JP2999614B2 - Axle drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axle drive device having a hydraulic continuously variable transmission arranged inside a housing.

[0002]

2. Description of the Related Art Conventionally, a technique of dividing a housing up and down along the axis of an axle is known.
For example, US Pat. No. 4,932,209 and US Pat. No. 4,986,073.

[0003]

However, in the above prior art, the hydraulic stepless transmission is housed between the upper half case and the lower half case and fixed to the upper half case. Since the hydraulic pump and hydraulic motor are fixed to the L-shaped center section, assembly must be performed in order, and the assembly process cannot be simplified. Also, the input shaft is supported by the upper half case. In order to do this, it was necessary to drill holes. The present invention is configured such that a hydraulic pump and a hydraulic motor are assembled in an L-shaped center section, and this assembly is sandwiched between divided housings so that an axle driving device can be easily assembled and further the housing can be machine-free. It was done.

[0004]

The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described. That is, in an axle drive device in which a hydraulic pump and a hydraulic motor whose rotation axes are combined so as to be orthogonal to each other are housed in a housing, both the rotation axis of the hydraulic pump and the rotation axis of the hydraulic motor are combined. The first plane L1-L1 included and the second plane L2-L2 parallel to the first plane L1-L1 and including the axis of the axle can be separated and joined.

[0005]

Next, the operation will be described. The hydraulic pump supported on the pump mounting surface 4a of the L-shaped center section 4 is driven by an input from the input shaft 5, and pressurized oil is supplied to the motor of the L-shaped center section 4 through a closed circuit in the L-shaped center section 4. The hydraulic motor supported on the surface 4b is driven. The output is output to the output shaft 6 of the hydraulic motor, and the differential gear device is driven from the output shaft 6 via the counter shaft 15 to rotate the axles 9L and 9R protruding left and right. According to the present invention, the housing of the axle drive device thus configured can be separated and joined on the first plane L1-L1 including the input shaft 5 and the shaft center 6 of the output shaft, and the hydraulic continuously variable transmission can be assembled and disassembled. Easy going.

[0006]

Next, an embodiment will be described. FIG. 1 is an overall perspective view of an axle drive device of the present invention, FIG. 2 is a plan sectional view of the axle drive device, and FIG. 3 is a state in which a first case 1 and a second case 2 of the axle drive device are also separated. 4 is a sectional view taken along the line AA of FIG. 2, FIG. 5 is a sectional view taken along the line BB of FIG. 2, FIG. 6 is a perspective view of the L-shaped center section 4, and FIG. It is a perspective view of.

Referring to FIG. 1, an overall external view of the axle drive device of the present invention will be described. The housing constituting the outer shape of the axle driving device is formed by joining the first case 1, the second case 2, and the third case 3. And a first plane L1-L where the first case 1 and the second case 2 are joined.
1, the input shaft 5, the output shaft 6, the shift operation shaft 27, and the axis of the counter shaft 15 of the hydraulic continuously variable transmission are arranged. The bearing portions are provided at appropriate locations in a semicircular shape. The axis of the axles 9L and 9R is arranged on the second plane L2-L2 where the second case 2 and the third case 3 are joined. The bearing portions are provided at appropriate locations in a semicircular shape. The speed change operation arm 26 is fixed to a portion where the speed change operation shaft 27 projects outside the housing. The portion of the output shaft 6 protruding outside the housing is covered with the brake cover 20, and the brake operation lever 45 is pivotally supported by the brake cover 20 so as to be rotatable. At the joint surface between the second case 2 and the third case 3, mounting brackets 46 and 47 for fixing to the body frame of the traveling work vehicle are formed.

A bypass valve operating shaft 48 projects through the first case 1, and the bypass valve operating arm 24 is fixed to a projecting portion of the bypass valve operating shaft 48. In FIG. 1, the axle drive device is attached to the traveling work vehicle with the joining surface being vertical, but the housing can be attached to the traveling work vehicle with the joining surface of the housing being horizontal.

FIG. 2 shows a horizontal sectional view of the axle drive unit. A cross-sectional view of a portion in which the counter shaft 15 (not shown in FIG. 1) is supported by being sandwiched between the joint surfaces of the first case 1 and the second case 2 is disclosed.
FIG. 3 shows the first case 1 side of the joint surface between the first case 1 and the second case 2.

First, in FIG. 3, a hydraulic pump is supported on a pump mounting surface 4a of an L-shaped center section 4 in a housing. The hydraulic pump includes an input shaft 5, a pump case 7, a pump piston 32, a movable swash plate 28, and the like. The rotation from the engine is transmitted to the input shaft 5. The input shaft 5 is supported by bearings inside the housing, and a pump case 7 is engaged with the outer periphery of the input shaft 5 inside the housing. A plurality of cylinder holes are formed in the pump case 7, and a pump piston 32 is inserted therein so as to be freely retractable. The pump case 7 is rotated by the rotation of the input shaft 5, and the pump piston 32 is rotated together with the pump case 7. Discharges pressure oil in forward and reverse directions. The hydraulic oil discharged from the hydraulic pump passes through an oil passage in the L-shaped center section 4 and supplies the hydraulic oil to the hydraulic motor supported on the motor mounting surface 4b of the L-shaped center section 4 via a closed circuit. .

