JPH11210862A - Axle driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compactly accommodate a PTO transmission system in the same housing in an axle driving device integrally provided with an HST, an axle, and a power transmission mechanism for transmitting power to the axle. SOLUTION: In a housing accommodating a power input shaft 6, having the axis of rotation extending longitudinally, an axle 7 having the axis of rotation extending laterally, and a PTO shaft 9 having the axis of rotation extending longitudinally, a front housing member 1, a center housing member 2, and a rear housing member 3 are longitudinally and serially provided. A partition wall is provided at a center part in the vertical direction of the front housing member 1 and the center housing member 2 to divide the center part into the first- or third chamber R1 and the second chamber R2, and the thid- or first chamber is formed between the center housing member 2 and the rear housing member 3. An HST is accommodated in the first - third chamber, a power transmission means for transmitting the output of the HST is accommodated in the second chamber, and a power transmission means for transmitting the input from the input shaft to the PTO shaft 9 is accommodated in the third- or first chamber R3, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for mounting an H
The present invention relates to a configuration for compactly storing a PTO transmission system in the same housing in an axle drive device integrally including an ST, an axle, and a power transmission mechanism for the axle.

[0002]

2. Description of the Related Art Conventionally, a technology in which an HST, an axle, and a power transmission mechanism for interlocking and connecting the HST and the axle to each other in a housing has been known.
A hydraulic pump and a hydraulic motor are arranged on the center section along the left and right direction, and the input shaft of the HST, that is, the pump shaft is arranged vertically, and the output shaft of the HST, that is, the motor shaft is arranged horizontally. It was arranged parallel to the axle. For example, the technology of US Pat. No. 5,456,068. Further, the technology in which the PTO unit is mounted on the axle drive device is disclosed in U.S. Pat. Nos. 5,366,877 and 5,515,677.

[0003]

As described above, the HST
If the input shaft is arranged vertically, the length of the housing will be short in the vertical direction and long in the front-back or left-right direction, but since the input shaft must protrude upward, This requires a certain amount of space for pulleys or sprockets. When the PTO shaft is provided, the input shaft is provided in the vertical direction, and the PTO shaft needs to be provided in the horizontal direction. Therefore, it is necessary to change the direction by using a bevel gear or the like. However, the case for mounting the PTO shaft is protruded rearward of the housing, which requires a large space.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the following means are used. That is,
2. A housing for accommodating an input shaft having a rotation axis extending in the front-rear direction, an axle having a rotation axis extending in the left-right direction, and a PTO shaft having a rotation axis extending in the front-rear direction. A HST that is formed by connecting at least two housings in the front-rear direction, and is driven by the input shaft on one side in the front-rear direction inside the housing;
Power transmission means for transmitting the output of the HST to the axle, and power transmission means for transmitting the power of the input shaft to the PTO shaft are separately housed on the other side of the front and rear.

According to a second aspect of the present invention, an input shaft having a rotation axis extending in the front-rear direction, an axle having a rotation axis extending in the left-right direction, and a PT having a rotation axis extending in the front-rear direction.
A housing accommodating an O-shaft, the housing having a front housing member, a center housing member, and a rear housing member connected in front and back, and a first room and a second housing between the front housing member and the center housing member. Forming a second room, forming a third room between the central housing member and the rear housing member, and housing the HST driven by the input shaft in the first or third room; A power transmission means for transmitting the output of the HST to the axle is housed in the room, and a PTO is provided in the third or first room from the input shaft.
It houses power transmission means for transmitting to a shaft.

According to a third aspect of the present invention, the HST is hydraulically connected by installing a hydraulic pump connected to the input shaft, a hydraulic motor connected to the axle, and the hydraulic pump and a hydraulic motor. A center section, the rotation axis of the hydraulic pump is substantially coincident with the rotation axis of the input shaft, the rotation axis of the hydraulic motor is disposed substantially parallel to the rotation axis of the axle, and the hydraulic pump is located above the axle. The hydraulic motors are arranged vertically.

According to a fourth aspect of the present invention, the hydraulic pump is disposed between the hydraulic motor and the axle.
The power transmission means for arranging the PTO shaft near the axle, drivingly connecting the hydraulic motor and the axle, and transmitting power from the input shaft to the PTO shaft. The means are overlapped in side view.

According to a sixth aspect of the present invention, the third or first room is configured to allow oil to flow freely with respect to the second room. According to a seventh aspect, the inside of the first or third room and the inside of the second room can be freely circulated through a filter means.

According to another aspect of the present invention, the power transmission means to the PTO shaft includes a hydraulic clutch capable of connecting and disconnecting power transmission from the input shaft to the PTO shaft. A hydraulic pump that is driven and supplies hydraulic oil to the hydraulic clutch is disposed.

[0010] In the ninth aspect, a part of the pressure oil discharged from the hydraulic pump is used as the HST operating oil. In the tenth aspect, a recess is formed in the housing member so as to be recessed toward the first or third room, and the hydraulic clutch located in the third room faces the inside of the recess. is there. In the eleventh aspect, an axle housing is formed integrally with one of the housing members, and a steering case for four-wheel steering is mounted on an end of the axle housing.

[0011]

Next, an embodiment in which the axle drive device of the present invention is mounted on a tractor will be described. FIG. 1 is an overall side view of a tractor equipped with the axle drive device of the present invention, and FIG.
3 is a side view of the axle driving device, FIG. 3 is a sectional view taken along the line AA in FIG. 2, FIG. 4 is a sectional view taken along the line BB in FIG.
6 is a front view of the center section, FIG. 6 is a side view thereof, FIG. 7 is a sectional view taken along the line CC in FIG. 5, FIG. 8 is a hydraulic circuit diagram, and FIG. 9 is a sectional view taken along the line DD in FIG. 10 is a sectional view taken along the line EE in FIG. 4, FIG. 11 is a sectional view taken along the line FF in FIG. 10, FIG. 12 is a side sectional view showing another housing configuration, and FIG. H sectional view, FIG. 1
4 is a front sectional view of an axle driving device in the case of a four-wheel steering type, FIG. 15 is a plan view of a rear wheel steering section, FIG. 16 is a side view sectional view of a PTO switching gear case, and FIG.
FIG. 18 is an external side view of the PTO switching gear case.

