JPH0744935U - Work vehicle axle drive - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the size of the entire axle drive device, reduce the weight of the work vehicle, reduce the line resistance as much as possible, increase the efficiency of the hydraulic take-out pump, and configure it at low cost. To aim. [Structure] The hydraulic pump P is installed inside the mission case 9.
And a hydraulic motor M driven by pressure oil from the hydraulic pump
And an axle 1 interlockingly connected to the motor shaft 6 of the hydraulic motor.
A hydraulic drive pump T for driving an actuator S of the working machine.
Is arranged therein so as to suck the oil accumulated in the mission case and is interlockingly connected to the pump shaft 29 of the hydraulic pump, and the transmission case has an actuator for receiving the pressure oil discharged from the hydraulic take-out pump. An oil supply port 13 for guiding the oil and a return oil port 15 from the actuator are provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an axle drive device mounted on a work vehicle.

[0002]

[Prior art]

 2. Description of the Related Art Conventionally, an HST transmission having good operability has been used as an axle drive device. For example, it is like the technique described in Japanese Examined Patent Publication No. 63-16630.

[0003]

[Problems to be solved by the device]

 In the conventional axle drive system as described above, the HST transmission is mounted outside the mission case. In addition, a hydraulic take-out pump that supplies pressurized oil for raising and lowering work machines such as mowers was directly attached to the engine. In the present invention, the hydraulic pump and the hydraulic motor that form the HST transmission that has been conventionally provided externally are placed inside the transmission case of the axle drive device, and at the same time, they have been taken out conventionally. The pump is also placed inside the mission case.

[0004]

[Means for Solving the Problems]

 The object of the present invention is as described above. Next, the configuration for achieving the object will be described. The transmission case 9 accommodates a hydraulic pump P, a hydraulic motor M driven by pressure oil from the hydraulic pump P, and an axle 17 linked with a motor shaft 6 of the hydraulic motor M. Which is an axle drive device for a working vehicle, in which a hydraulic take-out pump T for driving an actuator S 1 of the working machine is arranged therein so as to suck the oil accumulated in the mission case 9, and a pump for the hydraulic pump P is provided. The transmission case 9 is provided with an oil supply port 13 for guiding the pressure oil discharged from the hydraulic pressure extraction pump T to the actuator S and a return oil port 15 from the actuator S, as well as being linked to the shaft 29. It is a thing.

[0005]

【Example】

 The purpose and constitution of the present invention are as described above, and the constitution of the embodiment shown in the accompanying drawings will be described below. 1 is a front sectional view of an axle drive device of the present invention, FIG. 2 is a right sectional view of the same, FIG. 3 is a plan view with an upper mission case 9b removed, and FIG. 4 is hydraulic oil of a hydraulic take-out pump T. FIG. 5 is a drawing showing a hydraulic circuit for driving the mower device R, and FIG. 5 is a perspective view of the oil filter 5.

1, FIG. 2, and FIG. 3, a hydraulic pump P and a hydraulic motor M of an HST type transmission arranged in a transmission case 9 and a manifold 1 supporting the hydraulic pump P and the hydraulic motor M. The power transmission path to the charge pump C attached to the manifold 1 and the axles 17L and 17R will be described. The upper mission case 9b and the lower mission case 9a are vertically aligned and fastened with connecting bolts to form one mission case 9. The bearing surface of the hydraulic motor shaft 6, the counter shaft 38, and the axles 17L and 17R is formed on the mating surface of the lower mission case 9a and the upper mission case 9b.

The manifold 1 is formed in a substantially L-shape in a sectional view and includes a horizontal portion and a vertical portion, and the horizontal portion is fixed to the upper mission case 9b side with four bolts. A hydraulic pump P is provided on the upper surface of the horizontal portion of the manifold 1, and a hydraulic motor M is arranged on the standing surface of the vertical portion of the manifold 1. As the hydraulic pump P, a variable displacement type is used, and its movable swash plate 28 is rotatably arranged along the arcuate recess of the upper mission case 9b.

The hydraulic pump shaft 29 is erected on a horizontal portion of the manifold 1, and its upper end projects from the upper mission case 9b to input engine power. A concave operation engagement portion projects laterally from the movable swash plate 28, and the arm arm 10 is engaged with the operation engagement portion. The lever arm 10 is fixed to the speed change lever shaft 2, and the speed change arm 11 is fixed to a position where the speed change lever shaft 2 penetrates and projects into the upper surface of the upper transmission case 9b. When the movable swash plate 28 is rotated by the arm arm 10, the swash plate angle of the movable swash plate 28 is changed and the discharge direction and discharge amount of the pressure oil from the hydraulic pump P are changed. In the hydraulic motor M, a piston is brought into contact with the fixed swash plate 33 to obtain the rotational force of the hydraulic motor shaft 6, and an output gear 34 is fixed in the middle of the hydraulic motor shaft 6, and the outer end of the hydraulic motor M is fixed. The brake drum 24 of the brake device is fixedly installed in this. As shown in FIG. 3, the output gear 34 fixed to the hydraulic motor shaft 6 meshes with the large-diameter gear 35 on the counter shaft 38, and the small-diameter gear 36 on the counter shaft 38 forms the diff gear. It meshes with the ring gear 37 of the device D. The differential gear device D differentially connects the left and right axles 17L and 17R.

