JPH0249049Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a drive device for a small tractor with a mower device attached to the front or abdomen.

(b) Prior Art A technique related to a small tractor equipped with a mower device is known as disclosed in Japanese Utility Model Application Publication No. 19822/1983.

(c) Problems to be solved by the invention The present invention is a reduction gear device in which a drive axle and a differential gear device are supported in a compact transmission case, and a reduction shaft and a brake shaft extend horizontally from the supporting part. All of these are placed inside a small mission case.

The transmission case is also provided with a mounting surface for a hydraulic pump/hydraulic motor co-located HST type transmission, so that only the small transmission case is equipped with all of the traveling transmission.

Further, the brake shaft 7 is provided with a brake device, and the brake device is also integrally constructed.

Furthermore, in order to simply configure the power transmission from the engine, the hydraulic pump and hydraulic motor are co-located.
The drive shaft of the hydraulic pump of the HST type transmission A is arranged vertically.

In addition, the motor shaft that inputs the hydraulic pump/hydraulic motor to the HST type transmission, and the pump drive shaft that drives the hydraulic pump from the HST type transmission.
They are placed on the left and right sides of the reduction gear to ensure good balance.

(d) Means for solving the problem The purpose of the present invention is as described above. Next, the configuration for achieving the purpose will be explained.

In a transmission case that supports a differential gear device D inside and has driving axles 19L and 19R protruding left and right from the differential gear device D, reduction shafts 8, 9 and brake shaft 7, and a hydraulic pump/hydraulic motor co-located type HST is installed on the wall of the transmission case where the reduction gear is placed.
A mounting surface B is provided for the HST transmission A, and the motor shaft 6 of the HST transmission A mounted on the mounting surface B is inserted into the brake shaft 7 in the transmission case from one side of the left and right sides of the reduction gear. The brake shaft 7 and the deceleration shaft 9 are connected to transmit the decelerated rotation to the differential gear device D, and the pump drive shaft 1 is connected to the left and right sides of the deceleration device D.
4 arranged vertically.

(e) Structure of the embodiment The purpose 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 plan view of the driving device for a traveling vehicle according to the present invention, FIG. 2 is a cross-sectional view taken along the Z-Z line in FIG.
The figures are also a Y-Y cross-sectional view in Fig. 1, Fig. 4 is a plan view of the third transmission case, and Fig. 5 is a plan view of the third transmission case.
The figure is a cross-sectional view taken along the line X-X in FIG. FIG. 2 is an overall side view of the tractor.

The overall structure of the small tractor will be explained with reference to FIG.

The front wheels are drive wheels 27, 27, and the rear wheels are steering wheels 2.
6.26. And the drive shafts 27, 27
An engine E, a seat 28 and a steering handle 29 are mounted on a frame supported by steering wheels 26, 26.
is placed.

The crankshaft of engine E is projected downward, and a V pulley 35 is attached to the lower end of the crankshaft.
Equipped with a hydraulic pump and hydraulic motor
V-belt 3 to hydraulic pump P of HST type transmission A
Power is transmitted by 3.

That is, the pump drive shaft 14 of the hydraulic pump P is vertically installed on the right side of the reduction gear, and the pump drive shaft 14
A V-pulley 12 is attached to the V-pulley 12, and a V-belt 33 is wound between the V-pulley 12 and the aforementioned V-pulley 35.

Further, the mower device 25 is attached to the machine body by a lift arm 45 so as to be able to be raised and lowered.

The transmission case is the first transmission case 1.
It is composed of a second mission case 2 and a third mission case 3, with the first mission case 1 in the middle and the second mission case 2 on top.
is constructed in the shape of a sander beach with a third transmission case 3 fixedly attached to the lower side.

Of the transmission cases with this configuration, on the rear upper surface of the first transmission case 1, on the side surface of the part of the reduction gear constituted by the reduction shafts 8, 9 and the brake shaft 7.
This constitutes the mounting surface B of the HST type transmission A.

A differential gear device D and drive axles 19L, 19R are supported within the transmission case, and a link 45 projects forward from the drive axles 19L, 19R that protrude left and right.
is supported so that it can move up and down freely.

Next, the configuration of the HST type transmission A will be explained.

The HST type transmission A is configured as a hydraulic pump/hydraulic motor co-located type HST type transmission. That is, as shown in FIG. 1, the hydraulic motor M is arranged on the left side in the direction of travel of the tractor,
A hydraulic pump P is arranged on the right side, and both are integrally constituted.

A pump drive shaft 14 protruding upward is disposed on the hydraulic pump P, and the V pulley 12 is fixedly attached to the pump drive shaft 14 as described above, and power is transmitted from the engine E through the V belt 33. .

A speed change shaft 11 is protruded from the side surface of the hydraulic pump P, and by rotating the speed change shaft 11 with a speed change lever, the swash plate of the hydraulic pump P is rotated.
The discharge amount of the hydraulic pump P is changed, and the rotational direction and rotation speed of the hydraulic motor M are changed.

