JP2005028914A - Axle driving device and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an axle driving device having a motor unit and a brake unit for each driving axle, in which the whole device can be constructed in a small size. <P>SOLUTION: The axle driving device is equipped with an axle case to support the driving axle using its outer wall facing outside in the vehicle width direction, the motor unit having a motor shaft supported by the inner wall facing inward in the vehicle width direction of the axle case and coupled with the inner wall, a speed reduction transmitting unit to make speed reducing transmission from the motor shaft to the driving axle and having an intermediate shaft positioned over the motor shaft and a final gear supported on the driving axle in such a way as not able to make relative rotation, and the brake unit capable of giving a braking force to the intermediate shaft. The motor unit is arranged so that at least part thereof is overlapped on the final gear when viewed in the axial direction of the driving axle, while the brake unit is supported on the inner wall of the axle case in such a way as positioned over the motor unit. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an axle drive device that independently drives a drive axle by a motor unit provided for each drive axle.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an axle drive device in which a motor unit constituting a continuously variable transmission is provided for each drive axle in cooperation with an actuator is known.
Hereinafter, a conventional axle drive device will be described using a hydraulic pump unit as the actuator and a hydraulic motor unit fluidly connected to the hydraulic pump unit as the motor unit (Patent Documents 1 and 2) as an example. To do.
[0003]
The axle drive devices described in Patent Documents 1 and 2 have the advantage that the turning performance of the vehicle, in particular, the small turning ability, can be improved because each drive axle can be independently driven at different speeds. On the other hand, there has been room for improvement in terms of downsizing the entire apparatus.
[0004]
In particular, in order to make the vehicle turn further, it is preferable to provide a brake unit for each drive axle, but none of the above-mentioned patent documents describes such a brake unit. There is no description about downsizing of the entire apparatus including the above.
[0005]
[Patent Document 1]
US Pat. No. 4,920,733
[Patent Document 2]
Japanese Utility Model Publication No. 56-77437
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of the prior art, and an object of the present invention is to reduce the size of the entire apparatus in an axle drive apparatus having a motor unit and a brake unit for each drive axle.
Further, the present invention provides a vehicle provided with an axle drive device having a motor unit and a brake unit for each drive axle, and ensures a large free space between the drive wheels without increasing the distance between the drive wheels. For other purposes.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a vehicle from the outer wall so that the inner end in the vehicle width direction of the driving axle is positioned between the outer wall that rotatably supports the driving axle and the outer wall. A motor unit that constitutes a continuously variable transmission under the cooperation of an axle case having an inner wall spaced inward in the width direction and an actuator that is spaced from the inner case, the outer end of the vehicle width direction being the axle case A motor shaft supported on the inner wall so as to be rotatable about an axis so as to be positioned in the housing space, a motor main body coupled and supported on the inner wall from the outside, and a vehicle width direction of the motor shaft An output gear supported so as not to rotate relative to the outer end, a final gear supported so as not to rotate relative to the inner end of the drive axle in the vehicle width direction, and the speed reduction transmission from the output gear to the final gear. A reduction gear transmission unit having a gear train including an intermediate shaft supported by the axle case so as to be positioned above the motor shaft, and selectively applying a braking force to the intermediate shaft based on an external operation. An additional brake unit, and the motor unit is arranged so that at least a part thereof overlaps with the final gear when viewed along the axial direction of the drive axle, and the brake unit includes: An axle drive device supported on an inner wall of the axle case so as to be positioned above the motor unit is provided.
Preferably, the brake unit is arranged so that at least a part thereof overlaps the hydraulic motor unit in plan view.
[0008]
Preferably, a base end portion may be further connected to the body frame, and a mounting stay that supports the axle case at the distal end portion may be further provided.
The mounting stay is configured to form a surrounding space in which the motor unit is positioned between an inner wall of the axle case and the body frame, and at least an upper portion is an opening.
In this aspect, the brake unit is supported by the rotation member that is non-rotatably supported by the intermediate shaft, the fixing member that is supported by the axle case, and the rotation member and the fixing member that are relatively non-rotatable. A friction braking device having a pair of friction plates and selectively applying a braking force to the rotating member based on an external operation, and the friction by swinging about a pivot axis arranged in parallel with the intermediate shaft. An operating arm for operating the braking device, and the operating arm is operable from an upper opening of the surrounding space.
[0009]
In the above aspect, more preferably, the motor unit is configured such that a connection portion with the actuator faces upward between the operation arm and the body frame in the brake unit.