Referring to FIG. 1, the entire configuration of a lawn tractor equipped with the axle drive device of the present invention will be described. An engine 102 is mounted on the front of the body frame 101, and left and right mounting stays 101a and 1 are provided on the rear of the body frame 101.
Axle housing 1b of axle drive device 103
1b is fixed, and the axles 7L and 7R protrude to both sides from the axle driving device 103 to support the rear wheels 105.
The front wheels 104
Is suspended. A mower 106 is mounted on the abdomen of the body between the front wheel 104 and the rear wheel 105 so as to be able to move up and down as a mid-mount working machine. Then, power is transmitted from the output shaft of the engine 102 to the input shaft 6 of the axle drive device 103 via the universal joint and the transmission shaft 107, and the rear wheel 1
05 can be driven. Also, the axle driving device 10
3 has a mid-PTO shaft 9 protruding forward, and a mower 10 via a universal joint and a transmission shaft 108.
The mower 106 can be driven by transmitting power to a gear box 109 provided on the upper part of the gear 6.

Next, referring to FIG. 2 and FIG. 3, the overall configuration of the axle drive device will be described. The housing of the axle drive device includes a front housing member 1, a center housing member 2, and a rear housing member 3 that can be separated and joined in the longitudinal direction of the body, and forms a joining surface on a surface along the left-right direction of each housing. Are connected to each other to form a single housing.

A motor shaft 4 is rotatably supported in the left and right directions at an upper level of a space surrounded by the front housing member 1 and the central housing member 2, and an input shaft 6 and a counter shaft serving as a pump shaft are provided at an intermediate level. 26 is rotatably supported, the input shaft 6 with respect to the motor shaft 4 is arranged at right angles, and the counter shaft 26 is arranged in parallel. Further, axles 7L and 7R are rotatably supported in the left and right direction at the lower level, and a mid PTO shaft 9 is further rotatably supported in the front and rear direction at the lower level. By projecting the input shaft 6 and the mid PTO shaft 9 forward, power transmission from the engine 102 to the input shaft 6 and from the mid PTO shaft 9 to the mower 106 is performed via the universal joint, the transmission shaft, and the like. Power transmission to improve the transmission efficiency compared to the conventional belt transmission and have a maintenance-free configuration.

Since the motor shaft 4 and the counter shaft 26 are supported inside the front housing member 1, a semicircle receiving the shaft ends of the motor shaft 4 and the counter shaft 26 on the inner surface of the front wall of the front housing member 1. The front housing member 1 is provided with a bearing member having a separable semicircular recess. A concave portion 2b having a concave cross section is projected from the front / rear partition wall 2a of the central housing member 2 toward the inside of the front housing member 1, and the input shaft 6 is a bearing between the concave portion 2b and the front housing member 1. Have been.

At the intermediate level of the front housing member 1, trunnion shafts 35L and 35R, which will be described later, are rotatably supported in the left and right directions. The front axle 7L and 7R are displaced forward from the joint surface of the
Is rotatably supported. Each of the inner ends of the axles 7L and 7R is differentially coupled by a differential gear device 23. Both ends of the axles 7L and 7R protrude outward from axle housings 1b and 1b formed integrally with the left and right outer walls of the front housing member 1. The wheels 105 are fixed.

A PTO clutch shaft 92 and a counter shaft 98, which will be described later, are rotatably supported between the central housing member 2 and the rear housing member 3 in the front-rear direction. The front and rear partition walls 2a of the member 2 and the front portion thereof are rotatably supported by the front wall of the front housing member 1 via bearings. The rear end of the mid PTO shaft 9 extending outward from the rear housing member 3 is covered by a cover 111.

The interior of the housing comprises a first chamber R1 for housing a hydrostatic transmission (hereinafter referred to as HST) between the front housing member 1 and the front and rear partition walls 2a of the central housing member 2, and a motor shaft 4 Room R2 for accommodating the power transmission means for transmitting power from the gearbox to the differential gear device 23 and the axles 7L and 7R.
The first room R1 and the second room R2 are defined substantially right and left by right and left partition walls 8 extending from front and rear partition walls 2a of the front housing member 1 and the central housing member 2. A third room R3 is formed between the front and rear partition walls 2a of the central housing member 2 and the rear housing member 3. The housing is formed by integrating the central housing member 2 and the rear housing member 3 shown in FIG. 2 and the like, and is constituted by the rear housing member 3 as shown in FIGS. The rear end opening edge of the front housing member 1 may be joined to the front end opening edge. In this case, the third room R3
Is formed between the rear wall 3a of the rear housing member 3 'and the bearing plate 300 attached to the inside of the front end of the rear housing member 3'.

The first chamber R1, the second chamber R2, and the third chamber R3 are filled with a common lubricating oil to form an oil reservoir, and the second chamber above the front housing member 1 is formed. An oil supply lid 112 is provided in R2, and a reservoir tank 10 is provided in the first room R1 with a cover member 48 interposed therebetween. An oil filter 56 to be described later communicates with a lower portion of the reservoir tank 10.

