Wheeled vehicle running gear

Abstract

To supply a sufficient amount of a lubrication oil to a bearing supporting a rotary shaft on a constant basis.SOLUTION: A travel device includes: a cylindrical spindle; a rotary shaft 14 which is provided at the inner periphery side of the spindle and rotated by a driving motor; a wheel attachment cylinder which is rotatably provided at the outer periphery side of the spindle and attached with a wheel and contains a lubrication oil therein; a speed reduction mechanism which reduces a speed of rotation of the rotary shaft 14 and transmits the rotation to the wheel attachment cylinder; a retainer 42 having a bearing fitting hole 42A and provided at the inner periphery side of the spindle; and a bearing 44 attached to the retainer 42 and supporting the rotary shaft 14. An annular flange part 42D which contacts with the bearing 44 is provided at a driving motor side surface of the retainer 42. An oil reservoir plate 47 which forms an oil reservoir part 49 of the lubrication oil with a flange part 42D and an inner peripheral surface 42C of the bearing fitting hole 42A is provided on a speed reduction mechanism side surface of the retainer 42.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a traveling device that is suitable for use in a wheeled vehicle having wheels, such as a dump truck. [Background technology]

[0002] In general, a traveling device provided on a wheeled vehicle, for example, a dump truck, includes a cylindrical spindle fixed to the vehicle body, a rotating shaft extending axially from the inner periphery of the spindle and driven to rotate by a drive source, a wheel mounting case rotatably provided on the outer periphery of the spindle, with wheels attached on the outer periphery and containing lubricant on the inner periphery, and a planetary gear reduction mechanism that reduces the rotation of the rotating shaft and transmits it to the wheel mounting case. The planetary gear reduction mechanism reduces the rotational output of a drive source such as an electric motor and transmits it to the wheels (drive wheels) via the wheel mounting case, thereby generating a large rotational torque at the drive wheels and allowing the dump truck to travel (see Patent Document 1).

[0003] The rotating shaft of the travelling gear is located between the drive source and the planetary gear reduction mechanism (sun gear) with the inner periphery of the spindle extended in the axial direction. Therefore, the middle portion of the rotating shaft in the longitudinal direction is rotatably supported relative to the spindle by a bearing located on the inner periphery of the spindle. Dump trucks transport heavy loads such as crushed stone excavated from mines, so a large rotational load acts on the travelling gear. For this reason, it is necessary to supply sufficient lubricating oil to the bearings to keep the rotating shaft and bearings in a state where they can rotate smoothly at all times.

[0004] If a large amount of lubricating oil is stored inside the traveling device, the resistance (stirring resistance) generated when the lubricating oil is stirred by the planetary gear reduction mechanism can cause energy loss and heat generation in the traveling device. For this reason, the amount of lubricating oil stored inside the traveling device is generally set to the minimum necessary amount (e.g., approximately 1 / 5 to 1 / 3 of the internal volume of the wheel mounting sleeve). When the lubricating oil amount is set to the minimum necessary amount, the lubricating oil level is located below the rotating shaft, so the rotating shaft and bearings are not submerged in the lubricating oil, but only the planetary gears, carriers, and other components of the planetary gear reduction mechanism are partially submerged in the lubricating oil. Therefore, when the traveling device is driven, the lubricating oil is splashed up by the planetary gear reduction mechanism and dispersed as a mist, allowing it to be supplied appropriately to the bearings.

[0005] However, the traveling device according to Patent Document 1 has a configuration in which mist-like lubricating oil is supplied to the bearings that support the rotating shaft by being splashed up by a planetary gear reduction mechanism, which poses the problem that it is not possible to always supply sufficient lubricating oil to the bearings.

[0006] In response to this, a traveling device has been proposed in which an oil passage that guides lubricating oil to the bearing is formed in the retainer that holds the bearing to the spindle (see Patent Document 2). This traveling device uses a pump to suck up lubricating oil contained inside the wheel mounting sleeve (drum) and supplies it to the oil passage formed in the retainer, thereby supplying sufficient lubricating oil to the bearing. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2004 / 0065169 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-116963 Summary of the Invention [Problem to be solved by the invention]

[0008] However, with the traveling device disclosed in Patent Document 2, when the traveling device rotates at high speed, centrifugal force presses the lubricating oil contained inside the wheel mounting case against the inner circumferential surface of the wheel mounting case, which can cause the lubricating oil level to drop.This causes the pump to be unable to suck up the lubricating oil contained inside the wheel mounting case, resulting in a problem in which lubricating oil cannot be supplied stably to the bearings.

[0009] SUMMARY OF THE INVENTION An object of the present invention is to provide a running device for a wheeled vehicle that can always supply sufficient lubricating oil to bearings that support a rotating shaft. [Means for solving the problem]

[0010] The present invention provides a cylindrical spindle that is fixed to the body of a wheeled vehicle and has a small-diameter cylindrical portion that is open at its tip; a rotating shaft that extends axially from the inner periphery of the spindle, with its tip projecting from the open end of the small-diameter cylindrical portion of the spindle and having a sun gear attached to the tip, and that is rotatably driven by a drive source; a wheel mounting case that is rotatably provided on the outer periphery of the spindle, with a wheel attached to the outer periphery and containing lubricating oil inside; a reduction mechanism that includes the sun gear and reduces the rotation of the rotating shaft before transmitting it to the wheel mounting case; a retainer that has a bearing fitting hole and is provided on the inner periphery of the small-diameter cylindrical portion of the spindle and is located between the drive source and the reduction mechanism; a bearing that is inserted into the bearing fitting hole of the retainer and rotatably supports an axially intermediate portion of the rotating shaft with respect to the spindle; and a bearing that is fitted on the rotating shaft and abuts against the reduction mechanism side of the bearing, and an annular stopper that positions a drive source-side retainer in the axial direction of the rotating shaft, the retainer having an annular flange that protrudes radially inward from the bearing fitting hole and abuts against the bearing, and an oil sump plate that forms an oil sump for lubricating oil together with the flange and the inner surface of the bearing fitting hole is provided on the reduction mechanism side of the retainer at a position axially opposite the flange with the bearing interposed therebetween, the oil sump plate comprising an annular mounting portion attached to the retainer and an annular wall portion that protrudes radially inward from the annular mounting portion and faces the flange of the retainer over its entire circumference, an angle θ between the annular wall portion and an axial center line of the rotating shaft is set in the range of 0<θ<90°, and a radially inner edge of the annular wall portion substantially coincides with an end face of the stopper on the reduction mechanism side in the axial direction of the rotating shaft. [Effects of the Invention]

