JP2006168541A - Wheel motor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a hydraulic motor unit in a wheel motor device constituted so as to independently drive a driving axle by the hydraulic motor unit. <P>SOLUTION: A radial piston type hydraulic motor unit constitutes a HST in cooperation with an axle housing connected to a vehicle frame and a hydraulic pump unit separately arranged therefrom, and a wheel motor device comprises the hydraulic motor unit having an oil receiving member with at least a part thereof being located in an internal space of the axle housing, a hydraulic motor body which is arranged in the internal space of the axle housing in an oil pumping and relatively rotatable manner with respect to the oil receiving member, and a motor shaft which is not relatively rotatable with respect to the hydraulic motor body, and a deceleration transmission unit which is arranged in the internal space of the axle housing to perform the deceleration transmission of the rotational output of the hydraulic motor body to a driving axle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wheel motor device provided for each drive axle, and relates to a wheel motor device that cooperates with a hydraulic pump unit to independently drive a drive axle.

  A wheel motor device provided with a hydraulic motor unit that forms a continuously variable transmission in cooperation with spaced hydraulic pump units, and is installed in a vehicle frame so that a corresponding drive axle can be driven independently. A wheel motor device is conventionally known (for example, see Patent Document 1 below).

  Since such a wheel motor device can independently drive the pair of drive axles independently of each other, it is possible to improve the turning performance of the vehicle, in particular, the small turning ability, and freely between the pair of vehicle frames. There is an advantage that space can be secured.

  However, in the conventional wheel motor device, since the motor shaft is directly connected to the drive axle, a large-torque, low-rotation type motor body configured as a radial piston type must be used as the hydraulic motor body. Accordingly, there is a problem that the hydraulic motor main body is increased in size and cost, and the amount of hydraulic oil leakage from the hydraulic motor main body is increased, resulting in deterioration in transmission efficiency.

There is also an axial piston type motor body. However, since the motor body itself is elongated in the direction of the rotation axis, it is not suitable for the purpose of securing the above-described free space in the frame.
US Pat. No. 4,903,792

  The present invention has been made in view of the prior art, and is a wheel motor device configured so that a drive axle can be independently driven by a hydraulic motor unit, and the wheel motor capable of reducing the size of the hydraulic motor unit. One object is to provide an apparatus.

  In order to achieve the above-mentioned object, the present invention provides an axle housing connected to a vehicle frame, and an outer wall that rotatably supports a drive axle whose outer end in the vehicle width direction is connected to a wheel of a drive wheel. And an axle housing having an inner wall spaced inward in the vehicle width direction from the outer wall so that a vehicle width direction inner end portion of the drive axle is located in an inner space defined between the outer wall and the outer wall; A radial piston type hydraulic motor unit that constitutes a continuously variable transmission in cooperation with a hydraulic pump unit that is spaced apart, wherein at least a part thereof is located in the inner space of the axle housing. An oil transfer member connected to the inner wall, and an internal space of the axle housing in a state where oil can be supplied to and discharged from the oil transfer member and is relatively rotatable. A hydraulic motor unit having a hydraulic motor body disposed therein, a motor shaft that is not rotatable relative to the hydraulic motor body, and a reduction transmission unit disposed in the inner space of the axle housing. A wheel motor device is provided that includes a reduction transmission unit that transmits the rotation output of the hydraulic motor main body to the drive axle.

Preferably, the oil transfer member is a shaft portion that protrudes into the inner space of the axle housing, and includes a shaft portion that supports the hydraulic motor body so as to be relatively rotatable, and a hydraulic oil port for the hydraulic pump unit. A plate portion connected to an outer surface of the inner wall of the axle housing.
In such an aspect, the oil transfer member is configured such that the hydraulic oil port is positioned inward in the vehicle width direction from the vehicle frame in a state where the axle housing is connected to the vehicle frame.

  In the preferred embodiment, the vehicle frame is provided with a through hole, and the axle housing is a surface facing the vehicle width direction outward in the vehicle frame in a state where the plate portion of the oil transfer member is inserted into the through hole. Can be linked.

  In the various aspects, a brake unit that can selectively apply a braking force to the motor shaft based on an external operation can be provided.

In the various aspects, preferably, the motor shaft is concentrically disposed with respect to the drive axle, and the motor shaft and the drive axle are in a state in which opposite end portions of each other can rotate relative to each other around an axis. With concavo-convex engagement.
Preferably, the reduction transmission unit includes a sun gear that is not rotatable relative to the motor shaft, a planetary gear that meshes with the sun gear so as to revolve around the sun gear, and an internal that meshes with the planetary gear. A planetary gear train having a gear and a carrier that supports the planetary gear and rotates around the sun gear in response to the revolution of the planetary gear, the carrier being operatively connected to the drive axle; Is done.
More preferably, the internal gear is detachable from the axle housing. In such an aspect, the internal gear is concavo-convexly engaged with the inner surface of the axle housing so that the internal gear cannot rotate about the axis with respect to the motor shaft and the radial position with respect to the motor shaft can be adjusted. obtain.

