JPH0526576U - Axle drive - Google Patents

Abstract

(57) [Abstract] [Purpose] A pump for driving hydraulic oil for a hydraulic transmission and for driving other hydraulic actuators, and a set hydraulic valve for the pump are housed in a space-saving manner to facilitate assembly. An axle drive device capable of supplying discharge oil from a single pump driven by an input shaft of a hydraulic transmission for supplying hydraulic oil to the hydraulic transmission and for driving other hydraulic operating devices. , The supply hydraulic pressure setting valve and the drive hydraulic pressure setting valve are housed in the pump case, the discharge port of the pump is connected to the pump port of each valve, and the working port of the supply hydraulic pressure setting valve is the hydraulic oil supply circuit of the hydraulic transmission. , A part of the pump case is penetrated from the axle case to be exposed, the action port of the drive hydraulic pressure setting valve is opened on the exposed surface, and it is connected to the hydraulic circuit of another hydraulic actuator via a piping member. The returned oil was returned to the reservoir tank.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a configuration of an axle drive device in which a pump for replenishing hydraulic oil for a hydraulic transmission and for driving other hydraulic actuation devices is internally provided in an axle case to facilitate extraction of external hydraulic pressure.

[0002]

[Prior Art]

 Conventionally, there is known a technique in which a hydraulic oil supply pump for a hydraulic transmission and a drive pump for an external hydraulic operation device are provided inside an axle case. For example, it is a technique disclosed in Japanese Utility Model Publication No. 2-51763.

[0003]

[Problems to be solved by the device]

 However, if two pumps are provided in the axle case as in the conventional case, the storage space will increase the size of the axle case, resulting in cost increase due to an increase in the number of assembly steps and the number of parts, and the center section or the bottom of the axle case. If the drive pump for the hydraulic actuator is installed in the external equipment, the drive hydraulic pressure setting valve and the like will be installed externally through the piping members, and there will be many places and materials that seal the installation space and connection part. As a result, assembly was troublesome. Furthermore, since the return oil from the external hydraulic actuator was returned to the lower part of the axle case, the air existing in the hydraulic equipment and piping at the beginning of assembly mixed with the hydraulic oil in the axle case, and the hydraulic pressure from the filter It was sucked into the pump and air was trapped, making the operation of the hydraulic transmission unstable.

[0004]

[Means for Solving the Problems]

 In order to solve such a problem, the present invention mounts a hydraulic transmission that is interlocked with an axle and a single pump that is driven by an input shaft of the transmission in an axle case. In the axle drive device that can supply the discharge oil from the hydraulic transmission for replenishing hydraulic oil and for driving other hydraulic actuating devices, the replenishment hydraulic pressure setting valve and the drive hydraulic pressure setting valve are stored in the pump case. , Connect the discharge port of the pump to the pump port of each valve, and connect the working port of the replenishment hydraulic pressure setting valve to the hydraulic oil replenishment circuit of the hydraulic transmission to expose a part of the pump case through the axle case. Then, the action port of the drive hydraulic pressure setting valve is opened on the exposed surface and is connected to the hydraulic circuit of another hydraulic actuating device via a piping member. In addition, a reservoir tank that is in an open state is provided above the axle case through a communication port, and return oil from another hydraulic operating device is returned to the reservoir tank.

[0005]

【Example】

 The problems to be solved by the present invention and the means for solving the problems are as described above. Next, the structure of the embodiment shown in the accompanying drawings will be described. 1 is a plan sectional view of the axle case with the upper half case removed, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a sectional view taken along the line BB of FIG. 2 is an enlarged view of the pump case portion in FIG. 2, FIG. 5 is a sectional view taken along the line CC of FIG. 4, FIG. 6 is a sectional view taken along the line DD of FIG. 4, and FIG. 7 is a sectional view taken along the line E-E of FIG. FIG. 8 is a perspective view of the pump case, and FIG. 9 is a hydraulic circuit diagram.