[0011] According to the present invention, the lubricating oil supplied to the bearing supporting the rotating shaft can be stored in the oil reservoir formed by the flange of the retainer, the inner circumferential surface of the bearing fitting hole, and the oil reservoir plate. As a result, regardless of the running state of the vehicle body, the bearing can be sufficiently supplied with lubricating oil stored in the oil reservoir, allowing the rotating shaft to rotate smoothly. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a left side view showing a dump truck to which a traveling device according to a first embodiment of the present invention is applied. [Figure 2] FIG. 2 is a rear view of the dump truck. [Figure 3] 3 is a cross-sectional view of the rear wheel side traveling device as seen from the direction of arrows III-III in FIG. 1. [Figure 4] FIG. 4 is an enlarged view showing the rotating shaft, bearings, retainer, oil sump plate, etc. in FIG. 3. [Figure 5] 5 is a cross-sectional view of the rotating shaft, bearings, retainer, oil sump plate, etc., as viewed from the direction of arrows VV in FIG. 4. [Figure 6] 5 is an enlarged view of the same position as FIG. 4, showing the rotating shaft, bearings, retainer, oil sump plate, etc. according to the second embodiment. [Figure 7] 5 is an enlarged view similar to FIG. 4, showing the rotating shaft, bearings, retainer, oil sump plate, etc. according to a third embodiment. [Figure 8] 8 is a cross-sectional view of the rotating shaft, bearings, retainer, oil sump plate, etc., as viewed from the direction of arrows VIII-VIII in FIG. 7. [Figure 9] 5 is an enlarged view of a position similar to that of FIG. 4, showing a rotating shaft, bearings, a retainer, an oil sump plate, etc. according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] A travel device for a wheeled vehicle according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings, taking as an example a case where the travel device is applied to a rear-wheel drive dump truck. In the embodiment, the travel direction of the dump truck is defined as the front-rear direction, and the direction perpendicular to the travel direction is defined as the left-right direction.

[0014] 1 to 5 show a first embodiment of the present invention. In the drawings, a dump truck 1 includes a body 2 having a sturdy frame structure, a vessel (cargo bed) 3 mounted on the body 2 so as to be able to rise and fall, a cab 5 provided at the front of the body 2, and left and right front wheels 6 and left and right rear wheels 7 as wheels.

[0015] The vessel 3 is formed as a large container for carrying heavy loads such as crushed stone, and the rear bottom of the vessel 3 is connected to the rear end of the vehicle body 2 via a connecting pin 4 or the like so that it can be raised and lowered (tilted). A hood 3A that covers a cab 5 from above is integrally provided on the upper front side of the vessel 3. The cab 5 is provided at the front of the vehicle body 2, positioned below the hood 3A. The cab 5 forms a driver's cab, and inside the cab 5, a driver's seat, a steering handle, multiple operating levers (none of which are shown), etc. are provided.

[0016] The left and right front wheels 6 are rotatably mounted on the front side of the vehicle body 2 (only the left front wheel is shown). The left and right front wheels 6 constitute steering wheels that are steered by the driver. The left and right rear wheels 7 are rotatably mounted on the rear side of the vehicle body 2 (only the left rear wheel is shown). The left and right rear wheels 7 constitute drive wheels of the dump truck 1, and are rotated integrally with the wheel mounting sleeve 16 by the traveling device 11 shown in FIG. 3. The rear wheels 7 are configured to include two rows of tires 7A made up of dual-wheel tires, and rims 7B arranged radially inward of the tires 7A.

[0017] The engine 8 is located below the cab 5 and is provided inside the vehicle body 2. The engine 8 is configured by, for example, a diesel engine, and rotates a travel motor 13, a hydraulic pump (not shown), and other components mounted on the vehicle body 2, which will be described later. Pressurized oil discharged from the hydraulic pump is supplied to a hoist cylinder 9, a steering cylinder for power steering (not shown), and other components, which will be described later.

[0018] The hoist cylinders 9 are provided between the vehicle body 2 and the vessel 3. The hoist cylinders 9 are located between the front wheels 6 and the rear wheels 7, and are arranged on both the left and right sides of the vehicle body 2. The hoist cylinders 9 expand and contract in the upward and downward directions as pressure oil is supplied and discharged from the hydraulic pump, and raise and lower (tilt) the vessel 3 around the connecting pin 4.

[0019] The rear wheel axle housing 10 is provided at the rear side of the vehicle body 2. The axle housing 10 is made of a hollow cylindrical body extending in the left-right direction (axial direction), and is attached to the rear side of the vehicle body 2 via left and right rear wheel suspensions 10A. On the left and right sides of the axle housing 10, there are provided running devices 11 that drive the left and right rear wheels 7, respectively.

[0020] The traveling devices 11 are provided on both the left and right sides of the axle housing 10. As shown in Figure 3, the traveling devices 11 include a spindle 12, a traveling motor 13, a rotating shaft 14, a wheel mounting sleeve 16, a reduction mechanism 21, a retainer 42, bearings 44, and an oil sump plate 47. The traveling devices 11 reduce the rotation speed of the rotating shaft 14 using the reduction mechanism 21, and rotate the left and right rear wheels 7, which serve as drive wheels, with a large rotational torque.

[0021] The spindle 12 is attached to both the left and right sides of the axle housing 10. The spindle 12 is formed as a stepped cylinder extending in the left-right direction and has a tapered section 12A, an intermediate cylindrical section 12B, and a small-diameter cylindrical section 12C. The tapered section 12A has a tapered shape that gradually reduces in diameter from one axial side of the spindle 12 (the axle housing 10 side) to the other axial side, and is attached to the end of the axle housing 10 using multiple bolts 12D. The intermediate cylindrical section 12B is formed integrally with the reduced-diameter side of the tapered section 12A and extends in the axial direction. The small-diameter cylindrical section 12C has an outer diameter smaller than that of the intermediate cylindrical section 12B and is formed integrally with the tip side of the intermediate cylindrical section 12B.

[0022] A plurality of motor mounting seats 12E protruding radially inward are provided on one axial side of the tapered portion 12A, and travel motors 13 are attached to the motor mounting seats 12E. An annular flange portion 12F protruding radially outward is provided on the outer periphery of the tapered portion 12A, and a wet brake 35 (described later) is attached to the flange portion 12F.

