JPH0447474Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention incorporates a continuously variable transmission consisting of a hydraulic pump and a hydraulic motor into a gear transmission case, and also uses lubricating oil contained in the transmission case. The present invention relates to a transmission device for an agricultural tractor, which is provided with a charge pump that supplies hydraulic fluid to the continuously variable transmission device.

[Conventional technology]

In the above agricultural tractor, the charge pump has conventionally been placed outside the gear transmission case.

[Problem that the invention attempts to solve]

Therefore, as the charge pump protrudes from the outer surface of the gear transmission case, the entire transmission has a complex outer shape and is large. It was accompanied by the inconvenience of making it necessary. In addition, the oil passage connecting the gear transmission storage space of the gear transmission case and the charge pump or the oil passage connecting the continuously variable transmission and the charge pump has become long, which is disadvantageous in terms of oil passage formation. .

The purpose of the present invention is to modify the system to be simple and compact, to shorten the charge oil path, and to be relatively easy to manufacture.

[Means to solve the problem]

In order to achieve the purpose of the agricultural tractor transmission device according to the present invention, in the above-mentioned structure, a partition wall portion between the continuously variable transmission storage space and the gear transmission storage space in the transmission case; A continuously variable transmission case portion of the transmission case forming the continuously variable transmission storage space is removably attached to a gear case portion of the transmission case forming the gear transmission storage space, and the partition wall The charge pump is inserted into an assembly hole provided in the section, and each of the oil passage connecting the charge pump and the gear transmission storage space and the oil passage connecting the charge pump and the continuously variable transmission are connected to the It is bored in the partition wall. The functions and effects thereof are as follows.

[Effect]

By installing the charge pump inside the partition wall and drilling the oil passage in the partition wall, the charge pump and oil passage are not exposed from the gear transmission case, and the continuously variable transmission and gear transmission can be stored. There is no need to expand the storage space in order to prevent the charge pump and oil passages from coming into contact with the transmission and transmission components, as is the case when the storage space is installed inside the space.

By arranging the interior part of the charge pump as the partition wall, the partition wall is adjacent to either the transmission storage space or the gear transmission storage space. By taking it out from the gear transmission storage space and supplying it,
The charge pump can be connected to each of the transmission and gear transmission storage space through a relatively short oil path.

When assembling the charge pump into the partition wall and drilling an oil passage in the partition wall, the partition wall is formed as a separate part from the continuously variable transmission case part, and only the partition wall is handled, and the size of the parts to be handled is determined. While making it easier to handle the parts to be machined from the other side, it is also possible to form the partition wall part as an integral part with the continuously variable transmission case part, compared to forming it as an integral part with the gear case part. It is possible to easily form the pump assembly hole and oil passage and assemble the pump while easily handling the continuously variable transmission case part and the partition wall as parts to be machined. This is possible due to the above-mentioned mounting structure of the partition wall.

[Effect of idea]

Therefore, the entire transmission can be made simple and compact, it can be easily installed in a relatively narrow space, and the charge oil path can be shortened, making it easy to manufacture. It has also become easier to manufacture transmission devices because it is relatively easy to handle the workpieces when forming the pump assembly holes and oil passages and when assembling the charge pump.

〔Example〕

As shown in FIG. 6, a transmission case 3 forming the rear part of a traveling aircraft having a pair of left and right steering type front wheels 1, 1 and non-steering type rear wheels 2, 2 capable of driving each other, A riding-type agricultural tractor is constructed by attaching a soft arm 4 that connects various working devices such as a rotary tiller so that they can be raised and lowered, and a power take-off shaft 5 that transmits power to the connected working devices.

The transmission arrangement for the front and rear wheels 1, 2 and the power take-off shaft 5 is constructed as shown in FIG.