The hydraulic motor comprises an output shaft 6 and a motor case 8
, A motor piston 33, a fixed swash plate 35 and the like. The pressure oil becomes a force for pushing out the motor piston 33 inserted into the cylinder hole of the motor case 8, and the pushing force is changed to the rotational force of the motor case 8 by the fixed swash plate 35. Since the motor case 8 is engaged with the output shaft 6, the output shaft 6 rotates and outputs. The output shaft 6
Is provided with a small-diameter gear 34, which is in mesh with the large-diameter gear 16 of the counter shaft 15.
The rotation of the counter shaft 15 is transmitted from the small diameter engraving gear 18 to the ring gear 17. The differential gear device is constituted by the ring gear 17, the side gears 36, and the pinion gears 37. The differential rotation of the differential gear device is applied to the axle 9
L ・ 9R.

The above-described hydraulic pump is provided with a shift operation arm 26.
By rotating the lever arm 30 and the lever 31 via the speed change operation shaft 27 and the lever 31, the movable swash plate 28 is moved, and switching between forward and reverse pressure oil is performed. The L-shaped center section 4 is provided with bypass valve operating portions 22, 22.
The bypass valve operating shaft 25 rotates through the bypass valve operating shaft 4 and the bypass valve operating shaft 48, and the forked operating body 23 presses the bypass valve operating portions 22 by the bypass valve operating shaft 25. The bypass valve operating section 22 is provided with an L-shaped center section 4.
By simultaneously opening the check valves inside, the closed circuit between the hydraulic pump and the hydraulic motor is opened to the bypass circuit, and the rotation of the hydraulic motor is stopped.

A brake drum 19 is fixed to a portion where the output shaft 6 projects outside the housing, and a brake band 21 is wound around the brake drum 19.
The outside of the brake band 21 is covered with a brake cover 20, and a brake lever 45 is pivotally supported. An oil filter 29 is interposed between the inside of the bottom surface of the housing where the first case 1 and the second case 2 are joined and the lower surface of the L-shaped center section 4, and suction is performed via the oil filter 29. When the negative pressure is generated in the closed circuit in the L-shaped center section 4, the hydraulic oil is suctioned and supplied.

Since the L-shaped center section 4 cannot be fixedly supported on either the first case 1 or the second case 2 as in the prior art, the first case 1 and the second case 2 are joined together. , The fitting projections 4a and 4b protruding from the L-shaped center section 4 are sandwiched and fixed. In FIG. 4, fitting projections 4a and 4b project from the L-shaped center section 4 toward the first case 1 and the second case 2, respectively.
b is fitted in the fitting recess 1 a provided in the first case 1 and the fitting recess 2 a provided in the second case 2. Further, as described above, the bolts are not fixed to the second case 2, and the first case 1 and the second case 2 are simply fixed.
Is simply inserted and fixed between the inside of the joint bottom surface and the both side surfaces of the L-shaped center section 4.

Similarly, the fixed swash plate 35 also has fitting protrusions 35a and 35b protruding forward and backward so that it can be supported at the joint between the first case 1 and the second case 2. Then, as shown in FIG. 3, the first case 1 and the second case 2 are fitted and supported on a joint surface between the first case 1 and the second case 2.

[0016]

As described above, the present invention has the following advantages. That is, first, the hydraulic pump and the hydraulic motor constituting the hydraulic transmission are assembled into the housing by sandwiching the first case 1 and the second case 2 and the axle is connected to the second case 2 by the second case 2. Since the respective cases can be terminated by sandwiching the third case 3, the assembling process can be simplified. Further, the processing of the housing can be simplified.

Second, since the input shaft 5 and the output shaft 6 constituting the hydraulic transmission are supported by bearings on the same joint surface, the hydraulic transmission constituted by the hydraulic pump and the hydraulic motor is in an assembled state. , Can be assembled and disassembled,
Inspection and repair became easier.

Third, a joint surface L1-L1 bearing the input shaft 5 and the output shaft 6, and a joint surface L bearing the axles 9L and 9R.
Since 2-L2 is on a different surface, in the case of failure, etc., repair and repair can be performed by disassembling and inspecting only one joint surface, thereby simplifying maintenance.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an axle drive device of the present invention.

FIG. 2 is a plan cross-sectional view of the axle drive device.

FIG. 3 is a front view of the axle drive device in a state where a first case 1 and a second case 2 are separated from each other.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a sectional view taken along the line BB of FIG. 2;

FIG. 6 is a perspective view of an L-shaped center section 4;

7 is a perspective view of a fixed swash plate 35. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st case 2 2nd case 3 3rd case 4 L-shaped center section 4a, 4b Fitting protrusion 5 Input shaft 6 Output shaft 9L, 9R Axle

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 39/00-39/20 F16H 47/02 F16H 57/00-57/12 B60K 17/10-17 / 26

Claims (1)

(57) [Claims] 1. An axle drive device in which a hydraulic pump and a hydraulic motor whose rotational axes are mutually orthogonally combined are housed in a housing, wherein the housing comprises a hydraulic pump rotational axis and a hydraulic motor rotational axis. The first plane L1-L1 including both the cores and the second plane L2-L2 parallel to the first plane L1-L1 and including the axis of the axle can be separated and joined. An axle drive device characterized in that: