JP2007002919A - Traveling drive device of dump truck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the durability and life of bearings by increasing workability in manufacturing carriers and increasing the circulation performance of a lubricating oil. <P>SOLUTION: The carriers 30, 39 of planetary gear reduction mechanisms 25, 34 are fixedly installed on a cylindrical spindle 15 so that the rotation of the carriers 30, 39 can be arrested by the cylindrical spindle 15. An oil groove 59 is formed between the final stage carrier 39 and the cylindrical spindle 15 at their lowest portions to flow down the lubricating oil 100 in the cylindrical spindle 15 to a wheel mounting tube 19 side through the oil groove 59. An oil hole 60 is drilled at the annular projected part 15A of the cylindrical spindle 15 at a position lower than the first stage carrier 30, and the lubricating oil 100 is allowed to flow between the front and rear of the carrier 30 through the oil hole 60 to make equal oil levels in oil sumps 57 and 58 to each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

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, a mine, and the like, and in particular, a rotational torque during traveling using a reduction mechanism. The present invention relates to a travel drive device for a dump truck that is configured to increase the speed.

  In general, a large transport vehicle called a dump truck is provided with a vessel (loading platform) that can be raised and lowered on a frame of a vehicle body, and carries a heavy load such as crushed stones on the vessel. .

  For this reason, a travel drive device that travels and drives the drive wheels of a dump truck is provided with a cylindrical axle housing that is attached to a vehicle body, and is driven to rotate by a drive source such as a hydraulic motor that extends in the axial direction in the axle housing. A rotating shaft provided on the front end side of the axle housing, and a wheel mounting cylinder rotatably provided via a bearing, and a rotation of the rotating shaft provided between the wheel mounting cylinder and the axle housing. And a multi-stage planetary gear reduction mechanism (see, for example, Patent Documents 1 and 2).

  The multi-stage planetary gear speed reduction mechanism decelerates the rotational output of a drive source such as a hydraulic motor and transmits it to a wheel mounting cylinder (wheel), thereby greatly rotating the drive wheels such as the front wheels or rear wheels of the vehicle. Torque is generated to improve the transport performance of the dump truck (vehicle).

JP-A-5-193373 Japanese Patent Laid-Open No. 9-3000984

  By the way, in the above-described prior art, the planetary gear reduction mechanism for increasing the rotational torque of the vehicle is constituted by a sun gear, a plurality of planetary gears, a ring gear, a carrier, and the like. The carrier is configured to rotatably support a plurality of planetary gears that revolve while rotating according to the rotation of the sun gear via a plurality of support pins, and take out the revolutions of the planetary gears as rotation outputs to the outside. .

  However, since the carrier used for such a planetary gear speed reduction mechanism is formed as a heavy article of several hundred kg (kilograms) using means such as casting, the center of gravity of the carrier is slightly deviated from the center of rotation. As a result, a large vibration is generated when the carrier rotates with the rotation of the planetary gear.

  For this reason, in the prior art, it is necessary to strictly manage the center of gravity position in manufacturing the carrier, and it becomes difficult to distribute the load of the support pins and the plurality of planetary gears assembled to the carrier. There is a problem that productivity at the time and workability at the time of assembly cannot be improved.

  In addition, the carrier needs to secure sufficient rigidity for rotatably supporting a plurality of planetary gears, and for this purpose, the carrier is formed as a sturdy heavy object. However, in a planetary gear reduction mechanism of a type in which the carrier rotates, the carrier cannot be used as a strength member for a non-rotating part (for example, an axle housing) of the traveling drive device, and the weight of the carrier becomes a big problem. ing.

  In view of this, the present inventors have examined the provision of the carrier of each planetary gear reduction mechanism fixed to a non-rotating axle housing. However, when these carriers are configured to be fixed to the axle housing, the wheel mounting cylinder and the axle housing are partitioned into a plurality of spaces by the carrier, and the following unsolved problems occur. Arise.

  That is, in such a dump truck traveling drive device, a rotational load of a large torque acts, so that lubricating oil is supplied to a bearing provided between the axle housing and the wheel mounting cylinder, a multi-stage planetary gear reduction mechanism, and the like. However, it is necessary to keep them in a lubricated state.

  Also, inside the wheel mounting cylinder, the lubricating oil is accumulated at the lower position in the upward and downward directions, and the internal lubricating oil is forcibly sucked and discharged outside the apparatus using a lubricating oil pump or the like. Thus, it is known that the lubricating oil accumulated inside is sequentially replaced.

  In this case, if a large amount of lubricating oil is accommodated and stored in the apparatus, heat is generated due to the agitation resistance of the oil, and the load on the apparatus is increased. For this reason, the lubricating oil accommodated in the apparatus is generally set to a necessary minimum amount of oil (for example, about 1/5 to 1/3 of the internal volume).

  However, when the amount of lubricating oil stored in the device is reduced to the minimum required amount, the amount of lubricating oil tends to be non-uniform in each of the plurality of spaces partitioned by the carriers. This may cause an imbalance between the amount of oil supplied and the amount discharged.

  Also, due to the behavior during vehicle travel (for example, change in inertial force accompanying starting, acceleration, deceleration, etc. or traveling on sloping ground), the lubricant level in the device becomes uneven in the liquid level in each space, In each space, an imbalance occurs between the supply amount and the discharge amount of the lubricating oil.

  In particular, in the wheel mounting cylinder provided on the outer peripheral side of the axle housing through a bearing, the amount of oil sucked (discharged) by the lubricating oil pump may exceed the amount of lubricating oil supplied, resulting in a shortage of lubricating oil. There is. In such a case, sufficient lubricating oil cannot be supplied to the bearing that rotatably supports the wheel mounting cylinder, and there is a problem that durability and life of the bearing are reduced.

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to provide a carrier for a planetary gear reduction mechanism in a non-rotating state on an axle housing, thereby improving workability in manufacturing the carrier. An object of the present invention is to provide a traveling device for a dump truck capable of improving productivity, improving the circulation performance of a lubricating oil, and improving the durability and life of a bearing and the like.

  Another object of the present invention is to constrain the rotation of the carrier so that the carrier can be used as a strength member for the axle housing, so that the overall size and weight can be reduced. It is an object of the present invention to provide a traveling drive device for a dump truck that can improve the above.

  In order to solve the above-described problems, the present invention provides a cylindrical axle housing that is attached to the body of a dump truck in a non-rotating state, and extends axially in the axle housing and is rotationally driven by a drive source. A rotating shaft provided on the outer peripheral side of the axle housing via a bearing, and a wheel mounting cylinder on which a wheel is mounted, and provided between the wheel mounting cylinder and the axle housing for rotating the rotating shaft. A multi-stage planetary gear reduction mechanism that decelerates and transmits to the wheel mounting cylinder, and each of the planetary gear reduction mechanisms includes a sun gear, a ring gear, a plurality of planetary gears, and a carrier. Applied to the driving device.

  According to the first aspect of the present invention, the carrier constituting the planetary gear speed reduction mechanism of each stage is provided in the axle housing in a non-rotating state, and the inside of the axle housing and the wheel mounting cylinder are provided. Are provided with oil reservoirs for storing the lubricating oil supplied to the planetary gear speed reduction mechanism at each stage at the lower position in the upper and lower directions, respectively, and the last stage carrier and the axle housing among the carriers. Is provided with an oil passage through which the lubricating oil in each oil reservoir flows between the axle housing and the wheel mounting cylinder.

  According to a second aspect of the present invention, the first-stage carrier among the carriers is provided inside the axle housing, and the inner peripheral side of the axle housing is positioned below the first-stage carrier. Thus, another oil passage through which the lubricating oil flows is provided before and after the carrier.

  According to a third aspect of the present invention, in the axle housing, there is provided lubricating oil supply means for supplying lubricating oil to the planetary gear reduction mechanism, and an upper side and a lower side on the outer peripheral side of the axle housing. The portion to be provided is provided with lubricating oil discharging means for sucking and discharging the lubricating oil in the oil reservoir to the outside from between the wheel mounting cylinder and the axle housing.

  According to a fourth aspect of the present invention, the oil passage for providing a plurality of the bearings between the axle housing and the wheel mounting cylinder, and allowing the lubricating oil to flow between the axle housing and the wheel mounting cylinder, The plurality of bearings are arranged closer to the final stage carrier.

  As described above, according to the first aspect of the present invention, the carrier of each planetary gear reduction mechanism is provided in the axle housing in a non-rotating state, and at least one of the last stage carrier and the axle housing is provided with the axle housing. Since the oil passage for circulating the lubricating oil in the oil sump is provided between the cylinder and the wheel mounting cylinder, the rotation of the carrier can be restrained by the axle housing, and the carrier is manufactured as in the prior art. In this case, it is not necessary to specially manage the position of the center of gravity, and the load distribution of the plurality of support pins and planetary gears assembled to the carrier can be easily performed. The carrier has sufficient rigidity to rotatably support a plurality of planetary gears and can be formed into a sturdy structure, and the carrier can be used for a non-rotating portion (for example, an axle housing) of the traveling drive device. It can be utilized as a strength member, and the strength and rigidity of the entire apparatus can be increased. In addition, this can reduce the thickness of the axle housing and reduce the weight.

