JP2015025489A - Dump truck traveling drive assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable lubricant oil to be supplied to a first stage planetary gear reduction mechanism positioned at a more axial outer location of a second stage planetary gear reduction mechanism and a cooling performance of an entire device to be improved.SOLUTION: A cylindrical connecting part 38A of a final stage carrier 38 held under non-rotated state by a spindle 14 is formed with an oil storage tank 53 at a location lower than a rotating shaft 17. The oil storage tank 53 stores lubricant oil supplied in a direction of an arrow A from the extremity end part 47A of a supplying pipe 47 at the lower side. The lubricant oil flows out in a direction of arrow B toward axial outer side along the inner circumferential surface of a second stage sun gear 34. As a result, it is possible to supply lubricant oil to a first stage planetary gear reduction mechanism 25 placed at a position spaced apart from an opening end of the spindle 14 (in particular, a planetary bearing 28A arranged between the first stage planetary gear 28 and a supporting pin 29).

Description

  The present invention relates to a traveling drive device for a dump truck that is preferably used for transporting crushed stones mined in, for example, an open-pit mine, a quarry, and a mine.

  In general, a large transport vehicle called a dump truck has a loading platform that can be raised and lowered on a frame of a vehicle body, and transports a heavy load represented by a crushed stone in a large amount loaded on this loading platform.

  Therefore, a travel drive device that travels and drives the drive wheels of a dump truck includes an axle housing having a cylindrical spindle that is attached to a vehicle body in a non-rotating state, and an electric motor that extends in the spindle in the axial direction. A rotating shaft that is rotationally driven by a driving source such as a wheel, a wheel mounting cylinder that is rotatably provided on a front end side outer periphery of the spindle via a bearing, and on which a dump truck wheel is mounted; the rotating shaft and the wheel mounting cylinder; And a planetary gear reduction mechanism having a total of two stages, which is provided via the spindle and transmits the rotation of the rotary shaft to the wheel mounting cylinder at a reduced speed (see, for example, Patent Documents 1, 2, and 3). ).

  Here, the first stage planetary gear speed reduction mechanism is arranged on the outer side in the axial direction of the spindle than the second stage planetary gear speed reduction mechanism as the final stage, and supports the second stage planetary gear rotatably. The carrier at the stage is connected to the inside of the open end of the spindle in a non-rotating state. On the other hand, inside the spindle, there is provided a lubricating oil supply pipe that extends in the axial direction along the rotating shaft and supplies lubricating oil toward each planetary gear reduction mechanism. Lubricating oil stored in the wheel mounting cylinder is sucked up by a lubricating pump and cooled by an oil cooler. The lubricating oil supply pipe is configured to supply the lubricating oil discharged from the lubricating pump and cooled by the oil cooler so as to circulate into the spindle.

WO2009 / 016684 Publication JP 2010-19413 A US2004 / 0065169

  By the way, the above-described dump truck traveling drive device according to the prior art cannot always supply lubricating oil to the first stage planetary gear reduction mechanism at a sufficiently low temperature. In particular, there is a problem that it is difficult to supply low temperature lubricating oil to the planetary bearing between the first stage planetary gear and the support pin.

  In other words, the lubricating oil supply pipe only supplies lubricating oil toward the carrier of the second stage planetary gear speed reduction mechanism inside the spindle. On the other hand, the first-stage planetary gear reduction mechanism is disposed on the outer side in the axial direction of the spindle than the second-stage planetary gear reduction mechanism. Therefore, the lubricating oil is supplied to the first stage planetary gear reduction mechanism after passing through the second stage planetary gear reduction mechanism, and the temperature of the first stage planetary gear reduction mechanism is relatively low. High lubricating oil will be supplied.

  In addition, since the planetary gear speed reduction mechanism at the first stage has a higher rotation speed of the sun gear and the planetary gear than the planetary gear speed reduction mechanism at the second stage, there is a high possibility that the first stage planetary gear speed reduction mechanism generates heat early when the dump truck is driven. Therefore, there is a demand for a configuration that can effectively supply low-temperature lubricating oil to such a first stage planetary gear reduction mechanism.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to effectively supply lubricating oil to the planetary gear reduction mechanism in the preceding stage rather than the planetary gear reduction mechanism in the final stage, An object of the present invention is to provide a dump truck travel drive device capable of improving the cooling and lubrication performance of the entire device.

  In order to solve the above-described problem, the present invention provides an axle housing that is provided in a non-rotating state on the body of a dump truck and that has a cylindrical spindle at the front end side, and a drive source provided in the axle housing. An axially extending portion in the spindle is provided, a proximal end is connected to the drive source in the axle housing, a distal end protrudes from the open end of the spindle, and a wheel side bearing is provided on the outer peripheral side of the spindle. A wheel mounting cylinder rotatably provided through which the wheel is mounted, and a rotation of the rotation shaft with respect to the wheel mounting cylinder provided via the spindle between the protruding end side of the rotation shaft and the wheel mounting cylinder. A multi-stage planetary gear speed reduction mechanism that transmits the reduced speed and the spindle and the rotation shaft. A plurality of planetary gear speed reduction mechanisms, wherein the first stage planetary gear speed reduction mechanism is disposed at a position far from the drive source, and the last stage planetary gear speed reduction mechanism is provided. Is arranged near the opening end of the spindle close to the drive source, and the last stage carrier that rotatably supports the last stage planetary gear enters the inside of the opening end of the spindle. A cylindrical connecting portion connected to the inner peripheral surface of the spindle in a non-rotating state; the rotating shaft is inserted in the axial direction on the inner peripheral side of the cylindrical connecting portion; And is applied to a traveling drive device for a dump truck in which lubricating oil is supplied from the lubricating oil supply pipe to the planetary gear reduction mechanism at the final stage through the cylindrical connecting portion.

  A feature of the configuration adopted by the invention of claim 1 is that the cylindrical connecting portion of the carrier at the final stage is provided with an oil storage tank for storing the lubricating oil supplied from the lubricating oil supply pipe. There is.

  According to invention of Claim 2, the said oil storage tank is located in the inner peripheral surface of the cylindrical connection part of the said carrier, and the axial direction one side of the said cylindrical connection part located in the said spindle. A partition wall and a second partition wall provided on the other axial side of the cylindrical coupling portion so as to face the first partition wall in the axial direction, the first partition wall, The dam height of the lubricating oil accumulated in the cylindrical connecting portion is set higher than the dam height of the second partition wall portion.

  According to a third aspect of the present invention, the first and second partition walls each have an inner diameter hole through which the rotation shaft is inserted with a gap, and the first partition wall is more than the second partition wall. Also, the diameter of the inner diameter hole is made small.

  According to the invention of claim 4, the planetary gear speed reduction mechanism at the final stage is disposed on the outer peripheral side of the protruding end of the rotating shaft so as to be relatively rotatable, and the sun gear to which the rotation reduced by the planetary gear speed reduction mechanism at the previous stage is transmitted. A plurality of planetary gears that mesh with the sun gear and transmit reduced rotation to the wheel mounting cylinder, and each planetary gear is rotatably supported via a support pin, and the cylindrical connecting portion is the spindle. The oil tank is fixedly attached to the inner peripheral surface of the cylindrical connecting portion of the carrier and on one side in the axial direction of the cylindrical connecting portion located in the spindle. The second partition wall portion is configured by a first partition wall portion provided and a second partition wall portion that is opposed to the sun gear in the axial direction and is provided on the other axial side of the cylindrical coupling portion. Is ejected from the meshing portion between the sun gear and each planetary gear. And the lubricating oil in the structure that forms the guide surface for guiding between the respective support pin and the planetary gears.

  According to the invention of claim 5, on the inner diameter side of the second partition wall portion, the lubricating oil in the oil storage tank inserted through the inner peripheral surface of the sun gear is led out toward the inner peripheral surface of the sun gear. The lead tube portion is provided.

  According to the first aspect of the present invention, the final stage carrier connected to the inner peripheral surface in the non-rotating state on the opening end side of the spindle is supplied from the lubricating oil supply pipe located inside the cylindrical connecting portion. An oil storage tank for storing lubricating oil is formed. Here, the lubricating oil sequentially supplied from the lubricating oil supply pipe overflows as overflow oil when the oil storage tank is full. This overflow oil flows outward in the axial direction along the inner peripheral surface of the sun gear constituting the final stage planetary gear reduction mechanism. As a result, the first stage planetary gear reduction mechanism (for example, the first stage planetary gear) is located farther away from the drive source than the final stage planetary gear reduction mechanism and is positioned axially outward from the opening end of the spindle. The overflow oil can be supplied as a low-temperature lubricating oil to a planetary bearing provided between the gear and the support pin.

  According to invention of Claim 2, the oil storage tank of lubricating oil can be comprised with the internal peripheral surface of a cylindrical connection part, and a 1st, 2nd partition part. The first partition provided in the spindle on one side in the axial direction of the cylindrical connecting part is more lubricating oil than the second partition provided on the other side in the axial direction of the cylindrical connecting part. The height of the weir is formed high. For this reason, it is possible to prevent the lubricating oil stored in the oil storage tank from overflowing from the second partition wall side having a low weir height and overflowing from the first partition wall side. . As a result, the overflow oil can be led out to the outside in the axial direction along the inner peripheral surface of the sun gear at the final stage.

