JPH0519224Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is a mid-mount type in which a mower is disposed between the front and rear wheels, and a transmission case that pivotally supports the rear wheels is disposed behind the mower. Regarding lawn tractors.

[Conventional technology]

In this type of mid-mount type lawn tractor, the hydraulic continuously variable transmission was installed on the upper transmission side of the transmission case. Conventionally, it was installed on the front side of the transmission case (for example,
Publication No. 195025).

[Problem that the invention attempts to solve]

However, in this case, the hydraulic continuously variable transmission protrudes into the working space of the mower, so it is located above the working space of the mower. Therefore, this hydraulic continuously variable transmission device affected the deck of the driving section, making the shape of the deck poor in terms of livability, with the middle part in the width direction being high.

The purpose of this invention is to reduce the influence on the drive unit deck by changing the mounting position of the hydraulic continuously variable transmission to the transmission case, and to reduce the heat generation phenomenon of this hydraulic continuously variable transmission. It is designed to eliminate the inconvenience caused.

[Means for solving problems]

The characteristic structure of the present invention is that the lower surface of the hydraulic continuously variable transmission, in which the input rotating body receiving power from the engine is mounted on the lower surface, is placed on the upper front surface of the transmission case to enable transmission connection. A downward blowing cooling fan is attached to a rotary shaft protruding from the top surface of the continuously variable transmission, and its functions and effects are as follows.

[Effect]

In other words, since the hydraulic continuously variable transmission is mounted on the upper surface of the transmission case, it is located at the rear of the mower operating space, rather than above the mower operating space as in the conventional case, so that the drive unit deck and hydraulic There is no interference with the continuously variable transmission, and the drive deck can be made horizontally flat. Moreover,
Since the input rotating body of this hydraulic continuously variable transmission is attached to the lower surface side, the engine and the transmission mechanism for this rotating body can be installed at a low position. For example, when the engine is installed at the front of the aircraft, the transmission mechanism is located below the driving section deck, but since the transmission mechanism is located at a low position, the driving section deck does not need to be located at a high position.

In addition, a cooling fan with downward blowing is provided on the top surface of the hydraulic continuously variable transmission that does not interfere with the drive deck, so it is possible to apply a cooling effect to the hydraulic continuously variable transmission. It can blow away grass clippings that fall on the transmission and transmission case.

[Effect of idea]

Depending on the function, the deck shape can be made flat, resulting in good livability and driving operability. Also, due to the function, the driving deck can be installed at a lower position, making it easier to get on and off the vehicle. Furthermore, according to the above, it is possible to prevent abnormal heating of the hydraulic continuously variable transmission and the transmission case, thereby preventing early deterioration and seizure of the oil. It is possible to prevent grass clippings, etc. attached to the lawn case from burning up or "smoldering", thereby eliminating the cause of a fire.

〔Example〕

As shown in FIG. 4, a belt 2 is stretched from the front engine 1 to the lower side of the left and right flat deck 33, and a hydraulic type that can be switched forward and backward is attached to the front upper surface of the transmission case 3 that supports the rear axle 19. The continuously variable transmission 4 of the continuously variable transmission 4 is interlocked and connected, and the power from the engine 1 is transferred to the continuously variable transmission 4 by a pulley serving as an input rotating body 6 fixed to the downward first input shaft 5 of the continuously variable transmission 4. A mid-mount type lawn tractor is constructed in such a manner that the speed is changed and input to the transmission case 3, and a mower 9 is disposed between the front wheels 7 and the rear wheels 8.

The structure of the mission case 3 will be explained in detail.

As shown in FIGS. 2 and 3, an input opening 3A that opens upward is formed on the upper surface of the front part of the mission case 3, and two large and small bearings 10, 10 are fitted in the upper and lower parts of this opening 3A. A vertical second input shaft 11 is supported through the shaft, and an output bevel gear 12 is integrally formed at the lower end of the second input shaft 11. A horizontal first transmission shaft 13 extending along the width direction of the aircraft body is supported below the second input shaft 11, and the output bevel gear 12 and the input bevel gear 14 of a constant engagement type are spline-fitted to the first transmission shaft 13. At the same time, the first output gear 15 is fitted with a spline. A second transmission shaft 16 is supported below and parallel to the first transmission shaft 13, and the first output gear 15 and a first input gear 17 of a constant engagement type are fixed to the second transmission shaft 16, and , and a first output sprocket 18 are integrally formed. A rear axle 19 is pivotally supported rearwardly and upwardly of the second transmission shaft 16, and the left and right rear axle portions 19A, 19B are relatively rotatable.
It is divided into . The left and right rear axle portions 19
Differential side gear 2 is installed at the butt fitting part of A and 19B.
A two-piece differential case 22 is provided with a differential pinion gear 21 and a differential pinion gear 21 directly supported on its inner surface. A first input sprocket 23 is fixed to the stepped portion of one differential case 22 via a differential case 22 assembly bolt 24, and is configured to be capable of chain transmission with the first output sprocket 18.

Next, the hydraulic oil tank section 4A, the pump section 4B,
The mounting structure of the continuously variable transmission 4, which has a transmission section 4C and can be switched between forward and reverse directions, to the transmission case 3 will be described in detail. As shown in FIGS. 1 and 3, a cylindrical boss supports a downward first input shaft 5 on the lower surface of the pump section 4B, and has an input rotating body 6 fixed to the first input shaft 5 with a pin 26. 27 is externally fitted and fixed with a key 28 and a locking bolt 32. Said transmission section 4C
A downward facing output shaft 29 is supported like the first input shaft 5 on the lower surface, and a spline type coupling 30
It is configured such that it can be freely disconnected from the second input shaft 11 on the transmission case 3 side via. The upper end opening 3
A is provided with a position regulating sleeve 25 whose one end 25a is fitted into the output boss 4a of the transmission section 4C and whose other end 25b is fitted into the inner peripheral surface 3a of the input opening 3A. The continuously variable transmission 4 is connected to the transmission case 3 by the bolt 31 via the sleeve 25.
It is fixed in place.

As shown in FIG. 1, a rotating shaft 34 is supported upward on the upper surface of the pump section 4B of the hydraulic continuously variable transmission 4, and a cooling fan 35 for blowing air downward is attached to the rotating shaft 34.

[Brief explanation of drawings]

The drawings show an embodiment of a mid-mounted lawn tractor according to the present invention, FIG. 1 is a side view showing how the hydraulic continuously variable transmission is attached to the transmission case, and FIG. 2 shows the structure of the transmission case. FIG. 3 is a longitudinal sectional view showing the attachment structure of the hydraulic continuously variable transmission and the transmission case, and FIG. 4 is an overall side view. 1... Engine, 3... Mission case, 4
... Hydraulic continuously variable transmission, 6 ... Input rotating body, 7
...Front wheel, 8...Rear wheel, 9...Mower, 34
... Rotating shaft, 35 ... Disposal fan.

Claims (1)

[Scope of utility model registration request] It is a mid-mount type lawn tractor in which a mower 9 is disposed between the front and rear wheels 7 and 8, and a transmission case 3 with a rear wheel 8 pivotally supported is disposed behind the mower 9. The lower surface of the hydraulic continuously variable transmission 4, on which the input rotary body 6 for receiving power is attached, is placed on the front upper surface of the transmission case 3 so that transmission can be connected. This is a mid-mount type lawn tractor in which a downward blowing cooling fan 35 is attached to a rotary shaft 34 protruding from the upper surface of the tractor.