In the manifold 1, a pair of oil passages P1 and P2 connected to the suction side and the discharge side of the hydraulic pump P are provided in the horizontal part, and a pair of oil passages P1 and P2 are connected to the vertical part to the suction side and the discharge side of the hydraulic motor M. Oil passages 1e and 1f are opened, and the oil passages P1 and P2 and the oil passages 1e and 1f are connected to each other by a pair of linear oil passages 1c and 1d. Are configured. Check valves 8 and 8 that open only in a direction in which pressure oil from a charge pump C described later is supplied to the closed circuit are arranged at the open ends of the oil passages 1c and 1d, and the oil inlets of the check valves 8 and 8 are It is connected to a charge port 1a opened on the lower surface of the horizontal portion of the manifold 1 through oil passages 1b and 1b. A charge pump C is mounted on the lower surface of the horizontal portion of the manifold 1, and the pump gear 7 is connected to a hydraulic pump shaft 29 that penetrates the horizontal portion. A suction oil passage 3a is opened on the lower surface of the charge pump case 3 for accommodating the pump gear 7, and the periphery thereof is covered with a ring-shaped oil filter 5 made of a porous material.

The charge pump C is driven by the hydraulic pump shaft 29, the oil in the mission case 9 is sucked from the suction circuit 3a, and the charge oil passage 1a is directly supplied from the discharge side of the charge pump C. The pressure oil that has passed through the oil passages 1b and 1b reaches the oil inlet of the check valves 8 and 8, and the check valve 8 on the low pressure side is opened to replenish the closed circuit. The operating levers of the check valves 8 and 8 are projected to the side of the valve seat 42. The operating rods are connected by one connecting plate 40, and the push pins 39 are pushed from behind. The mechanical pumps can be opened simultaneously and the closed circuit can be short-circuited to put the hydraulic pump P into a no-load state.

With the above-mentioned configuration, the present invention is configured as follows. That is, the hydraulic take-out pump T for supplying the oil accumulated in the mission case 9 of the axle drive device to the hydraulic actuator S that moves up and down of the work machine R such as the mower device mounted on the work vehicle is provided inside the mission case 9. It is located in. Specifically, the hydraulic take-out pump case 4 accommodating the pump gear 12 is fixed to the inner bottom wall of the lower mission case 9a, and the hydraulic take-out pump shaft 14 integrated with the pump gear 12 is attached to the charge pump case 3. The lower end of the hydraulic pump shaft 29 protruding from the lower surface is connected. A suction oil passage 4a is opened on the upper surface of the extraction pump case 4, and the periphery thereof is covered with the oil filter 5. The oil filter 5 is sandwiched between the charge pump case 3 and the hydraulic pressure extraction pump case 4. An oil supply port 40 and a return oil port 41 are formed in the lower mission case 9a, and the discharge side of the hydraulic pressure discharge pump T is directly connected to the oil supply port 40.

A hydraulic actuator S for raising and lowering the work implement R is disposed outside the axle drive device, and a switching valve V for switching the operation of the hydraulic actuator S and a relief valve for setting the operating hydraulic pressure of the hydraulic actuator S, etc. Is attached. The oil supply port 40 and the return oil port 41 are respectively connected to the pipes 13 and 15 connected to the switching valve V. When the engine of the work vehicle is operating and the hydraulic pump shaft 29 is constantly rotating, the hydraulic take-out pump T is constantly driven, and the oil in the mission case 9 is sucked through the suction oil passage 4a, so that the pressure oil is supplied from the oil supply port 40. Taken out. By appropriately switching the switching valve V, the hydraulic actuator S receives the pressure oil and operates, and the returned oil after the operation is returned to the inside of the mission case 9 from the return oil port 41 and is stored therein. The pump gear 7 and the pump gear 12 are configured as internal gear pumps in the embodiment, but the invention is not limited to the configuration.

Next, the embodiment shown in FIG. 6 will be described. In FIG. 1, the hydraulic take-out pump T attached to the inner bottom surface of the lower mission case 9a is removed, the pipes 13 and 15 are removed, and the oil supply port 40 and the return oil port 41 are blindly plugged, respectively. The state in which only the attached charge pump C is used is disclosed.