  According to invention of Claim 3, the 1st partition part is formed so that the hole diameter of the internal diameter hole in which a rotating shaft is penetrated is smaller than the 2nd partition part. For this reason, the weir height of the lubricating oil stored in the oil storage tank is determined by the hole diameter of each inner diameter hole, and the hole diameter of the first partition wall portion having the smaller inner diameter hole diameter is The large second partition wall portion can reduce the dam height of the lubricating oil. As a result, the lubricating oil stored in the oil storage tank does not overflow from the first partition wall side, but overflows from the second partition wall side as overflow oil. It can be led out in the axial direction along the inner peripheral surface of the gear.

  In the invention of claim 4, the second partition wall portion can be disposed at a position facing the final stage sun gear in the axial direction. As a result, even when the last stage planetary gear and the sun gear mesh with each other and rotate, even if the lubricating oil is ejected from the meshing surfaces of the two gears, the ejected oil is axially inside (that is, inside the cylindrical coupling portion of the carrier). ) Can be prevented by the second partition wall. Moreover, the second partition wall portion can form a guide surface for guiding the ejected oil between the planetary gears and the support pins. That is, the jetted oil is guided between the planetary gears and the support pins by colliding with and reflected by the second partition wall. For this reason, the said jetting oil can be supplied as a lubricating oil with respect to the planetary bearing provided between each planetary gear of the last stage and each support pin.

  According to the invention of claim 5, the lead-out cylinder part inserted through the inner peripheral surface of the sun gear at the final stage is provided on the inner diameter side of the second partition wall part. For this reason, the lead-out cylinder part guides the overflow oil (that is, the lubricating oil in the oil storage tank) overflowing from the second partition part to the outer side in the axial direction toward the inner peripheral surface of the sun gear. Can do. As a result, the first stage planetary gear reduction mechanism (for example, the first stage planetary gear and the support pin is located at a position farther away from the opening end of the spindle than the final stage planetary gear reduction mechanism (the outer position in the axial direction). The overflow oil can be supplied as lubricating oil to a planetary bearing provided therebetween.

1 is an overall view showing a dump truck to which a traveling drive device according to a first embodiment of the present invention is applied. It is sectional drawing which expanded the traveling drive apparatus by the side of a rear wheel from the arrow II-II direction in FIG. It is sectional drawing which expands and shows the oil storage tank in FIG. 2, a 2nd step | paragraph sun gear, a planetary gear, a support pin, and a carrier. It is a disassembled perspective view which shows the 1st partition part and 2nd partition part which comprise an oil storage tank. It is sectional drawing which expands and shows the oil storage tank by 2nd Embodiment, the 2nd step | paragraph sun gear, a planetary gear, a support pin, and a carrier. It is sectional drawing which expands and shows the oil storage tank by 3rd Embodiment, the 2nd step | paragraph sun gear, a planetary gear, a support pin, and a carrier.

  Hereinafter, a dump truck traveling drive apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking a rear-wheel drive type dump truck as an example.

  1 to 4 show a traveling drive device for a dump truck according to a first embodiment of the present invention.

  In the figure, reference numeral 1 denotes a dump truck employed in the first embodiment. As shown in FIG. 1, the dump truck 1 is configured as a large vehicle including a vehicle body 2 having a sturdy frame structure and a cargo bed 3 mounted on the vehicle body 2 so as to be undulated.

  The loading platform 3 is formed as a large container having a total length of 10 to 13 meters in order to load a large amount of heavy luggage represented by crushed stone. The rear bottom portion of the loading platform 3 is connected to the rear end side of the vehicle body 2 via a connecting pin 4 so as to be able to undulate (tilt). On the upper front side of the loading platform 3, a flange 3 </ b> A that covers a cab 5 described later from above is integrally provided.

  The cab 5 is provided on the front side of the vehicle body 2 so as to be located below the flange portion 3A. The cab 5 forms a cab in which a driver of the dump truck 1 gets on and off. Inside the cab 5, a driver's seat, a start switch, an accelerator pedal, a brake pedal, a steering handle, and a plurality of operation levers (all not shown) are provided. The heel part 3A of the loading platform 3 covers the cab 5 almost completely from the upper side, thereby protecting the cab 5 from flying stones such as rocks and protecting the driver in the cab 5 even when the vehicle (dump truck 1) falls. It has a function to do.

  The left and right front wheels 6 are rotatably provided on the front side of the vehicle body 2. The left and right front wheels 6 constitute steering wheels that are steered by the driver of the dump truck 1. Like the rear wheel 7 described later, the front wheel 6 is formed with a tire diameter (that is, an outer diameter dimension) of, for example, 2 to 4 meters. Between the front part of the vehicle body 2 and the front wheel 6, a front wheel side suspension 6SP made of a hydraulic shock absorber is provided.

  The left and right rear wheels 7 are rotatably provided on the rear side of the vehicle body 2. The left and right rear wheels 7 constitute drive wheels of the dump truck 1 and are rotationally driven integrally with the wheel mounting cylinder 18 by a travel drive device 11 described later shown in FIG. The rear wheel 7 includes an inner tire 7A and an outer tire 7A made of a double-wheel tire, and a rim 7B disposed on the radially inner side of each tire 7A. Between the rear part of the vehicle body 2 and the rear wheel 7, a rear wheel side suspension 7SP made of a hydraulic shock absorber is provided.

  The engine 8 is provided in the vehicle body 2 at the lower side of the cab 5. The engine 8 is constituted by, for example, a large diesel engine, and rotationally drives a vehicle-mounted generator and a hydraulic pump (none of which is shown) serving as a hydraulic source. Pressure oil discharged from the hydraulic pump is supplied to a hoist cylinder 9 described later, a steering cylinder (not shown) for power steering, and the like.

  The hoist cylinder 9 is a pair of cylinder devices for raising and lowering the loading platform 3. As shown in FIG. 1, the hoist cylinder 9 is located between the front wheel 6 and the rear wheel 7 and is disposed on both the left and right sides of the vehicle body 2. The hoist cylinder 9 is attached between the vehicle body 2 and the loading platform 3 so as to be extendable in the upward and downward directions. That is, the hoist cylinder 9 expands and contracts in the upward and downward directions when the pressure oil from the hydraulic pump is supplied and discharged, and raises (tilts) the loading platform 3 around the connecting pin 4 on the rear side. is there.

  As shown in FIG. 1, the hydraulic oil tank 10 is located below the loading platform 3 and attached to the side surface of the vehicle body 2 or the like. The hydraulic oil stored in the hydraulic oil tank 10 is discharged while being sucked in by the hydraulic pump, and is supplied to and discharged from the hoist cylinder 9 and the steering cylinder for power steering as pressure oil.

  Next, the traveling drive device 11 that is provided on the rear wheel 7 side of the dump truck 1 and is the main part of the first embodiment will be described.

  The travel drive device 11 includes an axle housing 12, a travel motor 16, a wheel mounting cylinder 18, and a reduction gear mechanism 24, which will be described later. The travel drive device 11 decelerates the rotation of the travel motor 16 by the reduction gear mechanism 24 and travels and drives the rear wheel 7 as a drive wheel of the vehicle together with the wheel mounting cylinder 18 with a large rotational torque.

  Reference numeral 12 denotes an axle housing for the rear wheel 7 provided in a non-rotating state on the rear side of the vehicle body 2. The axle housing 12 is formed as a cylindrical body that extends between the left and right rear wheels 7 and 7 in the axial direction. The axle housing 12 is formed as a cylindrical body extending in the vehicle width direction (left and right directions), and is attached to the rear side of the vehicle body 2 via the respective rear wheel side suspensions 7SP, and the suspension cylinder 13 The spindle 14 is provided on each of the left and right sides.

  Here, the spindles 14 are formed as cylindrical bodies, and are respectively provided on both ends of the axle housing 12 in the axial direction. As shown in FIG. 2, the spindle 14 has a large-diameter cylindrical portion 14 </ b> A that is positioned on one side in the axial direction and has a tapered shape and is detachably fixed to the suspension cylinder 13 via a bolt 15. It is comprised by the circular cylinder part 14B integrally formed by the axial direction other side of 14A. The circular cylinder portion 14B is disposed so as to extend in the axial direction in a wheel mounting cylinder 18 which will be described later. The outer peripheral side of the circular cylinder portion 14B is to rotatably support the wheel mounting cylinder 18 on the rear wheel 7 side through wheel support bearings 20 and 21 described later.

  On the other hand, on the outer peripheral side of the spindle 14, an annular flange portion 14 </ b> C that protrudes radially outward from an intermediate portion in the length direction (axial direction) of the large-diameter cylindrical portion 14 </ b> A and a wet brake 40 described later is attached, and a retainer 42 described later. Is formed integrally with an annular step portion 14D provided on one side in the axial direction of the circular cylindrical portion 14B. A plurality of motor mounting seats 14E protruding inward in the radial direction are integrally formed on one side in the axial direction of the large-diameter cylindrical portion 14A, and a traveling motor 16 described later is mounted on the motor mounting seat 14E. .