  Therefore, workability and productivity in manufacturing the carrier can be improved, and workability in assembling the planetary gear reduction mechanism can be improved. Also, the oil passages provided in the last stage carrier or axle housing allow the lubricating oil stored in the oil reservoirs of the axle housing and the wheel mounting cylinder to flow smoothly from the axle housing toward the wheel mounting cylinder. The circulation performance of the lubricating oil between the axle housing and the wheel mounting cylinder can be enhanced. As a result, lubricating oil can be smoothly supplied to a bearing or the like provided between the axle housing and the wheel mounting cylinder, and the durability and life of the bearing can be improved.

  According to the second aspect of the invention, on the inner peripheral side of the axle housing, there is another oil passage located below the first stage carrier and through which the lubricating oil flows before and after the carrier. For example, the oil level accumulated inside the axle housing can be prevented from becoming uneven by the other oil passages before and after the carrier, and the liquid level of both can be kept uniform. be able to. Then, by lowering the amount of lubricating oil contained in the axle housing to the minimum required liquid level, stirring of the lubricating oil by the movable part of the planetary gear reduction device (for example, sun gear, ring gear, planetary gear) is performed. The resistance can be reduced, heat generation can be suppressed, and the rotational load of the apparatus can be reduced.

  According to a third aspect of the present invention, a part of the lubricating oil supplied from the lubricating oil supply means to the planetary gear speed reduction mechanism is stored in oil reservoirs respectively provided in the axle housing and the wheel mounting cylinder. The bearing provided between the axle housing and the wheel mounting cylinder can be kept in a lubricated state. In addition, a configuration is provided in which a lubricating oil discharging means for sucking and discharging the lubricating oil in the oil reservoir to the outside from between the wheel mounting cylinder and the axle housing is provided at a lower portion on the outer peripheral side of the axle housing. Therefore, the lubricating oil in the oil sump can be smoothly discharged from the outer peripheral side of the axle housing through the lubricating oil discharging means instead of the inner peripheral side of the axle housing, and the lubricating oil in each oil sump can be circulated efficiently. Can be made.

  Therefore, it is possible to prevent used lubricating oil having a high oil temperature from remaining in the oil reservoir, and to supply new lubricating oil having a low oil temperature to the bearing provided between the axle housing and the wheel mounting cylinder. Moreover, in the wheel mounting cylinder, the amount of oil discharged by the lubricating oil discharging means (for example, a lubricating oil pump) exceeds the amount of lubricating oil supplied and the lack of lubricating oil occurs due to the oil passage. The lubricating oil can be sufficiently supplied to the bearing. In addition, the lubricant discharged from the oil reservoir, for example, on the supply side of the lubricant provided outside the travel drive device, removes foreign matters such as metal powder and wear powder using a filter, for example, a cooler, etc. The lubricating oil after cooling using can be supplied again toward the planetary gear reduction mechanism or the like. As a result, fresh lubricating oil can be continuously supplied to the planetary gear reduction mechanism and the bearing, and the durability and life of the planetary gear reduction mechanism and the bearing can be improved.

  Furthermore, the invention according to claim 4 is configured such that the oil passage is provided at a position closer to the carrier at the final stage than the plurality of bearings provided between the axle housing and the wheel mounting cylinder. The lubricating oil flowing from the oil reservoir to the oil reservoir in the wheel mounting cylinder through the oil passage is more in the final stage carrier side (axial direction) than the plurality of bearings provided between the axle housing and the wheel mounting cylinder. ) And flows into the wheel mounting cylinder (oil sump), and the plurality of bearings can be efficiently lubricated by the lubricating oil at this time.

  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.

  Here, FIG. 1 to FIG. 8 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a dump truck employed in the present embodiment. The dump truck 1 includes a vehicle body 2 having a sturdy frame structure as shown in FIG. 1, and a loading platform mounted on the vehicle body 2 so as to be undulated. And the vessel 3 as a whole.

  The vessel 3 is formed as a large container having a total length of 10 to 13 m (meters) in order to load a large amount of heavy loads such as crushed stones, and its rear bottom is pinned to the rear end side of the vehicle body 2. It is connected via a connecting part 4 or the like so as to be able to undulate (tilt). Further, on the upper front side of the vessel 3, a flange 3 </ b> A that covers a cabin 5 described later from above is integrally provided.

  A cabin 5 is provided at the front of the vehicle body 2 and is located below the flange 3A. The cabin 5 forms a driver's cab in which a driver of the dump truck 1 gets on and off, and a driver's seat is provided in the cabin. A start switch, an accelerator pedal, a brake pedal, a steering handle, a plurality of operation levers (all not shown), and the like are provided.

  The flange portion 3A of the vessel 3 covers the cabin 5 almost completely from the upper side, thereby protecting the cabin 5 from, for example, rocks and the like, and also in the cabin 5 when the vehicle (dump truck 1) falls. It has a function to protect the driver.

  6 and 6 are left and right front wheels rotatably provided on the front side of the vehicle body 2, and each front wheel 6 constitutes a steering wheel that is steered (steered) by the driver of the dump truck 1. It is. And the front wheel 6 is formed with the tire diameter (outside diameter dimension) which extends to 2-4 m like the rear wheel 7 mentioned later, for example.

  7 and 7 are left and right rear wheels rotatably provided on the rear side of the vehicle body 2, and each rear wheel 7 constitutes a drive wheel of the dump truck 1, and will be described later as a travel drive device shown in FIG. 11 is driven to rotate integrally with the wheel mounting cylinder 19. The rear wheel 7 is detachably fitted to two tires 7A and 7A, rims 7B and 7B disposed inside the tires 7A, and an rim 7B on the axially outer side of the rims 7B. And a wheel cap 7C (see FIG. 1) provided together.

  Reference numeral 8 denotes an engine as a prime mover provided in the vehicle body 2 at the lower side of the cabin 5. The engine 8 is composed of, for example, a large diesel engine or the like, and an alternator 9 as a generator as shown in FIG. Is to drive. The engine 8 rotationally drives a hydraulic pump (not shown) serving as a hydraulic power source, and pressure oil from the hydraulic pump is used for an undulating cylinder 76, a power steering steering cylinder (not shown), and the like. Will be supplied and discharged.

  Reference numeral 10 denotes an electric controller that constitutes a control device for the dump truck 1. The electric controller 10 is configured by a switchboard or the like that is positioned on the rear side of the cabin 5 and is erected on the vehicle body 2 as shown in FIG. Yes. The electric controller 10 charges the battery (not shown) generated by the alternator 9 shown in FIG. 2 and outputs this electricity to the electric motor 17 described later, and individually sets the rotation speed of the electric motor 17. It has a function for feedback control.

  Reference numeral 11 denotes a travel drive device provided on the rear wheel 7 side of the dump truck 1, and the travel drive device 11 includes an axle housing 12, an electric motor 17, a wheel mounting cylinder 19, a speed reduction mechanism 24, and the like, which will be described later. . The travel driving device 11 decelerates the rotation of the electric motor 17 by the speed reduction mechanism 24 and travels and drives the rear wheel 7 as a driving wheel of the vehicle together with the wheel mounting cylinder 19 with a large rotational torque.

  Reference numeral 12 denotes an axle housing for the rear wheel 7 provided on the rear side of the vehicle body 2. The axle housing 12 is a cylindrical body extending in the axial direction between the left and right rear wheels 7, 7, as shown in FIG. It is formed as. The axle housing 12 is provided on an intermediate suspension cylinder 13 attached to the rear side of the vehicle body 2 via a shock absorber (not shown) such as a shock absorber, and on both the left and right sides of the suspension cylinder 13. The motor housing cylinder 14 and the cylindrical spindle 15 which will be described later are configured.

  Reference numerals 14 and 14 denote motor housing cylinders as drive source housing portions provided on both ends of the suspension cylinder 13. Each motor housing cylinder 14 is formed as a cylindrical body having a tapered shape as shown in FIGS. The large diameter portion 14A side is detachably fixed to the suspension cylinder 13 shown in FIG. 2 using bolts or the like. Further, as shown in FIGS. 4 and 6, a cylindrical spindle 15 which will be described later is detachably fixed to the motor accommodating cylinder 14 via a bolt 16 or the like, as shown in FIGS. It is a reduction gear housing space A.

  An electric motor 17 (to be described later) serving as a drive source for the rear wheels 7 is accommodated in the motor accommodating cylinder 14. An annular partition plate 14 </ b> C is provided between the motor housing cylinder 14 and the electric motor 17, and the partition plate 14 </ b> C is provided with lubricating oil 100 in an oil reservoir 57, which will be described later, of the electric motor 17. It suppresses leakage to the surroundings.

  Reference numeral 15 denotes a cylindrical spindle that constitutes the opening on the front end side of the axle housing 12, and the cylindrical spindle 15 is composed of a large-diameter stepped cylindrical body having an inner diameter of, for example, about 80 to 100 cm. As shown in FIGS. 3, 4, and 6, the first reduction gear housing space A for housing the first stage planetary gear speed reduction mechanism 25 is formed. The outer peripheral surface of the cylindrical spindle 15 is configured to rotatably support a wheel mounting cylinder 19 on the rear wheel 7 side through bearings 20 and 21 described later.

