JP2551736Y2 - Axle drive - Google Patents

Description

[Detailed description of the invention]

[0001]

This invention relates to an axle drive in which an axle case is provided with a charge pump for replenishing hydraulic oil for a hydraulic transmission and for driving other hydraulic operating devices inside an axle case, and pressure oil can be taken out to the outside. It relates to the configuration of the device.

[0002]

2. Description of the Related Art Conventionally, there has been known a technology in which a pump for supplying hydraulic oil for a hydraulic transmission and a pump for driving an external hydraulic actuator are provided inside an axle case. For example, this is a technique disclosed in Japanese Utility Model Laid-Open No. 2-51763.

[0003]

However, if two pumps are provided in the axle case as in the prior art, the axle case becomes large due to the storage space, and the cost increases due to an increase in the number of assembly steps and the number of parts. When the drive pump of the hydraulic operating device is provided on the center section or the bottom of the axle case, the drive hydraulic pressure setting valve and the like are provided outside via a piping member, and the installation space and the connection portion are sealed. The number of parts and members increased, and assembly was troublesome. Furthermore, since the return oil from the external hydraulic actuator was recirculated to the lower part of the axle case, air existing in the hydraulic equipment and piping at the initial stage of assembly was mixed into the hydraulic oil in the axle case, and the hydraulic pump This causes the operation of the hydraulic transmission to become unstable due to the air being sucked into the air. The present invention solves the problems of the prior art as described above.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. The hydraulic transmission device interlockingly connected to the axle is housed in the axle case formed by joining the upper half case and the lower half case together, and a pump in the center section of the hydraulic transmission. An axle drive device in which a charge pump is mounted on the back surface of the mounting portion and discharge oil from the charge pump can be supplied for replenishing hydraulic oil of a hydraulic transmission and for driving other hydraulic operating devices,
A supply hydraulic pressure setting valve and a drive hydraulic pressure setting valve are housed in the wall of the upper half case , a discharge port of the charge pump is connected to a pump port of each valve, and an operation port of the supply hydraulic pressure setting valve is provided in the axle case. It is opened and connected to the hydraulic oil supply circuit of the hydraulic transmission, the working port of the drive hydraulic pressure setting valve is opened outside the axle case, and connected to the hydraulic circuit of another hydraulic operating device via a piping member. .
According to a second aspect of the present invention, the half upper case is provided with a reservoir tank through which oil can flow in the axle case, and the return oil from another hydraulic operating device is returned to the reservoir tank. In claim 3, the center section has an inverted L-shape including a substantially horizontal pump mounting portion parallel to the dividing surface of the axle case, and a substantially vertical motor mounting portion extending downward from one end of the pump mounting portion. It was done.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The problem to be solved by the present invention and the means for solving it are as described above. Next, the configuration of the embodiment shown in the accompanying drawings will be described. 1 is a plan cross-sectional view of the axle case with the upper half case removed, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, FIG. 3 is a cross-sectional view taken along the line BB in FIG. FIG. 5 is a sectional view taken along the line CC in FIG. 1, FIG. 5 is a sectional view taken along the line DD in FIG. 2, and FIG. 6 is a hydraulic circuit diagram.

The axle case includes a half upper case 1 and a half lower case 2, and includes a hydraulic transmission F, an axle 4, and power transmission means for interlocking the two. The division surface of the axle case runs along the horizontal direction and the hydraulic motor M
Is substantially coincident with an imaginary line connecting the axis of the rotation shaft, the axis of the power transmission shaft (counter shaft) described later, and the axis of the axle 4 in a straight line. The hydraulic transmission F has a reverse L
Hydraulic pump P on center section 10
And made by mounting a hydraulic motor M, the center section 10 is fixed from below into half upper case 1. The upper surface of the center section 10 is positioned above the division surface as being parallel to the division surface , and the hydraulic pump P is mounted here.
Formed on the pump mounting brake. Pump mounting
At one end of the section, there is a vertical section 10 extending downward therefrom.
b is formed, and a hydraulic motor M is provided on the side of the vertical portion 10a.
Or it is attached to so that extend over half the upper case 1 and half both cases of the lower case 2.