[0010]
In one aspect, the actuator is a hydraulic pump unit, and the motor unit is fluidly connected to the hydraulic pump unit through a flow path so as to form an HST in cooperation with the hydraulic pump unit. A unit.
In the aspect, the hydraulic motor unit may include an oil passage that forms a part of the flow path, and has a center section in which an oil passage forming one end portion forming the connection portion with the actuator is perforated. .
[0011]
In order to achieve the above object, the present invention provides a fuselage frame having a pair of main frames disposed along the vehicle longitudinal direction, an engine supported by the fuselage frame, and an output portion of the engine. Provided is a vehicle including a power branching device having a pair of operatively coupled hydraulic pump units, a pair of driving axles, and a pair of axle driving devices that independently drive the pair of driving axles.
Each of the pair of axle drive devices is separated from the outer wall so that the inner end in the vehicle width direction of the drive axle is located between the outer wall and the outer wall that rotatably supports the corresponding drive axle. An axle case having an inner wall spaced inward in the vehicle width direction and connected to and supported by the corresponding main frame, and the hydraulic pump unit so as to form an HST in cooperation with the corresponding hydraulic pump unit. A hydraulic motor unit fluidly connected via a path, and a motor shaft supported on the inner wall so as to be rotatable about an axis so that an outer end portion in a vehicle width direction is located in a housing space of the axle case; A hydraulic motor unit having a hydraulic motor main body coupled and supported on the inner wall from the outside, a reduction transmission unit for transmitting the deceleration from the motor shaft to the corresponding driving axle, and an external operation The corresponding drive axle can and a brake unit for adding an actuation braking force.
The speed reduction transmission unit includes an output gear supported in a relatively non-rotatable manner at an outer end portion in the vehicle width direction of the motor shaft, a final gear supported in a non-rotatable manner at an inner end portion in the vehicle width direction of the drive axle, A gear train that transmits a reduced speed from the output gear to the final gear and includes an intermediate shaft that is supported by the axle case so as to be positioned above the motor shaft.
The brake unit is configured to selectively apply a braking force to the intermediate shaft based on an external operation.
Further, the hydraulic motor unit is disposed so that at least a part thereof overlaps with the final gear when viewed along the axial direction of the drive axle, and the brake unit includes the hydraulic motor unit. It is supported on the inner wall of the axle case so as to be positioned above.
[0012]
In the vehicle, preferably, each of the pair of axle driving devices may further include a mounting stay having a base end portion connected to a corresponding main frame and supporting the axle case at a tip end portion.
The mounting stay is configured to form an enclosed space in which the hydraulic motor unit is positioned between an inner wall of the axle case and the corresponding main frame, and at least an upper portion is opened. .
The brake unit includes a rotating member that is non-rotatably supported by the intermediate shaft, a fixing member that is supported by the axle case, and a friction plate that is supported by the rotating member and the fixing member so as not to be relatively rotatable. A friction braking device having a pair and selectively applying a braking force to the rotating member based on an external operation; and swinging around a pivot axis arranged in parallel to the intermediate shaft, the friction braking device An operating arm for operating, and the operating arm is operable from an upper opening of the enclosed space.
[0013]
More preferably, the hydraulic motor unit has a center section in which an oil passage that forms a part of the flow path between the hydraulic pump unit and the hydraulic pump unit is perforated, and the oil passage is operated in the brake unit. It is assumed that it opens upward between the arm and the main frame.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of an axle drive device according to the present invention will be described with reference to the accompanying drawings.
The axle drive device 1 according to the present invention includes a motor unit that constitutes a continuously variable transmission in cooperation with an actuator for each single drive axle, and the single drive axle is independently driven for speed change. It is configured to be able to.
[0015]
In the present embodiment, a case where a hydraulic pump unit is used as the actuator and a hydraulic motor unit that constitutes an HST in cooperation with the hydraulic pump unit is used as the motor unit will be described as an example. The axle drive device according to the present invention includes an aspect in which an electric motor unit is provided as the motor unit. When such an electric motor unit is used, a generator or the like is used as the actuator.
[0016]
First, an embodiment of a vehicle to which the axle drive device 1 according to the present embodiment is applied will be described.
1 to 3 are a schematic side view, a schematic plan view, and a schematic rear view, respectively, of a vehicle 500 to which the axle drive device 1 according to the present embodiment is applied. 4 and 5 are hydraulic circuit diagrams of the vehicle 500, respectively.