[0023] Meanwhile, the tip of the small diameter cylindrical portion 12C is an open end, and a cylindrical protrusion 33A of a second stage carrier 33 (described later) is splined to its inner periphery. An annular inner protrusion 12G that protrudes radially inward is integrally formed on the inner periphery of an axially intermediate portion of the small diameter cylindrical portion 12C, and a retainer 42 (described later) is attached to the inner protrusion 12G. Furthermore, a radial hole 12H that penetrates the lower portion of the small diameter cylindrical portion 12C in the vertical direction (radial direction of the small diameter cylindrical portion 12C) is drilled, and a tip 38A of a suction pipe 38 (described later) is inserted into this radial hole 12H.

[0024] The travel motor 13 serving as a drive source is disposed within the axle housing 10 and the tapered portion 12A of the spindle 12. A plurality of mounting flanges 13A are provided on the outer periphery of the travel motor 13, and the mounting flanges 13A are attached to a motor mounting seat 12E of the spindle 12 (tapered portion 12A) using bolts or the like. The travel motor 13 is constituted by an electric motor, and is supplied with electric power from a generator (not shown) mounted on the vehicle body 2 to rotate the rotary shaft 14.

[0025] The rotating shaft 14 is provided so as to extend axially from the inner peripheral side of the spindle 12. The rotating shaft 14 is formed using a single long rod-shaped body, and one end of the rotating shaft 14 is connected to the output shaft (not shown) of the travel motor 13 via a coupling 15, and the rotating shaft 14 is rotated by the travel motor 13. The other end of the rotating shaft 14 protrudes from the open end of the small-diameter cylindrical portion 12C of the spindle 12, and a sun gear 23, which will be described later, is attached to the other end (protruding end) of the rotating shaft 14. An intermediate portion of the rotating shaft 14 in the axial direction is supported by a bearing 44 so as to be rotatable relative to the spindle 12.

[0026] The wheel mounting sleeve 16 is rotatably mounted on the outer periphery of the small diameter cylindrical portion 12C that constitutes the spindle 12 via two roller bearings 17, 18. The wheel mounting sleeve 16 is supported by the roller bearings 17, 18 and has a hollow cylindrical portion 16A that extends axially on the outer periphery of the small diameter cylindrical portion 12C, and an extended cylindrical portion 16B that protrudes axially from the tip of the hollow cylindrical portion 16A and extends in a direction away from the spindle 12. A cylindrical rim 7B that constitutes the rear wheel 7 is detachably attached to the outer periphery of the wheel mounting sleeve 16, and the rear wheel 7 rotates integrally with the wheel mounting sleeve 16. An internal gear 32 and an outer drum 19, which will be described later, are fixed integrally to the end of the extended cylindrical portion 16B of the wheel mounting sleeve 16 using long bolts 20. The outer drum 19 is made of a cylindrical body, and a flange portion 19A provided on one axial side is fixed to the wheel mounting case 16 via an internal gear 32, and the other axial side is an open end.

[0027] The reduction mechanism 21 is provided between the rotating shaft 14 and the wheel mounting case 16. The reduction mechanism 21 is made up of a first-stage planetary gear reduction mechanism 22 and a second-stage planetary gear reduction mechanism 29, and reduces the rotation of the rotating shaft 14 in two stages before transmitting it to the wheel mounting case 16.

[0028] The first-stage planetary gear reduction mechanism 22 includes a sun gear 23, multiple planet gears 24, and a carrier 26. The sun gear 23 is splined to the tip of the rotary shaft 14 that protrudes from the spindle 12 (small-diameter cylindrical portion 12C). The multiple planet gears 24 mesh with the sun gear 23 and a ring-shaped internal gear 25, and revolve around the sun gear 23 while rotating on their own axes. The carrier 26 is fixed via bolts or the like to the open end of the outer drum 19 that is integrated with the wheel mounting case 16, and rotatably supports the planet gears 24 via support pins 27.

[0029] Here, the internal gear 25 is formed using a ring gear and surrounds the sun gear 23 and the plurality of planetary gears 24 from the radial outside. The internal gear 25 is arranged to be rotatable relative to the inner circumferential surface of the outer drum 19 via a radial gap. The rotation of the internal gear 25 is transmitted to a second-stage planetary gear reduction mechanism 29 via a coupling 28.

[0030] The coupling 28 is provided between the first-stage planetary gear reduction mechanism 22 and the second-stage planetary gear reduction mechanism 29. The coupling 28 is formed in a disk shape with a boss 28A in the center. The outer periphery of the coupling 28 is spline-connected to the first-stage internal gear 25, and the inner periphery of the boss 28A of the coupling 28 is spline-connected to the second-stage sun gear 30, which will be described later. The coupling 28 transmits the rotation of the first-stage internal gear 25 to the second-stage sun gear 30, causing the sun gear 30 to rotate integrally with the first-stage internal gear 25.

[0031] The first-stage planetary gear reduction mechanism 22 converts the rotation of the sun gear 23 into rotational motion and revolutional motion of the multiple planetary gears 24 as the sun gear 23 rotates integrally with the rotary shaft 14 due to the travel motor 13. The rotational motion of the planetary gears 24 is then transmitted to the internal gear 25 as reduced rotation, and the rotation of the internal gear 25 is transmitted to the second-stage planetary gear reduction mechanism 29 via a coupling 28. Meanwhile, the revolutional motion of the planetary gears 24 becomes rotation of the carrier 26, which is transmitted to the wheel mounting case 16 via the outer drum 19. At this time, because the wheel mounting case 16 rotates integrally with the second-stage internal gear 32, the revolution of the planetary gears 24 is suppressed to rotation synchronized with the wheel mounting case 16.

[0032] The second-stage planetary gear reduction mechanism 29 includes a cylindrical sun gear 30, multiple planet gears 31, and a carrier 33. The sun gear 30 is splined to the inner periphery of a boss 28A of the coupling 28 and rotates integrally with the coupling 28. The multiple planet gears 31 mesh with the sun gear 30 and a ring-shaped internal gear 32 and revolve around the sun gear 30 while rotating on their own axes. The carrier 33 rotatably supports the planet gears 31 via support pins 34. A cylindrical protrusion 33A is provided at the center of the carrier 33, and the outer periphery of the cylindrical protrusion 33A is splined to the inner periphery of the small-diameter cylindrical portion 12C. Here, the second stage internal gear 32 is formed using a ring gear that surrounds the sun gear 30, multiple planetary gears 31, etc. from the radial outside, and is integrally fixed between the extended cylindrical portion 16B of the wheel mounting case 16 and the outer drum 19 using long bolts 20.