  Here, an annular convex portion 15A that protrudes radially inward from the inner peripheral surface of the cylindrical spindle 15 is formed integrally with the intermediate portion in the axial direction. The carrier 30 is fixedly attached. The cylindrical spindle 15 has a connecting portion 15B that is connected to the motor housing cylinder 14 via a bolt 16 or the like on one side in the axial direction (base end side), and on the other side (tip side) in the axial direction, As shown in FIGS. 6 and 7, an annular flange portion 15 </ b> C protruding outward in the radial direction is integrally formed.

  A final stage carrier 39 to be described later is fixedly attached to the flange portion 15C of the cylindrical spindle 15. In this case, the outer peripheral side of the flange portion 15C is the largest outer diameter portion having the largest outer diameter size in the cylindrical spindle 15, and the outer diameter of the flange portion 15C is substantially equal to the outer diameter size of the bearings 20 and 21 described later. Dimension is formed.

  The cylindrical spindle 15 has a function of receiving a rotational reaction force generated in planetary gear speed reduction mechanisms 25 and 34 (described later) with sufficient strength via the carriers 30 and 39. That is, the carrier 30 and 39 of the planetary gear speed reduction mechanisms 25 and 34 are fixedly provided on the cylindrical spindle 15 as described later. Thereby, the cylindrical spindle 15 is assembled as a covered cylindrical body having a sturdy structure, and supports the wheel mounting cylinder 19 (rear wheel 7) from the inside with high rigidity (strength) on the outer peripheral side thereof.

  Here, as shown in FIGS. 4 and 6, the first reduction gear housing space A is surrounded by the motor housing cylinder 14 and the cylindrical spindle 15, and one side (inner side) in the axial direction thereof is a partition plate 14 </ b> C and will be described later. It is closed by the electric motor 17 and the other side (outside) in the axial direction is covered with a coupling 33 and the like which will be described later. In the reduction gear housing space A, a first-stage planetary gear speed reduction mechanism 25 described later is housed.

  Reference numeral 17 denotes an electric motor as a drive source which is detachably provided on the motor housing cylinder 14 of the axle housing 12, and the electric motor 17 rotates the left and right rear wheels 7, 7 independently of each other as shown in FIG. For driving, they are mounted in left and right motor housing cylinders 14 and 14 located on both sides of the axle housing 12, respectively.

  Reference numeral 18 denotes a rotating shaft that constitutes an output shaft of the electric motor 17, and the rotating shaft 18 is rotationally driven by the electric motor 17 in the forward direction or the reverse direction. Here, the rotating shaft 18 extends in the axial direction from the motor housing cylinder 14 toward the reduction gear housing space A in the cylindrical spindle 15 as shown in FIGS. 3 and 4. And the sun gear 26 mentioned later is spline-coupled to the front end side of the rotating shaft 18 so that it may rotate integrally.

  Reference numeral 19 denotes a wheel mounting cylinder that rotates integrally with the rear wheel 7 as a wheel. The wheel mounting cylinder 19 constitutes a so-called wheel hub, and rims 7B and 7B of the rear wheel 7 are press-fitted on the outer peripheral side thereof. It is detachably attached using means. As shown in FIG. 6, the wheel mounting cylinder 19 includes a one-side cylinder portion 19 </ b> A extending in the axial direction between the bearings 20 and 21, and an axial direction from the end of the one-side cylinder portion 19 </ b> A toward the ring gear 36 described later. The inner peripheral surface 19B1 is formed as a stepped cylindrical body by the other side cylinder portion 19B formed with an inner diameter larger than the one side cylinder portion 19A.

  In addition, the one side cylinder portion 19A of the wheel mounting cylinder 19 is provided with bearing mounting portions 19C and 19D on the inner peripheral side thereof, with bearings 20 and 21 (described later) fitted and attached as steps. Further, on the inner peripheral side of the one-side cylinder portion 19A, the retainer 66 of the seal device 63, which will be described later, is attached to be positioned between the end surface on the one side in the axial direction and the bearing attachment portion 19C. A retainer mounting portion 19E as an expanding portion is formed.

  Here, the other side cylinder portion 19B of the wheel mounting cylinder 19 has an inner peripheral surface 19B1 having an inner diameter dimension substantially equal to a disk holding cylinder 22 described later. And the other side cylinder part 19B surrounds the collar part 15C etc. of the cylindrical spindle 15 from the radial direction outer side, and has the function to distribute | circulate the lubricating oil 100 smoothly from the reduction gear accommodation space B mentioned later toward the annular space C. It is what you have.

  In addition, a ring gear 36 and a disk holding cylinder 22 which will be described later are integrally fixed to the other side cylinder portion 19B of the wheel mounting cylinder 19 using a long bolt 43 or the like, whereby the wheel mounting cylinder 19 is attached to the ring gear 36. And rotate together. That is, the wheel mounting cylinder 19 is transmitted via the ring gear 36 the rotation that has become a large torque by decelerating the rotation of the electric motor 17 by the speed reduction mechanism 24. And the wheel attachment cylinder 19 rotates the rear wheel 7 used as a driving wheel of a vehicle with a large rotational torque.

  In this case, the inner peripheral side of the wheel mounting cylinder 19, the disk holding cylinder 22, and the ring gear 36 is formed as a second speed reducer accommodation space B in which a second stage planetary gear speed reduction mechanism 34 described later is accommodated. The second reduction gear housing space B is surrounded by a coupling 33 and the like, which will be described later, with the first reduction gear housing space A located on the one side in the axial direction. Is covered with a carrier 39, an inner cap 42, a seal device 74 and the like which will be described later.

  Further, the space between the wheel mounting cylinder 19 and the cylindrical spindle 15 is an annular space C that annularly surrounds the outer peripheral side of the cylindrical spindle 15, and the lower part of the annular space C contains the lubricating oil 100. Is. The annular space C is always in communication with the second reduction gear housing space B through a gap in the bearing 21 and the like.

  Further, the one side cylinder portion 19A of the wheel mounting cylinder 19 has an inner circumferential surface located between the bearing mounting sections 19C and 19D gradually from the bearing 21 side toward the bearing 20 side as shown in FIGS. It is formed as a tapered guide surface (hereinafter referred to as an inclined surface 19F) that expands in diameter, and the lubricating oil 100 in the annular space C is guided toward the later-described discharge pipe 72 side by the inclined surface 19F. . On the one side (inner side) in the axial direction of the wheel mounting cylinder 19, a seal device 63 described later is provided at a position between the motor housing cylinder 14 of the axle housing 12, the cylindrical spindle 15 and the wheel mounting cylinder 19. It has been.

  Reference numerals 20 and 21 denote bearings that rotatably support the wheel mounting cylinder 19 on the outer peripheral side of the cylindrical spindle 15, and the bearings 20 and 21 are configured by using, for example, the same tapered roller bearing. Further, the bearings 20 and 21 are disposed apart from each other in the axial direction between the one side cylinder portion 19 </ b> A of the wheel mounting cylinder 19 and the cylindrical spindle 15.

  That is, one bearing 20 is fitted and mounted in a bearing mounting portion 19C of the wheel mounting cylinder 19, and the other bearing 21 is fitted and mounted in a bearing mounting portion 19D of the wheel mounting cylinder 19. Yes. The outer diameter dimensions of the bearings 20 and 21 (the inner diameter dimensions of the bearing mounting portions 19C and 19D) are larger than the inner diameter of the one side cylinder portion 19A and the inner diameter of the other side cylinder portion 19B as shown in FIGS. It is formed smaller than (inner peripheral surface 19B1).

  Reference numeral 22 denotes a disk holding cylinder that constitutes a part of the wheel mounting cylinder 19 together with the ring gear 36. The disk holding cylinder 22 has a ring gear 36, which will be described later, at a position outside the wheel mounting cylinder 19 in the axial direction as shown in FIG. It is attached by being sandwiched, and is detachably fixed to the wheel mounting cylinder 19 using each of the long bolts 43 described later.

  As shown in FIG. 5, a ring-shaped (annular) disk 23 is attached to the disk holding cylinder 22 in a non-rotating state, and the disk 23 is applied with a braking force by a disk brake 56 described later. Is done. That is, the rear wheel 7 and the wheel mounting cylinder 19 rotate integrally with the disk holding cylinder 22 and the disk 23, and the rotation during traveling is stopped (braking) by the braking force applied to the disk 23.

  Reference numeral 24 denotes a speed reduction mechanism provided between the cylindrical spindle 15 and the wheel mounting cylinder 19, and the speed reduction mechanism 24 includes a first stage planetary gear speed reduction mechanism 25 and a second stage planetary gear speed reduction mechanism 34, which will be described later. The rotation of the rotary shaft 18 is decelerated and transmitted to the wheel mounting cylinder 19 on the rear wheel 7 side.

  Reference numeral 25 denotes a first-stage planetary gear speed reduction mechanism provided in the cylindrical spindle 15 of the axle housing 12, and the planetary gear speed reduction mechanism 25 has a rotating shaft as shown in FIG. 3, FIG. 4, FIG. For example, three planetary gears 28 (only one) are engaged with the sun gear 26 splined to the tip end side of the 18 and the sun gear 26 and the inner teeth 27A of the ring gear 27 and rotate according to the rotation of the sun gear 26. And a carrier 30 which rotatably supports each planetary gear 28 via a support pin 29.