  In an aspect in which the planetary gear train is provided as the speed reduction transmission unit, preferably, the brake unit is not rotatable relative to the motor shaft so as to face the inner side surface of the internal gear facing inward in the vehicle width direction, and the axis line A brake disc supported in a slidable direction and a pushing member that pushes the brake disc toward the inner surface of the internal gear may be included.

  In the various aspects, preferably, the axle housing includes a partition member that separates the inner space into a motor housing chamber that houses the hydraulic motor main body and a gear chamber that houses the reduction gear transmission unit. In addition, the oil in the motor housing chamber can be taken out to the outside.

  According to the wheel motor device of the present invention, since the output of the hydraulic motor unit is transmitted to the drive axle via the deceleration transmission unit, a low torque / high rotation type hydraulic motor unit is used as the hydraulic motor unit. As a result, the hydraulic motor unit can be reduced in size and cost, and the transmission efficiency can be improved.

  Further, if a brake unit capable of selectively applying a braking force to the motor shaft in the hydraulic motor unit is provided, the deceleration by the deceleration transmission unit with respect to the transmission path from the hydraulic motor unit to the drive axle. A braking force can be applied in the previous stage. Therefore, the size of the brake unit can be reduced.

Hereinafter, a preferred embodiment of a wheel motor device according to the present invention will be described with reference to the accompanying drawings.
1 to 3 are a side view, a plan view, and a hydraulic circuit diagram of a vehicle 1A to which a wheel motor device 100 according to the present embodiment is applied, respectively.

  As shown in FIG. 1 to FIG. 3, the wheel motor device 100 according to the present embodiment is configured to cooperate with a separately disposed hydraulic pump unit 500 to drive the corresponding drive axle 50 at a variable speed. ing.

First, one mode of a vehicle 1A to which the wheel motor device 100 according to the present embodiment is applied will be described.
As shown in FIGS. 1 and 2, the vehicle 1A includes a body frame 30 having a pair of main frames 31 disposed along the vehicle front-rear direction, an engine 40 supported by the body frame 30, The hydraulic pump unit 500 operatively driven by the engine 40, a pair of drive wheels 60a and 60b, and a pair of first and second drives connected to the pair of drive wheels 60a and 60b in a relatively non-rotatable manner. Axes 50a and 50b, and first and second wheel motor devices 100a and 100b according to the present embodiment configured to be able to independently drive the first and second drive axles 50a and 50b, respectively. .

  In the illustrated embodiment, the vehicle 1A includes a pair of steering wheels 70 supported in front of the body frame 30 and the pair of steering wheels 70 and the drive wheels in the vehicle longitudinal direction in addition to the above-described configuration. 60, and a discharge duct 90 that forms a transport path for transporting grass cut by the mower device 80 to the rear of the vehicle.

As shown in FIG. 1, the engine 40 is supported by the pair of main frames 31 at a vehicle front position.
In the illustrated embodiment, the engine 40 is supported by the pair of main frames 31 via a cross member 45 placed on the upper surface of the pair of main frames 31 so as to straddle the pair of main frames 31. ing.
In the illustrated embodiment, the cross member 45 is provided with a through hole (not shown), and the output shaft 41 of the engine 40 extends downward through the through hole.
The output shaft 41 extending downward is operatively connected to the input shaft 510 of the hydraulic pump unit 500 via the pulley and the transmission belt 15 and the mower device 80 via the pulley and the transmission belt 16. Is operatively connected to the input shaft 81.
Preferably, the engine 40 is mounted on the base plate 45 via vibration-proof rubber at four locations, front, rear, left and right.

As shown in FIGS. 1 and 2, the hydraulic pump unit 500 is supported by the pair of main frames 31.
Specifically, as shown in FIGS. 1 to 3, the hydraulic pump unit 500 includes an input shaft 510 operatively connected to the output shaft 41 of the engine, a hydraulic pump body 520 driven by the input shaft 510, A pump case 530 that surrounds the hydraulic pump main body 520 and supports the input shaft 510 is provided.

In the present embodiment, the hydraulic pump unit 500 is of a variable displacement type that can change the supply / discharge oil amount of the hydraulic pump body 520 in accordance with an external operation (see FIG. 3).
That is, the hydraulic pump unit 500 includes an output adjustment member 540 (see FIG. 3) such as a movable swash plate that changes the supply / discharge oil amount of the hydraulic pump main body 520, and the output adjustment member 540. A control shaft 550 (see FIGS. 1 and 2) for operating the tilt position is provided.
As shown in FIG. 1, the control shaft 550 is linked to a speed change operation member such as a speed change pedal 20 provided near the driver's seat via an appropriate link mechanism 25.

Further, the hydraulic pump unit 500 has an auxiliary pump body 580 operatively driven by the input shaft 510 as shown in FIG.
As shown in FIG. 3, the auxiliary pump body 580 supplies hydraulic oil to the working machine hydraulic mechanism 85 (in this embodiment, the hydraulic lifting mechanism of the mower device 80). Yes.
The auxiliary pump body 580 sucks oil from the external tank 10 provided in the vehicle 1A.
The hydraulic pump unit 500 may include a cooling fan 590 that is operatively driven by the input shaft 510 (see FIG. 2).