[0033] In the second-stage planetary gear reduction mechanism 29, the cylindrical protrusion 33A of the carrier 33 is splined to the small-diameter cylindrical portion 12C of the spindle 12, thereby restricting the revolution of the planetary gears 31 (the rotation of the carrier 33). Therefore, the second-stage planetary gear reduction mechanism 29 converts the rotation of the sun gear 30 into the rotation of the planetary gears 31 as the sun gear 30 rotates integrally with the coupling 28, and transmits this rotation of the planetary gears 31 to the second-stage internal gear 32. As a result, the internal gear 32 rotates at a reduced speed, and a large-output rotational torque that has been reduced in two stages by the first-stage planetary gear reduction mechanism 22 and the second-stage planetary gear reduction mechanism 29 is transmitted to the wheel mounting case 16 to which the internal gear 32 is fixed.

[0034] Lubricating oil L is stored inside the wheel mounting case 16, and the level of the lubricating oil L is located lower than, for example, the bottommost part of the small-diameter cylindrical portion 12C that constitutes the spindle 12. Therefore, the lower parts of the roller bearings 17, 18 are immersed in the lubricating oil L, and a portion of the planetary gear reduction mechanisms 22, 29 is constantly lubricated by the lubricating oil L. Furthermore, the lubricating oil L splashed up by the planetary gear reduction mechanisms 22, 29 becomes a mist and is scattered inside the spindle 12, and is also supplied to the bearing 44 that supports the rotating shaft 14. As a result, when the traveling device 11 is operating, resistance due to agitation of the lubricating oil L is reduced, which suppresses energy loss and also suppresses heat generation by the traveling device 11.

[0035] The wet brake 35 is attached to the flange portion 12F of the spindle 12. The wet brake 35 is configured as a wet multi-plate hydraulic brake, and applies a braking force to a brake hub 36 attached to the wheel mounting case 16. This applies a braking force to the rotation of the wheel mounting case 16, i.e., the rotation of the rear wheel 7.

[0036] The partition wall 37 is provided inside the spindle 12. The partition wall 37 is formed from an annular plate, and the outer periphery of the partition wall 37 is attached using bolts or the like to the boundary between the tapered portion 12A and the intermediate cylindrical portion 12B of the spindle 12. The partition wall 37 divides the inside of the spindle 12 into a motor accommodating space 37A that accommodates the travel motor 13, and a cylindrical space 37B that communicates with the inside of the wheel mounting case 16.

[0037] The suction pipe 38 is provided within the spindle 12 and the axle housing 10. One longitudinal side of the suction pipe 38 extends axially within the axle housing 10 and is connected to the suction side of a lubricating oil pump 39. The other longitudinal side of the suction pipe 38 is located below the rotating shaft 14, extends axially within the spindle 12, and is held by a retainer 42, which will be described later. A tip 38A of the suction pipe 38 protruding from the retainer 42 is bent in an L shape, extends downward, and is inserted into a radial hole 12H of the spindle 12. As a result, the tip 38A of the suction pipe 38 is immersed in the lubricating oil L within the wheel mounting case 16, and the lubricating oil pump 39 sucks up the lubricating oil L through the suction pipe 38.

[0038] The supply pipe 40 is provided within the spindle 12 and axle housing 10, and forms a circulation circuit for the lubricating oil L together with the suction pipe 38, the lubricating oil pump 39, etc. One longitudinal side of the supply pipe 40 extends axially within the axle housing 10 and is connected to the discharge side of the lubricating oil pump 39. The other longitudinal side of the supply pipe 40 is located above the rotating shaft 14, extends axially within the spindle 12, and is held by a retainer 42. A tip 40A of the supply pipe 40 protruding from the retainer 42 bends in an S-shape and extends along the rotating shaft 14 into the cylindrical protruding portion 33A of the second-stage carrier 33. An oil cooler 41 is provided midway along the supply pipe 40. As a result, the lubricating oil L discharged from the lubricating oil pump 39 is cooled by the oil cooler 41 and supplied to the rotating shaft 14 through the tip 40A of the supply pipe 40, cooling the rotating shaft 14 and splashing from the rotating shaft 14 to lubricate bearings 44, etc.

[0039] The retainer 42 is attached to the inner protrusion 12G of the spindle 12 (small-diameter cylindrical portion 12C) using bolts or the like. The retainer 42 is a circular plate with a bearing fitting hole 42A formed in its center. The retainer 42 holds a bearing 44 fitted in the bearing fitting hole 42A and also holds the other longitudinal ends of the suction pipe 38 and the supply pipe 40. As shown in FIG. 4 , an annular flange 42D extending radially inward from an inner circumferential surface 42C of the bearing fitting hole 42A is provided on one axial side surface 42B of the retainer 42 facing the travel motor 13. An oil sump plate 47 (described later) is attached to the other axial side surface 42E of the retainer 42 facing the reduction gear mechanism 21. Furthermore, an oil passage 42F extending radially from the outer circumferential surface of the retainer 42 to the bearing fitting hole 42A is formed in the retainer 42. The oil passage 42F has one end (upper end) opening to the outer peripheral surface of the retainer 42 and the other end (lower end) opening to the bearing fitting hole 42A, and guides the lubricating oil L scattered on the outer peripheral surface of the retainer 42 to the bearing fitting hole 42A.

[0040] The sleeve 43 is provided on the rotating shaft 14 at a position corresponding to the bearing fitting hole 42A of the retainer 42. The sleeve 43 is a stepped cylinder having a shaft mounting hole 43A, and the outer circumferential surface of the sleeve 43 has a large-diameter outer circumferential surface 43B and a small-diameter outer circumferential surface 43C. Furthermore, an annular flange portion 43D is provided on one axial side of the sleeve 43 (the traveling motor 13 side) and projects radially outward from the large-diameter outer circumferential surface 43B.

[0041] The bearing 44 is disposed on the inner peripheral side of the spindle 12 via the retainer 42 and rotatably supports the rotary shaft 14 relative to the spindle 12. The bearing 44 includes an outer ring 44A, an inner ring 44B, and a plurality of rolling elements 44C. The outer ring 44A of the bearing 44 is fitted into the bearing fitting hole 42A of the retainer 42, and the inner ring 44B of the bearing 44 is fitted into the large-diameter outer peripheral surface 43B of the sleeve 43. The outer ring 44A of the bearing 44 is positioned in the axial direction by a flange portion 42D of the retainer 42 and a stop ring 45 attached to the inner peripheral surface 42C of the bearing fitting hole 42A. The inner ring 44B of the bearing 44 is positioned in the axial direction by a flange portion 43D of the sleeve 43 and an annular stopper 46 shrink-fitted to the small-diameter outer peripheral surface 43C.

