JPH1120484A - Transmission shaft layout structure for working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the sufficient lifting quantity of a mid mount mower by devising three-shaft layout structure of a main transmission shaft extended from an engine to an HST(hydrostatic continuously variable transmission), a front wheel driving shaft and a PTO transmission shaft. SOLUTION: Transmission shaft layout structure for a working machine is provided with a main transmission shaft 8 for interlockingly connecting an engine at a front part of a machine body to a transmission 6 at a rear part of the machine body, a front wheel driving shaft 15 for driving a front wheel 1, and a PTO transmission shaft 24 for interlockingly connecting a mid PTO shaft 11 of the transmission 6 and an input gear box 22 of a mower M arranged at a lower belly part of the machine body. The PTO transmission shaft 24 is extended frontward from the transmission 6 and arranged on the left side with respect to the lateral center C of the machine body, and the front wheel driving shaft 15 is arranged on the right side. The main transmission shaft 8 is arranged in a highest position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work machine in which a work device can be attached to a lower abdomen of a body such as a mid-mount riding lawn mower or a garden tractor, and more particularly, to a power transmission for interlocking an engine and a transmission. The present invention relates to a rational arrangement structure of three shafts including a shaft, a wheel drive shaft such as a front wheel extended from a transmission, and a PTO transmission shaft for driving a working device.

[0002]

2. Description of the Related Art The above working machine is disclosed in Japanese Patent Application Laid-Open No. 8-282.
No. 453 discloses a mid-mount lawn mower.
From FIG. 1 of the publication, the main transmission shaft extending from the engine at the front part of the fuselage to the transmission at the rear part of the fuselage, the front wheel drive shaft extending forward from the transmission, and the PTO transmission shaft interlockingly connecting the transmission and the mower. It can be understood that the three axes are arranged in the lower abdomen of the fuselage.

[0003]

An input gear box which receives power from a PTO transmission shaft is protrudingly provided on the mower housing. Conventionally, a front wheel drive shaft passes over the input gear box. Therefore, it was difficult to make the rise of the mower high enough. Also, the front end of the front wheel drive shaft and the front wheel differential mechanism located in the center of the left and right are interlockingly connected via a relay shaft having a pair of universal joints. Since it is arranged obliquely so as to be shifted toward the center and downward (see the phantom line in FIG. 3), the minimum gap with the mower housing is relatively narrow, and from this point, the amount of rise of the mower is clearly limited. was there.

[0004] If the amount of rise of the mower is insufficient, there is a disadvantage that the mower easily comes into contact with the ground during traveling and it is difficult to perform regular inspection and maintenance, and there is room for improvement. It is an object of the present invention to improve the working device arranged in the lower abdomen of the machine so that the lifting amount can be sufficiently obtained by the above-described three-axis arrangement structure.

[0005]

[Means for Solving the Problems]

[Structure] In the first invention, a main transmission shaft for interlocking and linking an engine arranged at one of the front and rear ends of the fuselage with a transmission arranged at the other end is provided, and an engine-side wheel on the engine arrangement side is driven. A PTO drive shaft for linking the power input unit of the working device arranged on the lower abdomen of the fuselage with the mid PTO shaft of the transmission extends from the transmission toward the engine arrangement side, and the wheel drive shaft The shaft and the PTO transmission shaft are arranged so as to be distributed to the left and right with respect to the center of the body in the left and right direction.

A second invention is characterized in that the main transmission shaft in the first invention is located above the wheel drive shaft and the PTO transmission shaft.

[0007] A third invention is the first or second invention, wherein:
A power input unit for the engine-side wheels and a relay shaft that interlocks and connects the front end of the wheel drive shaft are provided, and the power input unit side end of the relay shaft is closer to the center of the body than the wheel drive shaft side end of the relay shaft. So as to go away to the side
The relay shaft is arranged to be inclined.

According to the first aspect of the present invention, the PTO
Since the transmission shaft and the wheel drive shafts are arranged left and right with respect to the left and right center of the fuselage, the power input portion of the working device such as the input gearbox of the mower and the wheel drive shafts are separated to the left and right in plan view. As a result, no interference occurs between the power input unit and the wheel drive shaft due to the rise of the working device, and it is possible to increase the ascent limit position of the working device. For example, in a lawnmower, it is common to slightly offset the mower to the left in order to reduce the minimum uncut diameter in edge cutting, and the input gearbox is also offset to the left, so the front wheel drive shaft is What is necessary is just to arrange | position to the right side, and it is convenient for the structure of this claim.