  Further, the other axial side (front end side) of the circular cylindrical portion 14B is an open end, and a cylindrical connecting portion 38A of a carrier 38, which will be described later, is splined to the inner peripheral surface thereof. An annular inner protrusion 14F is integrally formed on the inner peripheral side of the intermediate portion in the axial direction of the circular cylindrical portion 14B. An outer retainer 51 described later is attached to the inner protrusion 14F via a bolt or the like. On the lower side of the circular cylindrical portion 14B, a radial hole 14G extending in the upward and downward direction (the radial direction of the circular cylindrical portion 14B) is formed, and a suction pipe to be described later is placed in the radial hole 14G. 46 suction parts 46A are inserted.

  The traveling motor 16 is used as a drive source for the rear wheels 7. The traveling motor 16 is detachably provided in the axle housing 12. The traveling motor 16 is constituted by a large electric motor that is rotationally driven by power supply from a generator (not shown) mounted on the vehicle body 2. The traveling motor 16 is mounted on the left and right sides of the suspension cylinder 13 in the spindle 14 so as to rotate the left and right rear wheels 7 and 7 independently of each other.

  The traveling motor 16 has a plurality of mounting flanges 16A on its outer peripheral side, and these mounting flanges 16A are detachably mounted on the motor mounting seat 14E of the spindle 14 using bolts. The traveling motor 16 is configured to rotationally drive a rotating shaft 17 described later when electric power is supplied from the generator.

  The rotating shaft 17 constitutes an output shaft of the traveling motor 16. The rotating shaft 17 is rotationally driven in the forward direction or the reverse direction by the traveling motor 16. The rotating shaft 17 is constituted by one long rod-like body extending in the axial direction (left and right directions) on the inner peripheral side of the spindle 14, and the base end side which is one end of the rotating shaft 17 is the driving motor 16. It is connected to the output side. On the other hand, the distal end side that is the other end of the rotating shaft 17 protrudes outward in the axial direction from the open end of the circular cylindrical portion 14 </ b> B constituting the spindle 14. A sun gear 26, which will be described later, is provided on the protruding end side of the rotating shaft 17 so as to rotate integrally.

  An intermediate portion in the axial direction of the rotary shaft 17 is rotatably supported in a circular cylindrical portion 14B of the spindle 14 using a shaft bearing 52 described later. An intermediate portion in the axial direction of the rotating shaft 17 (that is, the mounting position of the shaft bearing 52) is relative to the wheel support bearings 20 and 21 (described later) that rotatably support the wheel mounting cylinder 18 on the outer peripheral side of the spindle 14. It is arranged at an axial position between them.

  Reference numeral 18 denotes a wheel mounting cylinder that rotates integrally with the rear wheel 7 as a wheel. The wheel mounting cylinder 18 constitutes a so-called wheel hub, and each rim 7B of the rear wheel 7 is detachably mounted on the outer peripheral side thereof using means such as press fitting. The wheel mounting cylinder 18 extends in the axial direction between wheel support bearings 20 and 21, which will be described later, and has a hollow cylinder portion 18A having a hollow structure, and from the outer peripheral side end portion of the hollow cylinder portion 18A toward an inner gear 35 which will be described later. It is formed as a stepped cylindrical body by the extending cylindrical portion 18B extending integrally on the other side in the axial direction (that is, the outer side in the axial direction).

  An internal gear 35 and an outer drum 22 which will be described later are integrally fixed to the extending cylinder portion 18 </ b> B of the wheel mounting cylinder 18 using a long bolt 23. Thereby, the wheel mounting cylinder 18 is rotated integrally with the internal gear 35. That is, the rotation of the traveling motor 16 is decelerated by the reduction gear mechanism 24. For this reason, the rotation with large torque is transmitted to the wheel mounting cylinder 18 via the internal gear 35. Thereby, the wheel mounting cylinder 18 rotates the rear wheel 7 which becomes a driving wheel of the vehicle with a large rotational torque.

  The rim spacer 19 is formed by a cylindrical ring. The rim spacer 19 is disposed on the outer peripheral side of the wheel mounting cylinder 18 in order to ensure a predetermined axial clearance between the inner tire 7A and the outer tire 7A of the rear wheel 7. That is, as shown in FIG. 2, the rim spacer 19 is sandwiched between the rim 7B (that is, the inner rim 7B) on the inner side in the axial direction of the rear wheel 7 and the outer rim 7B (that is, the outer rim 7B). 7B is held at a constant interval in the axial direction.

  The wheel support bearings 20 and 21 are bearings that rotatably support the wheel mounting cylinder 18 on the outer peripheral side of the spindle 14. These wheel support bearings 20 and 21 are configured using, for example, tapered roller bearings. The wheel support bearings 20 and 21 are disposed apart from each other in the axial direction between the circular cylinder portion 14B of the spindle 14 and the hollow cylinder portion 18A of the wheel mounting cylinder 18. That is, one wheel support bearing 20 is positioned on the stepped portion 14D of the spindle 14 via a retainer 42 described later. The other wheel support bearing 21 is positioned on the outer periphery of the open end side of the circular cylindrical portion 14 </ b> B via another retainer 43.

  The inner ring sides of the wheel support bearings 20 and 21 are respectively positioned in the axial direction between the retainers 42 and 43 with respect to the circular cylindrical portion 14B of the spindle 14. The outer ring side of the wheel support bearings 20 and 21 is positioned in the axial direction with respect to the hollow cylinder portion 18A of the wheel mounting cylinder 18. As a result, the wheel mounting cylinder 18 is positioned in the axial direction with respect to the spindle 14 using the wheel support bearings 20 and 21 and the retainers 42 and 43, and is supported rotatably in the circumferential direction.

  The outer drum 22 constitutes a part of the wheel mounting cylinder 18 together with the inner gear 35. As shown in FIG. 2, the outer drum 22 is attached to a position on the outer side in the axial direction of the wheel mounting cylinder 18 with an internal gear 35 to be described later interposed therebetween, and is attached to the wheel mounting cylinder 18 using a plurality of long bolts 23. It is detachably fixed.

  Next, the reduction gear mechanism 24 provided via the spindle 14 between the protruding end (other end) side of the rotating shaft 17 and the wheel mounting cylinder 18 will be described.

  The reduction gear mechanism 24 reduces and transmits the rotation of the traveling motor 16 (that is, the rotating shaft 17) to the wheel mounting cylinder 18 on the rear wheel 7 side. Thereby, the wheel mounting cylinder 18 on the rear wheel 7 side is rotationally driven together with the rear wheel 7 with a large rotational force (torque) obtained by decelerating. The reduction gear mechanism 24 includes a first stage planetary gear reduction mechanism 25 and a second stage planetary gear reduction mechanism 33.

  Here, the planetary gear speed reduction mechanism 25 in the first stage is disposed at a position far from the traveling motor 16, that is, at the tip position of the rotating shaft 17 (an axial position on the outside). The second stage planetary gear reduction mechanism 33 as the final stage is disposed closer to the travel motor 16 than the first stage planetary gear reduction mechanism 25, that is, a position near the opening end of the spindle 14. In other words, the second stage planetary gear reduction mechanism 33 as the final stage is disposed at a position on the inner side in the axial direction of the wheel mounting cylinder 18 relative to the first stage planetary gear reduction mechanism 25. In other words, the first stage planetary gear speed reduction mechanism 25 is disposed at a position on the outer side in the axial direction of the wheel mounting cylinder 18 relative to the second stage planetary gear speed reduction mechanism 33.

  Reference numeral 25 denotes a first-stage planetary gear reduction mechanism that constitutes the reduction gear mechanism 24, and the planetary gear reduction mechanism 25 is spline-coupled to a protruding end side (an outer end portion in the axial direction) serving as a free end of the rotary shaft 17. A first-stage sun gear 26, a plurality (for example, 3 to 4) of first-stage planetary gears 28 that mesh with the sun gear 26 and a ring-shaped internal gear 27, and the planetary gears 28. The first stage carrier 30 is rotatably supported via a support pin 29. The first stage planetary gear speed reduction mechanism 25 is provided with a planetary bearing 28 </ b> A between each planetary gear 28 and each support pin 29.

  Here, the outer peripheral side of the carrier 30 is detachably fixed to the open end (end surface on the outer side in the axial direction) of the outer drum 22 integrated with the wheel mounting cylinder 18 via bolts. Rotate together with 22. For example, a disc-shaped cover plate 31 is detachably attached to the inner peripheral side of the carrier 30. The cover plate 31 is removed from the carrier 30 when, for example, maintenance and inspection of the meshing portion of the sun gear 26 and the planetary gear 28 is performed.

  The ring-shaped internal gear 27 is formed using a ring gear that surrounds the sun gear 26 and the planetary gears 28 from the outside in the radial direction. The internal gear 27 is disposed on the radially inner side of the outer drum 22 so as to be relatively rotatable, and a small radial gap is formed between the inner peripheral surface of the outer drum 22 and the internal gear 27. The rotation (revolution) of the internal gear 27 is transmitted to the second stage planetary gear speed reduction mechanism 33 via a coupling 32 described later.

  When the sun gear 26 is rotated integrally with the rotary shaft 17 by the traveling motor 16, the first-stage planetary gear speed reduction mechanism 25 converts the rotation of the sun gear 26 into rotation and revolution of each planetary gear 28. . The rotation (rotation) of each planetary gear 28 is transmitted to the ring-shaped internal gear 27 as a reduced rotation. The rotation of the internal gear 27 is transmitted to the second stage planetary gear reduction mechanism 33 via a coupling 32 described later. On the other hand, the revolution of each planetary gear 28 is transmitted to the outer drum 22 on the wheel mounting cylinder 18 side as the rotation of the carrier 30. However, since the wheel mounting cylinder 18 rotates integrally with a second-stage internal gear 35 to be described later, the revolution of each planetary gear 28 is suppressed to the rotation synchronized with the internal gear 35 (the wheel mounting cylinder 18).