[0017]
As shown in FIGS. 1 to 5, the vehicle 500 includes a body frame 510 having a pair of main frames 511 disposed along the vehicle longitudinal direction, an engine 520 supported by the body frame 510, A power branching device 600 for inputting the output from the engine 520 via the flywheel 530, a pair of drive wheels 540, and a pair of first and second drives coupled to the pair of drive wheels 540 so as not to rotate relative to each other. There are provided axles 550a, b and first and second axle drive devices 1a, b according to the present embodiment configured to be able to independently drive the first and second drive axles 550a, b, respectively. .
In the illustrated embodiment, the vehicle 500 includes a caster wheel 560 supported in front of the fuselage frame 500 and a caster wheel 560 and the drive wheel 540 in the vehicle longitudinal direction in addition to the above configuration. And a mower device 570 provided.
[0018]
As shown in FIGS. 1 to 3, the engine 520 is vibration-proof supported by the pair of main frames 511 via vibration-proof rubber 521 at a position rearward of the drive axle 550.
In the illustrated form, the engine 520 is supported by the pair of main frames 511 via vibration-proof rubber 521 at four locations, front, rear, left and right.
[0019]
FIGS. 6 and 7 show a developed plan view and a rear view of the power split device 600, respectively.
As shown in FIGS. 6 and 7, the power branching device 600 includes the case member 610, the flywheel 530, and the transmission shaft 535 with a universal joint so as to be operatively connected to the engine 520. An input shaft 620 supported by 610, first and second hydraulic pump units 700 a and 700 b connected to and supported by the case member 610, a PTO unit 650 accommodated in the case member 610, and the input shaft 620. The first and second hydraulic pump units 700a and 700b and a transmission mechanism 630 for transmitting power to the PTO unit 650 are provided.
[0020]
The first and second hydraulic pump units 700a and 700b form first and second HSTs in cooperation with first and second hydraulic motor units described later, respectively.
That is, as shown in FIGS. 4 and 5, the first hydraulic pump unit 700a and the following first hydraulic motor unit are fluidly connected to form a closed circuit by a flow path such as a pair of pipes, At least one of them is a variable volume type.
Similarly, the second hydraulic pump unit 700b and the following second hydraulic motor unit are fluidly connected to form a closed circuit by a flow path such as a pair of pipes, and at least one of them is a variable volume. It is a type.
In the present embodiment, the first and second hydraulic pump units 700a and 700b are variable displacement types, and the first and second hydraulic motor units described later in detail are fixed displacement types. Yes.
[0021]
In the present embodiment, the first and second hydraulic pump units 700 a and 700 b are arranged on the front and rear surfaces of the case member 610, respectively.
Specifically, as shown in FIGS. 6 and 7, the first and second hydraulic pump units 700a and 700b are respectively connected to the pump shaft 710 operatively connected to the input shaft 620 and the rotation of the pump shaft 710. A piston 720 that revolves around the axis of the pump shaft 710 and reciprocates in conjunction with the revolving motion, and a cylinder block that reciprocally accommodates the piston 720 and rotates with the piston unit. 730, the output adjustment member 740 that regulates the stroke length of the piston 720 by the tilt position, and changes the amount of suction / discharge oil by the piston unit 720, and the tilt position of the output adjustment member 740 is operated from the outside. A control shaft 750 connected to the output adjusting member 740, the cylinder block 730, the piston 720, and the output The adjustment member 740 has an opening 761 through which the adjustment member 740 can be inserted. The pump case 760 that accommodates the opening 761 and the cylinder block 730 are rotatably supported, and are connected to the pump case 760 so as to close the opening 761. And a center section 770.
In the illustrated embodiment, each of the first and second hydraulic pump units 700 a and 700 b has a back side 762 opposite to the opening 761 in the pump case 760 connected to the case member 610.
[0022]
The PTO unit 650 includes a PTO shaft 655 supported by the case member 610 so that one end thereof extends outward, a drive side member 660 operatively connected to the input shaft 620, and the PTO A driven side member 665 supported by a shaft 655 so as not to rotate relative to the shaft 655, and a hydraulic clutch device 670 for engaging / cutting off power transmission from the drive side member 660 to the driven side member 665 are provided.
In the illustrated embodiment, the PTO unit 650 includes a hydraulic brake device 680 that releases / applies braking force to the PTO shaft 655 in conjunction with engagement / disconnection of the hydraulic clutch device 670.
