JPH0249063Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a power transmission structure for a mower tractor that is used to mow lawns by attaching a mower device to a small tractor by front mounting or mid-mounting it.

(b) Prior Art Many applications have been filed in the past regarding mower tractors in which mid-mount type and front-mount type mower devices are attached to the tractor.

However, when installing such a mower device on a tractor, there was a problem in how to consider the power transmission of the PTO system, and it was difficult to downsize the tractor.

(c) Problems to be solved by the invention The purpose of the invention is to use the pump shaft 16 of the HST type transmission H as a PTO shaft, and to configure a relay part by this part to connect the engine to the mower equipment. This is a simple configuration of power transmission.

(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.

One side of the lower part of the differential gear case 1 protrudes horizontally, and an HST type transmission H having a motor shaft and a pump shaft vertically arranged on the upper surface thereof is mounted, and the horizontal support gear arranged on the lower surface of the differential gear case 1 allows the above-mentioned The power of the motor shaft is transmitted to a vertically arranged pinion shaft 24, and the power is transmitted by the pinion shaft 24 to the differential ring gear 18 in the differential gear case 1, and the pump shaft 16 is installed as an extension of the differential gear case 1. The PTO shaft is supported by penetrating the portion 1a and transmits power from the engine 2 to the mower 20.

(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.

Fig. 1 is an overall side view of the mower tractor of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a side sectional view of the transmission device M and the HST type transmission H, and Fig. 4 is a side view of the mower tractor of the present invention.
The figure is a side sectional view of the counter shaft 32 portion in the mission device M, FIG. 5 is a rear view of the mission device M portion, FIG. 6 is a side view, FIG. 7 is a front view, and FIG. 8 is a plan view 9 are perspective views of the differential gear case 1 of the present invention.

First, the overall structure of the present invention will be explained with reference to FIGS. 1 and 2.

A steering handle 10, a seat 14, and an engine 2 are arranged from the front on a body frame 23. The engine 2 uses an engine 2 with a vertical crankshaft 13. An output pulley 11 is fixed to the crankshaft 13 of the engine 2, and a pump of the HST type transmission H is connected from the output pulley 11 by a V belt 9. Power is transmitted to the input pulley 4 on the shaft 16. Further, the lower end of the pump shaft 16 protrudes downward from the differential gear case 1 to serve as a PTO shaft, and a PTO pulley 15 is fixed thereto. Applicable
From the PTO pulley 15 via the V belt 26,
Power is transmitted to the pulley of the mower device 20. 21 and 22 are V-belt tension clutches. Further, the mower device 20 in the embodiment is a front mount type and is mounted on the body frame 23.

In the present invention, the mower device 2 is more powerful than the engine 2.
Power is transmitted to V from PTO pulley 15.
The belt 26 passes under the axle housing 25R.

Power is transmitted to the hydraulic pump by the pump shaft 16 of the HST type transmission H, and the oil discharged from the hydraulic pump drives the hydraulic motor to rotate the motor shaft 8. The rotation of the motor shaft 8 is transmitted to the differential device 29 in the transmission device M.

Next, the configurations of the transmission device M and the HST type transmission H of the present invention will be explained based on FIGS. 3 and 4.

The transmission device M includes a differential gear case 1 and a lid 12 that closes a lower opening of the differential gear case 1. The differential gear case 1 has a cylindrical bulge at a portion into which the front axles 30L and 30R are inserted, and a differential device 29 is disposed inside the cylindrical portion. The pinion 24a of the pinion shaft 24, which is vertically supported, meshes with the ring gear 18 of the differential gear, thereby inputting the power of the HST type transmission H to the differential gear.

The differential gear case 1 has a flat surface on the other side of the bulge housing the differential device, and
Equipped with HST type transmission H.

The HST type transmission H includes a hydraulic pump P and a hydraulic motor M on the left and right sides, and a motor shaft 8 projects downward from the flat surface of the differential gear case 1. A fixed gear 33 and a brake disc 36 are arranged at the lower part of the motor shaft 8, and the brake disc 36 is configured to push out the cam ball 35 and apply the brake by rotation of the cam disc 37.