The pump case 530 is supported by the pair of main frames 31 via a cross member (not shown) placed on the upper surface of the pair of main frames 31 so as to straddle the pair of main frames 31. Yes.
Specifically, as shown in FIGS. 1 and 2, the pump case 530 includes a case main body 531 provided with an opening through which the hydraulic pump main body 520 can be inserted, and a case main body 531 that closes the opening. And an oil transfer member 535 to be connected.

The oil transfer member 535 is formed with a supply / discharge oil passage for the hydraulic pump main body 520.
Specifically, as shown in FIG. 3, one end of the oil transfer member 535 is open to the outer surface to form a pump-side hydraulic oil port 610 </ b> P, and the other end is the hydraulic pump body 520. A pair of pump side hydraulic fluid passages 610 fluidly connected to the suction / discharge ports, one end portion opening on the outer surface to form a charge port 620P, and the other end portion of the pair of pump side hydraulic fluid passages. A charge oil passage 620 fluidly connected to each of the 610 via a check valve 625 and a bypass oil passage 630 communicating between the pair of pump-side hydraulic fluid passages 610, A bypass oil passage 630 having a bypass valve 635 inserted therein and a flushing oil passage 640 that communicates the forward low pressure hydraulic fluid passage 610 (R) of the pair of pump side hydraulic fluid passages 610 with the oil reservoir. A flushing oil passage flushing valve 645 interposed therein is formed.

The pair of pump-side hydraulic oil passages 610 are a pair of operations for fluidly connecting the hydraulic pump body 520 and the first and second hydraulic motor bodies 170a and 170b in the first and second wheel motor devices 100a and 100b. Part of line 400 is formed.
That is, the pair of pump-side hydraulic oil passages 610 are connected to the pump-side hydraulic oil port 610P via the external piping (see FIGS. 1 to 3), the first and second hydraulic motor main bodies 170a and 170b. Is fluidly connected.

  As shown in FIG. 3, a charge relief valve 621 for setting a charge pressure is inserted in the charge oil passage 620, and pressure oil from the charge pump main body 16 that is operatively driven by the drive source 40. Is adjusted to a set hydraulic pressure by the charge relief valve 621 and replenished to the pair of pump side hydraulic fluid passages 610.

  The flushing valve 645 moves forward in the pair of pump side hydraulic oil passages 610 when the hydraulic pressure in the forward high pressure side hydraulic fluid passage 610 (F) of the pair of pump side hydraulic fluid passages 610 becomes a predetermined value or more. The hydraulic oil in the low-pressure side hydraulic oil passage 610 (R) is drained into the oil reservoir (inside the space of the pump case 530), thereby promoting the replenishment of the hydraulic oil supplied through the charge oil passage 620, While ensuring the amount of hydraulic oil flowing through the pair of operating lines 400, the temperature of the hydraulic oil is effectively prevented from being increased.

Next, the first and second wheel motor devices 100a and 100b will be described.
FIG. 4 shows a longitudinal rear view of the first wheel motor device 100a. FIG. 5 is a cross-sectional view taken along the line VV in FIG.
The second wheel motor device 100b is a mirror image of the first wheel motor device 100a except that the second wheel motor device 100b is mirror-imaged with the first wheel motor device with reference to a virtual center longitudinal line L of the vehicle (see FIG. 2). And substantially the same configuration.
Accordingly, with respect to the second wheel motor device 100b, the reference numerals of the corresponding members in the first wheel motor device 100a are replaced with “b”, and detailed description thereof will be omitted as appropriate.

  As shown in FIG. 4, the first wheel motor device 100 a includes a first axle housing 110 that supports a corresponding first drive axle 50 a so as to be rotatable about an axis, and a radial that is connected to and supported by the first axle housing 110. A piston-type first hydraulic motor unit 150 and a first reduction transmission unit 200a for reducing and transmitting the output of the first hydraulic motor unit 150a to the first drive axle 50a are provided.

As shown in FIG. 4, the first axle housing 110 supports the inner end portion in the vehicle width direction of the first drive axle 50a whose outer end portion in the vehicle width direction is connected to the wheel 61a so as to be rotatable about the axis. It is configured.
That is, the first drive axle 50a has an inner end in the vehicle width direction that is inserted into the inner space of the axle housing 110, and an outer end in the vehicle width direction can be connected to the wheel 61a of the corresponding drive wheel 60a. The first axle housing 110 is supported by the first axle housing 110 so as to be rotatable about its axis in a state of protruding outward from the first axle housing 110.

