JPH0530648B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention applies to a traveling vehicle such as a tractor,
This relates to a configuration in which an axle is driven by a hydraulic motor of an HST type transmission.

(b) Prior Art Conventionally, the swash plate seat that supports the movable swash plate has been constructed as an inclined protrusion having an opening for the motor shaft to pass through, and a bearing wall that supports the motor shaft after passing through the inclined protrusion has been provided separately. Techniques for providing an output gear between the inclined protrusion and the bearing wall are known. For example, there is a technique described in Japanese Patent Publication No. 49-36298.

In addition, in other prior art, the following two structures are known for connecting a hydraulic motor to a reduction gear in a transmission case.

First, what is shown in U.S. Patent No. 4,513,834 is
The output gear is fixed to the end of the hydraulic motor shaft that extends outside the case, and this is inserted into the transmission case and connected to the reduction gear, but the stress applied to the output gear causes the end of the hydraulic motor shaft to bend. Since this acts as stress, it is necessary to increase the strength of the bearing portion of the motor shaft and oil passage plate.

In the system disclosed in JP-A-61-185120, the output gear is first supported by a bearing on the transmission case and connected to the reduction gear, and when the hydraulic motor is attached, the end of the hydraulic motor shaft is output. It is inserted into the engaging part provided on the gear. According to this structure, bending stress is not applied to the motor shaft, but four bearings are arranged on the motor shaft, resulting in excessive quality and high cost.

(c) Problems to be Solved by the Invention The present invention solves the above-mentioned problems of the conventional art.The fixed swash plate, which is a component of the hydraulic motor, is provided on the outer surface of the transmission case, and the inner wall of the motor case is fixed. The motor shaft, which is supported by The motor shaft is constructed with two bearings so that no bending stress is applied to the motor shaft.

(d) Means for Solving the Problems The objects of the present invention are as described above, and the structure for achieving the objects will now be explained.

An opening 11 through which the motor shaft 24 is inserted into the outer surface of the transmission case housing the axles 6L and 6R.
c, the motor case 12 is mounted so as to cover the opening 11c, one end of the motor shaft 24 is supported by a bearing on the inner wall of the motor case 12, and the rotor 22 is fixed to the motor shaft 24.
the other end of the motor shaft into the opening 11.
c, the output gear 13 is fixed, and the output gear 13 is interlocked and connected to the axles 6L and 6R, the other end is supported by a transmission case, a fixed swash plate is arranged around the opening 11c, and the rotor 22 A hydraulic motor M is constructed by bringing the head of a piston 23 protruding from the piston into contact with the head.

(E) Embodiment The object and structure of the present invention are as described above, and next, the structure of the embodiment shown in the attached drawings will be explained.

Fig. 1 is an overall side view of a tractor equipped with an HST integrated axle drive system of the present invention, Fig. 2 is a plan cross-sectional view of the HST integrated axle drive system of the present invention, and Fig. 3 is an implementation of the same as shown in Fig. 2. FIG. 4 is a front sectional view taken as a cross section of the hydraulic motor shaft 9 in the example, and FIG. 4 is an overall perspective view.

Referring to FIG. 1, the overall configuration of a tractor equipped with a mower device R will be described.

The aircraft body is supported between a front wheel 1, which is a driving wheel, and a rear wheel 2, which is a running wheel, and an engine E with a vertical crankshaft protruding from the aircraft body is mounted.

An output pulley 3 is fixed to the vertical crankshaft of the engine E. Power is transmitted from the output pulley 3 to the input pulley 4 of the HST integrated axle drive device via a V-belt 5 stretched horizontally.
The input pulley 4 is fixed to a pump shaft 9 of a hydraulic pump P of the HST integrated axle drive system.

The axles 6L and 6R of the tractor are horizontally protruded left and right, whereas the pump shaft 9 of the hydraulic pump P is arranged vertically parallel to the vertical crankshaft.

As shown in the embodiment, the hydraulic pump P is constructed separately from the axle case 11, and the oil passages are connected so that the hydraulic pump shaft 9 can be protruded horizontally by changing the mounting state. It makes up the division.

The mower device R is a front mower device R as shown in Fig. 1.
It can also be used as a Mitsodomoor device R' and mounted on the abdomen of a tractor.

Next, the embodiment shown in FIG. 2 will be explained.

In this embodiment, the axle case 11, motor case 12, and pump case 31 are all constructed separately. Further, the axle case 11 is divided into a left axle case 11L and a right axle case 11R.

First, the axle case 11 is the left and right axle case 11.
L and right axle case 11R are joined to form one axle case 11, and a differential gear device is disposed inside to support axles 6L and 6R.

In addition, a gear reduction gear from the output gear 13 to the differential gear device is also arranged, and it also serves as a transmission case.

That is, the gear reduction device transmits power from the output gear 13 fixedly mounted on the motor shaft 24 to the large diameter gear 14 on the reduction shaft 18.

The other small diameter gear 15 of the reduction shaft 18 is configured to mesh with the ring gear 7 of the differential gear device.

The differential gear device does not include a gear case, and a hole in the inner diameter of the ring gear 7 also serves as the gear case. A pinion shaft 1 is attached to the inner diameter of the ring gear 7.
7 is fixed, and opposing pivot holes for the inner ends of the left and right axles 6L, 6R are formed in the center of the pinion shaft 17. The pinions 19 and 20 loosely fitted to the pinion shaft 17 mesh with the differential side gears 21L and 21R, and the axle 6 is connected to the differential side gears 21L and 21R.
The inner ends of L and 6R are fitted into spline engagement.