According to the second aspect of the present invention, since the main transmission shaft is located above the wheel drive shaft and the PTO transmission shaft, the power input portion of the working device and the main transmission shaft overlap in plan view. Even if they are arranged, they do not interfere with each other without waiting for the working equipment to rise sufficiently, and avoid interference between the power input unit and the wheel drive shaft to secure a sufficient amount of lifting of the working equipment. That is, it does not hinder the above operation.

According to the third aspect of the present invention, the relay shaft for connecting the tip of the wheel drive shaft and the power input portion of the engine-side wheel is provided.
From the wheel drive shaft offset from the left and right center of the aircraft,
Further, they are arranged obliquely toward the offset direction. This means that the relay shaft is located closer to the lateral side below the power input unit, so that the interference point between the relay shaft and the front end of the working device when the working device is raised is more laterally outward than in the past. I will stop by.

For example, in a three-blade type mower often used in a mid-mount lawn mower, the three blades are arranged in a triangular shape with the central blade leaning forward, so that the front edge of the housing in plan view is: As the position goes from the center to the left and right ends, the position is inclined rearward, so that the contact point between the relay shaft and the front edge of the housing is shifted rearward, and the height position is also increased. In other words, the differential mechanism does not necessarily have to be provided at the center of the body of the vehicle, and can be arranged to be shifted left and right, so that the relay shaft can be further directed laterally outward. Without changing the height of the working device, it is possible to make the height of the ascending limit higher than before.

[Effect] In the working machine according to any one of the first to third aspects, (a) the arrangement height of the shafts themselves can be improved by a simple modification such that the wheel drive shafts and the PTO transmission shafts are separately arranged to the left and right. A transmission shaft arrangement structure capable of raising the limit position of the working device without raising the position is obtained.

[0013] In the transmission shaft arrangement structure according to the second aspect, by arranging the main transmission shaft above the wheel drive shaft and the PTO transmission shaft, the above-described effect (regardless of the position in the left-right direction). There is an advantage that b) can be reliably demonstrated.

In the transmission shaft arrangement structure according to the third aspect, the relay shaft is directed laterally outward with respect to the front wheel drive shaft, so that the working device can be raised without being changed in height. The advantage that can be higher than before was obtained.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a lawn tractor, 1 is a front steering wheel (an example of an engine side wheel), 2 is a rear driving wheel, 3 is an engine, 4 is a steering wheel, 5 is a driving seat, 6 is a mission, and 7 is a transmission. An HST (hydrostatic continuously variable transmission) mounted on the mission 6, a main transmission shaft 8 for interlocking the engine 3 and the HST 7 in an interlocked manner, 9 an airframe, and M an anterior lower abdomen between the front and rear wheels. Moir (an example of a working device).

The transmission 6 has a rear PTO shaft 10, a mid PTO shaft 11, and a DT shaft 12 for driving front wheels, and supports a rear axle 13. A front wheel drive shaft (an example of a wheel drive shaft) 1 is provided to the DT shaft 12 via a front wheel transmission 14 which operates when the turning angle of the front wheel 1 becomes a predetermined angle or more.
5, the front wheel drive shaft 15 and an input shaft 17 of a front wheel differential mechanism (an example of a power input unit for the engine-side wheels) 16 are connected to a relay shaft 19 having a pair of universal joints 18 at both ends. It is interlocked and linked through.

As shown in FIG. 3, the mower M has a cutting blade 20.
And three input blades on the upper surface of the housing 25 on the cutting blade 20 at the center on the left and right.
2 are arranged. The input shaft 22a of the input gear box 22 and the mid PTO shaft 11 are connected to universal joints 23, 2
3 and a PTO transmission shaft 24 for interlocking connection. The mower M is arranged in the center cutting blade 20 so as to be slightly offset to the left with respect to the right and left center C of the machine body, so that the cutting performance in the left turning traveling is enhanced.