Further, the first room R1 and the second room R
Oil filter 1 at any position on left and right partition wall 8
8 are arranged. In this embodiment, as shown in FIG.
An oil filter 18 is arranged between the portion for storing the HST and the portion for storing the axle 7L and the mid-PTO shaft 9, so that the oil is supplied when the oil flows from the second room R2 to the first room R1. The cleaning is performed through a filter 18. Furthermore, a circulation hole is opened in the central housing member 2 so that oil can flow between the second room R2 and the third room R3. Therefore, the oil filled in the housing can be used in common for the HST operating oil and the lubricating oil for the gears and bearings. When oil enters the first chamber R1 from the second chamber R2, foreign substances such as gear abrasion powder harmful to the HST are filtered by the oil filter 18.

An HST is accommodated in the first room R1, and a center section 5 for mounting a hydraulic pump P and a hydraulic motor M constituting the HST includes: It has an elongated shape and is fixed to the front housing member 1. The center section 5 has a first room R as shown in FIGS.
In a state where the hydraulic motor M is fixed to the inside, a hydraulic motor M is disposed on the left side surface 91 at the upper part, and a hydraulic pump P is disposed on the front surface 90 at the lower part.

The hydraulic pump P and its input shaft 6 are located at an upper and lower intermediate level between the motor shaft 4 of the hydraulic motor M and the axle 7 so as to be orthogonal to each other. A pump mounting surface 40 is formed on the front surface 90 of the center section 5 of the hydraulic pump P. As shown in FIG. 4, the cylinder block 16 is rotatably slidable on the pump mounting surface 40. In the 16 cylinder holes,
Are reciprocally fitted via biasing springs, and the thrust bearings 11a of the movable swash plate 11 abut against the heads of the pistons 12, 12 ...
An opening 11b is provided at the center of the movable swash plate 11 so that the input shaft 6 can pass therethrough. The input shaft 6 is also arranged on the rotation axis of the cylinder block 16 and also serves as a pump shaft, so that it cannot rotate relatively. It is locked. The front end of the input shaft 6 projects outward from the front wall of the front housing member 1 and receives power from a prime mover (engine 102) via a transmission mechanism such as a universal joint or a transmission shaft.

The amount and direction of oil discharge from the hydraulic pump P can be changed by tilting the piston contact surface of the movable swash plate 11 with respect to the rotation axis of the cylinder block 16. As shown in FIG. 3, the movable swash plate 11 is disposed so that trunnion shafts 35L and 35R are integrally protruded on both sides and are parallel to the axle 7. The trunnion shaft 35R is rotatably supported by the left and right partition walls 8 of the front housing member 1, and the trunnion shaft 35L
Is rotatably supported by a lid 15 that closes an opening on the side surface of the upper housing 1 so that the movable swash plate 11 can be tilted about the trunnion shafts 35L and 35R. The output change operation of the hydraulic pump P can be performed by tilting the movable swash plate 11.

The cover 15 is attached to the trunnion shaft 35L.
And a control lever 38 is fixed to the control lever 38 by being extended outwardly through the mounting hole 38a of the control lever 38. The control lever 38 is connected to a driver's gear change operation tool via a rod or a wire (not shown), and is provided in the longitudinal direction of the vehicle. In order to simplify the link mechanism, the control lever 38 is rotated. In the housing of the trunnion shaft 35L, a coil-shaped neutral return spring 31 is externally fitted.
The two ends of the neutral return spring 31 intersect and extend rearward. Both ends of the neutral return spring 31 are provided with an engaging pin 39 projecting from an arm 11d formed to project rearward from the movable swash plate 11, and the lid body. 15 and the eccentric shaft 33 attached thereto.

Therefore, when the control lever 38 is rotated for shifting, the arm 11d is also rotated around the trunnion shaft 35, and one end of the neutral return spring 31 is pushed open by the engagement pin 39, and the neutral return is performed. The other end of the spring 31 is stopped by the eccentric shaft 33, and the control lever 38 is given a biasing force for returning to neutral. Then, when the operating force on the speed change operation tool is released, the engaging pin 39 is returned to the eccentric shaft 33 side by the restoring force generated on one end side of the neutral return spring 31, and is held at the neutral position. The portion of the eccentric shaft 33 extending outside the housing is formed as an adjusting screw, and the eccentric shaft 33 is appropriately rotated and locked, so that the arm 11d is connected to the trunnion shaft 35L via the neutral return spring 31. The movable swash plate 11 is displaced around so that the movable swash plate 11 can be adjusted to an accurate neutral position.

The control lever 38 provided at the outer end of the housing of the trunnion shaft 35 is, as shown in FIG.
It has a locking portion 38b protruding downward and is connected to the movable portion of the shock absorber 73,
The shock absorber 73 is disposed in a forwardly inclined position below the axle 7L, and a fixed portion of the shock absorber 73 is connected to a support plate 74 fixed to a lower portion of the central housing member 2. Thus, the shock absorber 73 is moved to the control lever 38.
And prevents sudden shifts, and prevents sudden return to the neutral direction due to the spring force of the neutral return spring 31 when the operating force of the shift operation tool is released, thereby applying a sudden deceleration. doing.

The pressure oil discharged from the hydraulic pump P is sent to a hydraulic motor M via an oil passage in the center section 5. The configuration of the hydraulic motor M is as shown in FIG.
A motor mounting surface 41 is formed on a vertical surface 91 of the center section 5, and the cylinder block 17 is rotatably supported on the motor mounting surface 41. A plurality of pistons 13 are reciprocally fitted in a plurality of cylinder holes of the cylinder block 17 via biasing springs. The head of the piston 13 is in contact with a fixed swash plate 37. The fixed swash plate 37 is fitted and fixed to the left and right partition walls 8 in the front housing member 1.