[0023]
The transmission mechanism 630 includes an input gear 631 supported on the input shaft 620 so as not to rotate relative to the input shaft 620, and a pump gear 632 supported on the pump shafts 710 in the first and second hydraulic pump units 700a and 700b so as not to rotate relative to each other. The pump gear 632 meshed with the input gear 631 and the PTO gear 633 provided on the drive side member 660 of the PTO unit 650, the PTO gear 633 meshing with the input gear 631. Yes.
In other words, in the illustrated embodiment, as shown in FIG. 7, the transmission mechanism 630 includes a hydraulic pump path for transmitting power from the input shaft 620 to the first and second hydraulic pump units 700a, 700b, and the input. And a PTO path for driving power from the shaft 620 to the PTO unit 650.
[0024]
The illustrated power branching device 600 includes a charge pump unit 690 operatively connected to the input shaft 620 in addition to the above-described configuration.
The charge pump unit 690 is configured to supply hydraulic oil to the hydraulic clutch device 670 and the hydraulic brake device 680 in the PTO unit 650, the first and second HSTs, and other hydraulic mechanisms provided in the vehicle 500. Has been.
[0025]
Next, the first axle drive device 1a will be described.
The second axle drive device 1b has a symmetric structure with the first axle drive device 1a with reference to a virtual central vertical plane P along the longitudinal direction of the vehicle (see FIG. 3). Accordingly, the following description relating to the first axle drive device 1a also applies to the second axle drive device 1b.
[0026]
8 to 10 show a longitudinal rear view, a plan view, and an exploded perspective view of the first axle drive device 1a, respectively.
The first axle driving device 1a includes a first axle case 10a that supports a corresponding first driving axle 550a so as to be rotatable about an axis, a first hydraulic motor unit 20a that is connected to and supported by the axle case 10a, and the first axle A first reduction gear transmission unit 40a for reducing transmission between the first hydraulic motor unit 20a and the first drive axle 550a, and a first brake unit capable of directly or indirectly applying a braking force to the first drive axle. 50a and a first support member 70a for connecting and supporting the first axle case 10a to the body frame 510.
[0027]
As shown in FIGS. 8 and 9, the first axle case 10a is positioned on the outer side in the vehicle width direction of one of the pair of main frames 511 (first main frame 511a). The first drive axle 550a can be supported in a state where the first drive axle 550a is connected.
That is, as shown in FIG. 3, the first and second axle cases 10a and 10b are located on the outer sides in the vehicle width direction of the first and second main frames 511a and 511b, respectively. A free space can be secured between the first and second main frames 511a and 511b.
According to such a configuration, it is possible to easily change the specifications between the center discharge type in which the discharge duct 575 of the mower device 570 is disposed between the pair of drive axles 550a and 550b and the other type.
[0028]
The first axle case 10a is configured such that the inner end of the first drive axle 550a is positioned between the outer wall 11 and the outer wall 11 that rotatably supports the first drive axle 550a around the axis. And an inner wall 13 spaced inward in the vehicle width direction.
That is, in the first axle case 10a, a housing space 10S is defined by the outer wall 11 and the inner wall 13, and the inner end portion of the first drive axle 550a is used as the housing space 10S of the axle case 10. It is designed to be located inside.
In the present embodiment, the first axle case 10a includes an outer member 12 having the outer wall 11 and an inner member 14 having the inner wall 13, and the outer member 12 and the inner member 14 are bolts. It is connected so that separation is possible by fastening members, such as.
[0029]
As described above, the first hydraulic motor unit 20a is fluidly connected so as to form a closed circuit with the first hydraulic pump unit 700a via a flow path such as a pair of pipes, and the first hydraulic pump unit. The first HST is configured in cooperation with 700a.
[0030]
As shown in FIG. 8, the first hydraulic motor unit 20a includes a motor shaft 21 that is rotatably supported on the inner wall so that its outer end in the vehicle width direction is located in the accommodation space of the axle case 10a. And a hydraulic motor main body 31a connected to and supported on the inner wall from the outside.
[0031]
The hydraulic motor main body 31a is a motor case 32 connected to the inner wall of the axle case 10a, the motor case 32 having an open end on the opposite side to the inner wall, and the opening of the motor case 32 is closed. And a center section 33 connected to the motor case, and the center section 33 is slidably supported around the motor shaft 21 so as to be located in an internal space defined by the motor case 32 and the center section 33. The cylinder block 34, a piston 35 accommodated in the cylinder block 34 so as to be reciprocally movable, and a swash plate 36 for regulating a reciprocating range of the piston 35 are provided.