A motor shaft 6 projects downward from the hydraulic motor M, and the motor shaft 6 is inserted into the mission case from the mounting surface B, and has a bevel gear 10 fixed at its tip.

Power is transmitted from the bevel gear 10 to a bevel gear 32 on the brake shaft 7, and the bevel gear 32 drives the brake shaft 7.

The motor shaft 6 is placed on the right side in the direction of movement of the reduction gear, and the motor shaft 6 is also placed on the left side, so that both shafts are arranged in a well-balanced manner on the left and right sides.

A brake shoe 31 is provided at the left end of the brake shaft 7.
is fixedly installed and constitutes a brake device. Further, power is transmitted from another gear 34 on the brake shaft 7 to a counter gear 35 on the reduction shaft 8. The counter gear 35 meshes with a large diameter gear 36 on the reduction shaft 9, and similarly transmits power from the small diameter gear 41 to the differential ring gear 15 of the differential gear device D.

The differential gear device D is mainly composed of a left differential gear case 16 and a right differential gear case 17, which sandwich and fix a differential ring gear 15 from the left and right sides and constitute a differential gear case. The differential ring gear 15 is formed by the left differential gear case 16 and the right differential gear case 17.
After the differential pinion shaft 18 is clamped and fixed, they are fastened together with bolts 30.

A differential pinion gear 2 is attached to the differential pinion shaft 18.
1 and 21 are loosely fitted, and the differential pinion gears 21 and 21 are connected to the left and right differential side gears 20L and 20.
It meshes with R. Right differential side gear 20R
A differential lock pin 22 is provided which integrates the right differential gear case 17 with the right differential gear case 17, and is configured to be deflockable by sliding a differential slider 24 using a differential shifter 23.

A deflock lever 4 is provided projecting from the upper part of the second transmission case 2, and by rotating the deflock lever 4, a deflock operation can be performed.

Drive axles 19L and 19R are spline-coupled to left and right differential side gears 20L and 20R.

Further, as shown in FIG. 5, a brake chamber surrounding the brake shoe 31 is formed on the right side of the joining surface of the first transmission case 1 and the third transmission case 3. That is, the brake chamber 1b of the first transmission case 1 and the brake chamber 3b of the third transmission case 3. After the two brake chambers are joined, a brake chamber cover is attached to the side surface to seal the brake chambers.

Also, on the upper surface of the first transmission case 1, there is a mounting surface B.
A mounting surface C for the oil filter 5 is formed on the left side surface of the first transmission case 1.

In fact, the mounting surface B provided on the top surface of the first transmission case 1 has an area on which only the hydraulic motor M portion is placed, and the lower end of the hydraulic pump P portion is not configured on the mounting surface B. be. This is because in this embodiment, the bearing cover 43 of the pump drive shaft 14 of the hydraulic pump P protrudes below the HST type transmission A, and the space corresponding to the bearing cover 43 is
An allowance gap is formed between the HST type transmission A and the upper surface of the first transmission case 1.

The first transmission case 1 is extended to the lower side of the hydraulic pump P to form an oil reservoir portion E.

In this embodiment, the third transmission case 3
It also protrudes to the lower side of the hydraulic pump P, covers the downward opening of the first transmission case 1, and forms a part of the oil reservoir E.

Further, the third mission case 3 is also recessed downward in its cover portion, and the third mission case 3 is recessed downward.
The inside thereof is constructed in a substantially symmetrical shape, thereby increasing the volume into which hydraulic oil can enter.

A mounting surface C for the oil filter 5 is formed on the side surface of the first transmission case 1 in the oil sump E portion, and the oil filter 5 is fixed from the side. The oil filter 5 is provided with a mounting screw 38, and the mounting screw 38 is connected to the oil passage 38 located approximately in the center of the mounting surface C of the first transmission case 1.
By screwing into the female screw portion formed at the 0 end, the oil filter 5 can be fixed, and the filtered hydraulic oil is guided to the oil path 40.

Also, the oil filter 5 has its mounting screw 38.
A plurality of suction holes 37 are provided at equal intervals on the outer peripheral surface, and on the mounting surface C of the first mission case 1,
A circular recess 44 faces the suction hole 37.
A hydraulic oil suction hole 44' is formed so that the oil reservoir E communicates with the recess 44. Hydraulic oil is sucked through the hydraulic oil suction hole 44', and the recess 4
4, filtered in an oil filter 5,
The oil is sucked into the hydraulic pump P from the oil passage in the mounting screw 38 via the oil passage 40.

A connecting oil passage 40' for connecting the oil passage 40 to the hydraulic pump P side is a separate oil passage pipe 3 as shown in FIG.
9, or as shown in FIG.
It may also be a cylindrical portion 1f integrally constructed with the first transmission case 1. In addition, the mounting surface B of the first transmission case 1 is provided below the hydraulic pump P, and the lower surface of the hydraulic pump P and the mounting surface B of the first transmission case 1 are directly connected to the connecting oil passage 40'. may also be configured.

