JPH0313373Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field The present invention is a small tractor, mainly a drive device for a mower tractor that is front-mounted and has a mower device for mowing lawns attached to the front of the machine body. This is related to the configuration of the .

(b) Prior Art Conventionally, in a tractor equipped with a mower device, a technology for transmitting power from a vertical type engine to a transmission case or a mower device is known.

For example, JP-A-60-1028, JP-A-59-
232012 publication, US Patent No. 3354981 publication,
This is similar to the technology described in US Pat. No. 3,008,282.

In another conventional technology, as shown in Figures 2a and 2b, an HST type transmission in which a hydraulic motor and a hydraulic pump are arranged in series on the same axis is mounted on a transmission case. Therefore, only the motor shaft could protrude below the transmission case, and the counter pulley shaft 38'
Separately, attach the bracket 5 inward to the fuselage frame 17.
0 is provided and supported, and the counter pulley shaft 3
A counter pulley 5' was fixedly installed at 8'.

(c) Problems to be solved by the invention The purpose of the invention is to arrange the counter pulley shaft, which interposes the counter pulley, at the lower end of the pump shaft, thereby making the power transmission path from the engine to the mower device compact. It is composed of

(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.

A differential device 29 is installed inside, and front axles 45L on the left and right,
HST with hydraulic motor M and hydraulic pump P placed side by side on the left and right side of transmission case M with 45R protruding.
A type transmission H is mounted, the motor shaft 8 of the hydraulic motor M is inserted into the transmission case M, and the lower end position of the pump shaft 16 of the hydraulic pump P is shifted from the transmission case M, A counter pulley shaft 38 is supported and protruded from the lower end of the pump shaft 16, and power is transmitted to the travel input pulley 4 at the upper end of the pump shaft 16 from the travel output pulley 3 of the vertical crankshaft 26 of the engine E. Counter pulley 5 on 38
a, 5b, and supports the counter pulley 5a and the PTO output pulley 39 of the crankshaft 26.
A belt is wound between the input pulley 6 of the mower device R and the input pulley 6 of the mower device R from the other counter pulley 5b to transmit power.

(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 a mower tractor equipped with the front mower of the present invention, Fig. 2a is a plan view showing the arrangement of the conventional counter pulley shaft 38' and counter pulley 5', and Fig. 2b is the same conventional one. FIG. 3 is a side sectional view of the mower tractor drive device of the present invention, FIG. 4 is a sectional view of the counter shaft portion of FIG. 3, and FIG. 6 is a front sectional view of the differential gear device portion of the transmission case M, FIG. 6 is a plan view of the same, and FIG. 7 is an external view of the HST type transmission.

First, the overall configuration will be explained with reference to FIG.

A steering device 20, a seat 9, and a vertical crankshaft 26 are mounted on the fuselage frames 17L and 17R.
An engine E equipped with the following is installed.

The engine E of the present invention is designed for the fuselage frames 17L and 17 due to the balance with the front mower device R.
It is located at the rear of R. And rear wheels 11, 11
are configured as running wheels, and the front wheels 10, 10 are configured as driving wheels.

A crankshaft 26 of the engine E projects vertically downward, and a traveling output pulley 3 and a PTO output pulley 39 are fixed to the crankshaft 26. From the travel output pulley 3
Rotation is input to the running input pulley 4 of the pump shaft 16 of the HST type transmission H.

The HST type transmission H projects perpendicularly from a transmission case M that is arranged to project rearward, and inside thereof, a hydraulic motor M and a hydraulic pump P, both of which have vertical shaft structures, are arranged in parallel. . Pressure oil is then discharged by the hydraulic pump P to drive the motor shaft 8.

The motor shaft 8 is inserted into a transmission case M, and drives a differential gear device from the motor shaft 8 inside the transmission case M via a gear train.

On the other hand, in the drive system of the mower device R, a V-belt is wound around the counter pulley 5a of the counter pulley shaft 38 from the PTO output pulley 39 of the crankshaft 26.

Next, a V-belt is wound around the input pulley 6 of the mower device R from the counter pulley 5b on the same counter pulley shaft 38 to transmit power.

The mower device R is supported by lifting links 7L, 7R, and the bases of the lifting links 7L, 7R are pivotally supported by body frames 17L, 17R.

The counter pulley shaft 38 is arranged at the bottom of the pump shaft 16 of the HST type transmission, and the counter pulleys 5a and 5b are arranged at this position. 13 and 14 are belt tension clutches.

Next, according to Figures 3, 4, 5, and 6,
Let me explain the structure of the transmission case M and the HST type transmission H.