The motor shaft 4 is integrally and horizontally disposed on the rotation axis of the cylinder block 17 so as to be locked so as not to rotate relatively. One end of the motor shaft 4 has a center section 5
The other side is inserted into the second room R2 through the left and right partition walls 8 of the front housing 1 and is supported by bearings 76 provided in the left and right partition walls 8. The motor shaft 4 is rotatably supported. The bearing 76 uses a sealed bearing to partition between the first room R1 and the second room R2. Also,
A gear 25 and a brake disc 19 are fixed adjacent to each other on the end of the motor shaft 4 located in the second chamber R2. The brake disc 19 rotates the brake arm 29a on the brake shaft 29b. By pressing the brake pad 29, the motor shaft 4 can be braked.

Next, the internal structure of the center section 5 on which the hydraulic pump P and the hydraulic motor M are mounted will be described with reference to FIGS. 5, 6, and 7. FIG. A bearing is formed at the center of the pump mounting surface 40 of the center section 5 so that the rear part of the input shaft 6 can be rotatably supported, and a pair of arcuate ports 40a and 40b are opened vertically about the bearing. And
Supply / discharge oil from the cylinder block 16 is introduced. As shown in FIG. 6, a pair of bow-shaped ports 41 a and 41 b are opened in the front-rear direction on the motor-attached surface 41 so that oil supply / discharge from the cylinder block 17 is introduced.

The arcuate ports 40a and 40b of the pump mounting surface 40 and the arcuate ports 41 of the motor mounting surface 41
The first and second linear oil passages 5a and 5b are drilled from the lower side to the upper side in the front-rear direction in order to connect the a and 41b to each other. A third linear oil passage 5c is communicated from the side at right angles to a middle portion of the second linear oil passage 5b to circulate hydraulic oil between the hydraulic pump P and the hydraulic motor M. Is configured.

That is, the arcuate port 40 of the pump mounting surface 40
a communicates directly with the first linear oil passage 5a, the arcuate port 40b communicates with the third linear oil passage 5c, the arcuate port 41a of the motor-attached surface 41 communicates directly with the first linear oil passage 5a, The bow port 41b communicates with the second straight oil passage 5b, so that the first straight oil passage 5a, the second straight oil passage 5b, and the third straight oil passage 5c are connected to the bow ports 40a and 40b. A closed circuit is formed by communicating with the ports 41a and 41b.

Check valves 54 and 5 are provided at the opening sides of the first linear oil passage 5a and the second linear oil passage 5b, respectively.
5 is closed and closed by plug members 64.
An oil passage 5 is provided at the inlet ports of the check valves 54 and 55.
d is communicated with the oil passage 5d.
It communicates with a supply port 5g that opens on the rear surface. On the other hand, a charge pump case 46 is fixedly provided on the rear surface of the center section 5, and a trochoid pump type charge pump 45 is housed in the charge pump case 46. 45 is driven. However, the charge pump may be an internal gear type or an external gear type.

When the charge pump case 46 is attached to the rear surface of the center section 5 as shown in FIG.
Oil passage 46a provided in the main relief valve 5
7, the pressure oil from the charge pump 45 is supplied to the drain port 45a of the main relief valve 57 by the oil passage 46a, and the supply port 5a.
g, oil passage 5d, and HS via check valves 54 and 55.
Hydraulic oil can be supplied into the closed circuit of T. 5
Reference numeral 8 denotes a relief valve for setting a supply oil pressure.

A flow control valve 50 is connected to the discharge port 45a. The flow control valve 50 divides oil discharged from the charge pump 45 into two-way oil flow, and one of the oil flows is output from an oil outlet port 46b opened on the rear surface of the charge pump case 46 as shown in FIG. And the other oil flow is
It is taken out of the housing and the external actuator 51
And the return oil from the external actuator 51 is again introduced into the charge pump case 46 and flows through the oil passage 46a.

The suction port of the charge pump 45 is connected to an opening 46b (FIGS. 5 and 10) formed on the upper surface of the charge pump case 46 for connecting a pipe-shaped oil filter 56. The oil filter 56 can be inserted toward the charge pump case 46 from an opening 1a opened on the upper surface of the front housing member 1, and is supported by being sandwiched between the cover member 48 and the charge pump case 46. Thus, the oil filter 56 can be easily replaced from the upper surface of the front housing member 1. The cover member 48 is provided with the opening 1
mounting flange and a reservoir tank 10 covering a
Is provided with a pipe-shaped joint member. The oil stored in the first room R1 in which the oil filter 56 is disposed generates heat and expands due to the driving of the HST. The volume change of the oil flowing into the tank 10 and flowing in the first chamber R1 is adjusted.

Further, a bypass operating lever (not shown) for opening the first linear oil passage 5a and the second linear oil passage 5b to the oil sump so that the axle can idle when the vehicle is towed is provided at the front. It is arranged in front of the front wall of the housing member 1,
By rotating the bypass operation lever, the bypass lever shaft supported by the front wall of the front housing member 1 is rotated, and the flat surface at the lower end of the bypass lever is pushed by the push pin supported by the center section 5 toward the cylinder block 17. And the push pin releases the close contact between the motor mounting surface 41 and the cylinder block 17, and the first linear oil passage 5a and the second linear oil passage 5b are connected to the housing oil through the arcuate ports 41a and 41b. It communicates with the reservoir so that the motor shaft 4 can freely rotate.

Next, from the motor shaft 4 to the differential gear device 2
The transmission of power to the gear 3 will be described with reference to a gear-type power transmission means. As shown in FIG. 3, a gear 25 provided on the motor shaft 4 protruding into the second room R2 meshes with a large-diameter gear 24 fixed on a counter shaft 26. Further, the small-diameter gear 21 fixed on the counter shaft 26 meshes with the differential input gear 22 of the differential gear device 23, and is decelerated from the motor shaft 4 to drive the differential gear device 23 by the differential input gear 22. A large-diameter gear 24 on the counter shaft 26 is arranged to overlap the side of the differential input gear 22 so that the length in the left-right direction is reduced.