As shown in FIGS. 2 and 4, the first axle housing 110 is connected to an outer side surface of the corresponding main frame 31 facing outward in the vehicle width direction.
In this way, by connecting the axle housing 110 to the outer side surface of the corresponding main frame 31 in the vehicle width direction, the distance between the pair of main frames 31 can be increased without increasing the distance between the pair of main frames 31 in the vehicle width direction. The free space can be effectively secured. Therefore, it is possible to easily change the specifications between the center discharge type (see FIG. 1) in which the discharge duct 90 of the mower device 70 is disposed between the pair of drive axles 50a and 50b and the other types.

Specifically, the first axle housing 110a is disposed between the outer wall 121 and the outer wall 121 that supports the corresponding driving axle (the first driving axle 50a in the first wheel motor device 100a) rotatably about the axis. The drive axle 50a has an inner wall 126 spaced from the outer wall 121 inward in the vehicle width direction so that the inner end in the vehicle width direction is located.
That is, the first axle housing 110 has a housing space defined by the outer wall 121 and the inner wall 126, and the inner end of the corresponding drive axle 50a is positioned in the housing space. The drive axle 50a is supported.

In the present embodiment, the first axle housing 110 includes an outer member 120 having the outer wall 121 and an inner member 125 having the inner wall 126, and peripheral edges of the outer member 120 and the inner member 125. The parts are brought into contact with each other so that they can be separated by a fastening member 115 (see FIG. 5) such as a bolt.
Reference numeral 129 in FIG. 5 denotes a frame mounting through hole formed in the peripheral edge of the inner wall, and corresponds to the inner member 125 by a fastening member (not shown) inserted through the through hole 129. The main frame 31 is connected.

  The first hydraulic motor unit 150a is fluidly connected to the hydraulic pump unit 500 via the pair of operating lines 400 so as to cooperate with the hydraulic pump unit 500 to form an HST.

Specifically, in the present embodiment, the first and second hydraulic motor units 150a and 150b in the first and second wheel motor devices 100a and 100b are connected to the hydraulic pump unit via the pair of operation lines 400. 500 is fluidly connected in parallel.
That is, as shown in FIG. 3, one of the forward high pressure side working lines 400 (F) of the pair of working lines 400 is fluidly connected to the forward discharge outlet of the hydraulic pump body 520 and the other. The end is fluidly connected to the forward suction port of the hydraulic motor body 170 in the first hydraulic motor unit 150a and the forward suction port of the hydraulic motor body 170 in the second hydraulic motor unit 150b.
Similarly, the forward low pressure side operating line (reverse high pressure side operating line) 400 (R) of the pair of operating lines 400 is fluidly connected at one end to the forward suction port of the hydraulic pump body 520, and The other end is fluidly connected to the forward discharge port of the hydraulic motor body 170 in the first hydraulic motor unit 150a and the forward discharge port of the hydraulic motor body 170 in the second hydraulic motor unit 150b.

In this manner, the first and second hydraulic motor units 150a and 150b are fluidly connected in parallel to the hydraulic pump unit 500 having a single hydraulic pump body 520, so that the hydraulic pump body 520 can The operating hydraulic pressure supplied to the hydraulic motor main bodies 170 of the first and second hydraulic motor units 150a and 150b can be automatically distributed according to the load applied to the first and second drive wheels 60a and 60b. it can.
Therefore, the first and second drive shafts 50a and 50b can be differentially driven without providing a mechanical differential gear mechanism.

  Specifically, the first hydraulic motor unit 150a includes an oil transfer member 160 in which a pair of motor-side hydraulic fluid passages 410 forming part of the pair of working lines 400 are formed, and the pair of motor-side hydraulic fluid passages. The hydraulic motor main body 170 is supported by the oil transfer member 160 so as to be rotatable relative to the oil transfer member 160 so that the oil can be supplied to and discharged from the motor 410, and the motor shaft 180 is not rotatable relative to the hydraulic motor main body 170. Yes.

The oil transfer member 160 is connected to the axle housing 110 in a state where at least a part thereof is located in the inner space of the axle housing 110.
FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. FIG. 7 is a sectional view taken along line VII-VII in FIG.

  As shown in FIG. 4, the oil transfer member 160 is a shaft portion 161 that protrudes into the internal space of the first axle housing 110a, and the hydraulic motor main body 170 is within the internal space of the first axle housing 110a. And a plate portion 165 connected to the outer surface of the inner wall 126 of the first axle housing 110a (the surface facing inward in the vehicle width direction).

  As shown in FIGS. 4 to 7, the pair of motor-side hydraulic oil passages 410 have one end portion on the outer surface of the plate portion 165 (in the illustrated form, the outer surface facing the front and rear of the vehicle). A pair of motor-side hydraulic oil ports 410P are formed to open, and the other end is fluidly connected to the hydraulic motor main body 170. Open on the surface.

In the present embodiment, as shown in FIG. 4, the oil transfer member 160 is connected to the main frame 31 with the first axle housing 110a, and the motor side hydraulic oil port 410P corresponds to the corresponding oil frame. The main axle 31 is connected to the first axle housing 110a so as to be located inward in the vehicle width direction.
Thus, by positioning the motor side hydraulic oil port 410P inward in the vehicle width direction from the corresponding main frame 31, the external pipe 411 connected to the motor side hydraulic oil port 410P (FIGS. 2 and 6). Reference) can be positioned in the vehicle width direction inner space of the pair of main frames 31, and this effectively prevents the external pipe 411 from interfering with an external member while the vehicle is running.