  The first stage carrier 30 is fixed to the annular convex portion 15A of the cylindrical spindle 15 in a non-rotating state and detachably using a bolt 31 (see FIG. 7) or the like. It is accommodated in the reducer accommodating space A of the cylindrical spindle 15 together with 28 and the like. Further, as shown in FIG. 7, a bearing 32 or the like is provided on the inner peripheral side of the carrier 30, and this bearing 32 applies a thrust load or the like from the rotating shaft 18 to smooth the rotation of the sun gear 26 and the like. It will be accepted.

  The first stage ring gear 27 is formed as a short cylindrical gear that surrounds the sun gear 26, the planetary gear 28, the support pin 29, the carrier 30, and the like from the outside in the radial direction, and is formed on the inner peripheral side of the cylindrical spindle 15. It arrange | positions so that relative rotation is possible via a small radial gap (for example, about 2-5 mm). Then, on the inner peripheral side of the ring gear 27, internal teeth 27A (see FIG. 7) that mesh with the planetary gears 28 are formed.

  Here, in the first stage planetary gear speed reduction mechanism 25, the revolution of the planetary gear 28 (rotation of the carrier 30) is restrained by fixing the carrier 30 to the cylindrical spindle 15. Then, when the sun gear 26 is integrally rotated by the rotating shaft 18 of the electric motor 17, the first stage planetary gear reduction mechanism 25 converts the rotation of the sun gear 26 into the rotation of the plurality of planetary gears 28.

  The planetary gear speed reduction mechanism 25 in the first stage takes out the rotation (rotation) of each planetary gear 28 as a reduced speed rotation of the ring gear 27 and rotates the rotation of the ring gear 27 through the coupling 33 described later to the second stage. Is transmitted to the planetary gear speed reduction mechanism 34.

  Further, as shown in FIG. 7, an oil passage 29A for supplying the lubricating oil 100 is formed in the support pin 29 of each planetary gear 28. The oil passage 29A is formed in the cylindrical spindle 15 in the axial direction. An after-mentioned conduit 45 extending is connected. Then, the lubricating oil 100 guided from the conduit 45 into the oil passage 29A is supplied so as to be injected toward the bearings 28A of the planetary gear 28, and the tooth surfaces of the bearings 28A and the planetary gear 28 are lubricated. It is something to keep in.

  Further, the carrier 30 of the planetary gear speed reduction mechanism 25 is provided with an oil passage 30A indicated by a dotted line in FIGS. 6 and 7, for example, at a position spaced apart from the planetary gear 28 in the circumferential direction. The branch pipe 49 and the conduit 50 are communicated with each other before and after the carrier 30. The carrier 30 is also provided with a fluid hole (not shown) through which brake fluid pressure flows between brake pipes 53 and 54 described later.

  Reference numeral 33 denotes a coupling as a rotation transmitting member that rotates integrally with the first stage ring gear 27, and the coupling 33 is provided between the first stage planetary gear reduction mechanism 25 and the second stage planetary gear reduction mechanism 34. The outer peripheral side is coupled to the first stage ring gear 27 by means such as a spline.

  Further, the inner peripheral side of the coupling 33 is coupled to a second stage sun gear 35 described later by means such as a spline. The coupling 33 transmits the rotation of the first-stage ring gear 27 to the second-stage sun gear 35 and rotates the sun gear 35 integrally with the ring gear 27 at the same speed. The coupling 33 has a plurality of oil holes through which the lubricating oil 100 in the first reduction gear housing space A flows toward the second reduction gear housing space B before and after the coupling 33 (see FIG. (Not shown) may be formed.

  Reference numeral 34 denotes a second-stage planetary gear reduction mechanism that is the final stage employed in the present embodiment, and the planetary gear reduction mechanism 34 is disposed between the cylindrical spindle 15 and the wheel mounting cylinder 19 in the first-stage planetary gear. It is arranged via a speed reduction mechanism 25 and, together with the first stage planetary gear speed reduction mechanism 25, reduces the rotation of the rotary shaft 18 and generates a large rotational torque in the wheel mounting cylinder 19.

  In this case, the planetary gear speed reduction mechanism 34 at the second stage is arranged so as to be coaxial with the rotary shaft 18 and rotates integrally with the coupling 33, and the internal teeth 36 </ b> A of the sun gear 35 and the ring gear 36. (See FIG. 7) and, for example, three planetary gears 37 (only one is shown) that rotate according to the rotation of the sun gear 35, and each planetary gear 37 is rotatably supported via a support pin 38. It is comprised by the carrier 39 grade | etc.,.

  The outer periphery of the second stage carrier 39 is fixed to the flange 15C of the cylindrical spindle 15 in a non-rotating state and detachably using a bolt 40 (see FIG. 7). As a result, the carrier 39 also serves as a lid that covers the reduction gear housing space A from the outside at the open end of the cylindrical spindle 15. Further, as shown in FIG. 7, a bearing 41 and the like are provided on the inner peripheral side of the carrier 39, and this bearing 41 supports the sun gear 35 between the coupling 33 so as to be rotatable from both sides in the axial direction. Yes.

  On the other hand, the second-stage ring gear 36 is formed as a short cylindrical body that surrounds the sun gear 35, the planetary gear 37, the support pin 38, the carrier 39 and the like from the outside in the radial direction, and the wheel mounting cylinder 19 and the disk holding cylinder 22. Are fixed integrally using a long bolt 43 described later. Then, on the inner peripheral side of the ring gear 36, internal teeth 36A (see FIG. 7) that mesh with the planetary gears 37 are formed.

  Here, in the second stage planetary gear speed reduction mechanism 34 as the final stage, the revolution of the planetary gear 37 (rotation of the carrier 39) is restrained by fixing the carrier 39 to the cylindrical spindle 15. Then, when the sun gear 35 rotates together with the coupling 33, the planetary gear speed reduction mechanism 34 at the second stage converts the rotation of the sun gear 35 into the rotation of the plurality of planetary gears 37, and this rotation (rotation). Is taken out from the ring gear 36 as a reduced speed rotation.

  That is, the ring gear 36 in this case is provided integrally with the wheel mounting cylinder 19 together with the disk holding cylinder 22. The wheel mounting cylinder 19 on the side of the rear wheel 7 is transmitted with a large output rotational torque reduced in two stages by the first stage planetary gear reduction mechanism 25 and the second stage planetary gear reduction mechanism 34. It is.

  Further, as shown in FIG. 7, an oil passage 38 </ b> A is formed in the support pin 38 of each planetary gear 37, and a later-described supply pipe 51 is connected to the oil passage 38 </ b> A from the outside of the carrier 39. Then, the lubricating oil 100 guided from the supply pipe 51 into the oil passage 38A is supplied so as to be injected toward the bearings 37A of the planetary gears 37, and the tooth surfaces of the bearings 37A and the planetary gears 37 are lubricated. It is something to keep in.

  Reference numeral 42 denotes an inner cap that covers the inner peripheral side of the carrier 39. The inner cap 42 is detachably provided on the inner peripheral side of the carrier 39 via a bolt or the like as shown in FIG. The carrier 39 is held in a retaining state. The inner cap 42 covers the opening end side of the cylindrical spindle 15 together with the carrier 39 to prevent the lubricating oil 100 and the like in the second reduction gear housing space B from leaking from the inside of the carrier 39. is there.

  43 are long bolts which are fixing means for fixing the disk holding cylinder 22 to the wheel mounting cylinder 19, and these long bolts 43 are arranged in the circumferential direction of the disk holding cylinder 22 as shown in FIG. Are attached at predetermined intervals. As shown in FIG. 6, the long bolt 43 is connected to the disk holding cylinder 22 and the ring gear 36 in addition to the wheel mounting cylinder 19 with the ring gear 36 sandwiched between the wheel mounting cylinder 19 and the disk holding cylinder 22. It is detachably fixed to the side tube portion 19B.

  Reference numeral 44 denotes a first lubricating oil supply path provided as a lubricating oil supply means provided in the axle housing 12, and this lubricating oil supply path 44 includes a conduit 45 extending in the axial direction in the cylindrical spindle 15 and each planet. The oil passage 29A and the like are formed in the support pin 29 of the gear 28. One side (base end side) of the conduit 45 is connected to the lubricating oil supply pipe 46 at the position of the partition plate 14C shown in FIG. It is connected to a lubricating oil pump (not shown).

  Further, the other side (tip side) of the conduit 45 is connected to an oil passage 29A of the support pin 29, and in this oil passage 29A, the lubricating oil discharged from the lubricating oil pump is connected to the supply pipe 46 and the conduit 45. Led through. The lubricating oil 100 in the oil passage 29A is supplied so as to be injected toward the bearings 28A of the planetary gear 28, and the tooth surfaces of the bearings 28A and the planetary gear 28 are kept in a lubrication state.

