JPH0137932Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a transmission device used to drive a small traveling vehicle.

(B) Prior art A technology for arranging a transmission, a power transmission device, and a differential gear device as a transmission device used in a small tractor is disclosed in Japanese Patent Application No. 104819/1983 (Japanese Patent Application Laid-open No. 61−261127
The technology was developed as described in the publication.

However, in this conventional technology, the pinion shaft of the differential gear device is also arranged vertically and parallel to the output shaft of the transmission device, which is arranged vertically, and a chain or It was necessary to drive it with a spur gear.

In such a configuration, the width of the pinion shaft bearing and sprocket becomes the thickness of the case.
Since this thickness extends to the sprocket portion fixed to the output shaft, the bottom of the horizontal mounting portion of the transmission is also thick.

In small tractors, the working machine is arranged below the transmission device so that it can be raised and lowered, so it is necessary to separate the two so that they do not interfere with the lower surface of the case of the horizontal mounting section when the working machine is raised and lowered.

As a result, when a working machine such as a mower is attached to the front of the machine, it needs to be supported at a large distance from the machine, making the lifting linkage large and unstable.

If it is a belly work machine, there must be enough space between the front and rear wheels to raise and lower it, so the only way to avoid interference is to make the distance between the front and rear wheels larger, which is an obstacle to downsizing the machine. be.

(c) Problems to be solved by the invention The purpose of the invention is to solve the problems of the prior art as in the earlier application. By intersecting the pinion shaft that transmits power to the device at an acute angle, a space into which the working machine can fit when raised below the horizontal mounting part is created.

The transmission device takes into account the lifting and lowering of the work equipment, so in the case of a front work equipment, the work equipment can be moved closer to the drive axle side of the machine, supporting the work equipment and stabilizing its running. In the case of an abdominal work machine, the work machine can be moved as close as possible to the transmission transmission transmission side, making it suitable for small work vehicles with a small distance between wheels.

(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. The input shaft 11 projects upward and the output shaft 8 projects downward. In a transmission device configured to transmit power from a transmission H having a transmission device H to a differential gear device D disposed in the same case through a power transmission section disposed in a case, a differential gear device D is disposed on one end side of the transmission device. A horizontal mounting part 1a is formed on the other end side of the case that accommodates the pinion shaft 7, and has an opening for inserting the output shaft 8 into the case, and on which the transmission H is placed. The output shaft 8 protrudes vertically into the case by locating the transmission H in the case.
A pinion shaft 7 is arranged to be inclined at an acute angle and reach a differential gear device D, and bevel gears 10 and 12 fixed to the end of the output shaft 8 and the pinion shaft 7 are meshed with each other.

In addition, the case housing the differential gear device D is divided into an upper case 1 and a lower case 2 along a plane substantially along the inclination direction of the pinion shaft 7, and the dividing line extends over the axle 3 that protrudes left and right from the differential gear device D. It is designed to pass through.

(e) Embodiments and operations The purpose and structure of the present invention are as described above. Next, the structure of the embodiment shown in the attached drawings and the operation of the invention will be explained. Figure 1 shows the structure of the present invention. 2 is a plan view of the transmission device of the present invention; FIG. 3 is a plan view of only the upper case; FIG. 4 is a plan view of only the lower case; The figure is a rear sectional view of the differential gear device portion, and FIG. 6 is a side sectional view of the hydraulic motor shaft and pinion shaft portion.

Referring to FIG. 1, the overall structure of a mower tractor as an example of a traveling vehicle will be explained. The mower tractor of this embodiment has a front wheel 18 and a rear wheel 1.
7, the front wheels 18 are configured as driving wheels, and the rear wheels 17 are configured as steering wheels. The mower device R is arranged in front of the front wheel 18 and is capable of vertical movement.

An engine E is mounted on the frame, and power is input from a V-pulley 21 fixed to the crankshaft of the engine E to an HST type transmission H.

The HST type transmission H is composed of a hydraulic pump 5 and a hydraulic motor 4, and power is transmitted from the V-pulley 21 of the engine E to the V-pulley 13 fixed to the input shaft 11 of the hydraulic pump 5. be.

A steering handle 20 is arranged in front of the seat 19 on the frame.

The power transmission structure of the mission device of the present invention will be explained with reference to FIGS. 5 and 6.

An HST type transmission H is shown as an example of a transmission used in the present invention, and the input shaft 11 of the hydraulic pump 5 is
The rotation of the engine E is transmitted to the hydraulic pump 5.
The hydraulic motor 4 performs forward/reverse rotation and continuously variable speed by the pressure oil discharged from the motor, and the output shaft 8 inputs the rotation after the speed change into the case.

In this embodiment, the output shaft 8 protrudes substantially vertically downward, and a bevel gear 10 is fixed to the lower end of the output shaft 8. On the other hand, the pinion shaft 7 of the differential gear device D is inclined forward and downward in side view, and the bevel gear 1 is located at a position where the tip of the pinion shaft 7 and the tip of the output shaft 8 intersect.
2 is permanently installed. The bevel gear 10
and 12 mesh to transmit the rotation of the hydraulic motor 4 to the differential gear device D.

22 and 23 are bearings for the pinion shaft 7 portion. A pinion 7a of the pinion shaft 7 meshes with the ring gear 6 of the differential gear device D.