[0042] The oil sump plate 47 is attached to the other side surface 42E of the retainer 42, which is located on the reduction mechanism 21 side. That is, the oil sump plate 47 is provided on the reduction mechanism 21 side of the retainer 42, at a position (surface) that axially faces the flange portion 42D via the bearing 44. As shown in FIGS. 4 and 5 , the oil sump plate 47 is formed as a crescent-shaped plate having a length dimension greater than the outer diameter dimension of the rotating shaft 14 and a height dimension smaller than the outer diameter dimension of the rotating shaft 14. The oil sump plate 47 has an attachment portion 47A attached to the retainer 42 below the center of the bearing fitting hole 42, and a wall portion 47B that rises upward from the attachment portion 47A and faces the flange portion 42D of the retainer 42 in the axial direction.

[0043] The oil sump plate 47 has a mounting portion 47A attached to the other side surface 42E of the retainer 42 using a plurality of bolts 48. The center of the oil sump plate 47 in the longitudinal direction coincides with a vertical line passing through the axial center of the rotating shaft 14. In this state, the wall portion 47B of the oil sump plate 47 faces the flange portion 42D of the retainer 42 in the axial direction, with the bearing 44 interposed therebetween. As a result, the oil sump plate 47, together with the inner circumferential surface 42C of the bearing fitting hole 42A of the retainer 42 and the flange portion 42D, forms an oil sump portion 49 that stores lubricating oil L.

[0044] Here, upper edge 47C of wall portion 47B protrudes above lowermost portion 42G of inner circumferential surface 42C of bearing fitting hole 42A formed in retainer 42, and is positioned lower than lowermost portion 42J of inner circumferential edge 42H of flange portion 42D. This prevents lubricating oil L from overflowing flange portion 42D of retainer 42 and overflowing toward travel motor 13, even if the lubricating oil L stored in oil reservoir 49 exceeds the capacity of oil reservoir 49, thereby protecting travel motor 13.

[0045] As described above, in this embodiment, oil sump plate 47, inner circumferential surface 42C of bearing fitting hole 42A of retainer 42, and flange 42D form oil sump 49. As a result, lubricating oil L that is discharged from lubricating oil pump 39 and supplied to rotating shaft 14, and then splashes from rotating shaft 14 and moves from the inner circumferential surface of spindle 12 to the outer circumferential surface of retainer 42, or mist-like lubricating oil L that is splashed up by reduction gear mechanism 21 or the like and splashed onto the outer circumferential surface of retainer 42, is guided to bearing fitting hole 42A through oil passage 42F of retainer 42 and stored in oil sump 49.

[0046] The traveling device 11 of the dump truck 1 according to this embodiment has the configuration described above, and its operation will now be described.

[0047] When the driver in the cab 5 of the dump truck 1 starts the engine 8, the hydraulic pump is driven to rotate and the generator (neither of which is shown) generates electricity. When the dump truck 1 is driven to travel, power is supplied from the generator to the travel motor 13, which operates and rotates the rotary shaft 14.

[0048] The rotation of the rotary shaft 14 is reduced and transmitted from the sun gear 23 of the first-stage planetary gear reduction mechanism 22 to the planet gears 24, and the rotation of the planet gears 24 is reduced and transmitted to the sun gear 30 of the second-stage planetary gear reduction mechanism 29 via the internal gear 25 and the coupling 28. In the second-stage planetary gear reduction mechanism 29, the rotation of the sun gear 30 is reduced and transmitted to the planet gears 31. At this time, the cylindrical protrusion 33A of the carrier 33 supporting the planet gears 31 is spline-coupled to the small-diameter cylindrical portion 12C of the spindle 12, so the revolution of the planet gears 31 (the rotation of the carrier 33) is restricted.

[0049] Therefore, the planetary gears 31 only rotate around the sun gear 30, and rotation slowed down by the rotation of the planetary gears 31 is transmitted to the internal gear 32 fixed to the wheel mounting case 16. As a result, the wheel mounting case 16 rotates with a large rotational torque that has been reduced in two stages by the first-stage planetary gear reduction mechanism 22 and the second-stage planetary gear reduction mechanism 29. As a result, the left and right rear wheels 7, which serve as drive wheels, rotate integrally with the wheel mounting case 16, enabling the dump truck 1 to travel and drive.

[0050] An axially intermediate portion of the rotating shaft 14 is rotatably supported by the spindle 12 via a bearing 44 and a retainer 42. This makes it possible to prevent the axially intermediate portion from bending radially or from vibrating due to eccentricity of the rotating shaft 14 when the rotating shaft 14 rotates at high speed, thereby increasing the durability of the rotating shaft 14.

[0051] When the traveling device 11 is in operation, the lubricating oil L stored in the wheel mounting case 16 is scooped up by the planetary gears 24, 31 and the like that make up the planetary gear reduction mechanisms 22, 29, and is supplied to the meshing portions between the gears, the roller bearings 17, 18, the bearing 44, etc. The lubricating oil L then drips downward and is collected at the bottom of the wheel mounting case 16.

[0052] Lubricating oil L collected at the lower side of wheel mounting case 16 is sucked up from tip 38A of suction pipe 38 by lubricating oil pump 39, cooled in oil cooler 41, and then discharged from tip 40A of supply pipe 40 onto the outer circumferential surface of rotating shaft 14. The lubricating oil L discharged onto the outer circumferential surface of rotating shaft 14 not only cools rotating shaft 14, but is also scattered by the rotation of rotating shaft 14, lubricating bearings 44, planetary gear reduction mechanisms 22, 29, etc.

[0053] At this time, some of the lubricating oil L splashed up by the planetary gear reduction mechanisms 22, 29 and scattered by the rotation of the rotating shaft 14 adhere to the inner circumferential surface of the small diameter cylindrical portion 12C that constitutes the spindle 12. The lubricating oil L adhering to the inner circumferential surface of the small diameter cylindrical portion 12C moves along the inner protrusion 12G of the small diameter cylindrical portion 12C to the outer circumferential surface of the retainer 42, and is then guided to the bearing fitting hole 42A through the oil passage 42F of the retainer 42. The lubricating oil L guided to the bearing fitting hole 42A lubricates the bearing 44 and flows to the lower side of the bearing fitting hole 42A, where it is collected in the oil reservoir 49 formed by the inner circumferential surface 42C, flange 42D, and oil reservoir plate 47 of the bearing fitting hole 42A.

