck 1, such as a fault detection function or a lubrication function, while facilitating the manufacture of the spindle 12.

[0077] Also, in the above embodiment, a rear-wheel drive dump truck has been described as an example of the dump truck 1. However, the dump truck 1 may be, for example, a front-wheel drive dump truck, or a four-wheel drive dump truck in which both the front and rear wheels are driven.

[0078] [Second embodiment] The traveling gear 11 of the dump truck 1 according to the second embodiment will be described with reference to Fig. 6. In the traveling gear 11 according to the second embodiment, the description of the same components as those in the first embodiment will be omitted.

[0079] 6 is a detailed view of the vicinity of the bearing retainer 42 in the traveling device 11 of the second embodiment. FIG 6 is a view corresponding to FIG 5.

[0080] In the traveling device 11 of the second embodiment, the bearing retainer 42 may be divided into a plurality of parts to hold the shaft bearing 46.

[0081] Specifically, the bearing retainer 42 is divided into a first member 42X that is positioned and fixed to the spindle 12, and a second member 42Y that holds the shaft bearing 46. The first member 42X is fitted to the inner peripheral surface of the spindle 12 by, for example, a clearance fit, and is positioned and fixed radially to the inner peripheral surface of the spindle 12. The first member 42X also has a fitting hole 52 that is in the same phase (same circumferential position) as a fitting hole 51 of the spindle 12, and is positioned and fixed axially and circumferentially to the spindle 12 by a support member 50.

[0082] The second member 42Y is fitted to the inner peripheral surface of the spindle 12 by, for example, a clearance fit, and is positioned and fixed radially relative to the inner peripheral surface of the spindle 12. The second member 42Y has a structure that holds the shaft bearing 46 on its inner peripheral surface. The second member 42Y is connected to the first member 42X by a connecting member 53 such as a bolt. In this case, it is preferable that the first member 42X is connected to a surface on one side in the axial direction of the second member 42Y. By connecting the first member 42X and the second member 42Y, the shaft bearing 46 can be held and an intermediate portion in the axial direction of the shaft 22 can be rotatably supported.

[0083] As described above, the traveling device 11 of the second embodiment has a bearing retainer 42 including a first member 42X supported on the inner circumferential surface of the spindle 12 by a support member 50, and a second member 42Y that holds the shaft bearing 46. The first member 42X is a separate member from the second member 42Y, and is connected to the second member 42Y by a connecting member 53.

[0084] As a result, in the traveling gear 11 of the second embodiment, only the shaft 22 and the shaft bearing 46 coupled together with the second member 42Y can be disassembled and reassembled while keeping the first member 42X of the bearing retainer 42 fixed to the spindle 12. This allows the traveling gear 11 to easily replace parts during maintenance. The traveling gear 11 of the dump truck 1 used in mines and the like tends to have heavy and expensive parts, and efficient replacement of consumable parts is required, so ease of part replacement is an advantage.

[0085] Furthermore, in the traveling device 11 of the second embodiment, the first member 42X of the bearing retainer 42 is connected to one axial surface of the second member 42Y. This prevents the second member 42Y from interfering with the first member 42X when the second member 42Y is disassembled and reassembled while the first member 42X is fixed to the spindle 12. Therefore, the traveling device 11 can more easily replace parts during maintenance.

[0086] [Third embodiment] The traveling gear 11 of the dump truck 1 according to the third embodiment will be described with reference to Fig. 7. In the traveling gear 11 according to the third embodiment, the description of the same components as those in the first and second embodiments will be omitted.

[0087] 7 is a detailed view of the vicinity of the bearing retainer 42 in the traveling device 11 of the third embodiment. FIG 7 is a view corresponding to FIG 5.

[0088] The traveling device 11 of the third embodiment may be provided with a sensor 70 in a space G located between the bearing retainer 42 and the second carrier 39, for monitoring at least one of the temperature and vibration of the shaft bearing 46.