Preferably, as shown in FIG. 4, the main frame 31 is provided with a through hole 32 penetrating the inner surface in the vehicle width direction and the outer surface in the vehicle width direction, and the plate portion 165 of the oil transfer member 160 is disposed outside in the vehicle width direction. The first axle housing 110a can be connected to the outer surface of the main frame 31 in the vehicle width direction while being inserted into the through hole 32 from the side.
With such a configuration, the motor-side hydraulic oil port 410P can be positioned inward of the main frame 31 in the vehicle width direction while stably connecting the first axle housing 110a to the main frame 31. it can.

  As shown in FIGS. 4, 5, and 7, the hydraulic motor main body 170 is relative to the shaft portion 161 of the oil transfer member 160 in a state where oil can be supplied to and discharged from the pair of motor-side hydraulic oil passages 410. A cylinder block 171 that is rotatably supported; a piston unit 172 that is accommodated in a radially movable manner with respect to the cylinder block 171; and a bearing member 173 that is in sliding contact with a free end of the piston unit 172, And a bearing member 173 arranged eccentrically with respect to the shaft portion 161 of the oil transfer member 160.

  In such a hydraulic motor main body 170, the piston unit 172 reciprocates in the radial direction by the hydraulic oil supplied and discharged via the pair of motor side hydraulic oil passages 410, whereby the cylinder block 171 is moved to the oil block. The shaft member 161 rotates around the shaft portion 161.

  In the present embodiment, the hydraulic motor main body 170 is a fixed displacement type in which the eccentric position of the bearing member 173 with respect to the shaft portion 161 of the oil transfer member 160 is fixed. It is also possible to adopt a variable displacement type in which the eccentric position can be changed based on an external operation.

In the present embodiment, the motor shaft 180 is detachably connected to the cylinder block 171 via a fastening member such as a bolt.
Specifically, the motor shaft 180 includes a base end portion 181 connected to an end face of the cylinder block 171 facing outward in the vehicle width direction, and a shaft portion extending outward from the base end portion 181 in the vehicle width direction. 182.

Preferably, the shaft portion 161 of the oil transfer member 160 is disposed concentrically with the corresponding first drive axle 50a, whereby the shaft portion 182 of the motor shaft 180 is concentric with the first drive axle 50a. Can be placed on top. Then, the shaft portion 181 of the motor shaft 180 and the opposite end portions of the first drive axle 50a, which are arranged concentrically with each other, can be engaged with each other in a concavo-convex manner in a state where they can be relatively rotated around the axis line ( (See FIG. 4).
With such a configuration, rotation blur of the motor shaft 180 and the first drive axle 50a can be prevented, and rotation of both shafts 180, 50a can be stabilized.

More preferably, the mutually opposing end portions of the motor shaft 180 and the first drive axle 50a can be abutted (see FIG. 4).
With this configuration, the cylinder block 171 and the motor shaft 180 can be prevented from moving outward in the vehicle width direction without providing position fixing means.

The end face of the cylinder block 171 facing inward in the vehicle width direction is in contact with a mount 127 provided on the inner wall 126 of the first axle housing 110a, as shown in FIGS. Thereby, the cylinder block 171 and the motor shaft 180 are prevented from moving inward in the vehicle width direction.
That is, the inner wall 126 of the first axle housing 110a has a thick mount portion 127 that supports the shaft portion 161 of the oil transfer member 160. The mount portion 127 is a vehicle of the cylinder block 171. It is in contact with an end face facing inward in the width direction.

As described above, the first deceleration transmission unit 200a is configured to decelerate and transmit the rotational output of the first hydraulic motor unit 150a to the first drive axle 50a.
Thus, the first wheel motor device 100a according to the present embodiment includes the reduction transmission unit 200a between the first hydraulic motor main body 150a and the corresponding first drive axle 50a. Therefore, a highly reliable low torque / high rotation type motor can be used as the first hydraulic motor main body 150a.
Such a low-torque / high-rotation motor can be made more compact than a high-torque / low-rotation motor, and can reduce the amount of hydraulic oil leakage and improve transmission efficiency.

Preferably, the internal space of the first axle housing 110a is liquid-tightly separated into a motor housing chamber that houses the first hydraulic motor main body 170a and a gear chamber that houses the first reduction gear transmission unit 200a. it can.
Thus, by separating the motor chamber and the gear chamber in a liquid-tight manner, it is possible to effectively prevent leakage oil from the first hydraulic motor main body 170a from becoming a stirring resistance with respect to the first reduction gear transmission unit 200a. it can.
In the present embodiment, as shown in FIG. 4, the first axle housing 110 a is a partition member 111 having a through hole through which the shaft portion 181 of the motor shaft 180 is inserted in a liquid-tight manner. A partition member 111 fastened via a fastening member is provided on the peripheral portion of the member 125, and the motor housing chamber and the gear chamber are separated by the partition member 111.