As shown in FIG. 5, the ring gear 6 is fixed to a differential case 9, and by rotating the differential case 9, the differential pinion shaft 15 is revolved, and further rotating the differential pinion gears 14, 15, the differential This rotates the side gears 16L and 16R. Axles 3L, 3R are fixed to the differential side gears 16L, 16R, and rotation is transmitted to the axles.

The power transmission structure of the present invention is as described above, and the output shaft 8 of the hydraulic motor 4 and the pinion shaft 7 of the differential gear device D are crossed, and the bevel gears 10 and 1
By configuring the power transmission unit 2 to transmit power, the distance between the two can be narrowed. Additionally, conventionally a counter shaft and intermediate gear were interposed between the two shafts, but these have become unnecessary.

Further, in order to make it possible to manufacture the transmission device having the power transmission structure at low cost, the case is constructed into a split mold of an upper case 1 and a lower case 2. The upper case 1 and the lower case 2 formed into split molds can be manufactured by die-casting from aluminum die-casting, making precision casting possible, thereby eliminating the need for machining.

In addition, in this configuration, in order to be able to manufacture the upper case 1 and the lower case 2 by split molding, the parting line is configured to pass through the center of the axles 3L and 3R, which is the most problematic part, and the parts are divided into upper and lower parts from the axle part. It is configured to suit.

Therefore, upper case 1 and lower case 2 each have half bearings 20L, 20R and bearing metal 2.
The openings into which 1L and 21R fit are formed. The openings sandwich and fix the bearings 20L, 20R and the bearing metals 21L, 21R.

Further, between the upper case 1 and the lower case 2, the bearing openings of the bearings 22 and 23 of the pinion shaft 7 are opened as semicircles, and when both cases are tightened, the bearings 22 and 23 are also tightened. be.

The upper case 1 is constructed as shown in FIG. 3, and the joint surface with the lower case 2 is configured to be inclined, but there is a horizontal mounting part 1a for the HST type transmission H provided on the upper surface. is constructed on a substantially horizontal plane.

The lower case 2 is constructed as shown in FIG. 4, and has an open inclined joint surface so as to be in close contact with the joint surface of the upper case 1. Lower case 2
After disposing the differential gear device D inside, the upper case 1 with the HST type transmission H fixedly mounted on the horizontal mounting portion 1a is covered and fixed by tightening at the tightening flange portion.

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

First, since the transmission H and the differential gear D are interlocked and connected by the inclined pinion shaft 7, the two can be placed as close as possible in the front and back direction, making it possible to shorten the space between them. Therefore, the transmission H can be placed lower than the differential gear D in the vertical direction as well.

Therefore, the entire transmission device can be made compact, making it possible to respond to miniaturization of traveling vehicles.

Second, by arranging the pinion shaft 7 at an angle on the outer surface of the case housing the bevel gear 12 as shown in FIG. Work machine R,
The working machine R can be moved up and down without any interference while being placed as close as possible to the case.

Thirdly, according to claim 2 of the utility model registration, the case is divided into an upper case 1 and a lower case 2 along a plane along the inclination direction of the pinion shaft 7, and the dividing line passes over the axle 3. Since the upper and lower cases are constructed to have the desired shape, both the upper and lower cases can be constructed as split molds.For example, by precision casting, such as aluminum die-casting, the case does not require machining and can be easily assembled. It is something that

[Brief explanation of drawings]

Fig. 1 is an overall side view of a mower tractor equipped with the transmission device of the present invention, Fig. 2 is a plan view of the transmission device of the invention, Fig. 3 is a plan view of only the upper case, and Fig. 4 is the lower case. FIG. 5 is a rear sectional view of the differential gear device portion, and FIG. 6 is a side sectional view of the hydraulic motor shaft and pinion shaft portion. D...Differential gear device, H...Transmission device, R...
Mower device, 1... Upper case, 1a... Horizontal mounting part, 2... Lower case, 3L, 3R... Axle, 4
... Hydraulic motor, 5 ... Hydraulic pump, 6 ... Ring gear, 7 ... Pinion shaft, 8 ... Output shaft, 9
... Differential case, 10, 12 ... Bevel gear.

Claims (1)

[Claims for Utility Model Registration] (1) The power of a transmission H having an input shaft 11 projecting upward and an output shaft 8 projecting downward,
In a transmission device configured to transmit power to a differential gear device D arranged in the same case through a power transmission section arranged in the case, the other end of the case accommodates the differential gear device D and the pinion shaft 7 on one internal end side. On the side, a horizontal mounting part 1a is formed, which has an opening for inserting the output shaft 8 into the case, and on which the transmission H is placed.By placing the transmission H on the horizontal mounting part 1a, the inside of the case is A pinion shaft 7 that is inclined at an acute angle and reaches a differential gear device D is disposed with respect to an output shaft 8 that projects perpendicularly to the output shaft 8.
A transmission device for a traveling vehicle, characterized in that bevel gears 10 and 12 fixed to the ends of an output shaft 8 and a pinion shaft 7 are engaged with each other. (2) Place the case that accommodates the differential gear device D on the upper case 1 with a surface substantially along the inclination direction of the pinion shaft 7.
A transmission device for a traveling vehicle according to claim 1, which is divided into a lower case 2 and a lower case 2, and the dividing line passes over an axle 3 projecting left and right from a differential gear device D.