An elevating link mechanism A for driving up and down the mower M includes swing arms 26, 26 pivotally supported by the body frame 9 at a front fulcrum P, and a lift link connected to the rear end of the swing arm 26. 27, 27 and lift links 27, 27
Arm 29 for linking the hydraulic cylinder 28
And support arms 30, 30 pivotally supported at the front end of the fuselage. The support arms 30, 30 are pivotally supported at the front of the housing 5, and the swing arms 26, 26 are pivotally supported at the rear of the housing 25. As shown in FIG. The mower M can be moved up and down in parallel by the operation.

As shown in FIGS. 1 and 3, the front wheel drive shaft 15 and the PTO transmission shaft 24 are separately arranged so as to be located on the right and the PTO transmission shaft 24 on the left with respect to the fuselage center C. The transmission shaft 8 includes the front wheel drive shaft 15 and the PTO transmission shaft 2.
4 and above the upper surface of the body frame 9. The mid-PTO shaft 11 in the mission 6 is disposed to the left with respect to the fuselage center C, the front wheel drive shaft 15 is disposed to the right, and the main transmission shaft 8 passes just above the fuselage center C. That is, the main transmission shaft 8, the front wheel drive shaft 15, and the PTO transmission shaft 24 are arranged in parallel with each other in plan view.

The relay shaft 19 interlockingly connected to the front wheel drive shaft 15 has its front end (the end on the power input unit side) more to the right than the rear end (the end on the wheel drive shaft side) from the center C of the body. In order to move away from the side, the front end is inclined toward the lower right. That is, as shown in FIG. 3, the front end edge 25a of the housing 25 and the relay shaft 19 are substantially orthogonal to each other in a plan view, and compared to the position of the conventional relay shaft 19j indicated by a virtual line. The contact point s between the front edge 25 and the relay shaft 19 is closer to the rear than the conventional contact point sj.

Therefore, in side view, the contact point s according to the present invention is
Is higher than the conventional contact point sj, and the input gear box 22 and the front wheel drive shaft 22 are separated to the left and right, and the main transmission shaft 8 is the input gear in plan view. Although it interferes with the box 22, the elevation height of the mower M is made higher than before without changing the set height positions of the main drive shaft 8 and the front wheel drive shaft 15 because the arrangement height is sufficiently high. Have been successful.

[Another Embodiment] The engine 3 is mounted on the rear of the fuselage.
The mission 6 is mounted on the front of the fuselage.
The present invention is also applicable to a working machine having a structure in which a rear wheel drive shaft (an example of a wheel drive shaft) and a mid-PTO shaft are protruded rearward from the rear.

[Brief description of the drawings]

FIG. 1 is a side view of a lawn tractor.

FIG. 2 is a side view of a state in which a mower is raised.

FIG. 3 is a plan view showing an arrangement relationship of transmission shafts and a mower.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine side wheel 3 Engine 6 Mission 8 Main transmission shaft 11 Mid PTO shaft 15 Wheel drive shaft 16 Power input portion for engine side wheel 19 Relay shaft 22 Power input portion of work equipment 24 PTO transmission shaft C Left and right center of body M Mower

Claims (3)

[Claims] A main transmission shaft for interlocking an engine disposed at one of front and rear ends of a body with a transmission disposed at the other end, and driving an engine-side wheel on the engine disposed side. A wheel drive shaft, and a PTO transmission shaft interlockingly connecting a power input unit of a working device disposed on a lower abdomen of the fuselage and a mid PTO shaft of the transmission, extending from the transmission toward the engine arrangement side; A transmission shaft arrangement structure of a working machine in which a wheel drive shaft and the PTO transmission shaft are disposed so as to be divided left and right with respect to the center of the machine body in the horizontal direction. 2. The transmission shaft arrangement structure for a working machine according to claim 1, wherein the main transmission shaft is located above the wheel drive shaft and the PTO transmission shaft. 3. A relay shaft for interlockingly connecting a power input portion for the engine-side wheel and a front end of the wheel drive shaft is provided, and the power input portion side end of the relay shaft is connected to the wheel on the relay shaft. The transmission shaft arrangement structure for a working machine according to claim 1, wherein the relay shaft is arranged to be inclined so as to be further laterally away from the center of the machine body than an end portion on the drive shaft side.