More preferably, oil in the motor housing chamber can be taken out, thereby preventing oil from staying in the motor housing chamber and improving the cooling efficiency of the hydraulic motor main body 170 housed in the motor housing chamber. be able to.
In the present embodiment, as shown in FIGS. 4 and 6, a through hole 425 is provided in the inner wall 126 of the first axle housing 110a to communicate the motor housing chamber with the outside. Then, the inner wall 126 of the first axle housing 110a is connected to the plate portion 165 of the oil transfer member 160 connected to the inner wall 126 of the first axle housing 110a so that one end thereof is fluidly connected to the through hole 425. And the other end portion opens to the outer surface (the upper surface in the present embodiment) to form a take-out oil passage 420 that forms a take-out port 420P.
By providing such a configuration, an external pipe 425 having one end fluidly connected to the take-out port 420P and the other end fluidly connected to the external tank 10 is provided inward in the vehicle width direction from the pair of main frames 31. It is possible to effectively prevent the external pipe 125 from interfering with an external member while the vehicle is running (see FIGS. 2 and 4).

In the present embodiment, the first reduction gear transmission unit 200a is a planetary gear train, and is as compact as possible while ensuring a reduction ratio.
Specifically, as shown in FIG. 4, the first reduction transmission unit 200 a includes a sun gear 210 that is not rotatable relative to the motor shaft 180, and the sun gear that revolves around the sun gear 210. A planetary gear 220 that meshes with 210, an internal gear 230 that meshes with the planetary gear 220, and a carrier 240 that rotates around the sun gear 210 along with the revolution of the planetary gear 220.

FIG. 8 is a sectional view taken along line VIII-VIII in FIG.
As shown in FIGS. 4 and 8, in the present embodiment, the sun gear 210 is integrally formed with the shaft portion 182 of the motor shaft 180.
By providing such a configuration, the pitch diameter of the sun gear 210 can be reduced as much as possible, and thereby the entire planetary gear train can be reduced in size while ensuring a reduction ratio of the planetary gear train. it can.
Of course, the sun gear 210 may be a separate member from the motor shaft 180. In such a case, the sun gear 210 is extrapolated to the shaft portion of the motor shaft 180 so as not to be relatively rotatable.

The internal gear 230 is a fixed element that cannot rotate.
In the present embodiment, the internal gear 230 is detachable with respect to the first axle housing 110a, and is not rotatable in the radial direction when mounted on the first axle housing 110a.
Specifically, as shown in FIGS. 5 and 8, the inner peripheral surface of the first axle housing 110 a has a projecting portion 117 projecting radially inward and a recess 118 defined by the projecting portion. Is provided.
The internal gear 230 has an outer peripheral shape that engages with the protrusion 117 and the recess 118 in a concavo-convex manner.

Preferably, the concave / convex engagement between the first axle housing 110a and the internal gear 230 has a margin in the radial direction, so that the internal gear 230 can move in the radial direction with respect to the axis of the sun gear 210. It may be configured to allow a slight movement.
By providing such a configuration, it is possible to distribute the load of the planetary gear train.

The carrier 240 has a pivot shaft 241 that supports the planetary gear 220 and is not rotatable relative to the first drive axle 50a.
Therefore, when the planetary gear 220 revolves around the sun gear 210, the carrier 240 rotates around the sun gear 210 via the pivot shaft 241 so that the first drive axle 50a is rotationally driven. It has become.

As described above, a planetary gear train is employed as the speed reduction transmission unit 200 for reducing the power transmission from the motor shaft 180 to the first drive axle 50a while coaxially arranging the motor shaft 180 and the first drive axle 50a. Accordingly, as shown in FIG. 4, at least a part of the deceleration transmission unit 200 can be positioned in the rim 62a of the first drive wheel.
Accordingly, a free space between the pair of first and second wheel motor devices 100a and 100b is secured as much as possible without increasing the installation interval in the vehicle width direction of the pair of first and second drive wheels 60a and 60b. can do.

Further, as shown in FIGS. 4 and 8, the first wheel motor device 100a is configured to be able to operatively apply a braking force to the corresponding first drive axle 50a based on an external operation. 300a.
In the present embodiment, the first brake unit 300a is configured to be able to apply a braking force to the motor shaft 180 before being decelerated by the first deceleration transmission unit 200a. The required brake capacity is reduced.

  Specifically, as shown in FIGS. 4 and 8, the first brake unit 300a includes a brake disc 310 supported on the shaft portion 182 of the motor shaft 180 so as to be movable in the axial direction and not relatively rotatable, It has a pushing member 320 that pushes the brake disk 310 toward the braking surface, and a brake operation shaft 330 that operates the pushing member 320 based on an external operation. It is comprised so that may be added.

