JPS6345973B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a drive device for a tractor equipped with a mid PTO shaft and a rear PTO shaft.

(b) Prior art Conventionally, the HST type transmission device A has been used to change gears,
Regarding the drive structure of a traveling work vehicle equipped with a rear PTO shaft and a mid-PTO shaft, U.S. Patent No. 4304141
The technology disclosed in the above publication was considered to be publicly known.

However, even in this conventional technology, the PTO system power transmission path and the travel system power transmission path are branched from the hydraulic pump shaft and hydraulic motor shaft portion of the HST type transmission, and the PTO system and the travel system are connected to the transmission case. They are placed in the front and back.

Additionally, the Mitsudo PTO shaft is located in the abdomen of the transmission case.

(C) Problems to be Solved by the Invention In the case of the prior art, the PTO system power transmission path and the traveling system power transmission path are separated and arranged in front and behind the transmission case, so that the transmission The case becomes longer from front to back, the overall length of the aircraft becomes larger, and the mid-PTO protrudes from the abdomen.
The axle had a defect in that it lowered the minimum ground clearance of the aircraft.

The object of the present invention is to overcome the disadvantages of the prior art.

(d) Means for Solving the Problems The objects of the present invention are as described above, and the configuration for achieving the objects will now be explained.

In a configuration in which the differential gear device 16 is disposed inside the transmission case and the HST type transmission device A is attached to the front of the transmission case, in the space in the longitudinal direction between the HST type transmission device A and the differential gear device 16, Hydraulic motor shaft 7 of HST type transmission A,
A driving system power transmission path configured between the pinion shaft 9 and the hydraulic pump shaft 6 of the HST type transmission A,
The PTO system power transmission path configured between the PTO switching shaft 11 is overlapped in side view, and the pinion shaft 9
The bevel pinion 9a provided at the rear end meshes with the differential gear device 16, and the front end allows front wheel driving force to be taken out, and the PTO switching shaft 11 is unevenly supported on one side in the left and right direction at the front of the transmission case. The protruding mid PTO shaft 3 and the rear PTO supported approximately in the center of the rear surface of the transmission case in the left and right direction.
The power can be switched between the shafts.

(e) Embodiments and operations The purpose and structure of the present invention are as described above. Next, the structure of the embodiments shown in the attached drawings and the operations of the invention will be explained.

The overall configuration will be explained with reference to FIGS. 1 and 2.

The transmission case is the front transmission case 4.
and a rear transmission case 5, and an HST type transmission A is fixedly installed at the front of the front transmission case 4. Power is transmitted from the engine E to the hydraulic pump shaft 6 of the HST type transmission A. 2 is the front wheel power take-off shaft, 1 is the rear PTO shaft, and 3 is the mid PTO shaft.

The configuration of the hydraulic lift device installed at the rear of the PTO clutch device B will be explained with reference to FIG.

A control valve device 60 for a hydraulic lift device is fixedly installed on the upper surface of the rear transmission case 5. A hydraulic cylinder 56 is installed on the side of the PTO clutch device B.

The base end of the lift arm 57 connected to the piston of the hydraulic cylinder 56 is connected to the support bracket 5.
The lift arm 57 is pivotally supported at the rear end of the lift arm 57, and the tip of the lift arm 57 is rotated up and down by the expansion and contraction of the piston in the hydraulic cylinder 56.

Next, the traveling power transmission path will be explained with reference to FIGS. 3 and 5.

The rotation after shifting is transmitted to the front transmission case 4 from the motor shaft 7 of the hydraulic motor located at the lower stage of the HST type transmission A. A fixed gear 19 at the rear end of the hydraulic motor shaft 7 meshes with a fixed gear 20 on the transmission shaft 8, and other fixed gears 21 and 22 on the transmission shaft 8 are driven.

The fixed gears 21 and 22 mesh with loosely fitted gears 24 and 25 on the pinion shaft 9, and the shift slider 23 moves back and forth via the shifter arm 23b due to rotation of the rotation shaft 23a. It is configured as a power transmission path for the driving system by changing gears.

The rotation of the pinion shaft 9 is caused by a pinion 9a meshing with a differential ring gear of a differential gear device 16 disposed within the rear transmission case 5 on one side in the left-right direction of the vehicle.

The left and right differential rotation is transmitted by the differential gear device 16 to the differential side gears 29L and 29R, and the axle 17
It drives L and 17R. Axle 17L, 17R
Above is the steering brake device disc plate 18.
L and 18R are interposed. 26a is a rotation shaft for operating the differential shifter 26b, 27 is a differential slider, and 28 is a differential pin.

15L and 15R are rear axle housings fixed to the side surfaces of the rear transmission case 5.