The axle case includes a half upper case 1 and a half lower case 2, and a hydraulic transmission F, an axle 4, and a power transmission means for interlocking and connecting the two are internally provided. The vertical dividing line of the axle case is configured to substantially coincide with an imaginary line that connects the rotation axis of the hydraulic motor M, the axis of the power transmission axis (counter axis) described later, and the axis of the axle 4 in a straight line. is doing. The hydraulic transmission F is equipped with a hydraulic pump P and a hydraulic motor M on a center section 10 formed in an inverted L shape in cross section. The hydraulic pump P is mounted on the upper surface of the center section 10 and on the vertical side surface. The hydraulic motors M are mounted respectively.

Further, as shown in FIG. 2, an input shaft 11 which is a pump shaft is penetrated at a substantially central position on the upper surface of the center section 10, and the input pulley is fixed outside the upper half case 1 at the upper end of the input shaft 11. A cylinder 21 accommodating pistons 22, 22 ... Is fitted around the input shaft 11 on the center section 10 at the center of the input shaft 11, and the heads of the pistons 22. The variable swash plate 13 is brought into contact with the variable swash plate 13. The angle of the variable swash plate 13 can be changed by rotating an arm 15 fixed to the speed change shaft 14, and the discharge direction and discharge amount of the pressure oil of the hydraulic pump P can be changed. The rotation direction and the rotation speed of the motor shaft 16 can be changed by adjustment.

In the hydraulic motor M, one side of the motor shaft 16 is pivotally supported at the center of the outer surface of the vertical portion 10 a of the center section 10, the other end is supported by the axle case, and the brake drum 17 is mounted on the outer motor shaft 16. Is fixed. A cylinder 25 accommodating pistons 26, 26, ... Is externally fitted to the motor shaft 16, and the heads of the pistons 26, 26 ,.

In the center section 10 between the cylinder 21 and the cylinder 25, oil passages 10b and 10c for discharge and return oil are bored to connect the hydraulic pump P and the hydraulic motor M to each other to form a closed circuit. The check valves 19a and 19b are fitted into the ends of the oil passages 10b and 10c, and the check valves 19a and 19b are opened by pushing the release rods 20 and 20 to open the hydraulic pump P and the hydraulic motor. The pressure oil in the closed circuit between M and M can be drained to make the motor shaft 16 rotatable, and the release rods 20 and 20 are slid by rotating a release lever 23 provided outside the axle case. Be moved.

Further, an engraved gear 16a is engraved on the motor shaft 16, and a gear 31 on a counter shaft 30 is meshed with the engraved gear 16a, as shown in FIG. The ring gear 32 of the diff device is meshed with the engraved gear 30a engraved on the first and second wheels to differentially connect the pair of axles 4.

A pump case 7 is attached to the lower surface of the center section 10, and a pump P1 for supplying hydraulic fluid to the hydraulic transmission F and for driving other hydraulic operating devices is provided in the center of the upper surface of the pump case 7. And is driven by the input shaft 11. The pump case 7 is formed in a cylindrical shape as shown in FIGS. 3 to 8. The pump P1 is arranged at the center of the upper surface and is attached to the center section 10. The lower half is perpendicular to the split surface of the axle case. In this direction, the opening of the half lower case 2 is exposed to the outside, and an O-ring 33 is interposed between the pump case 7 and the lower half case 2 to seal the case.

Further, a filter 24 is provided around the upper half of the pump case 7 located in the lower half case 2, and an intake port 7a of the pump P1 is opened inside the filter 24 so that the pump P1 is opened. The discharge port of the line filter 37 is connected to the line filter 37 through the oil passage 7b, the line filter 37 is attached to the lower half of the pump case 7, and the discharge side oil passage 7c of the line filter 37 is inside the pump case 7. The pressure reducing valve type replenishment hydraulic pressure setting valve 34, the driving hydraulic pressure setting valve 35, and the resistance valve 36 are connected in parallel.

The discharge side oil passage (action port) 7d of the replenishment hydraulic pressure setting valve 34 is communicated with the oil passage 10d that communicates between the oil passages 10b and 10c of the center section 10 and is in the closed circuit of the hydraulic transmission F. When the operating oil leaks and the pressure drops, the operating oil whose pressure is adjusted by the replenishment hydraulic pressure setting valve 34 is replenished via the check valves 19a and 19b. The oil after pressure adjustment is drained into the axle case through the oil passage provided in the pump case.