[0089] The sensor 70 is fastened to a surface of the bearing retainer 42 on the second carrier 39 side (the other axial side). The sensor 70 can directly measure at least one of the temperature and vibration of the shaft bearing 46. Alternatively, the sensor 70 can indirectly measure at least one of the temperature and vibration at a site in the vicinity of the shaft bearing 46 that is correlated with the shaft bearing 46. A sensor wiring 71 associated with the sensor 70 passes through a notched groove 42E provided on the outer circumferential surface of the bearing retainer 42 and is routed along the inner circumferential surface of the spindle 12 toward the electric motor 21 side (one axial side), enabling measurement operation from outside the traveling device 11.

[0090] The notched groove 42E is provided at a different phase (different circumferential position) from the support member 50 that positions and fixes the bearing retainer 42 to the spindle 12. Therefore, the positioning and fixing function of the support member 50 is not impaired by providing the notched groove 42E.

[0091] In this manner, in the traveling device 11 of the third embodiment, a sensor 70 is provided on the inner peripheral surface side of the spindle 12 to monitor at least one of the temperature and vibration of the shaft bearing 46. The sensor 70 is disposed in the gap G located between the bearing retainer 42 and the second carrier 39.

[0092] Thereby, the traveling device 11 of the third embodiment can quickly detect an abnormality or failure of the shaft bearing 46. The traveling device 11 can quickly replace parts or perform maintenance, and the operation downtime of the dump truck 1 can be shortened.

[0093] [Fourth embodiment] The traveling gear 11 of the dump truck 1 according to the fourth embodiment will be described with reference to Figures 8 to 10. In the traveling gear 11 according to the fourth embodiment, the description of the same components as those in the first to third embodiments will be omitted.

[0094] Fig. 8 is a detailed view of the vicinity of the bearing retainer 42 in the traveling device 11 of the fourth embodiment. Fig. 8 is a view corresponding to Fig. 5. Fig. 9 is a view showing the arrangement structure of the oil supply pipe 61 shown in Fig. 8. Fig. 10 is a view showing a supply source of lubricating oil to the oil supply pipe 80 shown in Fig. 9.

[0095] In the traveling device 11 of the fourth embodiment, a supply port 60A of an oil supply pipe 60 that supplies lubricating oil to the female spline portion 12G of the spindle 12 may be provided in the space G located between the bearing retainer 42 and the second carrier 39.

[0096] The bearing retainer 42 is provided with an oil passage hole 62 extending in the axial direction to guide lubricating oil. An oil supply pipe 60 having a supply port 60A is fastened to a surface of the bearing retainer 42 on the second carrier 39 side (the other axial side) and communicates with the oil passage hole 62. The oil passage hole 62 communicates with an oil supply pipe 61 fastened to a surface of the bearing retainer 42 on the electric motor 21 side (one axial side).

[0097] As shown in FIG. 9, the oil supply pipe 61 is routed along the inner surface of the spindle 12 toward the electric motor 21 (one side in the axial direction) and is connected to the oil supply pipe 80 via an oil passage hole 12I provided in the motor mounting seat 12F of the spindle 12.

[0098] The oil supply pipe 80 is disposed in the axle housing 10. As shown in FIG. 10, the oil supply pipe 80 communicates with an oil supply pipe 83 via an oil passage hole 12J provided in the motor mounting seat 12F of the spindle 12. A pump 84 and a filter 85 are provided in the middle of the oil supply pipe 80, and lubricating oil is sucked up by the power of the pump 84. The oil supply pipe 83 is arranged along the inner peripheral surface of the spindle 12 toward the bearing retainer 42 side (the other side in the axial direction). The oil supply pipe 83 is fastened to a surface of the bearing retainer 42 on the electric motor 21 side (one side in the axial direction) and communicates with an oil passage hole 86 provided in the bearing retainer 42. The oil passage hole 86 communicates with a suction pipe 82 fastened to a surface of the bearing retainer 42 on the second carrier 39 side (the other side in the axial direction).