The embodiment shown in FIG. 7 discloses a structure in which the extraction pump case 4 is attached to the inner bottom surface of the lower mission case 9a, and the charge pump case 3 is attached to the upper surface of the external extraction pump case 4. In this case, both the hydraulic take-out pump T and the charge pump C are fixed to the inner bottom surface of the lower mission case 9a. The oil filter 5 is interposed between the lower surface of the manifold 1 and the upper surface of the charge pump case 3, and the suction oil passages 3a and 4a are made to communicate with each other to suck the oil in the mission case 9 from the same location, thereby charging the charge pump. Oil is sent from C to the oil passage 1b from the check valves 8 and 8 via a pipe 19.

In the embodiment shown in FIG. 8, the hydraulic pump case 4 is attached to the lower surface of the charge pump case 3 fixed to the lower surface of the manifold 1, and is bolted together with the bolt B. Pressure oil is discharged from the hydraulic pressure extraction pump T to the oil supply port 40 through the discharge oil passage 4d and the pipe 19. The oil filter 5 is interposed between the lower surface of the hydraulic take-out pump case 4 and the inner bottom surface of the lower mission case 9a so that the charge pump C and the suction oil passages 3a and 4a of the hydraulic take-out port T are communicated with each other and the same portion is in the mission. The oil in the case is being sucked.

[0016]

[Effect of device]

 Since the present invention is configured as described above, it has the following effects. First, since the transmission case accommodates the hydraulic pump, the hydraulic motor driven by the hydraulic oil from the hydraulic pump, and the axle that is interlocked with the motor shaft of the hydraulic motor, the axle drive The entire device can be downsized.

Secondly, conventionally, an oil tank is mounted on a work vehicle, oil is sucked from the oil tank into a pressure oil by a pump directly mounted on the engine, and the hydraulic actuator of the working machine is operated by this pressure oil. Therefore, a pipe on the suction side that connects the oil tank and the pump is required, and the oil supply pipe to the hydraulic actuator becomes long.However, according to the present invention, the hydraulic pressure for driving the actuator of the working machine is increased. By arranging the take-out pump inside so that the oil stored in the transmission case of the axle drive device can be sucked in, the oil tank can be eliminated and the weight of the work vehicle can be reduced. , No pipe is required on the suction side, and when the work machine is a mid-mount mower device, the hydraulic actuator is installed near the mission case, so the oil supply pipe must be installed. It can be shortened and the line resistance can be reduced as much as possible to increase the efficiency of the hydraulic take-out pump.

Thirdly, since the leakage of the pressure oil from the mounting portion of the hydraulic take-out pump is not returned to the inside of the mission case as it is and is not leaked to the outside of the mission case, the sealing accuracy is improved. The setting can be made relatively rough, in other words, an inexpensive hydraulic pump can be used, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a front sectional view of an axle drive device of the present invention.

FIG. 2 is a right side sectional view of the same.

FIG. 3 is a plan view showing a state where an upper mission case 9b is removed.

FIG. 4 is a drawing showing a hydraulic circuit for driving a mower device R by the pressure oil of a hydraulic take-out pump T.

5 is a perspective view of an oil filter 5. FIG.

FIG. 6 is a front sectional view of the configuration of FIG. 1 with a hydraulic take-out pump T removed.

FIG. 7 is a front cross-sectional view showing a state in which a charge pump C and a hydraulic pressure extraction pump T are both fixedly installed on the inner bottom surface of the lower mission case 9a.

FIG. 8 is a front cross-sectional view showing a state in which a charge pump C and a hydraulic pressure take-out pump T are both fixedly installed on the bottom surface of the manifold 1.

[Explanation of symbols]

 C Charge Pump P Hydraulic Pump M Hydraulic Motor T Hydraulic Extraction Pump 1 Manifold 3 Charge Pump Case 4 External Extraction Pump Case 5 Oil Filter 7 Charge Pump Gear 9a Lower Mission Case 12 External Extraction Pump Gear

Claims (1)

[Scope of utility model registration request] 1. A transmission case 9 is provided with a hydraulic pump P, a hydraulic motor M driven by pressure oil from the hydraulic pump P, and an axle 17 linked to a motor shaft 6 of the hydraulic motor M. An axle drive device for a working vehicle housed therein, wherein a hydraulic take-out pump T for driving an actuator S of the working machine is disposed inside the hydraulic pump so as to suck the oil accumulated in the mission case 9. The transmission case 9 is provided with an oil supply port 13 for guiding the pressure oil discharged from the hydraulic pressure take-out pump T to the actuator S and a return oil port 15 from the actuator S, while being linked to the pump shaft 29 of P. An axle drive device for a work vehicle, characterized in that