The HST type transmission H is arranged parallel to the front axles 45L, 45R of the front wheels 10, 10. And the transmission case M has front axles 45L, 45R and
It is arranged in the longitudinal direction at right angles to the HST type transmission H. The pump shaft 16 of the HST type transmission H is disposed apart from the transmission case M, and conversely, the motor shaft 8 has its lower end protruding into the transmission case M.

As shown in FIGS. 3 and 4, the motor shaft 8
A fixed gear 33 and a brake disc 36 are located at the lower end of the
is fixedly installed, and when a brake cam plate 37 rotates around the brake disc 36, the cam ball 35 is pushed out and pressed, thereby applying braking. One of the double gears 30 and 31 of the counter shaft 32 is always meshed with the fixed gear 33.

Further, the other gear 31 of the double gear is meshed with the large diameter gear 1 of the bevel gear shaft 24. The large diameter gear 1
The power is transmitted to the bevel gear shaft 24, and the pinion gear of the bevel gear shaft 24 meshes with the ring gear 18 of the differential device 29, thereby inputting the power to the differential device 29.

The mission case M is made of die-cast aluminum, etc.
The lower surface of the casing is hermetically sealed by an oil pan 12, and the HST type transmission H is placed on the upper surface along with the case.

In FIG. 6, 40 is a brake arm that rotates the brake cam plate 37 to perform braking.

In Figure 5, large diameter gear 1 and bevel gear shaft 2
When the ring gear 18 is rotated via the bevel gear 24a and the bevel gear 24a, the differential case 19 is rotated. A differential pinion 25 is supported by the differential case 19 via a differential pinion pin 23, and the differential pinion 25 meshes with the differential side gears 22, 22. With this configuration, the left and right front axles 45L,
When different running resistances are applied to the 45R, differential rotation occurs. 28 is a bearing plate of the bevel gear shaft 24.

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

First, the power transmission system for driving the vehicle from the engine and the power transmission system for driving the mower are configured to overlap in the vertical direction of the aircraft between the crankshaft 26, the pump shaft 16, and the counter pulley shaft 38. Because it was placed closer to the transmission case, the space between the left and right fuselage frames could be narrowed, which made it possible to downsize the tractor.

Second, the counter pulley shaft 38 is smaller than the conventional one.
It can be shortened by the height of the HST type transmission H, thereby making the counter pulley shaft 38
This made it possible to increase the strength of the

Thirdly, since the counter pulley shaft 38 is made to protrude to the side of the mission case M,
Since the counter pulleys 5a and 5b are provided on the side portions of the mission case M, the lower end of the counter pulley 5 can be placed at approximately the same position as the bottom of the mission case M. .

As a result, the lower end of the counter pulley 5 does not protrude below the transmission case M, and the lowest ground clearance of the tractor is no longer lowered.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of a mower tractor equipped with the front mower of the present invention, Fig. 2a is a plan view showing the arrangement of the conventional counter pulley shaft 38' and counter pulley 5', and Fig. 2b is the same conventional one. FIG. 3 is a side sectional view of the mower tractor drive device of the present invention, FIG. 4 is a sectional view of the counter shaft portion of FIG. 3, and FIG. 6 is a front sectional view of the differential gear device portion of the transmission case M, FIG. 6 is a plan view of the same, and FIG. 7 is an external view of the HST type transmission. M...Mission case, H...HST type transmission, E...Engine, R...Mower device, 5a,
5b...Counter pulley, 8...Motor shaft, 16...Pump shaft.

Claims (1)

[Scope of utility model registration request] A differential device 29 is installed inside, and front axles 45L on the left and right,
HST with hydraulic motor M and hydraulic pump P placed side by side on the left and right side of transmission case M with 45R protruding.
A type transmission H is mounted, the motor shaft 8 of the hydraulic motor M is inserted into the transmission case M, and the lower end position of the pump shaft 16 of the hydraulic pump P is shifted from the transmission case M, A counter pulley shaft 38 is supported and protruded from the lower end of the pump shaft 16, and power is transmitted to the travel input pulley 4 at the upper end of the pump shaft 16 from the travel output pulley 3 of the vertical crankshaft 26 of the engine E. Counter pulley 5 on 38
a, 5b, and supports the counter pulley 5a and the PTO output pulley 39 of the crankshaft 26.
A drive device for a mower tractor, characterized in that a belt is wound between the input pulley 6 of the mower device R and the belt is wound around the input pulley 6 of the mower device R from another counter pulley 5b to transmit power.