[0032]
The center section 33 is perforated with an oil passage 101 constituting a part of the flow path 100a between the center section 33 and the corresponding first hydraulic pump unit 700a. One end of the oil passage 101 opens outward, and the other end communicates with the cylinder block 34 (see FIG. 5).
The piston 35 reciprocates in the cylinder block 34 by hydraulic oil supplied and discharged through the oil passage 101, and rotates around the motor shaft 21, thereby the cylinder block 34 and the motor. The shaft 21 rotates around the axis.
[0033]
The first reduction gear transmission unit 40a includes an output gear 41 that is supported at the outer end in the vehicle width direction of the motor shaft 21 so as not to be relatively rotatable, a first intermediate gear 42 that meshes with the output gear 41, and the first An intermediate shaft 43 provided with an intermediate gear 42, an intermediate shaft 43 supported by the axle case 10 a so as to be positioned above the motor shaft 21, and a second intermediate gear provided on the intermediate shaft 43 44, and a final gear 45 that meshes with the second intermediate gear 44, and is supported at the inner end in the vehicle width direction of the first drive axle 550a so as not to be relatively rotatable. The drive output from the motor shaft 21 can be decelerated and transmitted to the first drive axle 550a.
[0034]
As described above, the first axle drive device 1a according to the present embodiment includes the first reduction transmission unit 40a between the first hydraulic motor unit 700a and the corresponding first drive axle 550a. As a result, a highly reliable low torque / high rotation type motor can be used as the first hydraulic motor unit 20a.
Such a low-torque / high-rotation type motor has advantages in that it can be made more compact than a high-torque / low-rotation type motor, and has a small amount of hydraulic oil leakage and high volumetric efficiency.
[0035]
The first brake unit 50a can selectively apply a braking force to the corresponding first drive axle 550a by selectively applying a braking force to the intermediate shaft 43.
The first brake unit 50a is arranged using an upper dead space of the first hydraulic motor unit 20a.
Specifically, the intermediate shaft 43 is supported by the axle case 10a so that the inner end in the vehicle width direction extends outward. The first brake unit 50a is configured to be able to act on the inner end of the intermediate shaft 43 in the vehicle width direction.
[0036]
In the present embodiment, the inner wall 13 of the axle case 10a has ribs 15 extending inward in the vehicle width direction so as to surround the inner end portion of the intermediate shaft 43 in the vehicle width direction. The first brake unit 50a is attached to the rib 15.
[0037]
More specifically, the first brake unit 50a includes a rotating member 51 that is non-rotatably supported at an inner end of the intermediate shaft 43 in the vehicle width direction, a fixing member 52 that is supported by the axle case 10a, and the rotating member 51a. A friction braking device 53 that operatively applies a friction force between the member 51 and the fixed member 52 and an operation arm 54 that operates the friction braking device 53 by an external operation are provided.
[0038]
The friction braking device 53 includes a rotation-side friction plate 53a that is supported by the rotation member 51 so as not to rotate relative to the rotation member 51, and a fixed member that is supported by the fixing member 52 so as not to rotate relative to the rotation-side friction plate 53a. A side friction plate 53b and an operating member 53c that frictionally engages the rotation side friction plate 53a and the fixed side friction plate 53b based on the operation of the operation arm 54 are provided (see FIG. 5).
In the present embodiment, a cam mechanism with a ball is employed as the operating member 53c, and the operating member 53c swings the operation arm 54 around a pivot axis that is parallel to the intermediate shaft 43. By doing so, the rotational friction plate 53a and the fixed friction plate 53b can be frictionally engaged.
[0039]
The first support member 70a may have various configurations as long as the axle case 10a is connected to and supported by the first main frame 511a.
As shown in FIGS. 8 to 10, in the present embodiment, as the support member 70a, a base end portion is connected to the first main frame 511a, and a mounting stay that supports the axle case 10a at the distal end portion. 71 is used.
The mounting stay 71 is an enclosed space in which the first hydraulic motor unit 20a is positioned between the inner wall 13 of the axle case 10a and the first main frame 511a, and at least an enclosed space that is open at the top. It is configured to form.