As shown in FIG. 2, an input shaft 11, which is a pump shaft, is penetrated substantially in the center of the upper surface of the center section 10 as shown in FIG. 2, and an input pulley is fixed outside the upper half case 1 at the upper end of the input shaft 11. , On the center section 10 at the center of the input shaft 11 around the input shaft 11.
The cylinder 21 accommodating the piston 2
The heads of 2, 22,... Are in contact with a variable swash plate 13, and the angle of the variable swash plate 13 can be changed by rotating an arm 15 fixed to a transmission shaft 14, and The rotation direction and rotation speed of the motor shaft 16 can be changed by adjusting the discharge direction and discharge amount of the pressure oil.

[0008] Hydraulic motors M at one side of the motor shaft 16 is rotatably supported in the center of the outer side surface of the vertical portion 10a of the center section 10, the other end is supported by the axle case, axial core of the motor shaft 16 is the dividing plane And a brake drum 17 is fixed on the outer motor shaft 16. A cylinder 25 accommodating pistons 26 is externally fitted to the motor shaft 16.
6 ... The head is in contact with the fixed swash plate.

Then, the cylinder 21 and the cylinder 25
The oil passages 10b and 10c for the discharge oil and the return oil are formed in the center section 10 to communicate between the hydraulic pump P and the hydraulic motor M to form a closed circuit.
Check valves 19a and 19b are fitted into the ends of c, and the check valves 19a and 19b are opened by pressing the release rods 20 and 20, and the pressure in the closed circuit between the hydraulic pump P and the hydraulic motor M is increased. The oil can be drained so that the motor shaft 16 becomes rotatable.
20 is slid in a direction to open the check valves 19a and 19b by rotating a release lever 23 provided outside the axle case.

A gear 16 is provided on the motor shaft 16.
As shown in FIG. 1, a gear 31 on a counter shaft 30 is meshed with the gear 16a, and a gear 30a formed on the counter shaft 30 is
Are engaged with each other 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 charge pump P1 for supplying hydraulic oil to the hydraulic transmission F and driving another hydraulic operating device is disposed in the center of the pump case 7. is set, it is driven by engaging the gear of the charge pump P1 to the input shaft 11 lower end.
A filter 24 is interposed between the lower half case 2 and the center section 10 so as to cover the pump case 7, and a suction port 7a of the charge pump P1 is opened inside the filter 24 as shown in FIG. The charge pump P
1 of the discharge port 7b are communicated with the suction port of the line filter 37 which is attached to the lower surface of the half lower case 2, line filter 37 to half the lower case 2 as the suction port and the discharge port 7b of the line filter 37 matches of the mounting portion 2
a is provided. The discharge port of the line filter 37 is connected to a communication oil passage 10e formed in the center section 10 through a piping member 6 provided in the half-half lower case 2, and the communication oil passage 10e is connected via a piping member 8 to the communication oil passage 10e. supply provided in half the upper case 1 in the side wall oil pressure setting valve 34,
The drive hydraulic pressure setting valve 35 and the resistance valve 36 are connected in parallel.

The discharge-side oil passage (working port) of the supply oil pressure setting valve 34 is connected to an oil passage 10d communicating between the oil passages 10b and 10c of the center section 10 via a pipe member 9 as shown in FIG. When the hydraulic oil in the closed circuit of the hydraulic transmission F leaks and the pressure drops, the hydraulic oil adjusted by the supply hydraulic pressure setting valve 34 is supplied to the check valve 1.
It is replenished via 9a and 19b. The oil after pressure regulation is drained into the axle case.

The drive oil pressure setting valve 35 regulates the operating oil of another hydraulic operating device. When the pressure exceeds the set pressure, the valve is opened to drain into the axle case.
The resistance valve 36 allows a predetermined pressure oil to be supplied from a hydraulic outlet 38 to another hydraulic operating device, and the hydraulic outlet 38 is switched to a side surface of the half upper case 1 via a piping member 42. In this embodiment, a hydraulic cylinder 40 is connected to the switching valve 39 as a hydraulic operating device.