The fixed gear 33 meshes with the upper gear 30 side of the double gears 30 and 31 of the counter shaft 32 vertically supported on the bottom of the lid, and the lower gear 31 meshes with the large diameter gear 17 of the pinion shaft 24. It meshes with. The ring gear 18 is rotated by the motor shaft 8 through this gear train. 28 is a bearing body for the pinion shaft 24.

In this overall configuration, the main parts of the present invention are:
The differential gear case 1 is extended to one side to constitute a mounting part for the HST type transmission H, and further extends from the mounting part to form an extension part 1a, and a PTO shaft extending from the pump shaft of the hydraulic pump. was supported.

The pump shaft 16 of the hydraulic pump device P protrudes through the differential gear case 1, and has a front end at the lower end.
Since it also serves as the PTO shaft to which the PTO pulley 15 is fixedly installed, the pump shaft 1 is
6 is subjected to a bending force via the V-belt, and this bending force tends to affect the operation of the hydraulic pump. Furthermore, if bending force is applied, the pump shaft will break. As in the present invention, differential gear case 1
This inconvenience can be prevented by supporting the pump shaft 16 of the hydraulic pump device on the extended portion 1a.

5, 6, 7, 8, and 9 disclose the relationship among the differential gear case 1, the hydraulic pump device P, and the motor shaft 8. Especially the 9th
The figure clearly shows the shape of the differential gear case 1 of the present invention.

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

First, the differential gear case 1 is protruded horizontally,
The HST type transmission device H is mounted on the top surface of the differential gear case 1.
The horizontal support gear disposed on the bottom surface of the differential gear case 1 transmits power to the vertically disposed pinion shaft 24, and the pinion shaft 24 transmits power to the differential ring gear 18 inside the differential gear case 1. Now that we have configured the differential gear case 1
Since it can also be used as a support for the HST transmission, there is no need to provide a separate support for the HST transmission, which requires reliable strength.

Second, the HST type transmission H has a configuration in which the motor shaft 8 and the pump shaft 16 are installed vertically, and the pump shaft 16 is extended by passing through the extension part 1a of the differential gear case 1, and the mower device Since the transmission shaft for transmitting power to the mower device 20 can be constituted by the pump shaft 16, the bending force applied to the pump shaft 16 is received by the extending portion 1a of the differential gear case 1. This prevents bending force from occurring on the pump shaft of the HST type transmission, which would interfere with the operation of the hydraulic pump or damage the pump shaft.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of the mower tractor of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a side sectional view of the transmission device M and the HST type transmission H, and Fig. 4 is a side view of the mower tractor of the present invention.
The figure is a side sectional view of the counter shaft 32 portion in the mission device M, FIG. 5 is a rear view of the mission device M portion, FIG. 6 is a side view, FIG. 7 is a front view, and FIG. 8 is a plan view 9 are perspective views of the differential gear case 1 of the present invention. H...HST type transmission, M...Mission device, 1...Differential gear case, 1a...Extension part, 2
... Engine, 4 ... Input pulley, 12 ... Lid, 15 ... Front PTO pulley, 16 ...
Pump shaft, 18... differential ring gear, 24... pinion shaft.

Claims (1)

[Scope of utility model registration request] One side of the lower part of the differential gear case 1 protrudes horizontally, and an HST type transmission H having a motor shaft and a pump shaft vertically arranged on the upper surface thereof is mounted, and the horizontal support gear arranged on the lower surface of the differential gear case 1 allows the above-mentioned The power of the motor shaft is transmitted to a vertically arranged pinion shaft 24, and the power is transmitted by the pinion shaft 24 to the differential ring gear 18 in the differential gear case 1, and the pump shaft 16 is installed as an extension of the differential gear case 1. A mower tractor characterized by having a PTO shaft that is supported through a portion 1a and transmits power from an engine 2 to a mower 20.