[0040]
Specifically, as shown in FIGS. 9 and 10, the mounting stay 71 includes a pair of side wall portions 72 whose base end portions are connected to the first main frame 511 a, and distal end portions of the pair of side wall portions 72. A pair of mounting portions 73 extending in a direction close to each other from each other, and having a pair of mounting portions 73 having openings through which the first hydraulic motor unit 20a and the first brake unit 50a can be inserted between the opposing end portions. The surrounding space is defined by the pair of side wall portions 72, the mounting portion 73, and the first main frame 511a.
[0041]
By providing the mounting stay 71 having such a configuration, the first axle case 10a, the first hydraulic motor unit 20a, the first reduction transmission unit 40a, The assembly in which the first brake unit 50a is assembled can be attached to the mounting stay 71 from the outer side in the vehicle width direction, thereby improving the workability of assembling the first axle drive device 1a to the body frame 510. Can be improved.
Note that reference numerals 74 * and 75 in FIG. 10 denote a reinforcing plate and a fastening bolt, respectively.
[0042]
In the first axle drive device 1a having such a configuration, the following effects can be obtained in addition to the various effects described above.
That is, in the present embodiment, as well shown in FIG. 8, when viewed along the axial direction of the first drive axle 550a, the first hydraulic motor unit 20a is at least partially part of the final. It is connected to the inner wall 13 of the axle case 10a so as to overlap the gear 45.
Therefore, the first hydraulic motor unit 20a can be connected to and supported by the first axle case 10a without increasing the size of the first axle case 10a.
[0043]
Further, the first brake unit 50 a and the first hydraulic motor unit 20 a are arranged in an up-and-down manner in the surrounding space of the mounting stay 71.
That is, the first brake unit 50a is connected to the inner wall 13 of the axle case 10a in a surrounding space of the mounting stay 71 by using a dead space that exists above the first hydraulic motor unit 20a.
According to such a configuration, since the first brake unit 50a and the first hydraulic motor unit 20a are not juxtaposed in the vehicle width direction, the pair of drive wheels 540 are not lengthened without increasing the distance between the pair of drive wheels 540. A large free space can be secured between them.
In the present embodiment, the engine 520 is disposed in the upper part of the free space, and the center discharge duct 575 in the mower device 570 is disposed in the lower part (see FIG. 3 and the like).
[0044]
In the present embodiment, as described above, the first brake unit 50a is disposed in an enclosed space having an opening defined by the mounting stay 71. Therefore, as shown in FIGS. 8 to 10, the operation arm 54 in the brake unit 50 a can be operated through the upper opening of the surrounding space, thereby providing the operation arm 54 and the vicinity of the driver's seat. The link mechanism that links the parking lever 591 and the brake pedal 592 can be simplified.
[0045]
Further, in the present embodiment, as shown in FIGS. 8 and 9, one end portion of the oil passage 101 in the center section 33 is connected to the operation arm 54 in the brake unit 50a and the first main body in the vehicle width direction. It is configured to face upward between the frame 511a.
That is, one end portion of the oil passage 101 constituting a connection portion with the actuator (the hydraulic pump unit 700a in the present embodiment) avoids the first brake unit 50a in the vehicle width direction and moves upward. Facing.
Therefore, the connection work to the connection part (in this embodiment, one end part of the oil passage 101 in this embodiment) of the connection member (pipe such as a high-pressure hose in this embodiment) between the actuator, This can be easily performed through the upper opening of the surrounding space.
[0046]
Finally, a hydraulic circuit of the vehicle 500 to which the axle drive devices 1a and 1b according to the present embodiment are applied will be described with reference to FIGS.
As shown in FIG. 4, the charge pump unit 690 sucks oil from the external reservoir tank 800 through the filter 810. The pressure oil from the charge pump unit 690 is supplied to the first and second HST charge circuits 900a and 900b, the working machine lifting / lowering hydraulic circuit 910, and the PTO unit engagement / disconnection circuit 920, respectively. Supplied at a predetermined pressure.
Note that pressure oil is supplied to the charge circuits 900a and 900b through a charge port 820 provided on the back surface of each center section 770 in the first and second hydraulic pump units 700a and 700b (FIGS. 4 and 6) and pressure oil is supplied to the PTO unit engagement / disconnection circuit 920 through a PTO port 830 provided in the case member 610 (see FIGS. 4 and 6).
[0047]
The hydraulic oil leaking from the first and second hydraulic pump units 700a and 700b passes through the drain oil passage 840 formed in the pump case 760 and the case member 610, as shown in FIGS. After being assembled in the case member 610, it is returned to the external reservoir tank 800 via the external pipe 850.