[0054] When the traveling device 11 rotates at high speed, the lubricating oil L contained inside the wheel mounting case 16 may be pressed against the inner peripheral surface of the wheel mounting case 16 by centrifugal force, causing the liquid level of the lubricating oil L to drop. In this case, the tip 38A of the suction pipe 38 separates from the lubricating oil L, and the lubricating oil pump 39 is no longer able to suck up the lubricating oil L.

[0055] In contrast to this, in this embodiment, the lubricating oil L can be stored in the oil reservoir 49 formed by the inner circumferential surface 42C of the bearing fitting hole 42A, the flange 42D, and the oil reservoir plate 47. Therefore, the lubricating oil L stored in the oil reservoir 49 can be supplied sufficiently to the bearing 44 regardless of the traveling state of the dump truck 1. As a result, the rotating shaft 14 supported by the spindle 12 via the bearing 44 and the like can be rotated smoothly at all times, and the traveling device 11 can be operated stably for a long period of time, thereby improving its reliability.

[0056] Moreover, upper edge 47C of wall portion 47B of oil reservoir plate 47 is positioned lower than lowermost portion 42J of inner peripheral edge 42H of flange 42D provided on retainer 42. This prevents lubricating oil L from overflowing flange 42D of retainer 42 and overflowing toward travel motor 13, even if the lubricating oil L stored in oil reservoir 49 exceeds the capacity of oil reservoir 49, thereby protecting travel motor 13.

[0057] Thus, in the first embodiment, there is provided a cylindrical spindle 12 fixed to the vehicle body 2, a rotating shaft 14 extending axially from the inner peripheral side of the spindle 12 and driven to rotate by a travel motor 13, a wheel mounting case 16 rotatably provided on the outer peripheral side of the spindle 12, with a wheel 7 attached to the outer peripheral side and containing lubricating oil L inside, a speed reduction mechanism 21 that reduces the rotation of the rotating shaft 14 and transmits it to the wheel mounting case 16, a retainer 42 having a bearing fitting hole 42A and provided on the inner peripheral side of the spindle 12, positioned between the travel motor 13 and the speed reduction mechanism 21, In the traveling device 11, which is provided with a bearing 44 inserted into a bearing fitting hole 42A of a retainer 42 and supporting the rotating shaft 14 rotatably relative to the spindle 12, the surface of the retainer 42 facing the traveling motor 13 (one side 42B) is provided with an annular flange portion 42D that protrudes radially inward from the bearing fitting hole 42A and abuts the bearing 44, and the surface of the retainer 42 facing the reduction mechanism 21 (the other side 42E) is provided with an oil reservoir plate 47 that faces the flange portion 42D in the axial direction and forms an oil reservoir portion 49 for lubricating oil L together with the flange portion 42D and the inner surface 42C of the bearing fitting hole 42A.

[0058] According to this configuration, the lubricating oil L supplied to the bearing 44 that supports the rotating shaft 14 can be stored in the oil reservoir 49. As a result, the lubricating oil L stored in the oil reservoir 49 can be supplied sufficiently to the bearing 44 at all times, regardless of the traveling state of the dump truck 1. As a result, the rotating shaft 14 can be rotated smoothly at all times, which allows the traveling device 11 to operate stably for a long period of time and improves its reliability.

[0059] In this embodiment, the oil reservoir plate 27 has a mounting portion 47A attached to the retainer 42 below the center of the bearing fitting hole 42A, and a wall portion 47B that rises above the mounting portion 47A and faces the raised flange 42D in the axial direction, with the upper edge 47C of the wall portion 47B being positioned lower than the lowermost portion 42J of the inner peripheral edge 42H of the flange 42D. With this configuration, even if the lubricating oil L stored in the oil reservoir 49 exceeds the volume of the oil reservoir 49, the lubricating oil L is prevented from overflowing the flange 42D of the retainer 42 and overflowing toward the travel motor 13, thereby protecting the travel motor 13.

[0060] Next, Fig. 6 shows a second embodiment of the present invention. The feature of this embodiment is that an extension portion is provided between the mounting portion and the wall portion of the oil sump plate. In this embodiment, the same components as those in the first embodiment are given the same reference numerals, and their description will be omitted.

[0061] In the drawings, the oil sump plate 51 is attached to the other side surface 42E of the retainer 42, which is located on the side of the reduction gear mechanism 21. The oil sump plate 51 has an attachment portion 51A and a wall portion 51B, similar to the oil sump plate 47 according to the first embodiment. However, the oil sump plate 51 differs from the oil sump plate 47 according to the first embodiment in that an extension portion 51C is provided between the attachment portion 51A and the wall portion 51B.

[0062] The mounting portion 51A of the oil sump plate 51 is attached to the other side surface 42E of the retainer 42 using bolts 48 below the center of the bearing fitting hole 42. The extension portion 51C of the oil sump plate 51 protrudes from the mounting portion 51A toward the reduction gear mechanism 21 and extends in the axial direction toward the reduction gear mechanism 21. The wall portion 51B of the oil sump plate 51 rises upward from the protruding end of the extension portion 51C and faces the flange portion 42D of the retainer 42 in the axial direction. The upper edge 51D of the wall portion 51B protrudes above the lowermost portion 42G of the inner circumferential surface 42C of the bearing fitting hole 42A formed in the retainer 42 and is located at a position lower than the lowermost portion 42J of the inner circumferential edge 42H of the flange 42D.

[0063] As a result, oil reservoir plate 51, together with inner circumferential surface 42C of bearing fitting hole 42A of retainer 42 and flange portion 42D, forms oil reservoir portion 52 that stores lubricating oil L. In this case, oil reservoir plate 51 is provided with expansion portion 51C extending in the axial direction between mounting portion 51A and wall portion 51B, so the volume of oil reservoir portion 52 can be expanded by the amount of expansion portion 51C.

[0064] The traveling device according to the second embodiment has the oil reservoir plate 51 as described above, and its basic operation is not particularly different from that of the traveling device 11 according to the first embodiment. However, the oil reservoir plate 51 according to this embodiment is provided with an expansion portion 51C extending in the axial direction between the mounting portion 51A and the wall portion 51B, thereby expanding the volume of the oil reservoir 52 formed together with the inner circumferential surface 42C of the bearing fitting hole 42A and the flange portion 42D. As a result, the amount of lubricating oil L stored in the oil reservoir 52 can be increased, and the bearing 44 can be properly lubricated for a long period of time.