  Note that a plurality of (for example, three) planetary gears 28 are attached to the first stage carrier 30 via support pins 29, and other planetary gears 28 not shown in FIG. Lubricating oil is similarly supplied from a midway position of the conduit 45 through a branch pipe (not shown) branched by a joint 48 described later.

  Reference numeral 47 denotes a second lubricating oil supply path serving as a lubricating oil supply means for supplying the lubricating oil 100 to the second stage planetary gear speed reduction mechanism 34. The lubricating oil supply path 47 is connected to the conduit 45 as shown in FIG. The branch pipe 49 branched from the middle position of the branch pipe 49 through the joint 48, the oil passage 30A of the carrier 30 to which the tip side of the branch pipe 49 is connected, and the branch pipe 49 connected to the branch pipe 49 via the oil passage 30A. It is constituted by a lubricating oil conduit 50 and a supply pipe 51 described later.

  Here, the lubricating oil conduit 50 extends in the axial direction with a gap inside the second stage sun gear 35 as shown by a two-dot chain line in FIGS. 6 and 7, and the tip end side is attached to the inner cap 42. Yes. A supply pipe 51 (described later) is connected to the end of the conduit 50 drawn out from the inner cap 42. Further, the proximal end side of the conduit 50 is connected to the branch pipe 49 via the oil passage 30A or the like drilled in the first stage carrier 30 as described above.

  , 51 are supply pipes as other conduits for supplying the lubricating oil 100 to the second stage planetary gear speed reduction mechanism 34, and these supply tubes 51 are outside the carrier 39 as shown in FIG. It is connected to an oil passage 38A (see FIG. 7) of each support pin 38 at a position. Further, these supply pipes 51 are connected to a conduit 50 or the like indicated by a two-dot chain line in FIG. 7, and lubricating oil is supplied from the branch pipe 49 side. The lubricating oil 100 is supplied in an injection state into the oil passages 38 </ b> A of the support pins 38 through the supply pipes 51.

  52 is a return pipe provided outside the inner cap 42. This return pipe 52 is connected to the most downstream side of the supply pipe 51 as shown in FIG. 7 to return to the inside of the inner cap 42. The return oil (lubricating oil) is supplied to the bearing 41 and the like between the inner cap 42 and the sun gear 35, and then gradually falls and stored in an oil reservoir 58 described later.

  A brake pipe 53 is disposed in the cylindrical sun gear 35 with a gap and extends in the axial direction. Like the lubricating oil conduit 50, the brake pipe 53 is attached to the inner cap 42 from the inner cap 42. Has been pulled out. Further, the base end side (one side) of the brake pipe 53 extends toward the first-stage carrier 30, and the other through the above-described liquid hole (not shown) drilled in the first-stage carrier 30. The brake pipe 54 is connected.

  As shown in FIGS. 4 and 6, the other brake pipe 54 extends in the reduction gear housing space A of the cylindrical spindle 15 in the axial direction, and its base end side is a hydraulic pressure for a brake mounted on the vehicle. It is connected to a master cylinder (not shown) via a control valve or the like. When the brake is operated, the brake fluid pressure from the master cinder is supplied from the brake pipe 54 toward the brake pipe 53.

  Further, the front end side of the brake pipe 53 drawn out from the inner cap 42 is connected to a total of three branch pipes 55, 55,... (See FIG. 5) made of, for example, a flexible hose. These branch pipes 55 supply the brake fluid pressure from the brake pipe 53 side to each disk brake 56 described later.

  56, 56,... Are a plurality of disc brakes that constitute a brake means together with the disc 23. Each disc brake 56 is externally (decelerated) on the second stage carrier 39 as a final stage as shown in FIG. It is attached using bolts 56A and the like from the outside of the machine housing space A). Further, a total of three disc brakes 56 are provided at intervals in the circumferential direction of the disc 23 as shown in FIG.

  The disc brake 56 clamps the disc 23 from both sides in the axial direction by supplying the brake fluid pressure from the master cylinder via the brake pipes 54 and 53 and the branch pipes 55. A braking force is applied to the wheel mounting cylinder 19 (rear wheel 7) that rotates integrally.

  57 is an oil sump provided in the cylindrical spindle 15, and this oil sump 57 is formed at a position below the first reduction gear housing space A described above, and is a first stage planetary gear speed reduction mechanism. For example, the lubricating oil 100 supplied to the sun gear 26 and the planetary gears 28 constituting the gear 25 is accommodated at the liquid level shown in FIG. 6, for example.

  58 is an oil sump provided in the wheel mounting cylinder 19, and this oil sump 58 is formed at a position below the second reduction gear housing space B and the annular space C described above. The lubricating oil 100 supplied to the sun gear 35 and the planetary gears 37 constituting the planetary gear speed reduction mechanism 34 in the final stage is accommodated together with the oil reservoir 57 in the cylindrical spindle 15.

  In this case, the lubricating oil 100 in the oil reservoirs 57 and 58 has a liquid level lower than the center axis (the conduit 45 described later) of the planetary gear 28 and the support pin 29 in order to keep the stirring resistance of the oil liquid small. (For example, the liquid level shown in FIG. 6).

  That is, the oil amount of the lubricating oil 100 accommodated in the oil reservoirs 57 and 58 is set to a necessary minimum oil amount (for example, about 1/5 to 1/3 of the internal volume). As a result, the lubricating oil 100 in the oil reservoirs 57, 58 causes the rotational resistance (viscosity resistance of the lubricating oil) to be applied to the ring gears 27, 36 of the planetary gear reduction mechanisms 25, 34, the rotating planetary gears 28, 37, the coupling 33, and the like. , And the bearings 20 and 21 and the ring gears 27 and 36 are always kept in a lubricated state.

  Reference numeral 59 denotes an oil groove serving as an oil passage for connecting the oil reservoirs 57 and 58 between the cylindrical spindle 15 and the carrier 39. The oil groove 59 extends upward and downward from the end surface of the carrier 39 as the final stage. It is formed by notching and extends downward along the flange 15C of the cylindrical spindle 15 as shown in FIGS. That is, the oil groove 59 is formed in the uppermost and lowermost lower part of the carrier 39, and ensures an oil passage for the lubricating oil 100 between the flange 15 </ b> C of the cylindrical spindle 15 and the end surface of the carrier 39. Is.

  The radially inner side and the outer side of the carrier 39 are always in communication with each other through the oil groove 59, and lubrication supplied into the first and second reduction gear housing spaces A and B (oil reservoirs 57 and 58). The oil 100 flows through the oil groove 59 toward a position on the lower side of the wheel mounting cylinder 19. That is, the lubricating oil 100 stored in the cylindrical spindle 15 out of the oil reservoirs 57 and 58 flows down along the oil groove 59 on the end face side of the flange portion 15C, and the cylindrical spindle 15 (oil reservoir 57). The liquid level of the lubricating oil 100 is made uniform by the oil groove 59 between the inside and the wheel mounting cylinder 19 (oil sump 58).

  Reference numeral 60 denotes an oil hole as another oil passage provided on the inner peripheral side of the cylindrical spindle 15, and the oil hole 60 is located below the first stage carrier 30 as shown in FIGS. 6 and 7. Positioned and formed on the annular convex portion 15 </ b> A of the cylindrical spindle 15. The oil hole 60 extends through the annular protrusion 15A forward and rearward (in the axial direction). Thereby, the lubricating oil 100 stored in the oil reservoir 57 in the first reduction gear housing space A (cylindrical spindle 15) flows through the oil hole 60 before and after the carrier 30, and its liquid level. Is always made uniform before and after the oil hole 60.

  61 is a drain hole formed in the lowermost part of the wheel mounting cylinder 19, and this drain hole 61 extends in the axial direction through the ring gear 36 and the disk holding cylinder 22, as shown in FIGS. The distal end side is detachably closed by a plug 62. When the plug 62 is removed, the lubricating oil 100 accumulated in the oil reservoirs 57 and 58 (the wheel mounting cylinder 19) can be discharged to the outside through the drain hole 61.

  63 is a sealing device that seals the space between the cylindrical spindle 15 and the wheel mounting cylinder 19 in a liquid-tight manner, and the sealing device 63 is constituted by a so-called floating seal as shown in FIGS. 4, 6, and 8. . The sealing device 63 prevents the lubricating oil 100 accommodated in the annular space C between the cylindrical spindle 15 and the wheel mounting cylinder 19 from leaking to the outside of the retainer 64 described later, and earth and sand, rainwater, etc. Intrusion into the annular space C is prevented.

  Here, as shown in FIG. 8, the sealing device 63 includes a stationary retainer 64 sandwiched between the motor housing cylinder 14 of the axle housing 12 and the cylindrical spindle 15 via a bolt 16 and the like, and a wheel mounting cylinder. A retainer 66 on the rotating side, which is located in the retainer mounting portion 19E of 19 and is attached to the end surface on one axial side via a bolt 65 or the like, and a pair of O as a seal member between these retainers 64, 66 The ring 67 is composed of a pair of seal rings 68 and 68 disposed so as to be opposed to each other in the axial direction.

  The seal device 63 elastically deforms the pair of O-rings 67 between the retainers 64 and 66 and the seal rings 68 and 68 to seal between the retainers 64 and 66 and the respective O-rings 67, and the O-ring. An axial pressing force is applied to each seal ring 68 with an elastic restoring force of 67. As a result, the pair of seal rings 68 and 68 come in sliding contact with each other in the axial direction, and seal the sliding contact surfaces of both in a liquid-tight manner.

  Further, as shown in FIG. 8, the fixed-side retainer 64 has a cylindrical portion 64A that is fitted to the outer peripheral side of the cylindrical spindle 15, and projects radially inward from the base end side of the cylindrical portion 64A. 14 and an annular protrusion 64B sandwiched between the cylindrical spindle 15 and an annular flange 64D that protrudes radially outward from the base end side of the cylinder 64A and is integrally formed with a holding part 64C of an O-ring 67. It is comprised by.

  An annular protrusion 64B of the retainer 64 has a shim plate, which will be described later, on an end surface on one axial side (base end side) of the cylindrical spindle 15 when the cylindrical portion 64A is fitted to the outer peripheral side of the cylindrical spindle 15. 70, and is fixed to the end surface side of the cylindrical spindle 15 by a bolt 69. The retainer 64 constitutes a seal attachment body that is a part of a lubricating oil discharge portion 71 described later, and a discharge tube 72 described later is connected to the flange portion 64D.

  Reference numeral 70 denotes a shim plate sandwiched between a fixed-side retainer 64 and the cylindrical spindle 15 using a bolt 69, and the shim plate 70 extends in the circumferential direction along the proximal end surface of the cylindrical spindle 15. It is formed as an annular flat plate. The shim plate 70 variably adjusts the distance S (see FIG. 8) between the annular protrusion 64B of the retainer 64 and the end surface of the cylindrical spindle 15 in accordance with the thickness or number of the shim plates.

  In this case, the cylindrical portion 64A of the retainer 64 fitted to the outer peripheral side of the cylindrical spindle 15 is in contact with the inner ring of the bearing 20 at its distal end side, and the axial set load (thrust load) on the bearing 20 is applied to the shim plate. It is variably adjusted according to the thickness or the number of sheets. Further, the other bearings 21 arranged between the cylindrical spindle 15 and the wheel mounting cylinder 19 are also in contact with the flange 15C side of the cylindrical spindle 15 as shown in FIG. The set load (thrust load) of the bearing 21 is variably adjusted according to the thickness or number of shim plates 70.

  Reference numeral 71 denotes a lubricating oil discharge portion serving as a lubricating oil discharge means for sucking and discharging the lubricating oil 100 in the oil reservoirs 57 and 58 to the outside of the wheel mounting cylinder 19, and the lubricating oil discharge portion 71 includes the retainer 64 described above. It is configured by connecting a discharge pipe 72 to the flange portion 64D. Here, the lubricating oil discharge pipe 72 is disposed at the lowermost position between the cylindrical spindle 15 and the wheel mounting cylinder 19.

  The discharge pipe 72 is supplied with, for example, the lubricating oil 100 supplied in the first and second reduction gear housing spaces A and B and the annular space C and stored in the oil reservoirs 57 and 58 as described above. The oil is discharged while being sucked in the direction of arrow D in FIGS. 6 and 8 toward the outside of the annular space C by an oil pump or the like.

  In this case, the discharge pipe 72 is attached to the retainer 64 with one end portion serving as a suction port 72A, and this suction port 72A is equivalent to the roller (roller) of the bearing 20 below the cylindrical spindle 15. It is arranged at the height position. The discharge pipe 72 is drawn out of the axle housing 12 (motor housing cylinder 14) through the retainer 64 from the position of the suction port 72A. Further, the other end 72B on the downstream side of the discharge pipe 72 is attached to the large-diameter portion 14A side of the motor housing cylinder 14, and other pipes, filters, and the like from the suspension cylinder 13 side of the axle housing 12 shown in FIG. It is connected to the suction side of the lubricating oil pump via a cooling device (both not shown).

  Further, a detector (not shown) for detecting the level of the lubricating oil 100 accommodated in the oil reservoirs 57 and 58, for example, is provided on the small diameter portion 14B side of the motor accommodating cylinder 14. When the liquid level in the oil reservoirs 57, 58 becomes higher than a predetermined reference liquid level, the lubricating oil 100 in the oil reservoirs 57, 58 is discharged to the outside through the drain hole 61, for example. The

  As a result, the lubricating oil 100 in the oil reservoirs 57 and 58 becomes the liquid level illustrated in FIG. 6 (e.g., equivalent to or slightly lower than the central axis of the planetary gear 28 and the support pin 29). Liquid level). The lubricating oil discharged from the discharge pipe 72 is supplied to the supply pipe 46 side again after removing foreign substances with the filter and being cooled with the cooling device.

  73 is an air discharge pipe provided on the partition plate 14C of the motor housing cylinder 14. The air discharge pipe 73 is attached to the upper side of the partition plate 14C as shown in FIG. Exhaust air to the outside. Thereby, the inside of the cylindrical spindle 15 and the wheel mounting cylinder 19 is always kept at a pressure equal to or lower than the atmospheric pressure.

  74 is another sealing device disposed at a position on the outer side in the axial direction of the wheel mounting cylinder 19, and the sealing device 74 is configured as a so-called floating seal, and as shown in FIGS. 6 and 7, the disk holding cylinder 22. And a final stage (second stage) carrier 39 via a stationary retainer 74A and the like. The sealing device 74 is also configured in substantially the same manner as the sealing device 63 shown in FIGS. 6 and 8 disposed on one side (inside) in the axial direction of the wheel mounting cylinder 19, and is in the second reduction gear housing space B. This prevents the lubricating oil 100 from leaking to the outside from between the disk holding cylinder 22 and the retainer 74A on the carrier 39 side, and prevents the entry of external earth and sand, rainwater, and the like.

  75 is a wedge member that detachably fixes the rear wheel 7 to the outer peripheral side of the wheel mounting cylinder 19, and the wedge member 75 is arranged from the outer side in the axial direction of the wheel mounting cylinder 19 as shown in FIGS. 3 and 4. 7 is fitted between the rim 7B and the wheel mounting cylinder 19, and the rear wheel 7 is prevented from being pulled out of the wheel mounting cylinder 19 and held in a rotating state.

  For this reason, ten or more wedge members 75 are provided at intervals in the circumferential direction of the wheel mounting cylinder 19, and the rear wheel 7 is removed from the wheel mounting cylinder 19 by detaching these wedge members 75. is there. 6 to 8 show a state in which the rear wheel 7 and the wedge member 75 are removed from the outer peripheral side of the wheel mounting cylinder 19.

  1 is a hoisting cylinder for hoisting the vessel 3 of the lift truck 1 shown in FIG. 1, and the hoisting cylinder 76 is positioned between the front wheel 6 and the rear wheel 7 as shown in FIG. It is arranged on both the left and right sides. The undulation cylinder 76 expands and contracts in the upward and downward directions when pressure oil is supplied and discharged from the outside, and undulates (tilts) the vessel 3 around the pin coupling portion 4 on the rear side.

  Reference numeral 77 denotes a hydraulic oil tank. The hydraulic oil tank 77 is positioned below the vessel 3 and attached to the side surface of the vehicle body 2 as shown in FIG. The hydraulic oil stored in the hydraulic oil tank 77 is supplied to and discharged from the hoisting cylinder 76 and the power steering steering cylinder as pressure oil by the hydraulic pump.

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

  First, when a driver who has entered the cabin 5 of the dump truck 1 starts the engine 8 shown in FIG. 2, a hydraulic pump (not shown) serving as a hydraulic source is rotationally driven and power is generated by the alternator 9. The electricity is supplied to the electric controller 10 and the like while the electricity is charged in the battery and the like.

  When the vehicle is driven to travel, a drive current is supplied from the electric controller 10 to each electric motor 17 on the rear wheel 7 side. At this time, the electric controller 10 determines the rotational speeds of the left and right electric motors 17 and 17. Individual feedback control. As a result, the left and right rear wheels 7 and 7 serving as drive wheels of the vehicle are driven to rotate independently of each other, and are driven at the same rotational speed when traveling straight ahead.

  That is, the traveling drive device 11 provided on the rear wheel 7 side of the dump truck 1 reduces the rotation of the electric motor 17 (rotating shaft 18) by, for example, about 30 to 40 by the multi-stage planetary gear reduction mechanisms 25 and 34. The rear wheel 7 serving as a driving wheel is driven to travel with a large rotational torque together with the wheel mounting cylinder 19. The left and right rear wheels 7 are driven by the left and right electric motors 17 at independent rotation speeds.

  Further, in the first-stage and second-stage planetary gear speed reduction mechanisms 25, 34, etc., the lubricating oil 100 discharged from the on-vehicle lubricating oil pump (supply source) is supplied with the first lubrication through the supply pipe 46 shown in FIG. The oil is supplied to the oil supply path 44 and the second lubricating oil supply path 47, and the sun gears 26 and 35, the planetary gears 28 and 37, etc. are kept in a lubrication state. Then, the lubricating oil 100 at this time is sequentially dropped and stored in the lower oil reservoirs 57 and 58 by the action of gravity while lubricating the respective tooth surfaces and the like.