The hydraulic oil leaking from the first and second hydraulic motor units 20a, 20b is drain port 860 provided in each motor case 32 or each center section 33 in the first and second hydraulic motor units 20a, 20b. And returned to the external reservoir tank 800 through corresponding external pipes 870a and 870b.
[0048]
【The invention's effect】
According to the present invention, an axle case that supports a drive axle by an outer wall facing outward in the vehicle width direction, and a motor shaft that is supported by an inner wall facing inward in the vehicle width direction of the axle case are connected to the inner wall. A motor unit, a reduction transmission unit that transmits the reduction from the motor shaft to the drive axle, and includes an intermediate shaft positioned above the motor shaft and a final gear that is supported on the drive axle so as not to be relatively rotatable. A reduction gear transmission unit, and a brake unit capable of applying a braking force to the intermediate shaft, and the motor unit is at least partially in contact with the final gear when viewed along the axial direction of the drive axle. The axle case is disposed so as to overlap and the brake unit is positioned above the motor unit. Because it is supported by the inner wall, it is possible to reduce the size of the apparatus itself.
In particular, as compared with a configuration in which the motor unit and the brake unit are arranged in parallel in the vehicle width direction, a large free space can be provided between the drive wheels without increasing the distance between the drive wheels. Accordingly, it is possible to effectively prevent interference with other members such as a center discharge duct that can be provided in the vehicle abdomen.
[0049]
Further, the axle case is provided with an attachment stay configured to form an enclosed space in which the motor unit is positioned between an inner wall of the axle case and an airframe frame, and at least an upper portion is opened. Can be connected to and supported by the body frame, the operation arm of the brake unit can be easily accessed via the upper opening. Therefore, the link mechanism linked to the operation arm can be simplified.
[0050]
Further, if the connecting portion with the actuator that cooperates with the motor unit and constitutes the continuously variable transmission is configured to face upward between the operation arm and the body frame, the motor unit and the actuator It is possible to simplify the connecting member that connects the two.
[Brief description of the drawings]
FIG. 1 is a schematic side view of a vehicle to which an axle drive 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 schematic rear view of the vehicle shown in FIG. 1;
FIG. 4 is a hydraulic circuit diagram of a part of the vehicle shown in FIGS.
FIG. 5 is a hydraulic circuit diagram in another part of the vehicle shown in FIGS. 1 to 3;
6 is a developed plan view of the power branching device in the vehicle shown in FIGS. 1 to 3; FIG.
7 is a rear view of the power split device shown in FIG. 6. FIG.
FIG. 8 is a longitudinal rear view of an axle drive device according to an embodiment of the present invention.
FIG. 9 is a plan view of the axle drive device shown in FIG. 8;
10 is an exploded perspective view of the axle drive device shown in FIGS. 8 and 9. FIG.
[Explanation of symbols]
10a, 10b Axle case
11 Exterior wall
12 inner wall
20a, 20b Hydraulic motor unit
21 Motor shaft
31 Hydraulic motor body
40a, 40b Deceleration transmission unit
41 Output gear
43 Intermediate shaft
45 final gear
50 Brake unit
51 Rotating member
52 Fixing member
53 Friction braking device
54 Operation arm
71a, 71b Mounting stay
510 Airframe frame
511a, 511b main frame
520 engine
550a, 550b Drive axle
600 Power divider
700a, 700b Hydraulic pump unit

Claims (8)

An outer wall that rotatably supports the drive axle around an axis, and an inner wall spaced from the outer wall inward in the vehicle width direction such that an inner end portion in the vehicle width direction of the drive axle is located between the outer wall and the outer wall. An axle case,
A motor unit that forms a continuously variable transmission in cooperation with actuators that are spaced apart from each other, and is rotatable about an axis on the inner wall so that the outer end in the vehicle width direction is located in the housing space of the axle case A motor unit having a motor shaft supported on the inner wall and a motor main body coupled and supported from the outside to the inner wall
An output gear that is supported at the outer end in the vehicle width direction of the motor shaft so as not to rotate relative thereto, a final gear that is supported at the inner end of the drive axle in the vehicle width direction so as not to rotate relative thereto, and the final gear from the output gear. A speed reduction transmission unit having a gear train for speed reduction transmission to a gear, the gear train including an intermediate shaft supported by the axle case so as to be positioned above the motor shaft;
A brake unit that selectively applies a braking force to the intermediate shaft based on an external operation;
The motor unit is arranged so that at least a portion thereof overlaps the final gear when viewed along the axial direction of the drive axle.