The 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 4
1 is a reservoir tank 1 provided on the half upper case 1
The reservoir tank 1a is provided with a return oil port 41 on the side face as shown in FIG. 5, and a narrow communication port 1b is opened on the lower surface on the other side to communicate with the inside of the axle case. Are provided with guide walls 1c, 1c so that the hydraulic oil flows in a zigzag shape and the flow path becomes long, and when the hydraulic oil mixed with air is returned to the reservoir tank 1a at the initial stage of starting or the like, the communication port is formed. The air is separated in the reservoir tank 1a before returning to the axle case from 1b. 1e is a breather cap.

[0015]

[Effects of the Invention] With the above-described structure, the following effects can be obtained. As described in claim 1, since a single charge pump can supply hydraulic oil to the hydraulic transmission and drive other hydraulic actuators, the number of charge pumps and the number of parts are reduced, the number of assembly steps is reduced, and the cost is reduced. In addition, since the supply oil pressure setting valve and the drive oil pressure setting valve are built in the wall of the half upper case , space can be saved and the hydraulic circuit configuration is simplified, and the valves are concentrated. Maintenance and inspection could be easily performed, and the other of the divided axle cases could simply serve as a lid, thus simplifying the configuration.

Further, even when a charge pump is provided on the back surface of the center section and a line filter as shown in the embodiment is provided below the axle case, the minimum ground clearance can be secured. And in one of the divided axle cases with built-in drive oil pressure setting valve,
Since the piping to the other hydraulic operating device is mounted , the seal portion and the separate member can be configured to a minimum.

Further, since the return oil from the other hydraulic operating device is returned to the reservoir tank as described in claim 2, air existing in the piping of the other hydraulic operating device in the initial stage of assembly is transferred to the axle case. As a result, it was difficult to generate air bubbles in the hydraulic oil in the axle case, and the operation of the hydraulic transmission could be stabilized.

A center section according to a third aspect of the present invention.
The pump mounting part parallel to the split surface of the axle case,
A substantially vertical motor that extends downward from one end of the
Since the inverted L-shape consisting of the mounting section and the center section, when machining the cylinder block rotation sliding surface of the pump mounting section on the upper surface of the center section, the entire surface is flat, making the processing easier and the manufacturing cost of the center section Can be reduced.

[Brief description of the 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. 1;

FIG. 4 is a sectional view taken along the line CC in FIG. 1;

FIG. 5 is a sectional view taken along the line DD in FIG. 2;

FIG. 6 is a hydraulic circuit diagram.

[Explanation of symbols]

 F Hydraulic transmission P Hydraulic pump P1 Charge pump M Hydraulic motor 1 Half upper case 1a Reservoir tank 2 Half lower case 6.8.9 Pipe member 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 (3)

(57) [Scope of request for utility model registration] An axle case formed by joining an upper half case and a lower half case accommodates a hydraulic transmission that is interlocked with the axle, and mounts a pump on a center section of the hydraulic transmission. the charge pump is mounted on the rear surface of the part, in the transaxle apparatus can be supplied to drive the discharge oil hydraulic transmission hydraulic oil replenishment and other hydraulic actuators of the device from the charge pump, the half upper The supply hydraulic pressure setting valve and the drive hydraulic pressure setting valve are housed in the wall of the case, the discharge port of the charge pump is connected to the pump port of each valve, and the operation port of the supply hydraulic pressure setting valve is placed in the axle case. Open to connect to the hydraulic oil supply circuit of the hydraulic transmission, open the working port of the drive hydraulic pressure setting valve to the outside of the axle case, and connect to the hydraulic circuit of another hydraulic operating device via a piping member. Transaxle apparatus characterized by the. 2. The half upper case according to claim 1, further comprising a reservoir tank that allows oil to flow inside the axle case,
An axle drive device wherein return oil from another hydraulic operating device is returned to the reservoir tank. 3. A substantially horizontal pump mounting portion, comprising: a center section according to claim 1;
An axle drive device having an inverted L-shape comprising a substantially vertical motor mounting portion extending downward from one end of the pump mounting portion.