The brake disc 310 is supported by the motor shaft 180 so as to face an inner side surface of the internal gear 230 facing inward in the vehicle width direction.
The pushing member 320 is disposed on the opposite side of the inner surface of the internal gear 230 with the brake disc 310 interposed therebetween, and the brake disc 310 is attached to the internal gear 230 based on an external operation. It can be pressed toward the inner surface of the.
That is, in the present embodiment, the inner surface of the internal gear 230 is used as the braking surface, thereby reducing the size of the entire reduction gear device.
The outer surface of the internal gear 230 facing outward in the vehicle width direction is in contact with the inner peripheral surface of the first axle housing 110a, as shown in FIG. Is prevented from moving outward in the vehicle width direction.

  In the present embodiment, as described above, the inner surface of the internal gear 230 is used as the braking surface of the first brake unit 300a. However, as a matter of course, as the braking surface, for example, the first axle housing 110a. Any part can be used, or another member (not shown) that meshes with the internal gear 230 is provided so as not to move in the axial direction, and the other member can be used as the braking surface. .

The pushing member 320 presses the brake disc 310 toward the braking surface by turning around the axis of the brake operation shaft 330.
Specifically, as shown in FIGS. 4 and 8, the brake operation shaft 330 has an inner end protruding into the inner space of the first axle housing 110a and an outer end accessible from the outside. In this state, the first axle housing 110a is supported so as to be rotatable about an axis along the radial direction of the brake disc 310.

In the present embodiment, as shown in FIG. 4, a notch portion is provided at the inner end portion of the brake operation shaft 330, and the pushing member 320 includes the brake disk 310 and the brake operation shaft 330. It is engaged with the said notch so that it may be located between.
With such a configuration, even if the brake operation shaft 330 is rotated in any direction around the axis, the pushing member 320 causes the brake disk 310 to move the brake surface (in this embodiment, the internal gear 230 of the internal gear 230). The inner surface is pressed toward the inner surface.

A brake arm 340 is connected to the outer end portion of the brake operation shaft 330, and the brake arm 340 is provided in the vicinity of the driver's seat via an appropriate link mechanism (not shown). (Not shown).
The first brake unit 300a is used as an auxiliary brake when traveling is stopped or as a parking brake.

  In this manner, the brake operation shaft 330 is disposed along the radial direction of the brake disk 310, and the pushing member 320 is not moved even if the brake operation shaft 330 is rotated in any direction around the axis. By configuring the disk 310 to push toward the braking surface, the degree of freedom in designing a link mechanism for operating the brake operation shaft 330 can be improved.

In particular, in the present embodiment, as shown in FIGS. 4 and 8, the brake operation shaft 330 has the substantially vertical direction in a state where the first axle housing 110a is connected to the corresponding main frame 31. Is supported by the first axle housing 110a.
Therefore, the brake arm 340 for operating the brake operation shaft 330 about the axis can be easily extended inward in the vehicle width direction, and thereby the brake arm 340 and the brake arm 340 connected to the brake arm 340 can be extended. It is possible to effectively prevent the link mechanism from interfering with the drive wheel 60a.

Further, in such a configuration, the brake arm 340 and the link mechanism can be positioned between the pair of main frames 31 without any additional configuration, so that the distance in the width direction of the entire vehicle is allowed. In addition to being able to be shortened as much as possible, it is possible to effectively prevent the brake arm 340 and the link mechanism from colliding with an external member and being damaged or broken while the vehicle is running.
Further, in order to cause the pushing member 320 to push the brake disc 310 toward the braking surface regardless of which direction the brake operation shaft 330 is rotated about the axis, one type of axle housing is moved to a pair of left and right. It can be applied to any of the drive wheels, and the parts can be shared.

  In the present embodiment, as shown in FIG. 4, a through hole 33 through which the brake arm 340 is inserted is provided in the main frame 31, and the free end portion of the brake arm 340 is inserted through the through hole 33. Is configured to be located inward of the main frame 31 in the vehicle width direction.

Further, in the present embodiment, as shown in FIG. 4, the notch is provided at the inner end of the brake operation shaft 330, and the pushing member 320 is engaged with the notch.
Therefore, the vehicle width direction distance of the brake unit including the brake operation shaft 330, the pushing member 320, the brake disk 310, and the braking surface (in the present embodiment, the inner surface of the internal gear 230) (that is, The distance in the direction perpendicular to the brake disc 230) can be shortened as much as possible, so that it is possible to effectively reduce the size of the entire wheel motor device while providing a braking action.

In the present embodiment, the case where the first and second wheel motor devices according to the present invention are applied to the vehicle 1A in which the non-driving wheels are the steering wheels 70 has been described as an example. Can be applied to other forms of vehicles.
For example, the present invention can be applied to a vehicle in which non-driving wheels are caster wheels, and the first and second driving wheels 60a and 60b are independently driven at different speeds.

As shown in FIG. 9, such a vehicle 1B has a hydraulic pump unit 500B having a first hydraulic pump body 520a and a second hydraulic pump body 520b instead of the hydraulic pump unit 500 having a single hydraulic pump body 500. It has.
In the vehicle 1B, the first and second wheel motor devices 100a and 100b are respectively connected to the first and second hydraulic pump bodies 520a and 520b with a pair of first operating lines 400a and a pair of second operating lines. Fluid connection is made via 400b.