  The coupling 32 rotates integrally with the first-stage internal gear 27, and the coupling 32 is positioned between the first-stage planetary gear reduction mechanism 25 and the second-stage planetary gear reduction mechanism 33. It is formed as an annular rotation transmission member. That is, the outer peripheral side of the coupling 32 is splined to the first stage internal gear 27. The inner peripheral side of the coupling 32 is splined to a second stage sun gear 34 described later. As a result, the coupling 32 transmits the rotation of the first-stage internal gear 27 to the second-stage sun gear 34 and rotates the sun gear 34 integrally with the first-stage internal gear 27. The coupling 32 is formed with a plurality of oil circulation holes 32 </ b> A through which lubricating oil 100 described later flows in the front and rear directions (axial direction).

  Reference numeral 33 denotes a second-stage planetary gear reduction mechanism that is the final stage of the reduction gear mechanism 24. The planetary gear speed reduction mechanism 33 is disposed between the rotary shaft 17 and the wheel mounting cylinder 18 via the first stage planetary gear speed reduction mechanism 25 and together with the first stage planetary gear speed reduction mechanism 25, The rotation is decelerated. The planetary gear speed reduction mechanism 33 at the second stage (final stage) is arranged coaxially with the rotary shaft 17 and rotates integrally with the coupling 32, and the sun gear 34 and the ring-shaped internal gear 35. And a plurality of planetary gears 36 (only one is shown), and a second-stage (final stage) carrier 38 that rotatably supports each planetary gear 36 via a support pin 37. .

  The second stage (final stage) sun gear 34 is formed as a cylindrical spur gear, and the rotary shaft 17 is inserted through the inner peripheral side of the sun gear 34 with a gap. The sun gear 34 rotates relative to the periphery of the rotating shaft 17 (rotates at a lower speed than the rotating shaft 17) by transmitting the rotation decelerated by the planetary gear speed reduction mechanism 25 in the previous stage (first stage). The outer peripheral side of the sun gear 34 meshes with a plurality of (for example, 3 to 4) planetary gears 36 at the position of the meshing portion 39.

  Here, the second stage internal gear 35 is formed using a ring gear that surrounds the sun gear 34 and each planetary gear 36 from the outside in the radial direction. The internal gear 35 is integrally fixed using an elongated bolt 23 between the extended cylinder portion 18 </ b> B constituting a part of the wheel mounting cylinder 18 and the outer drum 22. The planetary gears 36 at the second stage (final stage) mesh with the internal teeth formed on the inner circumference side of the internal gear 35 over the entire circumference. Thereby, each planetary gear 36 transmits the reduced rotation to the wheel mounting cylinder 18.

  At the center of the second-stage carrier 38, a cylindrical connecting portion 38A extending in a cylindrical shape toward the one axial side toward the inside of the spindle 14 (circular cylindrical portion 14B) is integrally formed. The cylindrical connecting portion 38A enters inside the opening end of the spindle 14 (circular cylindrical portion 14B) and is connected to the inner peripheral surface of the circular cylindrical portion 14B in a non-rotating state. That is, the cylindrical connecting portion 38A is detachably fitted into the circular cylindrical portion 14B of the spindle 14 from the opening end side, and is fixed to the inner peripheral side of the circular cylindrical portion 14B by spline coupling. On the inner peripheral side of the cylindrical connecting portion 38A, the rotary shaft 17 is inserted with a gap and a supply pipe 47 described later is inserted.

  Here, in the planetary gear speed reduction mechanism 33 in the second stage, each planetary gear 36 revolves (rotation of the carrier 38) by spline coupling the cylindrical coupling portion 38A of the carrier 38 to the circular cylindrical portion 14B of the spindle 14. Is restrained. Therefore, when the sun gear 34 rotates together with the coupling 32, the second stage planetary gear reduction mechanism 33 converts the rotation of the sun gear 34 into the rotation of each planetary gear 36. The rotation of each planetary gear 36 is transmitted to the second-stage internal gear 35, and the internal gear 35 rotates in a decelerated state. As a result, the wheel mounting cylinder 18 to which the internal gear 35 is fixed has a large output rotational torque that is decelerated in two stages of the first stage planetary gear reduction mechanism 25 and the second stage planetary gear reduction mechanism 33. It is to be transmitted.

  As shown in FIG. 3, in the second stage sun gear 34, the end surface on one side in the axial direction protrudes from the planetary gear 36 toward the annular plate portion 56A side of the second partition wall portion 56, which will be described later. It is arranged at a close position. The sun gear 34 and each planetary gear 36 have a meshing portion 39 that meshes in a state of being lubricated by a lubricating oil 100 described later. From both meshing portions 39, the lubricating oil 100 is ejected in the axial direction of the meshing portion 39 as the sun gear 34 (the planetary gears 36) rotates.

  This jet oil (that is, the lubricating oil 100) collides with the annular plate portion 56A of the second partition wall portion 56 and faces radially outward from the oil guide passage 57 described later (for example, the direction indicated by the arrow C in FIG. 3). Guided by The annular plate portion 56A of the second partition wall portion 56 constitutes a guide surface that guides the jetted oil that collides as described above in the direction indicated by arrow C in FIG. Therefore, the jetted oil (lubricating oil 100) is led out toward the planetary bearing 36A of each planetary gear 36 through the oil guide path 57 without flowing into the cylindrical connecting portion 38A (oil storage tank 53 described later). The

  The wet brake 40 applies a braking force to the rotation of the wheel mounting cylinder 18 (that is, the left and right rear wheels 7), and is constituted by a wet multi-plate hydraulic brake. The wet brake 40 is provided between the spindle 14 of the axle housing 12 and the wheel mounting cylinder 18 via a brake hub 41 described later. The wet brake 40 applies a braking force to the brake hub 41 that rotates integrally with the wheel mounting cylinder 18.

  The brake hub 41 constitutes a part of the wet brake 40 and rotates integrally with the wheel mounting cylinder 18. The brake hub 41 is formed as a cylindrical body extending in the axial direction between the spindle 14 and the wet brake 40. On the one side in the axial direction of the brake hub 41, each rotating side disk of the wet brake 40 is attached so as to be movable in the axial direction in a non-rotating state. The other side in the axial direction of the brake hub 41 is detachably fixed to the hollow cylinder portion 18A of the wheel mounting cylinder 18 via a plurality of bolts.

  The retainer 42 positions the inner ring side of the wheel support bearing 20 in the circular cylindrical portion 14 </ b> B of the spindle 14. The retainer 42 is provided to be fitted to the outer peripheral surface of the circular cylindrical portion 14B. One side of the retainer 42 in the axial direction is in contact with the annular step portion 14 </ b> D of the spindle 14. The other axial side of the retainer 42 is in contact with the inner ring side of the wheel support bearing 20 in the axial direction. As a result, the wheel support bearing 20 is positioned in the axial direction on the outer ring side by the hollow cylinder portion 18A of the wheel mounting cylinder 18 and is positioned in the axial direction by the retainer 42 on the inner ring side.

  The other retainer 43 is attached to the open end of the spindle 14 via a plurality of bolts 44. The other retainer 43 is fixed to the circular cylindrical portion 14B of the spindle 14 and positions the inner ring side of the wheel support bearing 21 in the axial direction on the outer peripheral side of the circular cylindrical portion 14B. That is, the wheel support bearing 21 is positioned in the axial direction on the outer ring side by the hollow cylinder portion 18A of the wheel mounting cylinder 18 and is positioned in the axial direction by the other retainer 43 on the inner ring side.

  Next, a lubrication system for lubricating the reduction gear mechanism 24 (that is, the first and second planetary gear reduction mechanisms 25 and 33) and the wheel support bearings 20 and 21 will be described. This lubrication system includes a partition wall 45, a suction pipe 46, a supply pipe 47, an inner retainer 50, an outer retainer 51, a shaft bearing 52, an oil storage tank 53, and the like, which will be described later.

  As shown in FIG. 2, the lubricating oil 100 is stored inside the wheel mounting cylinder 18, and the first and second planetary gear reduction mechanisms 25 and 33 operate in a state where the lubricating oil 100 is supplied. In this case, the liquid level of the lubricating oil 100 is, for example, at a position lower than the lowermost part of the circular cylindrical portion 14 </ b> B constituting the spindle 14, and the lower portions of the wheel support bearings 20, 21 are immersed in the lubricating oil 100. Is set to such a position. Thereby, the resistance by stirring of the lubricating oil 100 can be kept small. When the travel drive device 11 is operated, the lubricating oil 100 is agitated by the first and second planetary gear speed reduction mechanisms 25 and 33 to perform scraping lubrication. By this scraping lubrication, the first and second planetary gear speed reduction mechanisms 25 and 33 are prevented from rising in temperature.

