JP2677591B2 - Axle drive - Google Patents

Description

The present invention relates to an axle drive device used as a propulsion device for a tractor.

(B) Conventional technology Conventionally, a drive device in which a mission case for driving an axle is divided into two parts, a car bearing portion is provided in the mission case, and an HST transmission is attached to a side surface or an upper surface of the mission case is known. It is publicly known. For example, it is as in Japanese Utility Model Publication No. 62-44198, which is an application of the same applicant.

(C) Problems to be Solved by the Invention However, in the case of the conventional configuration, the HST transmission is protruded from the mission case because the HST transmission is provided separately from the mission case. , It was necessary to provide the extra space.

In addition, if the HST transmission is external, when using the lubricating oil in the transmission case as the hydraulic oil for the HST transmission, piping is required between them and a filter etc. is also required to save space. It was necessary to secure it.

(D) Means for solving the problem The present invention has been made in view of such a point, and has the following configuration.

In a configuration in which a HST type transmission configured by a hydraulic pump P and a hydraulic motor M to drive the axle 13 is installed inside a mission case supporting the axle 13, the pump of the hydraulic pump P is attached to the bottom wall 1a of the mission case. A pump mounting surface 1b is formed to vertically erect the shaft 4, a standing wall 1i is provided on the mission case adjacent to the pump mounting surface 1b, and a motor mounting surface 1j is formed on the standing wall 1i. Mounting surface
The motor shaft 5 of the hydraulic motor M is supported by 1j in parallel with the axle 13 and orthogonal to the pump shaft, and the hydraulic pump P attached to the pump mounting surface 1b and the hydraulic motor attached to the motor mounting surface 1j. Connect to M with two oil passages,
The two oil passages are formed in the bottom wall 1a and the standing wall 1i of the mission case.

(E) Embodiment The purpose and configuration of the present invention are as described above. Next, the configuration of the embodiment shown in the attached drawings will be described.

1 is a rear sectional view of an axle drive device of the present invention, FIG. 2 is a sectional view taken along the line XX in FIG. 1, FIG. 3 is a sectional view taken along the line YY in FIG. 1, and FIG. It is a side view.

The mission case of the axle drive device is divided into a left-side mission case 1 and a right-side mission case 2, and one side of the left-side mission case 1 and the right-side mission case 2 is internally equipped with an HST transmission including a hydraulic pump P, a hydraulic motor M, and the like. On the other hand, the left side transmission case 1 and the right side transmission case 2 internally support the axles 13L, 13R and the differential gear device D.

That is, the pump mounting surface 1b is formed on the bottom wall 1a of the left mission case 1, and the half-moon shaped oil passages 1c, 1d are formed on the pump mounting surface 1b.
And a pump shaft 4 is erected vertically at the center of the pump mounting surface 1b.

A cylinder block 10 is externally fitted to the pump shaft 4, and springs 3, 3 ... Are housed in the cylinder block 10 and biased pistons 12, 12 ... Are fitted around the pump shaft 4, and the piston 12, The upper end of 12 ... is abutted on the thrust bearing 15,
The thrust bearing 15 is fixed to the swash plate 9. The swash plate 9
Is a gearshift lever shaft 6 pivotally supported by the left mission case 1.
The rotation of the arm 7 projecting from the position changes the inclination, thereby changing the discharge amount and the discharge direction of the pressure oil.

The swash plate 9 is covered with the lid 34, and the upper portion of the pump shaft 4 is supported. A detent device is provided on the lower surface of the lid 34.
20 is provided so that it can be held in the neutral position by fitting it into the notch provided in the arm 7.

Therefore, when the pump shaft 4 is rotated, the cylinder block 10 is rotated so that the pistons 12, 12, ... Extend and contract according to the inclination of the swash plate 9, and suction and discharge are performed from the oil passages 1c, 1d. To be seen.

A standing wall 1i is erected adjacent to the bottom wall 1a, a motor mounting surface 1j is provided on a side surface of the right mission case 2 of the standing wall 1i, and a central portion of the motor mounting surface 1j and a standing wall 2a of the right mission case 2 are provided. In parallel with the axles 13L, 13R, and
The pump shaft 4 and the shaft center position are discrepancies ΔH in a top view.
The motor shaft 5 is laterally mounted so as to do so. A cylinder block 11 is externally fitted to the motor shaft 5, pistons 14, 14 ... Energized by springs 29, 29 ... Are fitted to the cylinder block 11, and the pistons 14, 14 ... Tip are thrust bearings. The thrust bearing 16 is brought into contact with the fixed swash plate 32.
It is fixed to.

In addition, oil passages 1e and 1f are formed horizontally in the bottom wall 1a in a tapered shape toward the right mission case 2 side.
The f is directly communicated with the oil passage 1d, and the oil passage 1e is communicated with the oil passage 1c through an oil passage 1e ′ formed in a right angle direction in a top view. At the open end of the right side transmission case 2 of the oil passages 1e and 1f, as shown in FIG.
6, 27 are provided, and the check valves 26, 27 include balls 26a, 27a and valve holders 26b, 27b.
b and 27b are formed in the shape of a hollow pipe, valve seats 26c and 27c are formed inside the oil passages 1e and 1f, and balls 26a and 27a are formed on the oil passages 1e and 1f side.
Is releasably inserted to prevent the balls 26a, 27a from coming off 38,
39 is interposed between the standing wall 1i and the valve holders 26b and 27b.