Power is transmitted to the left and right axles 7L and 7R via the differential gear device 23. As shown in FIG. 9, the differential gear device 23 has a differential input gear 22 which is formed by a main body 22a and a ring-shaped gear portion 22b. A shaft hole 22c is formed in the center of the main body 22a to insert and support each of the abutting portions of the axles 7L and 7R.
A plurality of bolt holes 22e for fixing the gear portion 22b to the main body 22a with bolts are formed in the periphery of the main body 22a, and a plurality of bolt holes 22e are formed on the periphery of the main body 22a to remove the bolt. The main body 22a and the gear portion 22b
Are easily separated. The main body 22a is made of a sintered alloy or the like, and the gear portion 22b is manufactured by cutting or forging steel.

Differential gears 81L, 81R are spline-fitted to the inner ends of the axles 7L, 7R, and the axle opposite to the deceleration transmission on one side (in this embodiment, on the right side in the traveling direction). A support member 89 is externally fitted on 7L. The support member 89 is formed in a bowl shape, the differential side gear 81L is housed in a concave portion 89a, a mounting flange surface for the main body 22a is formed at an open end, and the main body 22a and the gear portion 2 are formed by the bolts.
2b. A slider 82 is axially slidably fitted on the outer periphery of the boss portion 89b outside the support member 89, and an engagement projection 82a formed of a pin is attached to the slider 82 in parallel with the axle. The tip of the mating projection 82 penetrates through the support member 89 and is located in the recess 89a, and is engageable with the recess 81a formed on the outer periphery of the rear surface of the differential side gear 81L. As described above, the differential lock mechanism is configured between the support member 89 and the differential side gear 81L, and the differential gear device 23 is configured to have no differential case, and is configured to be half covered by the support member 89.

The front side of the right axle 7R is rotatably supported in the front housing member 1 via a bearing, and the inside of the left axle 7L is provided via a bearing disposed on the outer periphery of the support member 89. It is rotatably supported in the front housing member 1. Also, the main body 22
The inner end shaft portion of the axle 7R supported by the shaft hole 22c of a is formed longer than the inner end shaft portion of the axle 7L. When the differential input gear 22 receives a force in the left-right direction, one side receives the force by the support member 89, and the other side is supported between the main body 22a and the axle 7R. Falling is reduced. A retaining ring 113 is provided at an intermediate portion of the axle 7L to prevent the axle 7L from coming off in the axial direction.
Are engaged.

Then, a slide fork 84 is engaged with the slider 82, and the base of the slide fork 84 is fixed to a shifter shaft 85 which is supported at both sides of the front housing member 1 in parallel with the axle 7, and Shifter shaft 8
5, one end of the bell crank arm 86 protrudes outward from the front housing member 1, one end of a bell crank arm 86 is locked to the shifter shaft 85, and the other end of the bell crank arm 86 is connected to a differential lock operating tool such as a differential lock pedal via a link mechanism. And the brake device.

In such a configuration, when the differential lock operating tool is operated, the bell crank arm 86 is rotated in the direction indicated by the arrow in FIG. 9, and the slide fork 84 slides to the left, and at the same time, the slider 82 slides. As a result, the engagement projection 82a engages with the concave portion 81a of the differential side gear 81L, and the differential lock is performed. When the brake pedal is depressed, the left and right axles 7L and 7R are integrally connected by assembling the link mechanism so that the brake device is braked and the differential lock is performed. The rear wheels 105 can be simultaneously braked without rotating.
This link mechanism is composed of a bell crank 86 and a brake arm 2
9a are arranged on the same side of the front housing member 1 so that it can be easily configured.

By providing a steering mechanism at the outer ends of the axle housings 1b of the front housing member 1, it is possible to change to a four-wheel steering (4WS) specification. 14 and 15, a steering case 120 is fixed to the outer end surface of the axle housing 1b, and the turning case 12 is attached to the steering case 120.
1 is mounted so as to be rotatable about the vertical axis. The rotating case 121 is pivotally supported on the steering case 120 by king pins 122 pivotally attached to the upper and lower surfaces. A wheel shaft 123 is rotatably supported by the rotating case 121, and the rear wheel 105 is fixed to the wheel shaft 123.

A knuckle arm 124 projects from the lower surface of the rotating case 121 toward the inside of the machine. A tie rod 125 is connected to the knuckle arm 124, and the tie rod 125 is connected to a bell crank arm 126. The central portion of the bell crank arm 126 is rotatably mounted on a center pin 127a pivotally supported by a bracket 127 fixed to the lower surface of the housing. The other end of the bell crank arm 126 is linked to a steering wheel together with a front wheel steering mechanism via a link or the like. The bracket 127 is provided with a pair of front and rear mounting portions 127b whose front and rear ends are bent to stand upright. The mounting portions 127b sandwich mounting portions of the front and rear front housing members 1 and the central housing member 2 to mount mounting bolts 127c. , The bracket 127 is fixed to the bottom of the housing.

On the other hand, the tip of the axle 7L is connected to the wheel shaft 123 via a universal joint 128. Although not shown, a steering mechanism similar to that described above is also provided at the end of the axle housing 1b that accommodates the axle 7R. As described above, in the axle drive device, the hydraulic pump P and the hydraulic motor M are vertically arranged above the axle 7L, so that the left and right width of the housing is reduced, and a steering mechanism is provided at the end of the axle housing 1b. Even if it is installed, the left and right width of the housing becomes narrow as described above, and a sufficient space for steering and turning the rear wheel 105 is obtained, and it is possible to easily cope with the specification in which a four-wheel steering mechanism is added. is there.