A lubricating plug 13 is arranged in the second mission case 2, and a drain hole 3a is arranged in the third mission case 3.

(f) Effects of the Embodiment Since the present invention is constructed as described above, it functions as follows.

The structure of the mission case is such that the first mission case 1 is sandwiched between the second mission case 2 at the top and the third mission case 3 at the bottom like a sandwich. Without drilling the shaft bearing hole in the transmission case,
It is constructed from aluminum die-casting and can be assembled without machining.

The joint surface of the first transmission case 1 and the second transmission case 2 is on the axis of the drive axle 19L, 19R, and when the first transmission case 1 and the second transmission case 2 are joined, the drive axle 19L, 19R bearings are connected together.

Further, the joint surface of the first transmission case 1 and the third transmission case 3 is located on the axis of the brake shaft 7, the deceleration shaft 8, and the deceleration shaft 9, and these bearings are fastened together to the joint surface. .

Since the deceleration shaft 8 is a fixed shaft and has a counter gear 35 loosely fitted on its outer periphery, it is necessary to stop its rotation.The rotation locking rib 1a is taken out from the first transmission case 1 as shown in Fig. 2 to decelerate it. The rotation of the deceleration shaft 8 is prevented by contacting the slotted surface 8a of the shaft 8.

The bearing fitting hole of the joint surface configured as above is
Both the top and bottom are not semicircular, but only one side is semicircular and the other is only a protrusion, so even if the circle of the bearing and the circle of the bearing fitting hole do not match perfectly, it can be fixed easily. It is composed of

Next, the suction of hydraulic oil from the hydraulic pump P will be explained. As engine E rotates, V pulley 12
The pump drive shaft 14 is rotated to absorb the hydraulic oil in the oil reservoir E, convert it into pressure oil, and send the oil to the hydraulic motor M. In the present invention, the hydraulic oil of the hydraulic pump P is sucked from the oil reservoir E formed by the first transmission case 1 and the third transmission case 3 through the hydraulic oil suction hole 44', and the oil filter 5 is The connecting oil passage 4 is then filtered through the mounting screw 38.
0' and is sucked into the hydraulic pump P.

(g) Effects of the invention Since the invention is constructed as described above, it has the following effects.

First, a drive axle and a differential gear device are supported within a compact transmission case, and a reduction gear consisting of a reduction shaft and a brake shaft is provided horizontally from the support, and all of these are mounted in a small transmission case. It was possible to place it inside.

Second, a hydraulic pump and
A mounting surface was also provided for an HST type transmission with a hydraulic motor installed, making it possible to have a complete traveling transmission with just a small transmission case.

Thirdly, the brake shaft 7 was provided with a brake device, and the brake device could also be configured integrally.

Fourthly, in order to simply configure the power transmission from the engine, the hydraulic pump and hydraulic motor are co-located.
The drive shaft of the hydraulic pump of HST type transmission A is arranged vertically, and the hydraulic pump and hydraulic motor are co-located.
The motor shaft input to the HST type transmission and the HST
The pump drive shafts that drive the hydraulic pump from the transmission are placed on the left and right sides of the reduction gear, allowing for good balance between the left and right sides of the transmission case.

[Brief explanation of the drawing]

FIG. 1 is an overall plan view of the driving device for a traveling vehicle according to the present invention, FIG. 2 is a cross-sectional view taken along the Z-Z line in FIG.
The figures are also a Y-Y cross-sectional view in Fig. 1, Fig. 4 is a plan view of the third transmission case, and Fig. 5 is a plan view of the third transmission case.
The figure is a cross-sectional view taken along the line X-X in FIG. FIG. 2 is an overall side view of the tractor. A...HST type transmission, B...HST type transmission mounting surface, D...Differential gear device, M...HST
Hydraulic motor of type transmission, P...Hydraulic pump of HST type transmission, 1...First transmission case, 2...Second transmission case, 3...Third transmission case, 6...Motor shaft , 7... Brake shaft, 8, 9... Deceleration shaft, 19L, 19R...
Drive axle, 14...pump drive shaft.

Claims (1)

[Scope of utility model registration request] In a transmission case that supports a differential gear device D inside and has drive axles 19L and 19R protruding left and right from the differential gear device D, reduction shafts 8 and 9 are inserted from near the differential gear device D in a direction perpendicular to the drive axles 19L and 19R. A deceleration device for the brake shaft 7 is provided protrudingly,
A mounting surface B for the hydraulic pump/hydraulic motor co-located HST type transmission A was provided on the wall of the transmission case in which the reduction gear was placed, and the HST type transmission A was placed on the mounting surface B.
The motor shaft 6 of the HST type transmission A is connected to the brake shaft 7 in the transmission case from either side of the deceleration device on either side, and connects the brake shaft 7 and the deceleration shaft 9.
A driving device for a running vehicle, characterized in that the reduced rotation is transmitted to a differential gear device D via a pump drive shaft 14, and a pump drive shaft 14 is vertically disposed on the other left and right sides of the speed reducing device.