[0099] The suction pipe 82 is a pipe for sucking the lubricating oil from the lubricating oil reservoir 81 in the traveling device 11. The level of the lubricating oil in the lubricating oil reservoir 81 is set below the small diameter cylindrical portion 12C of the spindle 12 in order to reduce the stirring resistance when the shaft 22 is rotated by the electric motor 21 and the rotational resistance of the various gears constituting the planetary gear reduction device 25. For example, the level of the lubricating oil in the lubricating oil reservoir 81 is set to a height at which the level of the lubricating oil is located between the outer peripheral surface of the small diameter cylindrical portion 12C of the spindle 12 and the inner peripheral surface of the hollow cylindrical portion 16A of the wheel mounting case 16 of the wheel 15. At least a part of the wheel bearings 17, 18 is immersed in the lubricating oil reservoir 81. The suction pipe 82 extends toward the lubricating oil reservoir 81 through the small diameter cylindrical portion 12C of the spindle 12. The suction pipe 82 has a suction port 82A for sucking the lubricating oil from the lubricating oil reservoir 81. The suction port 82A is immersed in a lubricating oil reservoir 81.

[0100] The lubricating oil sucked from the lubricating oil reservoir 81 into the suction port 82A by the power of the pump 84 passes through the suction pipe 82, the oil passage hole 86, the oil supply pipe 83, the oil passage hole 12J, and the oil supply pipe 80 in this order, and is then sucked up by the pump 84. The lubricating oil sucked up by the pump 84 passes through the filter 85, the oil supply pipe 80, the oil passage hole 12I, the oil supply pipe 61, the oil passage hole 62, and the oil supply pipe 60 in this order, and is then supplied from the supply port 60A to the female spline portion 12G of the spindle 12.

[0101] The oil supply pipes 60, 61, and 80 shown in FIG. 9 and the oil supply pipes 80, 83 and the suction pipe 82 shown in FIG. 10 are provided in different phases from each other and do not interfere with each other.

[0102] In this manner, the traveling device 11 of the fourth embodiment is provided with an oil supply pipe 60 having a supply port 60A that supplies lubricating oil to the female spline portion 12G of the spindle 12 on the inner peripheral surface side of the spindle 12. The supply port 60A of the oil supply pipe 60 is disposed in the space G located between the bearing retainer 42 and the second carrier 39.

[0103] As a result, the traveling device 11 of the fourth embodiment can supply lubricating oil to the female spline portion 12G of the spindle 12 which is located above the liquid level of the lubricating oil reservoir 81 and is prone to becoming short of lubricating oil. Furthermore, since the traveling device 11 supplies lubricating oil from the bearing retainer 42 side (one side in the axial direction) of the female spline portion 12G, it is possible to easily supply lubricating oil to the shaft bearing 46 near the bearing retainer 42 as well.

[0104] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to each embodiment, and various modifications can be made without departing from the spirit of the present invention. In the present invention, components of one embodiment can be added to components of another embodiment, components of one embodiment can be replaced with components of another embodiment, or some components of one embodiment can be deleted. [Explanation of symbols]