Next, the configuration of power transmission to the PTO shaft will be described. As shown in FIGS. 4, 10, and 11, the input shaft 6
The rear end of the input shaft 6 is inserted into the third chamber R3 through the recess 2b, and one end of the PTO input shaft 92 is rotatably supported on the same shaft core via a bearing at the end of the input shaft 6. And the P
A PTO clutch 88 composed of a hydraulic clutch is provided between the TO input shaft 92 and the input shaft 6.

That is, a rotating body 9 is provided on the shaft end of the input shaft 6.
3 is fitted with a spline, and a friction plate is engaged with the outer periphery of the rotating body 93. On the other hand, a clutch case 94 is fixed on the end of the PTO input shaft 92, a piston 95 is housed in the clutch case 94, and a friction plate is locked on a portion facing the rotating body 93. Polymerization is performed by alternately disposing the friction plates. Thus, the PTO clutch 88 is formed, and the PTO clutch 88 is accommodated in the concave portion 2b formed in the concave shape, and the PTO clutch 88 is provided by operating an electromagnetic valve 96 provided outside the housing.
The O clutch 88 can be connected and disconnected.

That is, the electromagnetic valve 96 is provided with a PTO (not shown).
It is linked with the operating tool and turned ON by operating the PTO operating tool.
Can be turned off. As shown in FIGS. 8, 10, and 11, a cylinder chamber for sliding the piston 95 in the clutch case 94 is provided in an oil passage 92a formed at an axial position from the end surface of the PTO clutch shaft 92. Are in communication. The rear end of the PTO clutch shaft 92 is oil-tightly fitted into a recess 3b formed in the rear wall 3a of the rear housing member 3 to form a rotary joint.
Is opened to an oil chamber provided in the recess 3b. On the other hand, the solenoid valve 96 is installed on the upper surface of the rear wall 3a of the rear housing member 3, and its switching valve portion is inserted into the rear wall 3a.

Further, on the rear wall 3a, an oil passage 135 communicating with an input port of the switching valve portion is provided on one of the left and right sides around the switching valve portion of the solenoid valve 96, and an output port of the switching valve portion is provided on the other of the left and right sides. Are respectively formed in the horizontal direction. A starting end 135a of the oil passage 135 is bent at a right angle as shown in FIG. 10 and is opened at a joint surface with respect to a rear end of the central housing member 2, and is connected to an oil outlet port 46b opened at a rear surface of the charge pump case 46. On the other hand, they are connected via an oil passage 136 extending in the front-rear direction and formed in the thick wall of the concave portion 2 b of the central housing member 2.

An oil passage 133 communicating with the oil chamber in the recess 3b is bored below the oil passage 134 in parallel.
The starting ends 134a and 133a of the two oil passages 134 and 133 are bent at right angles, open to the joint surface with the rear end of the center housing member 2, and formed in the joint surface with the vertically extending oil grooves 132 extending in the vertical direction. Thus, the oil passage 134 and the oil passage 133 are connected to each other. Also, rear housing mend 3
The rear wall 3a is connected to the oil chamber of
Relief valve 130 for setting the operating oil pressure of O clutch 88
Is disposed, and the relief oil discharged from the relief valve 130 is returned into the third chamber R3.

The anti-rotation brake 131 is disposed near the PTO clutch 88 on the side surface of the central housing member 2, and the brake pad 1 is attached to the tip of the piston 131a.
31b, the brake pad 131b is arranged opposite to the large-diameter boss outer peripheral surface 97a of the gear 97 fixed to the rear surface of the clutch case 94, and the piston 131
a is housed in a cylinder chamber 2c formed on the side surface of the central housing member 2, and is urged by a spring 131c so that the brake pad 131b comes into contact with the large-diameter boss outer peripheral surface 97a.

The cylinder chamber 2c is provided with an oil passage 13 extending in the front-rear direction and formed in a side wall of the central housing member 2.
3b is communicated with the start end 133a of the oil passage 133b via a joint surface with the front end of the rear housing member 3.
Is connected to Thus, the anti-rotation brake 1
31 is configured as a negative brake type,
Non-braking and braking are performed in synchronization with the operation and non-operation of the O clutch 88.

In such a configuration, when the PTO operating tool is not operated, the electromagnetic valve 96 is not operated, and the position shown in FIG. 8 is reached, and no pressure oil is supplied to the PTO clutch 88 and the anti-rotation brake 131. Further, the brake pad 131b is pressed against the clutch case 94 by the urging force of the spring 131c, so that the PTO clutch shaft 92 is prevented from rotating.

When the PTO operating tool is operated, the electromagnetic valve 96 is switched to the left position, and the oil passage 135 is turned off.
And the oil passage 134 are communicated with each other, and the oil discharge port 46b
Is supplied to the anti-rotation brake 131 and the PTO clutch 88, and the anti-rotation brake 131
The brake pad 131b releases the clutch case 94 to release the brake, the piston 93 of the PTO clutch 88 slides and presses against the friction plate, and the PTO clutch 88 is brought into "contact". Axis 9
Power is transmitted to 2.

As shown in FIGS. 4 and 10, the gear 97 on the PTO clutch shaft 92 is
4 and are connected so as not to rotate relative to each other. The gear 97 is engaged with a gear 99 fixed on the counter shaft 98,
Further, the gear 99 is meshed with a gear 100 fixed on the mid PTO shaft 9. In this way, by bringing the PTO clutch 88 into contact, the gears 97
Power is transmitted to the mid-PTO shaft 9 via 100 and power is transmitted from the mid-PTO shaft 9 to the mower 106 via a universal joint or a transmission shaft 108. Further, the power can be transmitted to the working machine disposed behind the machine with the cover 111 removed.

