JPS6321808Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement in the transmission structure of a working vehicle, in which the lubricating oil contained in the transmission case is used commonly as the hydraulic oil of the hydraulic mechanism.

Work vehicles such as agricultural vehicles such as tractors and combines, and various types of civil engineering and construction machinery are generally configured so that the lubricating oil in the transmission is shared with the hydraulic fluid of the hydraulic mechanism. However, in the conventional system, the suction part of the hydraulic mechanism was simply installed inside the transmission case, so problems caused by the operation of the gear group inside the transmission case, etc. If foreign objects such as iron powder are sucked in from the suction part and cause problems with the hydraulic mechanism, or if the hydraulic mechanism instantly sucks in a large amount of lubricating oil, the lubricating oil level in the transmission case may drop extremely low. As a result, problems have arisen in which the upper gear group within the case is no longer sufficiently lubricated.

Therefore, the present invention was implemented with the aim of providing a transmission structure that eliminates the above-mentioned drawbacks that occurred with conventional ones. To provide a transmission structure that can stably perform the operation and also ensure good lubrication in the transmission case at all times.

Hereinafter, the structure of the embodiment shown in the drawings will be explained in detail.

The drawing shows a case in which the work vehicle is an agricultural tractor, and shows the entire side view with some parts broken.

In the illustrated tractor, an output shaft of an engine 2 mounted on a vehicle body 1 is interlocked and connected to an input shaft 5 in a transmission case 4 via a main clutch 3, and is connected to an input shaft 5 in a transmission case 4 from a transmission gear group 6 to a final transmission part 7 to an axle case. The power is transmitted to the drive wheels 9, 9 supported by the wheels 8, 8, so that they can be forcibly driven.
10 are installed, and these steering wheels can be steered by a steering wheel 12 on a driving section 11 on the vehicle body.Furthermore, a work equipment connecting hitch 13 is disposed at the rear of the vehicle body. , the connecting hitch can be moved up and down as desired by a hydraulic mechanism 14.

In addition, 15 is a pump of a hydraulic mechanism, and 16 is a seat.

The overall arrangement as described above is almost the same as that of conventional tractors, but the present invention has transmission case 4.
It is characterized in that the transmission section housed therein has a structure as described below.

That is, the transmission case 4 is partitioned by a partition wall 17 between a portion A that accommodates the transmission gear group 6 and a portion B that accommodates the final transmission section 7, and the upper portion of the partition wall 17 has both the housing portions A, A communication path 18 is established to connect B, and a filter 19 is installed in the communication path.
Attached.

In the front part of the transmission gear group housing part A, an input transmission part 20 is provided for transmitting power downward from the input shaft 5 in multiple stages, and the lower end shaft of the input transmission part 20 is extended rearward. Then, a transmission gear group 6 is installed between that shaft and a required number of other shafts.

The output section of the transmission gear group 6 is interlocked and connected to a final transmission section 7 installed in another accommodation section B, and is supported at the lowest end within the accommodation section A and projects forward from the transmission case 4. The front PTO shaft 21 provided therein is also provided so as to be able to transmit variable speed transmission.

Although not shown in the figure, a propeller shaft can be connected to the front PTO shaft 21 if necessary, and when a four-wheel drive type that also forcibly drives the steering wheels 10, 10 side is used, The propeller shaft is connected to the steering wheel transmission mechanism installed on the front axle with a small degree of refraction, allowing the four wheels to rotate in synchronization.

In addition, a pump 1 of the hydraulic mechanism 14 is located at the lower part of the final transmission portion housing portion B near the partition wall 17.
A suction strainer 22 connected to the transmission gear 5 is installed, and the hydraulic oil return port 23 of the hydraulic mechanism 14 is opened and installed in the case wall above the input transmission section 20 in the transmission gear group housing section A.

Therefore, in a tractor having a transmission section configured as described above, the input transmission section 20,
The power that is arbitrarily set to be changed via the transmission gear group 6 is transmitted from the final transmission section 7 to the drive wheels 9, 9, and rotates those wheels to move the vehicle forward. When doing so, the power is transmitted to the driving wheels and also to the steering wheels 10, 10, so that the vehicle moves in a four-wheel forced drive state.

The hydraulic mechanism 14 installed on the tractor includes a pump 15
By sucking the lubricating oil in the mission case 4 from the suction strainer 22 through the operation of However, in the present invention, the suction strainer 22 is installed in the final transmission part accommodating part B where the number of gears is extremely small, and the accommodating part B is separated from the transmission gear group accommodating part A by a partition wall 17. At least in the transmission gear group accommodating part A, communication is made only in the communication passage 18 at the top of the bulkhead located above the lowermost front PTO shaft 21 in the transmission gear group accommodating part A. This prevents foreign matter such as generated iron powder from reaching the suction part of the strainer and destabilizing the suction of the hydraulic oil. Even if you are
Since the transmission gear group accommodating part A is only connected to the upper communication passage 18, there is no possibility of the lubricating oil level in the transmission gear group accommodating part becoming extremely low, thereby preventing lubrication failure. be.

Moreover, the hydraulic oil return port 23 of the hydraulic mechanism 14
is opened at the upper part of the transmission gear group housing part A, and the pressure oil from the return port 23 can be splashed onto the upper gear group in the housing part A, so that all the housing gear groups are lubricated with lubricating oil. Sufficient lubrication can be achieved even when the transmission is not in a corrosive state, so even if the transmission has large vertical dimensions, efficient lubrication can be achieved with a small amount of lubricant. It is possible to have a compact structure with a shortened direction, and the overall structure of the vehicle body can be made advantageous.

In addition, the suction strainer 22 is installed in the final transmission part accommodating part B, which has few operating parts, and forms a partition between it and the transmission gear group accommodating part A, which has many operating parts, so that the return pressure oil from the hydraulic mechanism is used for transmission. Since the oil is returned to the gear group accommodating section, the oil supplied to the hydraulic mechanism is less contaminated with iron powder, and damage to the hydraulic equipment can be prevented.

[Brief explanation of the drawing]

The drawing shows one embodiment of the present invention, and is a partially cutaway side view of a tractor. 4...Mission case, 6...Transmission gear group,
7... Final transmission part, 17... Bulkhead, 18...
...Communication path, 19...Filtering device, 22...Suction strainer, 23...Return port, A, B...Accommodating portion.

Claims (1)

[Scope of utility model registration request] The transmission case 4 is formed by partitioning a part A that accommodates the first gear group 6 and a part B that accommodates the final transmission part 7 with a partition wall 17. A suction strainer 22 of a hydraulic mechanism is disposed at the lower part of the final transmission part housing portion B near the partition wall, and the hydraulic mechanism return port 23
is configured such that it is opened at the upper part of the transmission gear group housing part A, and the communication passage 18 is provided only in the partition wall 17 located above the shaft 21 located at least in the lowermost position in the transmission gear group housing part A. A transmission structure for a work vehicle characterized by being open.