JPH072286Y2 - Axle drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an axle drive device suitable for a traveling vehicle with a low floor.

(B) Conventional technology Conventionally, a center section having a substantially L-shaped section, which is composed of a horizontal portion and a vertical portion continuous with the horizontal portion, is fixed to an axle case,
The technology of installing a hydraulic pump on the upper surface of the horizontal portion of the center section is known. For example, Japanese Patent Laid-Open No. 1-
This is the same as the technique described in Japanese Patent Publication No. 309871.

(C) Problems to be solved by the invention However, in the conventional technique, since the hydraulic pump is arranged on the upper surface of the center section, a depth for accommodating the hydraulic pump is required in the upper part of the axle case, and the hydraulic pressure protruding from the The input pulley provided at the shaft end of the pump is at a higher position correspondingly, and the position of the belt wound around the output pulley of the vertical engine is also higher, so it cannot be used for low-floor traveling vehicles. There was a problem.

The present invention solves the above problems.

(D) Means for Solving the Problems The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

The center section 5 having a substantially L-shaped cross section, which is composed of a horizontal portion 5h and a vertical portion 5v continuous with the horizontal portion 5h, is fixed in the axle case C,
Axle 7 on the horizontal part 5h and the vertical part 5v of the center section 5
In a configuration in which a hydraulic pump P for driving 7 and a hydraulic motor M are installed, the horizontal portion 5h of the center section 5 is penetrated to vertically support the hydraulic pump shaft 1 at the upper and lower parts of the axle case C, and the axle case C Hydraulic pump shaft 1 protruding from above
The input pulley 40 from the engine E is arranged at the end of the above, and the hydraulic pump P is arranged on the lower surface of the horizontal portion 5h of the center section 5.

(E) Embodiments 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 embodiments shown in the accompanying drawings will be described.

FIG. 1 is a side view of an axle drive device attached to a traveling vehicle, FIG. 2 is a sectional view taken along the line of a hydraulic pump shaft 1 and a hydraulic motor shaft 2, and FIG. 3 is a hydraulic pump shaft 1 and a shift lever shaft 14. FIG. 4 is a cross-sectional view taken along the line of FIG.
FIG. 5 is a plan view with 12 removed, FIG. 5 is a cross-sectional view taken along the line XX of FIG. 4, and FIG. 6 is a cross-sectional view taken along the line YY of FIG.

In FIG. 1, a low-floor type traveling vehicle is equipped with an axle drive device of the present invention. That is, in the vertical type engine E in which the crankshaft is vertically arranged, the output pulley 41 is attached to the lower end of the crankshaft protruding downward, and the hydraulic pump shaft protruding upward from the axle case C arranged below the seat. 1, an input pulley 40 is attached. Axles 7, 7 are projected from the axle case C to the left and right,
The rear wheel is attached to 7.

The embodiment shown in FIGS. 2 and 3 will be described.

The axle case C is constructed by joining and assembling the upper case 12 and the lower case 13 into upper and lower halves. Among the joining surfaces of the upper case 12 and the lower case 13, the lower case 13
Place the surface of the center section on the same height as the joining surface of
As a, the horizontal portion 5h of the center section 5 having a substantially L-shaped section
Is mounted and the fixing bolt 34 is inserted from above to fix the center section 5 to the lower case 13 side.

An oil filter mounting surface 5a for mounting the oil filter 3 is formed on the upper surface of the horizontal portion 5h of the center section 5. Further, a hydraulic pump installation surface 5b for rotatably installing the hydraulic pump P is formed on the lower surface of the horizontal portion 5h of the center section 5. The side surface of the vertical portion 5v of the center section 5 is used as the hydraulic motor installation surface 5c of the hydraulic motor M.

The hydraulic pump shaft 1 is an upper case 12 that constitutes an axle case C.
And the lower case 13 are rotatably supported by bearings, which pass through the inside of the cylindrical oil filter 3 and pass through the horizontal portion 5h of the center section 5 to reach the lower case 13.
Even the bearings of.

The pump case 4 is brought into contact with the hydraulic pump installation surface 5b of the center section 5 from below, and the pump pistons 8 are inserted into a plurality of cylinder holes provided in the pump case 4. The pump case 4 is fitted into a spline on the outer circumference of the hydraulic pump shaft 1, and the pump case 4 and the pump pistons 8 rotate with the rotation of the hydraulic pump shaft 1. The pump pistons 8 ... Are pressed by a piston biasing spring 19, and the lower end of the biased pump pistons 8 ... Abuts on the thrust bearing 10. The thrust bearing 10 is fitted in a movable swash plate 17, and by rotating the movable swash plate 17 by a gear shift lever shaft 14, the direction and amount of pump discharge oil can be changed.

The oil pressure discharged from the hydraulic pump P is a half-moon shaped oil passage a, which is opened on the lower surface of the horizontal portion 5h of the center section 5.
From the bottom, the half-moon oil passage E opened on the hydraulic motor installation surface 5c via the oil passage C inside the center section 5.
And is supplied into the cylinder hole of the motor case 6.

A motor piston 9 is provided in the cylinder hole of the motor case 6.
Is inserted and constantly urged by the piston urging spring 18 toward the thrust bearing 11.

The thrust bearing 11 is fitted in the fixed swash plate 16.
Since the motor piston 9 is pressed toward the thrust bearing 11 by the pressure oil supplied into the cylinder hole of the motor case 6 and the thrust bearing 11 is inclined,
The motor case 6 and the motor piston 9 rotate integrally.

By changing the inclination angle of the movable swash plate 17, the hydraulic motor shaft 2 spline-engaged with the motor case 6 rotates in the normal direction.
It is neutral and reverse.