Further, a spline is carved on the front end of the pinion shaft 9, and if front wheel drive is required, a fixed gear 30 is fixedly installed on the spline, and the fixed gear 30 is attached to the front wheel power take-off shaft. The loosely fitted gear 31 on the front wheel power take-off shaft 2 is engaged with the clutch slider 32, and the power is connected to and disconnected from the front wheel power output shaft 2 by moving the clutch slider 32 back and forth.

The position of the front wheel power take-off shaft 2 is on the side of the pinion shaft 9 as shown in FIG. There is.

Next, the PTO system power transmission path will be explained using Figure 4.

The pump shaft 6 is protruded into the front transmission case 4 from the upper stage hydraulic pump of the HST type transmission A.
Power is transmitted to the clutch drive shaft 12 of the PTO clutch device through a coupling.

Between the clutch drive shaft 12 and the clutch housing 51 fixed to the front end of the clutch driven shaft 14
A PTO clutch plate 47 is interposed.

Further, a PTO brake plate 46 is interposed between the outer periphery of the clutch housing 51 and the front transmission case 4.

By moving the PTO slider 44 back and forth, the PTO clutch pressing lever 45 swings in the vertical direction about the pivot pin 50, presses either the PTO clutch plate 47 or the PTO brake plate 46, and presses the PTO clutch plate 47 or the PTO brake plate 46. It engages and disengages the clutch device and brakes and releases the rotation of the PTO shaft. 44' is a rotation shaft for sliding the PTO slider 44.

The driven gear 33 at the end of the clutch driven shaft 14 is located inside the rear transmission case 5, and in addition to the above-mentioned differential gear device 16, the rear PTO shaft 1 is located approximately at the center of the rear transmission case 5. The rear end is supported by protruding from the rear surface.

The mid-PTO shaft 3 is disposed on the other side in the left-right direction of the machine body, is juxtaposed with the differential gear device 16, and has its front end protruding from the front surface of the rear transmission case 5.

The driven gear 33 is the gear 34 of the counter shaft 13.
The gear 34 meshes with the PTO switching shaft 11 to transmit rotation to the loosely fitted gear 38 on the PTO switching shaft 11. Rotation shaft 36a
The rotation of the switching slider 36 moves back and forth via the shifter arm 36b, so that the loosely fitted gear 3
When transmitting power to the loose fit gear 35 on 8,
It is switched when power is transmitted from the fixed gear 53 of the PTO switching shaft 11 to the fixed gear 39 of the rear PTO shaft 1.

The loosely fitted gear 35 meshes with a fixed gear 42 on the mid-PTO shaft 3, and drives the mid-PTO shaft 3.

Gear 34, loose fit gears 38, 35, fixed gear 3
9, 53, and 42 constitute a PTO system power transmission path.

40 is a PTO that operates the PTO slider 44
The clutch lever 41 is a shock absorber that dampens sudden engagement and disengagement of the clutch.

As described above, in the present invention, the HST type transmission device A is fixedly installed on the front surface of the transmission case, and the PTO system is overlapped on the left and right in the narrow space created between the transmission case and the differential gear device 16 inside the transmission case. A power transmission path and a driving system power transmission path are provided.

The PTO system power transmission path is capable of switching power to the mid PTO shaft 3 and the rear PTO shaft 1, and the driving system power transmission path receives power from the differential gear device 16 to drive the rear wheels, and from the front wheel power take-off shaft 2 to the front wheels. This makes it possible to transmit power to the driving force.

Next, the arrangement of each axis of the travel system and PTO system will be explained with reference to FIGS. 6 and 7.

FIG. 6 is a front view of the mission case. In the drawing, the same axes of the hydraulic pump shaft 6, clutch drive shaft 12, and clutch driven shaft 14 are arranged at the top, and the counter shaft 13 is arranged at the lower right when facing the direction of travel.

A PTO switching shaft 11 is arranged directly below the counter shaft 13, and the rotation after being switched by the switching device on the PTO switching shaft 11 is transferred to the rear PTO diagonally above.
It is transmitted to shaft 1 and the mid-PTO shaft 3 located diagonally below.

A speed change shaft 8 is arranged below the motor shaft 7, and a pinion shaft 9 is arranged further below. If front wheel drive is required, the front wheel power take-off shaft 2 is arranged diagonally above the pinion shaft 9.

As shown in FIG. 7, FIG. 9, and FIG. 10, a rear transmission case 5 is constructed, and the rear transmission case 5 has a first mounting plate to which the front transmission case 4 is joined to the front surface of the rear transmission case 5. Two standing walls are constructed: left and right standing walls 5c and front and rear standing walls 5a. Also the first
A second left and right standing wall 5d, which is shorter in the left-right direction than the standing wall 5c, is integrally formed at the rear of the left and right standing walls 5c, and is also integrally formed with the front and rear standing walls.