From the PTO clutch shaft 92 to the mid PT
The power transmission means to the O-shaft 9 can be constituted by a gear train composed of spur gears.
The power transmission means to the mid PTO shaft 9 can also be constituted by a gear train of spur gears, each having a narrow width and a compact configuration, and the power transmission means to the mid PTO shaft 9 is a differential input gear in side view. 22 so that the front-rear width is narrowed.

Further, the cover 111 is removed from the rear housing member 3, and the hole 3b is opened to open the mid P
By pulling out the gear 100 from the TO shaft 9 and attaching the PTO gear case 140 shown in FIGS.
The direction of power transmission to the mid work machine and the rear work machine can be arbitrarily switched. Optional or retrofitable configuration.

That is, the PTO gear case 140 is divided into front and rear parts, and the rear PTO input shaft 141, the counter shaft 142, and the rear PTO shaft 143 are rotatably supported in parallel along the front-rear direction. A gear 144 is fixed on the input shaft 141 and meshes with a gear 145 fixed on the counter shaft 142. A gear 146 is further fixed on the counter shaft 142 and fixed on the rear PTO shaft 143. The rear PTO input shaft 14 meshes with the gear 147 provided.
1 to the rear PTO shaft 143.

A hollow cylindrical rotator 148 inserted into the rear housing member 3 through the hole 3b is spline-fitted to the rear end of the mid PTO shaft 9.
A gear 149 is rotatably fitted on the outer periphery of the rotating body 148 via a bearing. The gear 149 has two teeth, and one of the teeth 149a meshes with the gear 99 on the counter shaft 98. The other tooth portion 149b is connected to the tooth portion 148a formed on the end of the rotating body 148 and the gear 1
The teeth 144a are formed in parallel with the teeth 144a formed at the ends of the teeth 44, and the clutch slider 150 is externally fitted on the teeth 144a, 148a, and 149b so as to mesh with the respective teeth.

A slide fork 151 is engaged with the clutch slider 150, and the slide fork 151
Is the fork shaft 15 fixed to the PTO gear case 140
2 is slidably supported on the slide fork 151
Is configured to be slid via an arm 154 by the rotation of a switching shaft 153 supported on the side wall of the gear case 140. The switching shaft 153 is connected via a link or the like to the PTO of the driver's seat.
Connected to the switching lever. The switching position can be detected by the sensors 155 and 156.

When the clutch slider 150 is positioned forward by the rotation of the switching shaft 153, the teeth 149b and 148a and the clutch slider
When the gears 0 mesh with each other, power is transmitted from the gear 149 to the mid PTO shaft 9, and only the mid working machine can be driven. When the slider 150 is positioned at the center in the figure, the clutch slider 150 is moved to the tooth portions 144a and 148.
a.149b can be driven to drive both the mid working machine and the rear working machine. When the clutch slider 150 is located rearward, the clutch slider 150 meshes with the teeth 144a and 148a, and power is transmitted to the rear PTO shaft 143, so that only the rear working machine can be driven.

As described above, while the hole 3b for inserting and removing the gear provided on the rear wall of the rear housing member 3 is closed by the PTO gear case 140 mounted in place of the cover 111, the third chamber is inserted through the hole 3b. The power from the PTO clutch 88 located in R3 is transferred to the PTO gear case 1
Guide into the mid PTO shaft 9 and the rear PTO shaft 1
43 is configured for transmission and addition.

[0063]

As described above, the present invention has the following advantages. In other words, according to the first and second aspects of the present invention, the center section of the HST is disposed inside the housing, so that oil leakage to the outside of the housing is prevented. Further, the number of parts of the housing member can be reduced while the power take-out mechanism is integrated in the housing.

Also, a hydraulic pump connecting the HST to the input shaft, a hydraulic motor connected to the axle, and the hydraulic pump and the hydraulic motor are installed and fluidly connected. A rotary shaft of the hydraulic pump substantially coincides with a rotational axis of the power input shaft, a rotational axis of the hydraulic motor is disposed substantially parallel to the rotational axis of the input shaft, and a hydraulic pressure is set above the axle. Since the pump and the hydraulic motor are arranged in the vertical direction, the housing can be made slender and the left and right widths can be compressed to make it compact. Also, a steering space for the rear wheels in the case of a four-wheel steering vehicle could be secured. Further, the input shaft can be directly connected to the hydraulic pump, and the hydraulic motor and the axle can be connected by a spur gear type gear train, thereby simplifying the configuration and realizing cost reduction.

Further, since the hydraulic pump is arranged between the hydraulic motor and the axle, the hydraulic pump is disposed between the hydraulic motor and the axle in the first or third room. By effectively utilizing the dead space generated, the vertical width of the housing can be compressed.

Further, the power transmission means for arranging the PTO shaft near the axle and drivingly connecting the hydraulic motor and the axle, as in claim 5,
Since the power transmission means for transmitting the power from the input shaft to the PTO shaft is overlapped in a side view, the front-rear width of the housing can be compressed, and the size can be reduced.

Further, since the third or first chamber is configured to allow oil to flow freely with respect to the second chamber, the power transmission means of the traveling system and the power transmission means of the PTO system can be used. Lubricating oil can be shared.

Further, since the oil in the first or third room and the oil in the second room can freely flow through the filter means, the power transmission means of the traveling system and the PTO While sharing the lubricating oil for the power transmission means of the system as the hydraulic oil for the HST, the oil in the first room is maintained in a clean state to protect the HST from foreign substances in the lubricating oil present in the second room. As a result, the durability can be improved.

Further, the power transmission means to the PTO shaft includes a hydraulic clutch capable of connecting and disconnecting power transmission from the input shaft to the PTO shaft, and the power transmission means is provided in the housing. Since the hydraulic pump that is driven by the shaft and supplies the hydraulic oil to the hydraulic clutch is arranged, the hydraulic pump is located near the hydraulic clutch, and the oil passage configuration for the hydraulic clutch is shortened, the pipeline resistance is reduced, and the loss is reduced. Horsepower can be reduced.