The drive hydraulic pressure setting valve 35 regulates the hydraulic oil of another hydraulic operating device, and when the set pressure is exceeded, the valve is opened to drain the hydraulic fluid into the axle case. The resistance valve 36 is interposed between the oil passage 7c on the discharge side and the hydraulic pressure outlet 38 so that a predetermined pressure oil can be sent to another hydraulic operating device. As shown in FIGS. 8 and 9, the pump case 7 is connected to the switching valve 39 via the piping member 42 by being opened at the exposed portion, and the switching valve 39 is provided with a hydraulic cylinder 40 as a hydraulic actuator in this embodiment. Connected.

Return oil from the switching valve 39 is connected to a return oil port 41 via a piping member 43, and the return oil port 41 is provided on a side surface of a reservoir tank 1 a provided on the half upper case 1. As shown in FIG. 1, the reservoir tank 1a is provided with a return oil port 41 on the side surface, and a narrow communication port 1b is opened on the lower surface of the other side to communicate with the inside of the axle case. 1c is provided so that the hydraulic oil flows in a zigzag manner and the flow path becomes long. When the hydraulic oil mixed with air is returned to the reservoir tank 1a in the initial stage of start-up, etc., from the communication port 1b into the axle case. By the way, the air is separated in the reservoir tank. 1e is a breather cap.

[0016]

[Effect of the device]

 Since it is configured as described above, it has the following effects. That is, since a single pump can supply hydraulic fluid to the hydraulic transmission and drive other hydraulic actuators with a single pump, the number of pumps and the number of parts are reduced, the number of assembly steps is reduced, and the cost is reduced. In addition, because the supply hydraulic pressure setting valve and the drive hydraulic pressure setting valve are built into the pump case, space can be saved and the hydraulic circuit configuration can be simplified, and since the valves are concentrated, maintenance and inspection are easy. It became possible. In addition, the pump case was exposed directly to the outside of the axle case, and the hydraulic outlet was located at the exposed part, so piping was easy and the number of seals could be minimized.

Since the return oil from the other hydraulic operating device is returned to the reservoir tank as described in claim 2, the air existing in the pipe of the other hydraulic operating device at the initial stage of the assembly is removed from the axle case. It was not possible to return it inside, and it became difficult for bubbles to form in the hydraulic oil inside the axle case, and the operation of the hydraulic transmission could be stabilized.

[Brief description of drawings]

FIG. 1 is a plan sectional view showing a state in which a half upper case of an axle case is removed.

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

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

FIG. 4 is an enlarged view of a pump case portion in FIG.

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

6 is a cross-sectional view taken along the line DD in FIG.

7 is a cross-sectional view taken along the line EE in FIG.

FIG. 8 is a perspective view of a pump case.

FIG. 9 is a hydraulic circuit diagram.

[Explanation of symbols]

 F Hydraulic Transmission P Hydraulic Pump P1 Pump M Hydraulic Motor 1 Half Upper Case 1a Reservoir Tank 2 Half Lower Case 7 Pump Case 10 Center Section 34 Supply Hydraulic Pressure Setting Valve 35 Drive Hydraulic Pressure Setting Valve 38 Hydraulic Pressure Outlet 39 Switching Valve 40 Cylinder 41 Return oil port 42/43 Piping member

Claims (2)

[Scope of utility model registration request] 1. A hydraulic transmission that is interlockingly connected to an axle,
A single pump driven by the input shaft of the transmission is installed in the axle case, and the discharge oil from the pump can be supplied for supplying hydraulic oil to the hydraulic transmission and for driving other hydraulic operating devices. In the above-mentioned axle drive device, the supply hydraulic pressure setting valve and the drive hydraulic pressure setting valve are housed in the pump case, the discharge port of the pump is connected to the pump port of each valve, and the action port of the supply hydraulic pressure setting valve is a hydraulic transmission. Connected to the hydraulic oil replenishment circuit, and expose a part of the pump case through the axle case to expose the working port of the drive hydraulic pressure setting valve on the exposed surface, and to connect the other hydraulic actuating device through the piping member. An axle drive device characterized by being connected to a hydraulic circuit. 2. An upper part of the axle case according to claim 1 is provided with a reservoir tank which is in an open state through a communication port, and the return oil from another hydraulic operating device is returned to the reservoir tank. Axle drive device featuring.