The hydraulic motor shaft 2 is supported by a bearing fitted into the joint surface between the upper case 12 and the lower case 13, and has a gear 23 formed therein.

As shown in FIG. 2, a closed circuit that connects two high and low pressure oil passages C and D in the center section 5 to stop the rotation of the hydraulic motor shaft 2 regardless of the rotation of the hydraulic pump shaft 1. A pressure release mechanism is configured.

By connecting the closed circuit with the closed circuit pressure release mechanism, it is possible to create a state in which the hydraulic motor shaft 2 can freely rotate.

The closed circuit pressure release mechanism is composed of a lever 31, a lever shaft 15, and an eccentric shaft 35 fixed to the lower end of the lever shaft 15. When the lever 31 is rotated, the eccentric shaft 35 rotates. Then
The double pressing body 30 is pressed toward the center section 5. As shown in FIG. 4, the tip of the double pressing body 30 is
A check valve configured to press the check valve opening protrusions 32 and 33 protruding from the center section 5 toward the dual pressing body 30 and to suck the working oil from the oil filter 3 by the negative pressure is used. It is configured to communicate by opening both the check valves in the oil passages.

In FIG. 2, a detent recess is formed in a portion where the lower end of the lever 31 contacts the upper surface of the upper case 12, and in order to hold the lever 31 in the rotated position, the detent recess is formed on the outer periphery of the lever shaft 15. The detent spring 36 is interposed.

Further, as shown in FIG. 3, a gear shift lever shaft 14 is arranged for rotating the movable swash plate 17 arranged on the lower portion of the inner surface of the lower case 13, and the upper end of the gear shift lever shaft 14 is at the upper case.
A gearshift arm 28 is fixedly provided, protruding from 12. Further, a shift lever 29 is fixed to the lower portion of the shift lever shaft 14, and the shift lever 29 is fitted and inserted into a lever fitting groove provided outside the movable swash plate 17.

Next, the embodiment shown in FIGS. 4, 5, and 6 will be described.

In this embodiment, the mounting surface of the center section 5 is the center section mounting surface 12a provided at substantially the same height as the case joint surface of the upper case 12.

Then, with the center section 5 coming into contact with the center section installation surface 12a from below, the fixing bolt 34 is inserted and fixed from below.

As shown in FIG. 4, the brake drum 20 is fixed to the portion where the hydraulic motor shaft 2 projects to the outside of the axle case C, and the brake band 21 is provided on the outer periphery of the brake drum 20. The periphery of the brake band 21 is covered with a brake case 22.

Also, the gear 23 engraved on the hydraulic motor shaft 2 is
Is engaged with a large-diameter gear 24 above the counter shaft 26
The small diameter gear 25 above the gear meshes with the ring gear 27 of the differential gear device D. Axles 7, 7 are provided on the left and right sides of the differential gear device D so as to project therefrom.

The number of fixing bolts 34 for fixing the center section 5 to the center section mounting surface 12a is three.

Further, as shown in FIG. 4, the hydraulic motor shaft 2, the counter shaft 26, and the axles 7 and 7 are arranged on the same plane, and by the bearings fitted on the contact surfaces of the upper case 12 and the lower case 13, respectively. It is supported.

In the mechanism shown in FIGS. 5 and 6, the mounting portion of the center section 5 is such that the center section installation surface 13a on the upper surface of the lower case 13 of the first cited example is transferred to the center section installation surface 12a on the lower surface of the upper case 12. The other configuration is almost the same, except that it is changed to.

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

First, since the hydraulic pump P is installed on the lower surface of the horizontal portion 5h of the center section 5, the position of the hydraulic pump shaft 1 can be lowered, and the input pulley 40 attached to the hydraulic pump shaft 1 can be lowered. As a result, the position of the input pulley 40 with respect to the engine E can be lowered so that it can be mounted on a low floor type traveling vehicle.

Second, the output pulley 41 of the vertical engine E
By directly transmitting the input pulley 40 of the hydraulic pump shaft 1 by belt transmission, the mounting position of the engine E can be lowered, and a stable traveling vehicle with a low center of gravity can be obtained.

[Brief description of drawings]

FIG. 1 is a side view of an axle drive device attached to a traveling vehicle, FIG. 2 is a sectional view taken along the line of a hydraulic pump shaft 1 and a hydraulic motor shaft 2, and FIG. 3 is a hydraulic pump shaft 1 and a shift lever shaft 14. FIG. 4 is a cross-sectional view taken along the line of FIG.
FIG. 5 is a plan view with 12 removed, FIG. 5 is a cross-sectional view taken along the line XX of FIG. 4, and FIG. 6 is a cross-sectional view taken along the line YY of FIG. C …… Axle case E …… Engine P …… Hydraulic pump M …… Hydraulic motor 1 …… Hydraulic pump shaft 2 …… Hydraulic motor shaft 3 …… Oil filter 4 …… Pump case 5 …… Center section 5h …… Center Horizontal part of section 5v …… Vertical part of center section 6 …… Motor case 40 …… Input pulley

Claims (1)

[Scope of utility model registration request] 1. An axle case C is provided with a center section 5 having a substantially L-shaped cross section, which is composed of a horizontal portion 5h and a vertical portion 5v continuous with the horizontal portion 5h.
It is fixed inside and the horizontal part 5h and the vertical part of the center section 5 are fixed.
Hydraulic pump P and hydraulic motor M that drive the axle 7 to 5v
With the configuration installed, the horizontal part of the center section 5
The hydraulic pump shaft 1 is erected and supported by the upper and lower parts of the axle case C penetrating 5h, and the input pulley 40 from the engine E is attached to the end of the hydraulic pump shaft 1 protruding from the upper part of the axle case C.
And the hydraulic pump P is arranged on the lower surface of the horizontal portion 5h of the center section 5.