  The partition wall 45 is formed by an annular plate provided in the spindle 14. The outer peripheral side of the partition wall 45 is detachably fixed to the inner peripheral side of the large-diameter cylindrical portion 14A of the spindle 14 using a bolt or the like. Here, the partition wall 45 is located inside the spindle 14 on one side in the axial direction and accommodates the motor housing space 45A in which the traveling motor 16 is housed, and on the other side in the axial direction inside the circular cylindrical portion 14B of the spindle 14. It is defined in the cylindrical space 45B that communicates.

  The suction pipe 46 is a suction pipe for collecting the lubricating oil 100 stored in the wheel mounting cylinder 18. The suction pipe 46 is provided such that one side in the length direction extends in the axial direction in the suspension cylinder 13 of the axle housing 12 and is connected to the suction side of a lubrication pump 48 described later. An intermediate portion in the longitudinal direction of the suction pipe 46 extends in the axial direction in the spindle 14 toward the wheel mounting cylinder 18 side. The front end side (the other side in the length direction) of the suction pipe 46 is a suction portion 46A that is bent in an L shape from the lower side of the rotating shaft 17 and extends downward. The suction portion 46A is inserted into the radial hole 14G of the spindle 14. As a result, the suction portion 46 </ b> A of the suction pipe 46 is immersed in the lubricating oil 100 in the wheel mounting cylinder 18, and this lubricating oil 100 is collected on the suction side of the lubricating pump 48.

  Reference numeral 47 denotes a lubricating oil supply pipe (hereinafter referred to as a supply pipe 47) that supplies the lubricating oil 100 to the reduction gear mechanism 24. The supply pipe 47 is disposed at a position above the suction pipe 46 and the rotary shaft 17 in the spindle 14 and extends between the spindle 14 and the rotary shaft 17 in the axial direction. The distal end portion 47A of the supply pipe 47 is a free end and extends into the second-stage carrier 38 (cylindrical coupling portion 38A). As shown in FIG. 3, the distal end portion 47A of the supply pipe 47 is inserted into the cylindrical coupling portion 38A of the carrier 38 through a notch 55B of the first partition wall portion 55 described later.

  As shown in FIG. 2, one side in the length direction (base end side) of the supply pipe 47 is connected to the discharge side of the lubrication pump 48 via an oil cooler 49. Lubricating oil 100 discharged from the lubricating pump 48 is cooled by an oil cooler 49, and from a tip end portion 47A (the other side in the length direction) of the supply pipe 47 to a cylindrical connecting portion 38A (an oil storage tank described later) of the carrier 38. 53) is supplied in the direction of arrow A toward the inside. The lubricating oil flows down to be sprayed around the rotating shaft 17 to cool the rotating shaft 17 and is supplied to the lower side of the wheel mounting cylinder 18 in the direction of arrow B through the oil storage tank 53. The

  Lubricating oil 100 stored on the lower side of the wheel mounting cylinder 18 is sucked from the suction portion 46 </ b> A of the suction pipe 46 by driving the lubrication pump 48. The lubricating oil 100 sucked by the lubricating pump 48 is cooled by the oil cooler 49. The cooled lubricating oil 100 is supplied to the first and second planetary gear speed reduction mechanisms 25 and 33 through the supply pipe 47 and into the cylindrical connecting portion 38A of the carrier 38. 33 is lubricated.

  The inner retainer 50 is formed as an annular body that is fitted to the axially intermediate portion of the rotating shaft 17. The outer retainer 51 is a member that positions and holds the shaft bearing 52 on the outer peripheral side of the inner retainer 50. Here, the inner retainer 50 rotates integrally with the rotating shaft 17 by press-fitting the inner peripheral side thereof into the intermediate portion of the rotating shaft 17. The outer retainer 51 is fixed to the inner protrusion 14F of the spindle 14 using a bolt or the like. As shown in FIG. 2, intermediate portions of the suction pipe 46 and the supply pipe 47 extend through the outer retainer 51 in the axial direction, thereby being positioned and fixed in the spindle 14 via the outer retainer 51. Yes.

  The shaft bearing 52 is disposed between the inner retainer 50 on the rotating shaft 17 side and the outer retainer 51 on the spindle 14 side. The shaft bearing 52 supports an intermediate portion in the axial direction of the rotating shaft 17 in the circular cylindrical portion 14 </ b> B of the spindle 14 via an inner retainer 50 and an outer retainer 51. Thereby, the long rotating shaft 17 can suppress the center runout at the intermediate portion in the axial direction, and can transmit the stable rotation of the rotating shaft 17 to the first-stage sun gear 26.

  Next, the configuration of the oil storage tank 53 employed in the first embodiment will be described. The oil storage tank 53 is disposed at a position below the rotating shaft 17 in the second stage carrier 38 constituting the final stage (ie, the second stage) planetary gear reduction mechanism 33. It is formed inside. The oil storage tank 53 overflows the lubricating oil 100 outward in the axial direction while storing the lubricating oil 100 supplied in the arrow A direction from the tip 47A of the supply pipe 47 which is a lubricating oil supply pipe. The lubricating oil 100 having a low temperature is led out toward the first planetary gear reduction mechanism 25 in particular.

  As shown in FIG. 3, the oil storage tank 53 is located on the inner peripheral surface 38B of the cylindrical coupling portion 38A of the carrier 38 and on the one side surface in the axial direction of the cylindrical coupling portion 38A. A first partition wall portion 55 fixed by a fixing tool 54 (for example, a bolt or a screw), and the other axial side surface of the cylindrical connecting portion 38A so as to face the first partition wall portion 55 in the axial direction. The second partition wall portion 56 is also fixed by a fixing tool 54 (for example, a bolt or a screw). Accordingly, the oil storage tank 53 is configured to dam up and store the lubricating oil 100 inside the cylindrical coupling portion 38 </ b> A between the first and second partition portions 55 and 56.

  Here, the first partition wall portion 55 is made of an annular plate formed using an oil-resistant synthetic resin material or a metal material, and an inner diameter hole 55A through which the rotary shaft 17 is inserted with a gap is formed inside. It is installed. The inner diameter hole 55A is formed with a radial dimension (that is, a hole diameter D1) larger than the outer diameter of the rotating shaft 17. The first partition wall 55 is formed with a notch 55B having an inverted U shape at a position above the inner diameter hole 55A. The notch 55B of the first partition wall portion 55 is a guide hole for inserting the distal end portion 47A of the supply pipe 47 into the cylindrical connecting portion 38A (see FIG. 3). The notch 55B is formed as a notch hole that always communicates with the inner diameter hole 55A.

  As shown in FIG. 4, the first partition 55 is provided with a plurality of (for example, four) through-holes 55C located radially outside the inner diameter hole 55A and the notch 55B. Each of the through holes 55C is provided in the circumferential direction of the first partition wall portion 55 with an interval (for example, an interval of 90 degrees). The plurality of fixtures 54 are configured to fix the first partition wall portion 55 in a surface contact state to one side surface in the axial direction of the cylindrical connecting portion 38A in a state of being individually inserted into the through holes 55C.

  The second partition wall portion 56 includes an annular plate portion 56A formed using the same material as the first partition wall portion 55, and a lead-out cylinder protruding from the inner periphery of the annular plate portion 56A toward the other side in the axial direction. It is comprised by the part 56B. This lead-out cylinder part 56 </ b> B is inserted into the inner peripheral side of the second-stage sun gear 34 and guides a part of the lubricating oil 100 accumulated in the oil storage tank 53 toward the inner peripheral side of the sun gear 34. Make up surface. The inner peripheral surface of the lead-out cylinder portion 56B is an inner diameter hole 56C through which the rotary shaft 17 is inserted with a gap. The inner diameter hole 56 </ b> C is formed with a radial dimension larger than the outer diameter of the rotating shaft 17 (that is, the hole diameter D <b> 2).

  In the second partition wall portion 56, a plurality of (for example, four) through holes 56D are formed on the outer peripheral side of the annular plate portion 56A at intervals in the circumferential direction. The fixtures 54 are inserted through the through holes 56D, respectively. In this state, each fixing tool 54 fixes the second partition wall portion 56 to the other axial surface of the cylindrical connecting portion 38A. As shown in FIG. 3, the annular plate portion 56 </ b> A of the second partition wall portion 56 opposes the sun gear 34 in the axial direction and is fixed to the other axial side surface of the cylindrical coupling portion 38 </ b> A in a surface contact state.

  As shown in FIG. 4, the inner diameter hole 56 </ b> C of the second partition wall portion 56 is formed such that the hole diameter D <b> 2 is larger than the inner diameter hole 55 </ b> A (hole diameter D <b> 1) of the first partition wall portion 55. In other words, the inner diameter hole 55A of the first partition wall 55 has a smaller diameter D1 than the inner diameter hole 56C (hole diameter D2) of the second partition wall 56 so as to satisfy the following equation (1). Is formed. Therefore, the lubricating oil 100 stored in the oil storage tank 53 does not overflow from the first partition wall portion 55 (inner diameter hole 55A) side, but overflows from the second partition wall portion 56 (inner diameter hole 56C) side. .

  Thus, the weir heights H1, H2 (H2 <H1) of the lubricating oil 100 stored in the oil storage tank 53 are determined by the hole diameters D1, D2 of the inner diameter holes 55A, 56C. That is, the first partition wall 55 having a small hole diameter D1 of the inner diameter hole 55A has a higher blocking height H1 of the lubricating oil 100 than the second partition wall 56, and the second partition wall 56C has a larger hole diameter D2 of the inner diameter hole 56C. The partition wall 56 can reduce the weir height H2 of the lubricating oil 100 by the difference δ (see FIGS. 3 and 4) according to the following equation (2).

  Therefore, the lubricating oil 100 stored in the oil storage tank 53 does not overflow from the first partition wall 55 side, but overflows as overflow oil from the second partition wall 56 side. As shown in FIG. 3, of the lubricating oil 100 stored in the oil storage tank 53, the overflow oil overflowed from the second partition wall 56 side is passed through the lead-out cylinder 56 </ b> B of the second partition wall 56. In addition to being guided to the inner peripheral surface of the gear 34, it is guided in the direction indicated by the arrow B along the inner peripheral surface of the sun gear 34 to the outside in the axial direction.

  As a result, the overflow oil is reduced to the first stage planetary gear reduction mechanism 25 located farther outward from the opening end of the spindle 14 in the axial direction than the second stage planetary gear reduction mechanism 33 as the final stage. Can be supplied as temperature lubricant. In particular, the overflow oil can be supplied to a planetary bearing 28 </ b> A provided between the first stage planetary gear 28 and the support pin 29.

  Here, the lubricating oil 100 lubricates gear parts and bearings that are subjected to high loads when operated at a low speed with a high torque, such as the planetary gear speed reduction mechanisms 25 and 33 used in the travel drive device 11 of the dump truck 1. In order to protect them, lubricating oils with relatively high viscosity are often used. For this reason, even if a gap exists between the lead-out cylinder portion 56B of the second partition wall portion 56 and the inner peripheral surface of the sun gear 34, the lubricating oil 100 does not flow out to a large amount from the gap. The outflow (leakage) amount is negligible compared to the supply amount from the supply pipe 47.

  The annular plate portion 56A of the second partition wall portion 56 is disposed at a position facing the second stage sun gear 34 and the planetary gear 36 in the axial direction. On the other hand, the lubricating oil 100 is ejected from the meshing portion 39 between the sun gear 34 and each planetary gear 36 in the axial direction of the meshing portion 39 as the sun gear 34 (each planetary gear 36) rotates. The lubricating oil 100 collides with the annular plate portion 56A of the second partition wall portion 56 and is guided radially outward (for example, in the direction indicated by arrow C in FIG. 3) from an oil guide passage 57 described later. The annular plate portion 56A of the second partition wall portion 56 constitutes a guide surface that guides the jetted oil that collides as described above in the direction indicated by arrow C in FIG. For this reason, the lubricating oil 100 is led out toward the planetary bearings 36A of the planetary gears 36 through the oil guide passages 57 without flowing into the cylindrical connecting portion 38A (oil storage tank 53 described later).

  The oil guide path 57 is formed between the annular plate portion 56 </ b> A of the second partition wall portion 56 and the axial end surface of the planetary gear 36. The oil guide path 57 allows the lubricating oil 100 ejected from the meshing part 39 of the sun gear 34 and the planetary gears 36 to be transmitted between the planetary gears 36 and the support pins 37 via the annular plate part 56A. It is led to the bearing 36A.

  The traveling drive device 11 of the dump truck 1 according to the first embodiment has the above-described configuration, and the operation thereof will be described next.

  When a driver who has entered the cab 5 of the dump truck 1 starts the engine 8, a hydraulic pump serving as a hydraulic source is rotationally driven and power is generated by a generator (none of which is shown). When the dump truck 1 is driven to travel, electric power is supplied from the generator to the traveling motor 16 so that the traveling motor 16 is operated and the rotating shaft 17 is rotated.

  The rotation of the rotating shaft 17 is decelerated and transmitted from the sun gear 26 of the first stage planetary gear reduction mechanism 25 to each planetary gear 28, and the rotation of each planetary gear 28 is transmitted via the internal gear 27 and the coupling 32. It is decelerated and transmitted to the sun gear 34 of the second stage planetary gear reduction mechanism 33. In the second stage planetary gear reduction mechanism 33, the rotation of the sun gear 34 is reduced and transmitted to each planetary gear 36. At this time, the carrier 38 supporting each planetary gear 36 is restrained from revolution (rotation of the carrier 38) of each planetary gear 36 because the cylindrical connecting portion 38A is splined to the circular cylindrical portion 14B of the spindle 14. The

  Thereby, each planetary gear 36 performs only rotation around the sun gear 34, and the rotation reduced by the rotation of the planetary gear 36 is transmitted to the internal gear 35 fixed to the wheel mounting cylinder 18. Thus, the wheel mounting cylinder 18 rotates with a large output rotational torque that is decelerated in two stages by the first-stage planetary gear reduction mechanism 25 and the second-stage planetary gear reduction mechanism 33. As a result, the left and right rear wheels 7 serving as drive wheels rotate integrally with the wheel mounting cylinder 18 and can drive the dump truck 1 to travel.

  During operation of the travel drive device 11, the lubricating oil 100 stored in the wheel mounting cylinder 18 causes the rotation of the wheel mounting cylinder 18 and the planetary gears 28 of the first and second planetary gear reduction mechanisms 25, 33. It is scraped up sequentially by 36 etc. For this reason, the lubricating oil 100 is supplied to the meshing portions of the gears, the wheel support bearings 20, 21 between the circular cylinder portion 14 </ b> B of the spindle 14 and the wheel mounting cylinder 18. Thereafter, the lubricating oil 100 is sequentially dropped downward and stored on the lower side of the wheel mounting cylinder 18.

  Lubricating oil 100 accommodated on the lower side of the wheel mounting cylinder 18 is sucked up from the suction portion 46 </ b> A of the suction pipe 46 by the lubrication pump 48. The lubricating pump 48 discharges the lubricating oil 100 to the supply pipe 47 side while being cooled by the oil cooler 49. As a result, the lubricating oil 100 is continuously supplied from the tip 47A of the supply pipe 47 toward the reduction gear mechanism 24 in the wheel mounting cylinder 18 (that is, the first and second planetary gear reduction mechanisms 25 and 33). be able to.

  By the way, the traveling drive device 11 of the dump truck 1 as described above can guide the lubricating oil 100 supplied from the tip portion 47A of the supply pipe 47 to the planetary gear reduction mechanism 33 in the final stage (that is, the second stage). . However, the lubricating oil 100 cannot necessarily be supplied to the planetary gear reduction mechanism 25 in the preceding stage (that is, the first stage) of the planetary gear reduction mechanism 33 in the final stage at a sufficiently low temperature. In particular, it is difficult to supply the low temperature lubricating oil 100 to the planetary bearing 28 </ b> A between the first stage planetary gear 28 and the support pin 29.

  In other words, the supply pipe 47 for the lubricating oil 100 is disposed inside the spindle 14 and supplies the lubricating oil 100 from the tip 47A toward the carrier 38 of the planetary gear reduction mechanism 33 at the second stage. On the other hand, the first-stage planetary gear reduction mechanism 25 is disposed on the outer side in the axial direction of the spindle 14 (circular cylindrical portion 14B) than the second-stage planetary gear reduction mechanism 33. For this reason, the lubricating oil 100 supplied from the tip portion 47A of the supply pipe 47 passes through the second stage planetary gear speed reduction mechanism 33 and is then stored on the lower side of the wheel mounting cylinder 18. In this state, the lubricating oil 100 is supplied to the first stage planetary gear reduction mechanism 25 by the rotation of the wheel mounting cylinder 18. As a result, the lubricating oil 100 supplied to the first stage planetary gear reduction mechanism 25 has a high oil temperature.

  Moreover, in the first stage planetary gear reduction mechanism 25, the rotational speed of the sun gear 26 and each planetary gear 28 is faster than that of the second stage planetary gear reduction mechanism 33 (sun gear 34 and each planetary gear 36). For this reason, the first stage planetary gear speed reduction mechanism 25 generates heat early when the dump truck 1 is driven to travel. Accordingly, it is desired that the lubricating oil can be supplied to the first stage planetary gear speed reduction mechanism 25 at a low temperature.

  Therefore, according to the first embodiment shown in FIGS. 2 to 4, the final stage carrier 38 held in the non-rotating state by the spindle 14 is cylindrical at a position below the rotating shaft 17. An oil storage tank 53 is formed inside the connecting portion 38A. The oil storage tank 53 stores the lubricating oil 100 supplied in the direction indicated by the arrow A from the tip portion 47A of the supply pipe 47 in the lower side, while the lubricating oil 100 overflowed from the oil storage tank 53 is axially outside (that is, the first oil storage tank 53). 1 to the planetary gear reduction mechanism 25) side.

  That is, the oil storage tank 53 is provided on the inner peripheral surface 38B of the cylindrical coupling portion 38A of the carrier 38 and on the one side surface in the axial direction of the cylindrical coupling portion 38A that is located in the spindle 14 (circular cylindrical portion 14B). Of the cylindrical connecting portion 38A between the first partition wall portion 55 and the second partition sun gear 34 in the axial direction and provided on the other axial side surface of the cylindrical connecting portion 38A. It is comprised by the 2nd partition part 56 which dams and accumulates the lubricating oil 100 inside.

  In addition, the first partition wall portion 55 is formed such that the hole diameter D1 of the inner diameter hole 55A through which the rotary shaft 17 is inserted is smaller than the hole diameter D2 of the inner diameter hole 56C of the second partition wall portion 56. For this reason, the weir heights H1 and H2 of the lubricating oil 100 stored in the oil storage tank 53 are determined by the hole diameters D1 and D2 of the inner diameter holes 55A and 56C. That is, the second partition wall portion 56 having a large hole diameter D2 has a damming height H2 (H2 <H1) of the lubricating oil 100 equal to the number of the first partition wall portion 55 having a small hole diameter D1 of the inner diameter hole 55A. It can be lowered by the difference δ according to the two equations.

  For this reason, the lubricating oil 100 that is sequentially supplied in the direction indicated by the arrow A from the distal end portion 47A of the supply pipe 47 into the oil storage tank 53 has a low dam height H2 in a state where the oil storage tank 53 is full. Overflows from the inner diameter hole 56C of the partition wall portion 56. This overflow oil flows in the direction indicated by the arrow B toward the outside in the axial direction along the inner peripheral surface of the sun gear 34 constituting the final stage (second stage) planetary gear reduction mechanism 33. As a result, the first-stage planetary gear reduction mechanism 25 (particularly the first-stage planetary gear) is located farther from the opening end of the spindle 14 than the second-stage planetary gear reduction mechanism 33 (the axially outer position). The overflow oil can be supplied to the planetary bearing 28A) provided between the support pin 29 and the support pin 29 as a low-temperature lubricating oil.

  The first partition wall portion 55 that is located in the spindle 14 and provided on one side surface in the axial direction of the cylindrical connecting portion 38A is opposed to the sun gear 34 in the axial direction on the other side surface in the axial direction of the cylindrical connecting portion 38A. The dam height H1 of the lubricating oil 100 is higher than the provided second partition wall 56. For this reason, the lubricating oil 100 stored in the oil storage tank 53 overflows from the second partition wall portion 56 side where the weir height H2 is low and overflows from the first partition wall portion 55 side. Can be prevented. As a result, the lead-out cylinder part 56B of the second partition wall part 56 can lead the overflow oil from the inner diameter hole 56C to the outside in the axial direction along the inner peripheral surface of the second-stage sun gear 34. .

  Moreover, the second partition wall portion 56 is integrally provided with a lead-out cylinder portion 56B, and the lead-out cylinder portion 56B is inserted into the inner peripheral side of the second-stage sun gear 34. For this reason, the lead-out cylinder part 56 </ b> B causes the overflow oil (that is, the lubricating oil 100 having a relatively low temperature in the oil storage tank 53) overflowing from the second partition wall part 56 to the inner peripheral side of the sun gear 34. It can lead out in the direction of arrow B toward the outside in the axial direction.

  As a result, the first stage planetary gear speed reduction mechanism 25 (for example, the second stage planetary gear speed reduction mechanism 33 is disposed at a position farther from the opening end of the spindle 14 than the second stage planetary gear speed reduction mechanism 33 (the axial outer position) The overflow oil can be supplied to the planetary bearing 28A) of the planetary gear 28 as a low-temperature lubricating oil. Thereby, the components (for example, the sun gear 26, the internal gear 27, the planetary gear 28, and the planetary bearing 28A) of the first stage planetary gear reduction mechanism 25 can be actively cooled and kept in a lubrication state.

  Therefore, according to the first embodiment, the low temperature lubricating oil 100 that is sequentially supplied from the distal end portion 47A of the supply pipe 47 into the oil storage tank 53 is used in the state where the oil storage tank 53 is full. It overflows from the inner diameter hole 56C of the partition wall 56. This overflow oil can be supplied to the planetary gear reduction mechanism 25 in the lower stage than the planetary gear reduction mechanism 33 in the second stage, which is the final stage, in a low temperature state. Can be improved.

  The annular plate portion 56A of the second partition wall portion 56 is disposed at a position facing the second stage sun gear 34 and the planetary gear 36 in the axial direction. Between the end surface in the axial direction of the planetary gear 36 and the annular plate portion 56 </ b> A, an oil guide passage 57 for the lubricating oil 100 ejected from the meshing portion 39 of the sun gear 34 and each planetary gear 36 is formed. Therefore, the lubricating oil 100 ejected in the axial direction from the meshing portion 39 of the sun gear 34 and each planetary gear 36 is transferred to the oil guide passage 57 by the annular plate portion 56A of the second partition wall portion 56 in FIG. The guide surface can be guided in the direction indicated by the arrow C, and the guide surface for guiding the jetted oil in the direction indicated by the arrow C in FIG.

  Thereby, the lubricating oil 100 is blocked by the annular plate portion 56A from flowing into the cylindrical connecting portion 38A (that is, the oil storage tank 53). Moreover, the oil guide path 57 can lead out the lubricating oil 100 at this time toward the planetary bearings 36A of the planetary gears 36, and the planetary bearings 36A between the planetary gears 36 and the support pins 37 are effective. Can be lubricated.

  Next, FIG. 5 shows a second embodiment of the present invention. A feature of the present embodiment is that a seal build-up portion is provided on the inner peripheral side of the sun gear constituting the final stage planetary gear speed reduction mechanism, and the lubricating oil in the oil storage tank is filled with the second partition wall portion and the seal build-up. It is in the structure which suppressed leaking from between the parts. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, 61 is the second stage sun gear employed in the second embodiment, and the sun gear 61 is configured in substantially the same manner as the sun gear 34 described in the first embodiment, The meshing portion 39 meshes with the plurality of planetary gears 36. However, the sun gear 61 in this case is provided with a seal build-up portion 61A. The seal build-up portion 61 </ b> A is formed as a reduced diameter portion protruding radially inward from the inner peripheral surface of the sun gear 61. The seal build-up portion 61 </ b> A is disposed at a position closer to one side in the axial direction on the inner peripheral side of the sun gear 61.

  As for the 2nd partition part 56 which comprises the oil storage tank 53, the derivation | leading-out cylinder part 56B is penetrated by the inner peripheral side (namely, the buildup part 61A for a seal | sticker) of the sun gear 61. For this reason, an annular gap S having a very small gap dimension in the radial direction is formed between the seal build-up part 61A and the lead-out cylinder part 56B of the sun gear 61. The annular gap S has a function of exerting a labyrinth effect between the seal build-up portion 61A and the lead-out cylinder portion 56B and suppressing leakage of the lubricating oil 100.

  That is, the lubricating oil 100 stored in the oil storage tank 53 overflows from the lead-out cylinder portion 56B of the second partition wall portion 56 to the inner peripheral surface side of the sun gear 61, and overflows. Leakage to the outside through the annular gap S between the build-up portion 61A and the lead-out cylinder portion 56B can be suppressed by the labyrinth effect. In addition, even if the sun gear 61 rotates, the lead-out cylinder portion 56B of the second partition wall portion 56 does not contact the seal build-up portion 61A of the sun gear 61, and the sun gear 61 is ensured to rotate smoothly. be able to.

  Thus, also in the second embodiment configured as described above, the lubricating oil 100 that overflows from the oil storage tank 53 through the lead-out cylinder portion 56B (inner diameter hole 56C) of the second partition wall portion 56 is allowed to flow inside the sun gear 61. It can be supplied to the first stage planetary gear speed reduction mechanism 25 side through the surface, and substantially the same operation and effect as in the first embodiment can be obtained. In particular, in the second embodiment, a seal build-up portion 61A protruding radially inward is provided on the inner peripheral surface of the sun gear 61, and the lead-out cylinder portion 56B of the second partition wall portion 56 and the seal build-up are provided. An annular gap S having a small radial dimension is formed between the portion 61A.

  For this reason, the labyrinth effect can suppress that the lubricating oil 100 overflowing from the oil storage tank 53 through the second partition wall 56 (inner diameter hole 56C) leaks to the outside through the annular gap S. In addition, the inner peripheral surface of the sun gear 61 is formed such that one side in the axial direction is smaller in diameter than the other side by the seal build-up portion 61A. As a result, the lubricating oil 100 overflowing from the lead-out cylindrical portion 56B of the second partition wall portion 56 to the inner peripheral surface side of the sun gear 61 can be caused to flow down in the direction indicated by the arrow B. 100 can be prevented from leaking outside through the annular gap S.

  Next, FIG. 6 shows a third embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted. However, the feature of the third embodiment is that the second partition wall 72 constituting the oil storage tank 71 is formed using a substantially flat annular plate.

  Here, the oil storage tank 71 is configured similarly to the oil storage tank 53 described in the first embodiment, except for the second partition wall 72. The second partition wall 72 is fixed to the other side surface in the axial direction of the cylindrical connecting portion 38A by a fixture 54 (for example, a bolt or a screw) so as to face the first partition wall portion 55 in the axial direction. Accordingly, the oil storage tank 71 is configured to dam up and store the lubricating oil 100 inside the cylindrical connecting portion 38 </ b> A between the first and second partition portions 55 and 72.

  However, the second partition wall portion 72 is made of an annular plate formed using an oil-resistant synthetic resin material or metal material, and an inner diameter hole 72A through which the rotary shaft 17 is inserted with a gap is formed inside the second partition wall portion 72. Has been. The inner diameter hole 72A is formed with the same radial dimension (that is, the hole diameter D2 shown in FIG. 4) as the inner diameter hole 56C of the second partition wall portion 56 described in the first embodiment.