An inclined protruding wall portion 11b that constitutes a fixed swash plate of a hydraulic motor M, which will be described later, is integrally formed on the outer surface of the left axle case 11L. An opening 11c into which the motor shaft 24 is inserted is formed in the inward portion.

A motor case 12 is attached to cover the inclined protruding wall portion 11b. One end of the motor shaft 24 is supported by a bearing on the inner wall of the motor case 12.

The motor shaft 24 is arranged parallel to the axles 6L and 6R, passes through the opening 11c, and has its other end supported by the bearing wall 11d of the right axle case 11R.
The output gear is fixed to a part in the middle.

Next, the configuration of the hydraulic motor M will be explained.
A rotor 22 fixed to a motor shaft 24 is rotatably attached to the thick inner wall of the motor case 12, and an oil passage is provided for flowing hydraulic pressure from a hydraulic pump P, which will be described later, into a cylinder chamber inside the rotor 22. 12a has been processed.

A plurality of cylinder chambers are provided within the rotor 22, and a piston 23 is arranged so as to be movable forward and backward.
The piston 23 has a spring inside it.

A thrust bearing 16 is fitted into the inclined protruding wall portion 11b to constitute a fixed swash plate, and the thrust bearing 1
6 is brought into contact with the head of the piston 23 which is projected by a spring.

Pressure oil sent from a hydraulic pump P attached to the outside of the motor case 12 through an oil path 12a flows into a cylinder in the rotor 22, causing a piston 23 to protrude, and the tip of the piston 23 is connected to a thrust bearing. 16, the rotor 22 is rotated by the pressing force of the piston 23.

In the present invention, the fixed swash plate against which the piston 23 is pressed is attached to the inclined protruding wall portion 30a on the outer surface of the axle case.
It is structured as follows.

Next, the configuration of the hydraulic pump P will be explained with reference to FIG.

The hydraulic pump P is configured so that the mounting position of the pump case 31 can be changed by 90 degrees, and the hydraulic pump shaft 9 can be changed between vertical and horizontal positions.

A rotor 27, a piston 26, and a rotating swash plate 25 are provided in the hydraulic pump P. The rotating swash plate 25 is rotated by operating the inclined rotation shaft 8 from the outside. This changes the direction and amount of hydraulic pressure discharged.

The pressure oil discharged from the hydraulic pump P flows through the oil passage 12.
The oil is sent to the hydraulic motor M inside the motor case 12 through the oil pump a.

FIG. 4 is an overall perspective view.

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

First, since the conventional hydraulic motor itself is constructed as an independent device, it is already stably supported by the motor case and the oil passage plate. If it is attached to the transmission case and the motor shaft is made to protrude from the oil passage plate in order to connect it to the axle, bending stress will be applied to the motor shaft as mentioned above, and an extra bearing will be required to prevent this. It becomes like this.

In the present invention, an opening through which the motor shaft is inserted is formed in the outer surface of the transmission case housing the axle, and the motor case is mounted to cover the opening, and one end of the motor shaft is attached to the inner wall of the motor case. The other end of the motor shaft is inserted through the opening, the output gear is fixed and interlocked with the axle, and the other end is attached to the transmission case. A hydraulic motor integrated axle drive device is constructed in which a hydraulic motor is constructed by supporting a bearing, a fixed swash plate is arranged around the opening, and the piston head protruding from the rotor is brought into contact with the motor case and transmission case. By using only two bearings distributed between the two bearings, it is possible to prevent bending stress from being applied to the motor shaft, making it possible to provide a low-cost, highly durable axle drive system with integrated hydraulic motor. .

Second, since the fixed swash plate part does not support bearings, the output gear 13 and the fixed swash plate part can be brought closer together, and the width of the motor case and transmission case can be made narrower. .

[Brief explanation of the drawing]

FIG. 1 is an overall side view of a tractor equipped with an integrated HST axle drive system of the present invention, FIG. 2 is a cross-sectional plan view of the HST integrated axle drive system of the present invention, and FIG. 3 is a portion of the hydraulic pump shaft 9. FIG. 4 is a front sectional view taken in section, and FIG. 4 is an overall perspective view. P...Hydraulic pump, M...Hydraulic motor, E...
Vertical crankshaft engine, 8... Swash plate rotating shaft,
9...Pump shaft, 11...Axle case, 11L...
...Left axle case, 11R...Right axle case.

Claims (1)

[Claims] 1 Opening 1 through which the motor shaft 24 is inserted into the outer surface of the transmission case housing the axles 6L and 6R
1c, the motor case 12 is mounted so as to cover the opening 11c, one end of the motor shaft 24 is supported by a bearing on the inner wall of the motor case 12, and the rotor 2 is fixed to the motor shaft 24.
2 in close contact with each other, and the other end of the motor shaft is inserted into the opening 1.
1c, the output gear 13 is fixed thereon, and the output gear 13 is interlocked and connected to the axles 6L and 6R, the other end is supported by a transmission case, a fixed swash plate is arranged around the opening 11c, and the rotor 22 1. A hydraulic motor integrated axle drive device, characterized in that a hydraulic motor M is constructed by abutting the head of a piston 23 protruding from the piston 23.