Further, since a part of the pressure oil discharged from the hydraulic pump is used as the hydraulic oil for the HST, the hydraulic pump can be used for supplying the hydraulic clutch oil to the HST.
, Which can be used for replenishing the working oil, thereby reducing the number of pumps to be used and reducing cost.

According to a tenth aspect of the present invention, a recess is formed in the central housing member so as to be recessed toward the first or third room, and the hydraulic clutch located in the third room is provided in the recess. , The dead space in the first room can be effectively used as a space for installing the hydraulic clutch, and the entire housing can be made compact.

Also, an axle housing may be integrally formed with any of the housing members.
By mounting the steering case for four-wheel steering at the end of the axle housing, even if the running wheels are steered and turned, the width of the housing is formed narrow, so that the tread does not need to be widened. Thus, the turning radius can be further reduced, and the steering performance and work efficiency can be improved by using the same body.

[Brief description of the drawings]

FIG. 1 is an overall side view of a tractor equipped with an axle drive device of the present invention.

FIG. 2 is a side view of the axle drive device.

FIG. 3 is a sectional view taken along the line AA in FIG. 2;

FIG. 4 is a sectional view taken along the line BB in FIG. 3;

FIG. 5 is a front view of a center section.

FIG. 6 is a side view of the same.

FIG. 7 is a sectional view taken along the line CC in FIG.

FIG. 8 is a hydraulic circuit diagram.

FIG. 9 is a sectional view taken along the line DD in FIG. 3;

FIG. 10 is a sectional view taken along the line EE in FIG. 4;

11 is a sectional view taken along the line FF in FIG. 10;

FIG. 12 is a side sectional view showing another housing configuration.

13 is a sectional view taken along the line HH of FIG.

FIG. 14 is a front cross-sectional view of the axle drive device in the case of a four-wheel steering type.

FIG. 15 is a plan view of a rear wheel steering unit.

FIG. 16 is a side view of a PTO switching gear case.

FIG. 17 is a front view of the same.

FIG. 18 is an external side view of a PTO switching gear case of a switching operation shaft portion.

[Explanation of symbols]

 R1 first room R2 second room R3 third room P hydraulic pump M hydraulic motor 1 front housing member 2 center housing member 2b recess 3 rear housing member 4 motor shaft 5 center section 6 input shaft 7L ・ 7R axle 9 PTO Shaft (mid PTO shaft) 18 Oil filter 45 Hydraulic pump (charge pump) 88 Hydraulic clutch (PTO clutch)

Claims (11)

[Claims] 1. A housing for accommodating an input shaft having a rotation axis extending in a front-rear direction, an axle having a rotation axis extending in a left-right direction, and a power take-out shaft (hereinafter, a PTO shaft) having a rotation axis extending in a front-rear direction. The housing is formed by connecting at least two housings in the front-rear direction, and a hydrostatic transmission (hereinafter, HS) driven by the input shaft is provided in one of the front and rear sides inside the housing.
T) and power transmission means for transmitting the output of the HST to the axle.
An axle drive device wherein power transmission means for transmitting to an O-shaft are housed independently of each other. 2. A housing for accommodating an input shaft having a rotation axis extending in the front-rear direction, an axle having a rotation axis extending in the left-right direction, and a power take-out shaft having a rotation axis extending in the front-rear direction. Comprises a front housing member, a central housing member, and a rear housing member connected in front and rear, a first room and a second room are formed between the front housing member and the central housing member, and the center housing member and the rear housing member are formed. A power transmission means for forming a third room between the member and the HST driven by the input shaft in the first or third room, and transmitting the output of the HST to the axle in the second room; An axle drive device, wherein a power transmission means for transmitting from the input shaft to the PTO shaft is housed in the third or first room. 3. The HST includes a hydraulic pump connected to the input shaft, a hydraulic motor connected to the axle, and a center section in which the hydraulic pump and the hydraulic motor are installed and fluidly connected. The rotation axis of the hydraulic pump is substantially coincident with the rotation axis of the input shaft, the rotation axis of the hydraulic motor is disposed substantially parallel to the rotation axis of the axle, and the hydraulic pump and the hydraulic motor are vertically moved above the axle. The axle drive device according to claim 1 or 2, wherein the axle drive device is arranged in a direction. 4. The axle drive device according to claim 3, wherein the hydraulic pump is disposed between the hydraulic motor and the axle. 5. The power transmission means for arranging the PTO shaft near the axle, drivingly connecting the hydraulic motor and the axle, and a PTO shaft from the input shaft.
3. The axle drive device according to claim 1, wherein the power transmission means for transmitting to the shaft is overlapped in a side view. 6. The axle drive device according to claim 1, wherein the third or first room is configured to allow oil to flow freely with respect to the second room. 7. The axle driving device according to claim 6, wherein oil can freely flow between the first or third room and the second room via a filter means. 8. The power transmission means to the PTO shaft includes a hydraulic clutch capable of connecting and disconnecting power transmission from the input shaft to the PTO shaft, and a hydraulic clutch driven by the input shaft in the housing. 3. The axle drive device according to claim 1, further comprising a hydraulic pump that supplies hydraulic oil to the clutch. 9. The axle drive device according to claim 8, wherein a part of the pressure oil discharged from the hydraulic pump is used as the hydraulic oil for the HST. 10. The housing member is provided with a concave portion which is recessed into the first or third room, and the hydraulic clutch located in the third room is exposed to the inside of the concave portion. The axle drive device according to claim 8, wherein 11. The axle drive device according to claim 3, wherein an axle housing is formed integrally with one of the housing members, and a steering case for four-wheel steering is mounted on an end of the axle housing.