FIG. 1 is a side view of a vehicle to which a wheel motor device according to an embodiment of the present invention is applied. FIG. 2 is a schematic plan view of the vehicle shown in FIG. FIG. 3 is a hydraulic circuit diagram of the vehicle shown in FIGS. 1 and 2. FIG. 4 is a longitudinal rear view of the wheel motor device according to the embodiment of the present invention. FIG. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. FIG. 9 is a hydraulic circuit diagram of another vehicle to which the wheel motor device according to one embodiment of the present invention is applied.

Explanation of symbols

1A, 1B Vehicles 50a, 50b First drive axle, second drive axles 60a, 60b First drive wheel, second drive wheel 100a First wheel motor device, second wheel motor devices 110a, 110b First axle housing, second Axle housing 111 Bulkhead member 121 Outer wall 126 Inner walls 150a, 150b First hydraulic motor unit, second hydraulic motor unit 160 Oil transfer member 161 Shaft portion 165 Plate portion 170 Hydraulic motor main body 180 Motor shaft 200 Deceleration transmission unit 210 Sun gear 220 Planetary gear 230 Internal gear 240 Carrier 300 Brake unit 310 Brake disc 320 Pushing member 330 Brake operation shaft 410P Hydraulic oil port 500, 500B Hydraulic pump unit

Claims (9)

An axle housing connected to a vehicle frame, an inner wall defined between said outer wall and an outer wall that rotatably supports a driving axle whose outer end in a vehicle width direction is connected to a wheel of a driving wheel about an axis An axle housing having an inner wall spaced from the outer wall inward in the vehicle width direction so that the inner end of the drive axle in the vehicle width direction is located in the space;
A radial piston type hydraulic motor unit that constitutes a continuously variable transmission in cooperation with a hydraulic pump unit that is spaced apart, wherein at least a part thereof is located in the inner space of the axle housing. An oil transfer member coupled to the inner wall, a hydraulic motor main body disposed in the inner space of the axle housing in a state where oil can be supplied to and discharged from the oil transfer member and is relatively rotatable, and the hydraulic pressure A hydraulic motor unit having a motor shaft that cannot rotate relative to the motor body;
A wheel motor device comprising: a speed reduction transmission unit disposed in an inner space of the axle housing, wherein the speed reduction transmission unit transmits the rotational output of the hydraulic motor body to the drive axle. . The oil transfer member is a shaft portion that protrudes into the inner space of the axle housing, and is a plate provided with a shaft portion that supports the hydraulic motor body so as to be relatively rotatable, and a hydraulic oil port for the hydraulic pump unit. A plate portion connected to an outer surface of the inner wall of the axle housing,
The oil transfer member is configured such that the hydraulic oil port is positioned inward in the vehicle width direction from the vehicle frame in a state where the axle housing is connected to the vehicle frame. 2. The wheel motor device according to 1. The vehicle frame is provided with a through hole,
The said axle housing is connected with the surface which faces the vehicle width direction outward in the said vehicle frame in the state which penetrated the plate part of the said oil transfer member to the said through-hole. Wheel motor device.   The wheel motor device according to any one of claims 1 to 3, further comprising a brake unit capable of selectively applying a braking force to the motor shaft based on an external operation. The motor shaft is arranged concentrically with the drive axle;
The wheel motor device according to any one of claims 1 to 4, wherein the motor shaft and the driving axle are engaged with each other in a concave-convex manner in such a manner that opposite ends of the motor shaft and the drive axle can rotate relative to each other around the axis.   The reduction transmission unit includes a sun gear that is not rotatable relative to the motor shaft, a planetary gear that meshes with the sun gear so as to revolve around the sun gear, meshes with the planetary gear, and is coupled to the motor shaft. An internal gear fixed to the axle housing so as not to rotate about an axis, and a pivot shaft that supports the planetary gear, and a carrier that rotates around the sun gear in accordance with the revolution of the planetary gear, 6. The wheel motor device according to claim 5, wherein the wheel motor device is a planetary gear train having a carrier operatively connected to the drive axle. The internal gear is detachable from the axle housing,
The wheel motor device according to claim 6, wherein the internal gear is engaged with the inner surface of the axle housing so as to adjust a radial position with respect to the motor shaft.   Based on an external operation, a brake disc supported on the motor shaft so as not to rotate relative to the motor shaft and slidably in the axial direction so as to face an inner side surface of the internal gear facing inward in the vehicle width direction. The wheel motor device according to claim 6, further comprising a pushing member that pushes toward an inner surface of the internal gear. The axle housing includes a partition member that separates the inner space into a motor housing chamber that houses the hydraulic motor main body and a gear chamber that houses the reduction gear transmission unit.
The wheel motor device according to any one of claims 1 to 8, wherein oil in the motor housing chamber can be taken out to the outside.

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