[0065] As described above, in the second embodiment, an extension portion 51C is provided between the mounting portion 51A and the wall portion 51B of the oil reservoir plate 51, extending in the axial direction from the mounting portion 51A toward the reduction gear mechanism 21 and expanding the oil reservoir portion 52. With this configuration, the amount of lubricating oil L stored in the oil reservoir portion 52 increases by the amount of the extension portion 51C provided, so that the bearing 44 can be properly lubricated for a long period of time.

[0066] 7 and 8 show a third embodiment of the present invention. This embodiment is characterized in that the oil sump plate is composed of an annular mounting portion attached to the retainer and an annular wall portion extending radially inward from the annular mounting portion. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and their description will be omitted.

[0067] In the drawing, the oil sump plate 61 is attached to the other side 42E of the retainer 42, which is located on the reduction gear mechanism 21 side. The oil sump plate 61 is made of an annular plate as a whole and has a flat annular mounting portion 61A located on the outer periphery and a tapered annular wall portion 61B that protrudes radially inward from the inner periphery of the annular mounting portion 61A. The inner periphery of the annular wall portion 61B forms a circular shaft insertion hole 61C, through which the rotating shaft 14 is inserted. The annular mounting portion 61A is attached to the other side 42E of the retainer 42 using bolts 48. The center of the oil sump plate 61 coincides with the center of the rotating shaft 14, and the annular wall portion 61B of the oil sump plate 61 faces the flange portion 42D of the retainer 42 along the entire circumference.

[0068] An inner peripheral edge 61D of the annular wall portion 61B is positioned radially inward of an inner peripheral surface 42C of a bearing fitting hole 42A formed in the retainer 42, and is positioned radially outward of an inner peripheral edge 42H of the flange portion 42D. As a result, the oil reservoir plate 61, together with the inner peripheral surface 42C of the bearing fitting hole 42A of the retainer 42 and the flange portion 42D, forms an oil reservoir portion 62 that stores lubricating oil L.

[0069] The annular wall portion 61B of the oil reservoir plate 61 tapers from the other side surface 42E of the retainer 42 toward the reduction gear mechanism 21 while gradually reducing in diameter toward the rotating shaft 14. Here, assuming that the axial center line of the rotating shaft 14 is AA, the angle θ between the tapered annular wall portion 61B and the axial center line AA of the rotating shaft 14 is set within a range greater than 0 and less than 90° (0<θ<90°). Thus, the tapered annular wall portion 61B covers the entire periphery of the bearing 44 of the rotating shaft 14 from the outer periphery. As a result, lubricating oil L splashed from the rotating shaft 14, sleeve 43, stopper 46, etc. during rotation of the rotating shaft 14 is received by the annular wall portion 61B and then smoothly guided along the tapered annular wall portion 61B to the oil reservoir portion 62.

[0070] The traveling device according to the third embodiment includes the oil sump plate 61 as described above, and its basic operation is not significantly different from that of the traveling device 11 according to the first embodiment. The oil sump plate 61 according to this embodiment includes a flat, annular mounting portion 61A attached to the other side surface 42E of the retainer 42 and an annular wall portion 61B extending radially inward from the inner periphery of the annular mounting portion 61A. The annular wall portion 61B tapers toward the reduction gear mechanism 21 while gradually reducing in diameter toward the rotating shaft 14. The angle θ between the annular wall portion 61B and the axial center line AA of the rotating shaft 14 is set within the range of 0<θ<90°. This allows the tapered annular wall portion 61B to collect lubricating oil L scattered from the rotating shaft 14, sleeve 43, stopper 46, etc., and efficiently store it in the oil sump 62. As a result, the rotating shaft 14 can be rotated smoothly at all times, and the traveling device 11 can be operated stably for a long period of time.

[0071] As described above, in the third embodiment, the oil reservoir plate 61 is composed of an annular mounting portion 61A attached to the retainer 42, and an annular wall portion 61B that projects radially inward from the annular mounting portion 61A and faces the entire circumference of the flange portion 42D of the retainer 42. With this configuration, the periphery of the bearing 44 of the rotating shaft 14 can be covered from the outer periphery by the tapered annular wall portion 61B, and lubricating oil L that has scattered from the periphery of the bearing 44 of the rotating shaft 14 can be received by the annular wall portion 61B and then guided to the oil reservoir portion 62 along the slope of the annular wall portion 61B.

[0072] In the third embodiment, the angle θ between the annular wall portion 61B of the oil reservoir plate 61 and the axial center line AA of the rotating shaft 14 is set in the range of 0<θ<90°. With this configuration, the lubricating oil L scattered around the bearing 44 of the rotating shaft 14 can be collected by the tapered annular wall portion 61B and efficiently stored in the oil reservoir 62.

[0073] Next, Fig. 9 shows a fourth embodiment of the present invention. This embodiment is characterized in that a cylindrical sleeve, the outer periphery of which serves as a bearing fitting portion, is attached to the rotating shaft, and an annular sleeve-side flange is provided on the surface of the sleeve facing the drive source, projecting radially outward from the bearing fitting portion. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and their description will be omitted.

[0074] In the drawings, sleeve 71 is provided on rotating shaft 14 at a position corresponding to bearing fitting hole 42A of retainer 42. Like sleeve 43 according to the first embodiment, sleeve 71 is made of a stepped cylindrical body having a shaft mounting hole 71A, and the outer circumferential surface of sleeve 71 has a large-diameter outer circumferential surface 71B as a bearing fitting portion and a small-diameter outer circumferential surface 71C that is smaller in diameter than large-diameter outer circumferential surface 71B. However, it differs from sleeve 43 according to the first embodiment in that a sleeve-side flange 71E, which will be described later, is provided on one axial side of sleeve 71 (the traveling motor 13 side).