Then, ball push rods 35 and 36 are slidably inserted into the valve holders 26b and 27b, respectively.
The tips 35a, 36a of the 5, 36 on the valve seats 26c, 27c side are formed in a taper shape, and the tips 35a, 36a are balled in a direction away from the valve seats 26c, 27c.
The valve can be opened by pressing 26a and 27a. The other ends of the ball push rods 35, 36 are brought into contact with a pressing portion 37a of a T-shaped operating rod 37, and the operating rod 37 is pushed when pulling a vehicle equipped with an HST type transmission device to check valve 26, 27 is opened and the pressure oil is drained so that the motor shaft 5 can rotate easily so that the HST transmission is not overloaded.

Further, suction holes 26d, 27d for lubricating oil are opened on the side surfaces of the valve holders 26b, 27b located on the outer circumferences of the tips 35a, 36a of the ball push rods 35, 36, and filters are provided so as to cover the suction holes 26d, 27d. 30,31 are fitted, and the lubricating oil is filtered and replenished as hydraulic oil for the HST transmission.

Oil passages 1g and 1h are formed in the standing wall 1i in a tapered shape from the upper surface, and the lower end communicates with the oil passages 1e and 1f as shown in FIG. The oil passages 1m and 1n formed in the above are communicated with, and the open hole portion at the upper end is covered with the lid 34.

Therefore, the oil passages 1e and 1f formed horizontally in the bottom wall 1a from the oil passages 1c and 1d and the oil passage 1 formed in the vertical direction in the standing wall.
The oil passages 1m, 1n are communicated via g, 1h, and the pressure oil from the hydraulic pump P enters from the oil passages 1c, 1e ', 1e, 1g, 1m at the pistons 14, 14 ... , The cylinder block 11 is rotated and oil is fed from the pistons 14, 14 to the oil passages 1n, 1h, 1f and 1d and is recirculated to the pistons 12, 12 of the hydraulic pump P, or is fed in the opposite direction. Then, the pressure oil from the hydraulic pump P pushes the pistons 14, 14, ... And rotates the motor shaft 5. Then, if the hydraulic oil of the HST transmission is leaked, it is replenished by the check valves 26 and 27.

The rotation of the motor shaft 5 is transmitted from the gear 17 engraved on the motor shaft 5 to the large diameter gear 21 on the counter shaft 24 meshing with the gear 17, and the small diameter gear engraved on the counter shaft 24. Axle that is transmitted from the diff gear device D to the ring gear 23 of the diff gear device D and is protruded left and right from the diff gear device D
13L and 13R are driven.

A brake drum 18 is fixed to the end of the motor shaft 5 protruding into the opening 2b of the right transmission case 2, and the brake shoe is contacted by the rotation of the brake arm 19 pivotally supported by the lid 33. It is configured to be contacted and braked. The above-mentioned oil passages 1e, 1e ′, 1f, 1g, 1h are formed by the taper-shaped casting process, and they are made together in the forming process of the left mission case 1, and no special processing such as drill holes is required. Is there.

(F) Effects of the Invention The present invention is configured as described above, and has the following effects.

First, since the HST type transmission that drives the axles is housed and arranged in the mission case, there is no need for a space for fixing the HST type transmission outside the mission case as in the conventional case, and the device It was possible to reduce the size and weight.

Secondly, since the oil passages of the hydraulic pump and the hydraulic motor are directly machined and formed on the mission case without using separate members such as an oil passage plate, the entire axle drive device can be made compact and the body of the tractor can be made smaller. The installation space for the is now small.

Thirdly, as in the prior art, the oil passage formed in the transmission case is communicated at a right angle without interposing a bevel gear device, even though the pump shaft is orthogonal to the axle. Allows the power transmission direction to the hydraulic motor to be changed to a right angle, and in the case of a small tractor with an engine having a vertical crankshaft, it is possible to easily input power to the hydraulic pump using a pulley and belt. It has become.

[Brief description of the drawings]

1 is a rear sectional view of an axle drive device of the present invention, FIG. 2 is a sectional view taken along the line XX in FIG. 1, FIG. 3 is a sectional view taken along the line YY in FIG. 1, and FIG. It is a side sectional view. M …… hydraulic motor P …… hydraulic pump 1,2 …… mission case 1a …… bottom wall 1i …… standing wall 1e, 1f, 1g, 1h …… oil passage 1b …… pump mounting surface 1j …… motor mounting surface 4 …… Pump shaft 5 …… Motor shaft 13 …… Axle 26,27 …… Check valve 26a, 27a …… Ball 26b, 27b …… Valve holder 26c, 27c …… Valve seat 26d, 27d …… Suction hole 30,31 …… Filter 34 …… Lid 35, 36 …… Ball push rod 37 …… Operating rod

Claims (1)

(57) [Claims] Claims: 1. In a transmission case supporting an axle 13, an HST type transmission constituted by a hydraulic pump P and a hydraulic motor M for driving the axle 13 is provided inside a mission case. A pump mounting surface 1b is formed so that the pump shaft 4 of the hydraulic pump P is erected vertically.
Adjacent to the pump mounting surface 1b, standing wall on the mission case
1i is provided, a motor mounting surface 1j is formed on the standing wall 1i, and the motor mounting surface 1j is made to support the motor shaft 5 of the hydraulic motor M so as to be parallel to the axle 13 and orthogonal to the pump shaft 4. A hydraulic pump P attached to the pump mounting surface 1b and a hydraulic motor M attached to the motor mounting surface 1j are connected by two oil passages, and the two oil passages are connected to the bottom wall 1a and the standing wall of the mission case. Axle drive device characterized by being formed in 1i.