  The second partition wall 72 is bent in a dish shape so that the annular portion 72 </ b> B positioned around the inner diameter hole 72 </ b> A approaches the axial end surface of the sun gear 34. That is, the annular portion 72B of the second partition wall portion 72 faces the axial end surface of the sun gear 34 via the small axial gap S1. For this reason, even when the lubricating oil 100 in the oil storage tank 71 overflows from the inner diameter hole 72A side of the second partition wall 72, the overflowing lubricating oil 100 leaks to the outside through the axial gap S1. Can be suppressed.

  In addition, the second partition 72 is disposed at a position facing the second stage sun gear 34 and the planetary gear 36 in the axial direction. The second partition wall portion 72 constitutes a guide surface for guiding the lubricating oil 100 ejected from the meshing portion 39 of the sun gear 34 and each planetary gear 36 outwardly in the arrow C direction. In addition, between the end face in the axial direction of the planetary gear 36 and the second partition wall 72, an oil guide path 73 for guiding the lubricating oil 100 to the planetary bearing 36 </ b> A between each planetary gear 36 and each support pin 37. Is formed.

  For this reason, the lubricating oil 100 ejected in the axial direction from the meshing portion 39 of the sun gear 34 and each planetary gear 36 is moved in the direction indicated by the arrow C in FIG. 6 by the second partition wall portion 72 and the oil guiding path 73. Can guide. Thereby, the lubricating oil 100 can be led out toward the planetary bearing 36A of each planetary gear 36 by the oil guide path 73 without flowing into the cylindrical connecting portion 38A (that is, the oil storage tank 71). The planetary bearings 36A between the planetary gears 36 and the support pins 37 can be effectively lubricated.

  Thus, also in the third embodiment configured as described above, the lubricating oil 100 overflowing from the oil storage tank 71 through the inner diameter hole 72A of the second partition wall 72 is passed through the inner peripheral surface of the sun gear 61 by one step. It can be supplied to the planetary gear reduction mechanism 25 side of the eye, and substantially the same operational effects as in the first embodiment can be obtained. In particular, in the third embodiment, the second partition wall 72 is formed as an annular plate.

  Therefore, unlike the second partition wall portion 56 used in the first embodiment, there is no need to provide the lead-out cylinder portion 56B that protrudes in the axial direction from the inner peripheral side of the annular plate portion 56A. Therefore, the shape of the second partition wall 72 can be simplified, the degree of design freedom can be increased, and the cost can be reduced.

  In the first embodiment, the case where the first and second partition wall portions 55 and 56 are respectively formed in an annular shape as shown in FIG. 4 has been described as an example. However, the present invention is not limited to this, and the first partition wall portion 55 may be a partition wall having a shape that can secure the weir height H1, for example, in order to store the lubricating oil in the oil storage tank, and includes a semicircular shape. You may comprise by an arc-shaped or rectangular board | plate material. The second partition wall portion 56 may be a partition wall having a shape that can secure the weir height H2, for example, and the shape can be changed in the same manner as the first partition wall portion described above. This also applies to the second and third embodiments, and the shapes of the first and second partition portions can be changed as appropriate.

  Further, in the first embodiment, the case where the distal end portion 47A of the supply pipe 47 is disposed on the upper side of the rotating shaft 17 in the cylindrical coupling portion 38A of the carrier 38 has been described as an example. However, the present invention is not limited to this. For example, the tip 47A of the supply pipe 47 extends downward so as to avoid the rotating shaft 17, and the lubricating oil is directly discharged (supplied) into the oil storage tank 53. Also good. In this respect, similar changes can be made in the second and third embodiments.

  In each of the above-described embodiments, the case where the reduction gear mechanism 24 is configured by the two-stage planetary gear reduction mechanisms 25 and 33 has been described as an example. However, the present invention is not limited to this, and for example, the reduction gear mechanism may be configured by a planetary gear reduction mechanism having three or more stages.

  Further, in each of the above embodiments, the rear wheel drive type dump truck 1 has been described as an example. However, the present invention is not limited to this, and can be applied to, for example, a front-wheel drive type or a four-wheel drive type dump truck that drives both front and rear wheels.

DESCRIPTION OF SYMBOLS 1 Dump truck 2 Car body 3 Loading platform 5 Cab 6 Front wheel 7 Rear wheel (wheel)
8 Engine 9 Hoist Cylinder 10 Hydraulic Oil Tank 11 Traveling Drive Device 12 Axle Housing 13 Suspension Cylinder 14 Spindle 16 Traveling Motor (Drive Source)
17 Rotating shaft 18 Wheel mounting cylinder 20, 21 Wheel support bearing 22 Outer drum 23 Long bolt 24 Reduction gear mechanism 25 First planetary gear reduction mechanism (first stage planetary gear reduction mechanism)
26 First-stage sun gear 28 First-stage planetary gear 29 First-stage support pin 33 Second planetary gear reduction mechanism (final-stage planetary gear reduction mechanism)
34, 61 Second stage sun gear (last stage sun gear)
36 Second stage planetary gear (last stage planetary gear)
37 Second stage support pin (last stage support pin)
38 Second stage carrier (final stage carrier)
38A Cylindrical connecting part 38B Inner peripheral surface 39 Engagement part 46 Suction pipe 47 Supply pipe (lubricating oil supply pipe)
47A Tip 48 Lubricating pump 49 Oil cooler 53, 71 Oil storage tank 55 First partition 55A, 56C, 72A Inner diameter hole 56, 72 Second partition 56A Annular plate (guide surface)
56B Leading cylinder part 57, 73 Oil guide path 61A Overlay part for seal 100 Lubricating oil H1, H2 Weiring height D1, D2 Hole diameter of inner diameter hole

Claims (5)

An axle housing that is provided in a non-rotating state on the body of the dump truck and has an opening with a cylindrical spindle at the front end side, a drive source provided in the axle housing, and a base that extends in the axial direction inside the spindle. A rotating shaft whose end side is connected to the drive source in the axle housing and whose front end side protrudes from the opening end of the spindle, and wheel mounting in which a wheel is mounted on the outer peripheral side of the spindle rotatably via a wheel side bearing A multi-stage planetary gear reduction mechanism that is provided between the protruding end side of the rotating shaft and the wheel mounting cylinder via the spindle and transmits the rotation of the rotating shaft to the wheel mounting cylinder at a reduced speed. A lubricating oil supply pipe that is provided so as to extend in the axial direction between the spindle and the rotating shaft and supplies lubricating oil toward the planetary gear reduction mechanism of the plurality of stages.
In the multi-stage planetary gear reduction mechanism, the first-stage planetary gear reduction mechanism is arranged at a position far from the drive source, and the final stage planetary gear reduction mechanism is located near the opening end of the spindle near the drive source. It is configured to be arranged,
The last stage carrier that rotatably supports the last stage planetary gear has a cylindrical coupling part that enters inside the opening end of the spindle and is coupled to the inner peripheral surface of the spindle in a non-rotating state. ,
On the inner peripheral side of the cylindrical connecting portion, the rotating shaft is inserted in the axial direction and the lubricating oil supply pipe is inserted.
In a traveling drive device for a dump truck, in which lubricating oil is supplied from the lubricating oil supply pipe to the planetary gear reduction mechanism at the final stage through the cylindrical connecting portion,
The dump truck travel drive device characterized in that an oil storage tank for storing the lubricating oil supplied from the lubricating oil supply pipe is provided in the cylindrical connecting portion of the carrier at the final stage. The oil storage tank includes an inner peripheral surface of the cylindrical coupling portion of the carrier, a first partition wall portion located in the spindle and disposed on one axial side of the cylindrical coupling portion, and the first The second partition wall provided on the other axial side of the cylindrical connecting portion so as to face the partition wall in the axial direction,
2. The dump truck according to claim 1, wherein the first partition wall portion is configured such that a weir height of the lubricating oil accumulated in the cylindrical connecting portion is higher than a weir height of the second partition wall portion. Travel drive device.   The first and second partition wall portions each have an inner diameter hole through which the rotation shaft is inserted with a gap, and the first partition wall portion has a hole diameter of the inner diameter hole larger than that of the second partition wall portion. The travel drive device for a dump truck according to claim 2, wherein the travel drive device is configured to be small. The last stage planetary gear speed reduction mechanism meshes with the sun gear, and is arranged so as to be relatively rotatable on the outer peripheral side of the projecting end of the rotating shaft and to which the rotation reduced by the preceding planetary gear speed reduction mechanism is transmitted. The plurality of planetary gears that transmit reduced rotation to the wheel mounting cylinder, and each planetary gear is rotatably supported via a support pin, and the cylindrical connecting portion is fixedly attached to the spindle. Have a carrier,
The oil storage tank includes an inner peripheral surface of the cylindrical connecting portion of the carrier, a first partition wall portion located in one side of the cylindrical connecting portion in the spindle, the sun gear, A second partition wall provided oppositely in the axial direction and provided on the other axial side of the cylindrical connecting portion;
The second partition wall portion is configured to form a guide surface for guiding the lubricating oil ejected from the meshing portion between the sun gear and each planetary gear between each planetary gear and each support pin. The travel drive device for a dump truck according to claim 1.   On the inner diameter side of the second partition wall portion, a lead-out cylinder portion that is inserted through the inner peripheral surface of the sun gear and guides the lubricating oil in the oil storage tank toward the inner peripheral surface of the sun gear is provided. The travel drive device for a dump truck according to claim 4.

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