The axle drive device according to claim 1, wherein the brake unit is supported on an inner wall of the axle case so as to be positioned above the motor unit. 2. The axle drive device according to claim 1, wherein the brake unit is arranged so that at least a part thereof overlaps the hydraulic motor unit in a plan view. The base end is connected to the fuselage frame, and further includes a mounting stay for supporting the axle case at the tip,
The mounting stay is an enclosed space in which the motor unit is positioned between an inner wall of the axle case and the body frame, and is configured to form an enclosed space having an opening at least at the top.
The brake unit includes a rotating member that is non-rotatably supported by the intermediate shaft, a fixing member that is supported by the axle case, and a friction plate pair that is supported by the rotating member and the fixing member so as not to be relatively rotatable. A friction braking device that selectively applies a braking force to the rotating member based on an external operation, and operates the friction braking device by swinging about a pivot axis that is arranged in parallel with the intermediate shaft. An operation arm,
The axle drive device according to claim 1 or 2, wherein the operation arm is operable from an upper opening of the surrounding space. 4. The axle drive device according to claim 3, wherein the motor unit is configured such that a connection portion with the actuator faces upward between the operation arm and the body frame in the brake unit. 5. . The actuator is a hydraulic pump unit,
The motor unit is a hydraulic motor unit that is fluidly connected to the hydraulic pump unit through a flow path so as to constitute an HST in cooperation with the hydraulic pump unit;
The hydraulic motor unit is an oil passage that constitutes a part of the flow path, and has a center section in which one end portion is perforated with an oil passage that forms the connection portion with an actuator. The axle drive device according to claim 4. A fuselage frame having a pair of main frames disposed along the vehicle longitudinal direction;
An engine supported by the fuselage frame;
A power branching device having a pair of hydraulic pump units operably connected to the output of the engine;
A pair of drive axles;
A pair of axle drive devices that independently drive the pair of drive axles,
The pair of axle drive units are respectively
An outer wall that rotatably supports a corresponding drive axle, and an inner wall spaced from the outer wall inward in the vehicle width direction so that an inner end in the vehicle width direction of the drive axle is located between the outer wall and the outer wall. An axle case connected to and supported by the corresponding main frame,
A hydraulic motor unit fluidly connected to the hydraulic pump unit via a flow path so as to form an HST in cooperation with a corresponding hydraulic pump unit, and an outer end in a vehicle width direction of the axle case A hydraulic motor unit having a motor shaft that is rotatably supported on the inner wall so as to be positioned in the accommodation space, and a hydraulic motor body that is connected and supported on the inner wall from the outside;
An output gear that is supported at the outer end in the vehicle width direction of the motor shaft so as not to rotate relative thereto, a final gear that is supported at the inner end of the drive axle in the vehicle width direction so as not to rotate relative thereto, and the final gear from the output gear. A speed reduction transmission unit having a gear train for speed reduction transmission to a gear, the gear train including an intermediate shaft supported by the axle case so as to be positioned above the motor shaft;
A brake unit that selectively applies a braking force to the intermediate shaft based on an external operation;
The hydraulic motor unit is arranged so that at least a portion thereof overlaps the final gear when viewed along the axial direction of the drive axle.
The vehicle, wherein the brake unit is supported on an inner wall of the axle case so as to be positioned above the hydraulic motor unit. Each of the pair of axle drive devices further includes a mounting stay whose base end portion is connected to a corresponding main frame and supports the axle case at a distal end portion thereof.
The mounting stay is an enclosed space in which the hydraulic motor unit is positioned between an inner wall of the axle case and the corresponding main frame, and is configured to form an enclosed space having at least an upper opening.
The brake unit includes a rotating member that is non-rotatably supported by the intermediate shaft, a fixing member that is supported by the axle case, and a friction plate pair that is supported by the rotating member and the fixing member so as not to be relatively rotatable. A friction braking device that selectively applies a braking force to the rotating member based on an external operation, and operates the friction braking device by swinging about a pivot axis that is arranged in parallel with the intermediate shaft. An operation arm,
The vehicle according to claim 6, wherein the operation arm is operable from an upper opening of the surrounding space. The hydraulic motor unit has a center section in which an oil passage that forms part of the flow path between the hydraulic pump unit and the hydraulic pump unit is drilled.
The vehicle according to claim 7, wherein the oil passage is opened upward between the operation arm and the main frame in the brake unit.

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