As shown in FIG. 8, a pinion shaft 9 and a transmission shaft 8 are supported between the splittable front transmission case 4 and the first left and right vertical walls 5c, as shown in FIG. The clutch drive shaft 12 of the clutch device is connected to the shaft support 4a of the front transmission case 4.
The clutch driven shafts 14 are supported by shaft supports 5f of the rear transmission case 5, respectively.

The counter shaft 13 is supported between the protruding support portion 4c of the front transmission case 4 and the second left and right vertical walls 5d, and is supported by a bearing portion formed on the second left and right vertical walls 5d and the rear end wall of the rear transmission case 5. Between 5e and
A rear PTO shaft 1 is supported approximately toward the center in the left-right direction of the aircraft.

The PTO switching shaft 11 is supported by the second left and right vertical walls 5d and the protruding support portion 4a of the front transmission case 4. The mid-PTO shaft 3 is supported between the first and second left and right vertical walls 5c and 5d, and is juxtaposed to a differential gear device 16 arranged on one side of the aircraft in the left-right direction as shown in FIG. It is made to protrude from the left and right standing walls 5c.

In addition, the rear transmission case 5 has a support hole 5b for supporting the differential gear device 16 toward one side in the left-right direction of the aircraft, and a hydraulic oil strainer insertion hole 5.
g is perforated.

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

First, a driving system power transmission device capable of driving the rear wheels and front wheels, a PTO system power transmission device capable of driving the mid PTO shaft and the rear PTO shaft, are connected to the HST type transmission A and the differential gear device 16. Although the transmission mechanism with the two types of functions described above, the traveling system and the PTO system, is placed side by side in the narrow space in the front and rear direction between the Can be in case, HST
Although the transmission case was equipped with a transmission, the overall length of the transmission case could be shortened, and the overall length of the tractor body as a whole could also be shortened.

Second, the PTO system power transmission path
It is possible to drive the PTO shaft 3 and the rear PTO shaft 1, and the rear and front wheels can be driven by the drive system power transmission path, so it is possible to select a wide range of drive systems according to the purpose of the tractor. It has become a reality.

Thirdly, by arranging the PTO system power transmission path in front of the differential gear device 16 and closer to the rear axle, the rear part protrudes from this position to a predetermined position rearward.
The length of the PTO shaft 1 can be made shorter than before, and the length of the front mid-PTO shaft 3 can also be made shorter.

Fourth, since the mid PTO shaft 3 is located at the front of the transmission case, the mid PTO shaft 3 does not need to protrude from the abdominal case of the transmission case, as in the conventional case, and the minimum ground clearance can be ensured. It was.

[Brief explanation of the drawing]

Fig. 1 is a side view of the transmission of the tractor of the present invention, Fig. 2 is a rear view, Fig. 3 is a side sectional view of the traveling drive system of the transmission case, and Fig. 4 is a side sectional view of the PTO drive system. Figure 5 is a plan sectional view of the differential gear device portion, Figure 6 is a front view showing the arrangement of each shaft in the transmission case of the present invention, and Figure 7 is a rear view showing the arrangement of the shafts in the transmission case. 8 is a side sectional view of the front transmission case 4 and rear transmission case 5 in an exploded state, FIG. 9 is a rear sectional view of the rear transmission case 5, and FIG. 10 is a plan sectional view, and FIG. Figure 11 is
FIG. 12, which is a drawing of the operating section of the PTO clutch, is a skeleton diagram of the transmission of the present invention. A...HST type transmission, 1...Rear PTO shaft,
3...Mitsudo PTO shaft, 4...Front transmission case, 5...Rear transmission case, 6...Hydraulic pump shaft, 7...Hydraulic motor shaft, 8...Transmission shaft, 9...Pinion shaft, 11...PTO switching axis,
12...Clutch drive shaft, 14...Clutch driven shaft, 16...Differential gear device.

Claims (1)

[Claims] 1. A differential gear device 16 is provided inside the transmission case.
In a configuration in which the HST type transmission A is attached to the front of the transmission case, the hydraulic motor shaft of the HST type transmission A is installed in the space in the longitudinal direction between the HST type transmission A and the differential gear device 16. 7 and the pinion shaft 9, the hydraulic pump shaft 6 of the HST type transmission A, and the PTO
The PTO system power transmission path configured between the switching shaft 11 and the PTO system power transmission path are overlapped in a side view, and the pinion shaft 9 engages a bevel pinion 9a provided at the rear end with the differential gear device 16.
The front end can be used to take out the front wheel driving force, and the PTO switching shaft 11 is supported unevenly on one side in the left and right direction at the front of the transmission case.
This HST-driven tractor is characterized in that power can be switched between the PTO shaft 3 and the rear PTO shaft 1 supported approximately at the center in the left-right direction on the rear surface of the transmission case.