  In this case, in the first lubricating oil supply passage 44, the lubricating oil 100 guided from the supply piping 46 through the conduit 45 into the oil passage 29 </ b> A of the support pin 29 is directed toward the bearings 28 </ b> A of the planetary gears 28. Let spray. Then, each planetary gear 28 that rotates can guide the lubricating oil 100 to the outside in the radial direction by the centrifugal force due to the rotation, and keep the meshing surfaces and the like of the planetary gear 28, the sun gear 26, and the ring gear 27 in a lubricated state. it can.

  Further, in the second lubricating oil supply passage 47, as illustrated in FIG. 6, the branch pipe 49 branched from the middle position of the conduit 45 through the joint 48, the oil passage 30A in the carrier 30, the conduit 50, and each supply The lubricating oil 100 introduced into the oil passage 38A of the support pin 38 through the pipe 51 (see FIG. 5) or the like is injected toward the bearings 37A of the planetary gears 37 and the like. These planetary gears 37 can guide the lubricating oil 100 to the outside in the radial direction by the centrifugal force generated by the rotation, and keep the meshing surfaces of the planetary gears 37, the sun gear 35, the ring gear 36, and the like in a lubricated state. .

  A return pipe 52 is connected to the most downstream side of the supply pipe 51 shown in FIG. 5, and excess lubricating oil in the supply pipe 51 is returned to the inside of the inner cap 42 by the return pipe 52. The return oil (lubricating oil) is supplied to the bearing 41 and the like between the inner cap 42 and the sun gear 35 and then gradually dropped into the oil reservoir 58 and stored.

  Further, the lubricating oil 100 accommodated in the oil reservoirs 57 and 58 is sequentially lifted upward by the internal teeth 27A and 36A of the rotating first-stage and second-stage ring gears 27 and 36, and the planetary gears are decelerated. It is possible to perform scraping lubrication or the like for the mechanisms 25 and 34. Then, the lubricating oil 100 stored in the oil reservoir 57 in the first reduction gear housing space A (cylindrical spindle 15) is positioned below the first stage carrier 30 and is annular in the cylindrical spindle 15. It is possible to circulate before and after the carrier 30 through the oil hole 60 formed in the convex portion 15 </ b> A, and make the liquid level always uniform before and after the oil hole 60.

  Further, between the last stage carrier 39 and the flange 15C of the cylindrical spindle 15, the end surface of the carrier 39 is cut upward and downward to extend downward along the flange 15C of the cylindrical spindle 15. An oil groove 59 is provided. Since the lubricating oil 100 stored in the cylindrical spindle 15 out of the oil reservoirs 57 and 58 flows down along the oil groove 59 on the end face side of the flange portion 15C, the liquid level is changed to the cylindrical shape. The oil groove 59 can equalize the inside of the spindle 15 and the wheel mounting cylinder 19.

  On the other hand, a seal device 63 that seals the lubricating oil 100 in the annular space C is provided between the cylindrical spindle 15 and the wheel mounting cylinder 19, and a retainer 64 that serves as a seal mounting body of the seal device 63 is provided in the retainer 64. The discharge pipe 72 of the lubricating oil discharge portion 71 is connected to the lowermost portion of the cylindrical spindle 15 and the wheel mounting cylinder 19. And the edge part used as the downstream of the discharge pipe 72 is connected to the suction side of the said lubricating oil pump through a filter, a cooling device (all are not shown), etc.

  Thus, when this lubricating oil pump is operated, the lubricating oil 100 discharged from the lubricating oil pump is supplied to the first and second planetary gear reduction mechanisms 25, 34, etc., as the first and second lubricating oils. The lubricating oil 100 that can be supplied from the supply passages 44 and 47 and stored in the oil reservoirs 57 and 58 can be forcibly discharged from the discharge pipe 72 to the outside. At this time, foreign matter in the discharged oil (lubricating oil) can be removed by filtering with the filter, and the lubricating oil can be cooled by the cooling device.

  By the way, in the oil reservoirs 57 and 58 provided in the cylindrical spindle 15 and the wheel mounting cylinder 19, the lubricating oil 100 supplied to the speed reduction mechanism 24 and the like is gradually dropped and stored. On the bottom side of 58, foreign matter such as wear powder and metal powder tends to stay, and the oil temperature of the lubricating oil 100 tends to increase.

  Therefore, according to the present embodiment, the axle housing 12 provided on the rear wheel 7 side of the vehicle is provided with the motor housing cylinder 14, the cylindrical spindle 15 provided detachably on the outer side in the axial direction of the motor housing cylinder 14, and the like. The lubricating oil 100 in the oil reservoirs 57 and 58 is externally passed from the annular space C between the wheel mounting cylinder 19 and the cylindrical spindle 15 to the lower part on the outer peripheral side of the cylindrical spindle 15. The lubricating oil discharge part 71 which is sucked into and discharged in the direction of arrow D is provided.

  The lubricating oil discharge portion 71 is more than the cylindrical spindle 15 with respect to the retainer 64 of the seal device 63 that seals the lubricating oil 100 in the annular space C between the cylindrical spindle 15 and the wheel mounting cylinder 19. The suction pipe 72 </ b> A of the discharge pipe 72 is connected at a lower position, and the discharge pipe 72 discharges the lubricating oil 100 in the annular space C from the suction opening 72 </ b> A to the outside of the retainer 64. .

  For this reason, when the lubricating oil 100 in the oil reservoirs 57, 58 is sucked and discharged from the suction port 72 </ b> A of the discharge pipe 72, the lubricating oil 100 is annular between the cylindrical spindle 15 and the wheel mounting cylinder 19. It is discharged to the outside through the space C, and it is possible to prevent the old lubricating oil 100 having a high oil temperature from staying in the annular space C, and the circulation (discharge) performance of the lubricating oil 100 in the annular space C Can be increased.

  The bearings 20 and 21 provided between the cylindrical spindle 15 and the wheel mounting cylinder 19 can be supplied with highly circulated lubricating oil 100 that circulates in the annular space C toward the suction port 72A of the discharge pipe 72. The bearings 20 and 21 can always be kept in a lubrication state with the new lubricating oil 100, and the lubricating oil 100 at this time is smoothly discharged to the outside of the wheel mounting cylinder 19 (annular space C) via the discharge pipe 72. be able to.

  Further, since an oil groove 59 as an oil passage is provided at the lowermost portion between the carrier 39 of the final stage and the cylindrical spindle 15, for example, the lubricating oil 100 supplied from the lubricating oil supply passage 44. Can be smoothly circulated from the cylindrical spindle 15 into the wheel mounting cylinder 19 through the oil groove 59, and the circulation performance of the lubricating oil 100 between the cylindrical spindle 15 and the wheel mounting cylinder 19 can be enhanced.

  In addition, since the oil hole 60 is formed in the annular convex portion 15A of the cylindrical spindle 15 below the first stage carrier 30, the first reduction gear housing space A (cylindrical spindle) is formed. 15) The lubricating oil 100 stored in the oil reservoirs 57 and 58 can be circulated in front of and behind the carrier 30 through the oil holes 60, and the liquid level is set in front of the oil holes 60, It can always be homogenized later.

  In addition, since the carriers 30 and 39 of the planetary gear speed reduction mechanisms 25 and 34 are provided on the cylindrical spindle 15 in a non-rotating state, the rotation of the carriers 30 and 39 can be restricted by the cylindrical spindle 15. , 39 is not required to be specially managed, and load distribution of the plurality of support pins 29, 38 and the planetary gears 28, 37 assembled to the carriers 30, 39 can be easily performed. it can.

  The carriers 30 and 39 have sufficient rigidity to support the plurality of planetary gears 28 and 37 so as to be rotatable, and can be formed into a sturdy structure. It can be used as a strength member for the rotating portion (for example, the cylindrical spindle 15), and the strength and rigidity of the entire apparatus can be increased. Further, this can reduce the thickness of the cylindrical spindle 15 and reduce the weight.

  Therefore, according to the present embodiment, it is possible to improve workability and productivity in manufacturing the carriers 30, 39 and the like, and to improve workability when the planetary gear speed reduction mechanisms 25, 34 are assembled. Can do. Further, the new lubricating oil 100 in the oil sump 57, 58 can be continuously supplied to the ring gears 27, 36 of the planetary gear speed reduction mechanisms 25, 34, and the durability of the bearings 20, 21 and the ring gears 27, 36, etc. can be maintained. And can improve the service life.

  Further, the lubricating oil 100 in the oil reservoirs 57 and 58 can be efficiently circulated toward the discharge pipe 72, and the discharge amount (the amount of oil sucked by the lubricating oil pump) on the discharge pipe 72 side is the lubricating oil. More than the supply amount of 100, for example, it is possible to eliminate problems such as lack of lubricating oil in the wheel mounting cylinder 19 (annular space C).

  As a result, fresh lubricating oil can be smoothly supplied to the bearings 20 and 21 provided between the cylindrical spindle 15 and the wheel mounting cylinder 19 so that the durability and life of the bearings 20 and 21 can be improved. it can. Further, by reducing the amount of the lubricating oil 100 accommodated in the cylindrical spindle 15 and the wheel mounting cylinder 19 to the necessary minimum liquid level, the stirring resistance in the apparatus can be reduced and heat generation can be suppressed. At the same time, the rotational load of the apparatus can be reduced.