[0075] The sleeve 71 has a large-diameter outer peripheral surface 71B as a bearing fitting portion into which the inner ring 44B of the bearing 44 fits, and an annular sleeve-side flange 71E that protrudes radially outward from the large-diameter outer peripheral surface 71B is provided on one side surface 71D that is one axial side (travel motor 13 side) of the sleeve 71. The outer diameter of the sleeve-side flange 71E is set to be larger than the outer diameter of the inner ring 44B that constitutes the bearing 44 and smaller than the inner diameter of the outer ring 44A. The inner ring 44B of the bearing 44 is positioned in the axial direction by abutting against the sleeve-side flange 71E and a stopper 46 that is fitted onto the small-diameter outer peripheral surface 71C of the sleeve 71. In this state, the outer peripheral edge of the sleeve side flange 71E faces the inner peripheral edge of the flange 42D provided on the retainer 42 with a small annular gap, and the sleeve side flange 71E, together with the flange 42D of the retainer 42, covers the bearing 44 from the side of the driving motor 13.

[0076] The traveling device according to the fourth embodiment has the sleeve 71 as described above, and its basic operation is not particularly different from that of the traveling device 11 according to the first embodiment. However, in this embodiment, the outer peripheral edge of a sleeve-side flange 71E provided on the sleeve 71 faces the inner peripheral edge of a flange 42D provided on the retainer 42 with a small annular gap therebetween, and the sleeve-side flange 71E, together with the flange 42D of the retainer 42, covers the bearing 44 from the traveling motor 13 side. As a result, even if the lubricating oil L stored in the oil reservoir 49 exceeds the capacity of the oil reservoir 49, the flange 42D of the retainer 42 and the sleeve-side flange 71E of the sleeve 71 can reliably prevent the lubricating oil L from overflowing onto the traveling motor 13 side, thereby protecting the traveling motor 13.

[0077] As described above, in the fourth embodiment, a cylindrical sleeve 71 having a large-diameter outer peripheral surface 71B on its outer periphery is attached to the rotating shaft 14, the bearing 14 is inserted into the bearing fitting hole 42A of the retainer 42 via the sleeve 71, and the surface of the sleeve 71 facing the travel motor 13 is provided with a sleeve-side flange 71E that protrudes radially outward from the large-diameter outer peripheral surface 71B and, together with the flange 42D of the retainer 42, covers the bearing 14 from the travel motor 13 side. With this configuration, if the lubricating oil L stored in the oil reservoir 49 exceeds the capacity of the oil reservoir 49, the flange 42D of the retainer 42 and the sleeve-side flange 71E of the sleeve 71 can prevent the lubricating oil L from overflowing onto the travel motor 13 side.

[0078] In the embodiment, the lubricating oil L supplied from a circulation circuit including the suction pipe 38, the lubricating oil pump 39, the supply pipe 40, etc., and the mist-like lubricating oil L splashed up by the reduction mechanism 21 are used to lubricate the rotating shaft 14, the roller bearings 17 and 18, the reduction mechanism 21, the bearing 44, etc. However, the present invention is not limited to this, and a configuration may be used in which only one of the lubricating oil L supplied from the circulation circuit and the mist-like lubricating oil L splashed up by the reduction mechanism 21 is used, for example.

[0079] In the first embodiment, the oil sump plate 27 is formed in a crescent shape. However, the present invention is not limited to this, and oil sump plates having various shapes, such as a rectangular shape, may be used.

[0080] Furthermore, in the embodiment, the description has been given taking the rear-wheel drive dump truck 1 as an example, but the present invention is not limited to this and may be applied to, 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. [Explanation of symbols]

[0081] 1 dump truck 2. Body 7 Rear wheel (wheel) 12 spindles 13. Travel motor (drive source) 14 Rotation axis 16 Wheel mounting tube 21 Reduction mechanism 42 Retainer 42A Bearing fitting hole 42C Inner surface 42D Tsubabe 44 Bearings 47, 51, 61 Oil sump plate 47A, 51A mounting part 47B,51B wall part 51C Extension 61A Annular mounting part 61B Annular wall 49, 52, 62 Oil reservoir 71 Sleeve 71B Large diameter outer surface (bearing fitting part) 71E Sleeve side flange

Claims

1. a cylindrical spindle fixed to a body of a wheeled vehicle and having a small-diameter cylindrical portion with an open tip; a rotating shaft that extends axially from the inner peripheral side of the spindle, has a tip that protrudes from the open end of the small-diameter cylindrical portion of the spindle, has a sun gear attached to the tip, and is rotated by a drive source; a wheel mounting sleeve rotatably provided on the outer periphery of the spindle, having a wheel mounted on the outer periphery and containing lubricating oil therein; a reduction mechanism including the sun gear that reduces the rotation of the rotary shaft and transmits the reduced rotation to the wheel mounting case; a retainer having a bearing fitting hole, the retainer being located between the drive source and the reduction mechanism and provided on the inner peripheral side of the small diameter cylindrical portion of the spindle; a bearing that is inserted into the bearing fitting hole of the retainer and supports an axially intermediate portion of the rotary shaft rotatably relative to the spindle; an annular stopper fitted to the rotating shaft and abutting against the reduction mechanism side of the bearing to position the bearing in the axial direction of the rotating shaft, the retainer has, on a surface facing the drive source, an annular flange portion that protrudes radially inward from the bearing fitting hole and abuts against the bearing, an oil reservoir plate that forms an oil reservoir for lubricating oil together with the flange and an inner peripheral surface of the bearing fitting hole is provided at a position axially opposite the flange via the bearing on the reduction mechanism side of the retainer, the oil sump plate is configured with an annular mounting portion attached to the retainer, and an annular wall portion that projects radially inward from the annular mounting portion and faces the flange portion of the retainer over the entire circumference, an angle θ between the annular wall portion and an axial center line of the rotation shaft is set in a range of 0<θ<90°; A running device for a wheeled vehicle, characterized in that the radially inner edge of the annular wall portion approximately coincides with the end face of the stopper on the side of the reduction mechanism in the axial direction of the rotation shaft.

2. A cylindrical sleeve having a bearing fitting portion on its outer periphery is attached to the rotating shaft, the bearing is inserted into the bearing fitting hole of the retainer via the sleeve, The running device for a wheeled vehicle as described in claim 1, characterized in that a sleeve side flange portion is provided on the surface of the sleeve facing the drive source, which protrudes radially outward from the bearing fitting portion and, together with the flange portion of the retainer, covers the bearing from the drive source side.

3. a lubricating oil pump that sucks in and discharges lubricating oil from within the wheel mounting case; 2. The traveling device for a wheeled vehicle according to claim 1, further comprising: a supply pipe for guiding the lubricating oil discharged from the lubricating oil pump to an upper portion of the retainer.

4. 4. The traveling device for a wheeled vehicle according to claim 3, wherein the retainer has an oil passage for guiding the lubricating oil supplied from the supply pipe to the bearing.

Images