[0105] 1...Dump truck, 2...Vehicle body, 3...Front wheel, 3A...Front wheel side suspension, 4...Rear wheel, 4A...Tire, 4B...Rear wheel side suspension, 5...Vessel, 5A...Eaves, 6...Connecting pin, 7...Cab, 8...Engine, 9...Hoist cylinder, 10...Axle housing, 11...Running gear, 12...Spindle, 12A...Large diameter cylinder portion, 12B...Intermediate cylinder portion, 12C...Small diameter cylinder portion, 12D...Brake mounting portion, 12E...Step portion, 12F...Motor mounting seat, 12G...Female spline portion (spline portion), 12H...Retainer fitting portion, 12I...Oil passage hole, 12 J...oil passage hole, 13...bolt, 15...wheel, 15A...rim, 16...wheel mounting tube, 16A...hollow tube portion, 16B...extended tube portion, 17, 18...wheel bearing, 19, 20...bearing retainer, 21...electric motor (rotation source), 21A...mounting flange, 21B...output shaft, 22...shaft, 22A...bearing mounting portion, 23...outer drum, 23A...flange portion, 24...long bolt, 25...planetary gear reduction device, 26...first planetary gear reduction mechanism, 27...sun gear, 28...internal gear, 29...planetary gear, 30...support pin, 31...carrier, 3 1A...bolt, 32...cover plate, 33...coupling, 34...second planetary gear reduction mechanism, 35...sun gear, 36...internal gear, 37...planetary gear, 38...support pin, 39...second carrier (carrier), 39A...cylindrical protrusion, 39B...male spline portion, 40...brake hub, 41...wet brake device, 41A...brake housing, 41B...non-rotating brake plate, 41C...rotating brake plate, 41D...brake movable body, 42...bearing retainer, 42B...bearing fitting hole, 42D...cylindrical outer circumferential surface, 42E...notched groove, 42X...first part member, 42Y...second member, 45...sleeve, 45A...bearing fitting portion, 45B...flange portion, 45C...male thread portion, 46...shaft bearing, 46A...inner ring, 46B...outer ring, 46C...rolling element, 47...retaining ring, 48...spacer, 50...support member, 51...fitting hole, 52...fitting hole, 53...connecting member, 60...oil supply pipe, 60A...supply port, 61...oil supply pipe, 62...oil passage hole, 70...sensor, 71...sensor wiring, 80...oil supply pipe, 81...lubricating oil reservoir, 82...suction pipe, 82A...suction port, 83...oil supply pipe, 84...pump, 85...filter

Claims

1. a cylindrical spindle having one axial side attached to a vehicle body and having a spline portion formed on an inner peripheral surface of the other axial side; a wheel on which a tire is mounted, the wheel being disposed on an outer circumferential surface side of the spindle and located on the other side of the spindle; a wheel bearing provided between the spindle and the wheel and configured to rotatably support the wheel relative to the spindle; a rotation source provided on the one side of the spindle and having an output shaft inserted into the inner peripheral surface side of the spindle; a shaft having one end located on an inner circumferential surface side of the spindle and connected to the output shaft of the rotation source, and having the other end protruding from the other side of the spindle; a planetary gear reduction device provided between the shaft and the wheel and located on the other side of the spindle, the planetary gear reduction device having a plurality of planetary gears rotatably supported by a carrier splined to the spline portion of the spindle; A traveling device for a dump truck including: a shaft bearing that is located on the one side of the carrier and is provided on the inner peripheral surface side of the spindle, and supports the shaft rotatably relative to the spindle, a bearing retainer that is a separate member from the spindle and that holds the shaft bearing is provided on the inner peripheral surface side of the spindle, The bearing retainer is fitted to the inner peripheral surface of the spindle, is disposed on the one side from each of the spline portion of the spindle and the carrier at a distance, and is supported on the inner peripheral surface of the spindle by a support member. A traveling device for a dump truck.

2. the bearing retainer includes a first member supported on the inner peripheral surface of the spindle by the support member, and a second member that holds the shaft bearing, The first member is a separate member from the second member and is connected to the second member by a connecting member.

2. A traveling device for a dump truck according to claim 1.

3. The first member is connected to the one side surface of the second member.

3. A traveling device for a dump truck according to claim 2.

4. a sensor for monitoring at least one of a temperature and a vibration of the shaft bearing is provided on the inner peripheral surface side of the spindle; The sensor is disposed in the space located between the bearing retainer and the carrier.

2. A traveling device for a dump truck according to claim 1.

5. an oil supply pipe having a supply port for supplying lubricating oil to the spline portion of the spindle is provided on the inner peripheral surface side of the spindle, The supply port of the oil supply pipe is disposed in the space between the bearing retainer and the carrier.

2. A traveling device for a dump truck according to claim 1.

Images