  Further, since the first stage planetary gear speed reduction mechanism 25 is accommodated inside the cylindrical spindle 15, the dimension of the second stage planetary gear speed reduction mechanism 34 projecting outward from the cylindrical spindle 15 in the axial direction is set. The axial length (full length) of the entire travel drive device 11 can be shortened, and the entire device can be reduced in size and weight.

  In addition, since the carriers 30 and 39 of the planetary gear speed reduction mechanisms 25 and 34 are provided on the cylindrical spindle 15 in a non-rotating state, the support pins 29 and 38 that rotatably support the planetary gears 28 and 37 are provided on the carrier 30. , 39 can be maintained in a non-rotating state, and the conduits 45, 50 of the lubricating oil supply passages 44, 47 can be stably connected to the oil passages 29A, 38A in the support pins 29, 38. .

  Such support pins 29, 38 are arranged at regular intervals around the sun gears 26, 35 and form the center of rotation of the planetary gears 28, 37. The lubricating oil supplied into the 38 oil passages 29A, 38A can be injected radially by the action of centrifugal force accompanying the rotation of the planetary gears 28, 37. For example, the planetary gears 28, 37 and the sun gears 26, 35 can be injected. The lubricating oil refined in the form of a mist can be supplied almost evenly to the meshing surfaces of the gears, the meshing surfaces of the planetary gears 28 and 37 and the ring gears 27 and 36, and the like.

  Thereby, the lubricating oil can be efficiently supplied to the speed reduction mechanism 24, and the durability and life of each component (gear) of the speed reduction mechanism 24 can be improved. The lubricating oil supplied to the meshing surfaces of the gears is stored in the oil reservoirs 57 and 58 by natural fall, and can lubricate, for example, the internal teeth 27A and 36A of the ring gears 27 and 36, and the rotating wheels. The bearings 20, 21 and the like can be kept in a lubrication state between the mounting cylinder 19 and the non-rotating cylindrical spindle 15.

  Further, in the carrier 30 provided in a non-rotating state in the cylindrical spindle 15, an oil passage 30A is formed at a position spaced apart from each planetary gear 28 in the circumferential direction as shown by a dotted line in FIGS. The branch pipe 49 and the conduit 50 of the lubricating oil supply passage 47 can be communicated with each other by the oil passage 30A before and after the carrier 30, and the oil passage 30A of the carrier 30 can be used as a lubricating oil supply passage.

  In the above-described embodiment, the lubricating oil 100 is circulated between the cylindrical spindle 15 and the wheel mounting cylinder 19 by the oil groove 59 formed by notching the end surface of the carrier 39 which is the final stage upward and downward. The case where the oil passage is configured has been described as an example. However, the present invention is not limited to this. For example, as shown in the modification shown in FIG. 9, the oil passage 59 'is constituted by an oil groove formed by cutting the end surface of the cylindrical spindle 15 upward and downward. May be.

  On the other hand, as shown by a two-dot chain line in FIG. 9, an oil passage 59 ″ is formed in the lower part of the carrier 39 as the final stage, and the oil reservoir 57 and the wheel in the cylindrical spindle 15 are formed by this oil passage 59 ″. The oil sump 58 in the mounting cylinder 19 may be configured to communicate with each other. In this case, the oil passage is provided in at least one of the carrier 39 and the cylindrical spindle 15 at a position on the axially outer side (the side of the carrier 39 at the final stage) from the bearing 21 shown in FIG. What should I do?

  In the above-described embodiment, the case where the first stage carrier 30 is fixed to the annular convex portion 15 </ b> A of the cylindrical spindle 15 with the bolt 31 has been described as an example. However, the present invention is not limited to this. For example, the first stage carrier may be integrally formed in the cylindrical spindle 15 using means such as casting or forging. It is sufficient that the configuration is provided in a non-rotating state.

  In the above-described embodiment, the case where the second stage carrier 39 is fixed to the flange portion 15 </ b> C of the cylindrical spindle 15 using the bolt 40 has been described as an example. However, the present invention is not limited to this. For example, the final stage carrier may be integrally formed on the opening end side of the cylindrical spindle 15 using means such as casting or forging.

  In the above-described embodiment, the case where the speed reduction mechanism 24 is configured by the first-stage and second-stage planetary gear speed reduction mechanisms 25 and 34 has been described as an example. However, the present invention is not limited to this. For example, the speed reduction mechanism may be configured by a planetary gear speed reduction mechanism having three or more stages.

  In the above embodiment, the case where the electric motor 17 is used as a drive source has been described as an example. However, the present invention is not limited to this. For example, a hydraulic motor or the like may be used as a drive source of the travel drive device.

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

It is a front view which shows the dump truck by embodiment of this invention. It is a block diagram which shows the traveling drive apparatus of a dump truck. It is the expanded sectional view which looked at the traveling drive device on the rear-wheel side from the direction of arrows III-III in Drawing 1 in the state where the wheel cap was removed. It is sectional drawing which expands and shows the motor accommodation cylinder, cylindrical spindle, wheel attachment cylinder, planetary gear reduction mechanism, etc. in FIG. It is a left view of FIG. 4 which expands and shows a disc brake etc. It is sectional drawing which expands and shows the wheel attachment cylinder in FIG. 4, a planetary gear reduction mechanism, etc. It is sectional drawing which expands further and shows the planetary gear reduction mechanism etc. in FIG. It is sectional drawing which expands and shows the sealing apparatus etc. which were provided between the cylindrical spindle in FIG. 6, and a wheel attachment cylinder. It is sectional drawing of the position substantially the same as FIG. 7 which shows the modification of an oil path.

Explanation of symbols

1 Dump truck 2 Car body 3 Vessel 5 Cabin 6 Front wheel 7 Rear wheel (wheel)
8 Engine 9 Alternator (generator)
DESCRIPTION OF SYMBOLS 10 Electric controller 11 Travel drive device 12 Axle housing 13 Suspension cylinder 14 Motor accommodating cylinder 15 Cylindrical spindle 17 Electric motor (drive source)
18 Rotating shaft 19 Wheel mounting cylinder 20, 21 Bearing 22 Disk holding cylinder 23 Disk 24 Reduction mechanism 25, 34 Planetary gear reduction mechanism 26, 35 Sun gear 27, 36 Ring gear 28, 37 Planetary gear 29, 38 Support pin 30, 39 Carrier 33 Coupling 44, 47 Lubricating oil supply path (lubricating oil supply means)
56 Disc brake 57, 58 Oil reservoir 59 Oil groove (oil passage)
59 ', 59 "Oil passage 60 Oil hole (other oil passage)
61 Drain hole 63, 74 Seal device 64 Retainer 67 O-ring (seal member)
71 Lubricating oil discharging part (lubricating oil discharging means)
72 discharge pipe 75 wedge member 76 undulation cylinder 100 lubricating oil

Claims (4)

A cylindrical axle housing that is attached to the body of the dump truck in a non-rotating state, a rotating shaft that extends in the axial direction in the axle housing and is driven to rotate by a drive source, and a bearing on the outer peripheral side of the axle housing A wheel mounting cylinder rotatably provided via a wheel, and a multi-stage planetary gear provided between the wheel mounting cylinder and the axle housing and transmitting the rotation of the rotary shaft to the wheel mounting cylinder at a reduced speed. In a traveling drive device for a dump truck comprising a gear reduction mechanism, and each of the planetary gear reduction mechanisms of each stage is constituted by a sun gear, a ring gear, a plurality of planetary gears, and a carrier.
The carrier constituting the planetary gear reduction mechanism of each stage is configured to be provided in a non-rotating state in the axle housing,
In the interior of the axle housing and the interior of the wheel mounting cylinder, an oil sump is provided for storing the lubricating oil supplied to the planetary gear speed reduction mechanism in each stage at the lower position in the upper and lower directions,
A configuration is provided in which at least one of the carrier of the last stage and the axle housing among the carriers is provided with an oil passage through which the lubricating oil in each oil reservoir is circulated between the axle housing and the wheel mounting cylinder. A dump truck travel drive device characterized by that.   The first-stage carrier of each of the carriers is provided inside the axle housing, and the inner side of the axle housing is positioned below the first-stage carrier, before and after the carrier. The dump truck traveling drive apparatus according to claim 1, wherein another oil passage through which lubricating oil is circulated is provided.   Lubricating oil supply means for supplying lubricating oil to the planetary gear speed reduction mechanism is provided in the axle housing, and the upper and lower portions on the outer peripheral side of the axle housing are arranged in the oil reservoir. The dump truck travel drive apparatus according to claim 1 or 2, further comprising a lubricating oil discharging means for sucking and discharging the lubricating oil from between the wheel mounting cylinder and the axle housing to the outside.   A plurality of the bearings are provided between the axle housing and the wheel mounting cylinder, and the oil passage through which the lubricating oil is circulated between the axle housing and the wheel mounting cylinder is more than the final stage than the plurality of bearings. The travel drive device for a dump truck according to claim 1, 2 or 3, wherein the drive device is arranged at a position close to the carrier.

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