That is, the output of the engine 6 is transmitted to the inside of the transmission case 3 via the clutch 7, the transmission shaft 8, and the input shaft 9, and this input is transmitted to the hydraulic pump 10 and the hydraulic pressure installed in the front part of the transmission case 3. The output of the transmission 12 is transmitted to the continuously variable transmission 12 which is composed of a motor 11 and can be switched between forward and reverse sides with a neutral position in between. The output of the auxiliary transmission transmission is transmitted to a traveling gear type auxiliary transmission transmission mechanism (not shown) installed inside, and the output of this auxiliary transmission transmission is transmitted to a rear wheel differential mechanism (not shown) installed inside the rear part of the transmission case 3, and the transmission case 3. It is branched and transmitted to a front wheel power transmission shaft 14 provided at the bottom of 3. The rotational force of the input shaft 9 is transmitted via a coupling 15 to a power take-off gear transmission 16 located behind the storage space A of the continuously variable transmission 12 and housed in the transmission case 3. It has been communicated.

The operation structure of the continuously variable transmission 12 is constructed as shown in FIG.

That is, an operating pedal 20 is interlocked with the transmission rotation operating shaft 17 via a swinging interlocking device 18 and a push/pull rod 19, and by stepping on this pedal 20 forward, the gear moves forward, and also towards the rear. By stepping on it, it becomes the reverse side. Then, the roller 22 connected to the mission case 3 via the swing arm 21 is connected to the swing interlocking tool 1.
A spring 23 is applied to and biased against the lower end cam surface 18a of the rotary operating shaft 17 and the pedal 20 so as to automatically restore the rotary operating shaft 17 and the pedal 20 to the neutral position when the operation is released. As shown in FIG. 3, a transmission side member 2 constitutes a partition wall 24 between the transmission storage space A and the gear transmission storage space B in the transmission case 3.
The rotary type neutral valve 25 is fitted into the assembly hole provided in 4a, and the rotary operating shaft 26 of the neutral valve 25 is connected to the swinging interlocking tool via the belt type interlocking mechanism 27 and the push/pull link 28. 18 is interlocked so that the operating stroke of this interlocking tool 18 is magnified and transmitted by a belt-type interlocking mechanism 27. In other words, pedal 20
When it reaches the neutral position, a pair of oil passages 29a and 29b bored in the partition wall component 24a as shown in FIG. 3 are connected to the pump 10 and the motor 11 as shown in FIG. The neutral valve 25 is opened to communicate via the oil passage 31 with the throttle part 30 formed in the partition wall component 24a, and the transmission 12 is securely in the neutral state. 20 to the forward or reverse position, the pair of oil passages 29
The neutral valve 25 is placed in a closed state in which a and 29b are disconnected from each other, allowing the pump 10 to drive the motor 11.

As shown in FIG. 1, the trochoid charge pump 32 is installed in the assembly hole provided in the gear transmission 16 side member 24b forming the partition wall 24, with the partition wall forming member 24b serving as a pump casing. And, it is fitted in a state where it is directly connected to the rotating shaft 16a of the transmission 16 so that it is constantly driven by the rotating shaft 16a. As shown in FIGS. 1 and 2, the suction side of the charge pump 10 is connected to an oil passage portion 33a formed in the partition wall component 24b and an oil passage formed in the main body of the transmission case 3. an oil passage 33 consisting of a portion 33b and a filter 3;
4 to the lower part of the gear transmission storage space B, and the discharge side of the charge pump 32 is connected to the lower part of the gear transmission storage space B through the oil passage part 24b, which is bored in the gear transmission side partition wall component 24b as shown in FIG. 35
The pair of oil passages 29 are
a, 29b, respectively, and a relief valve 36 and a check valve 37 for oil supply from the charge pump 32 are fitted into the assembly holes provided in the transmission side partition wall component 24a, The lubricating oil contained in the transmission case 3 is configured to be supplied to the continuously variable transmission 12 as hydraulic oil by a charge pump 32.

The continuously variable transmission case portion 3a forming the continuously variable transmission storage space A of the transmission case 3 is connected to the gear case 3b forming the gear transmission storage space B of the transmission case 3. By configuring the partition wall portion 24 and removably attaching the partition wall component member 24b on the gear transmission side to the gear case portion 3b, the partition wall portion 24 and the continuously variable transmission case portion 3a are connected to the gear case. It is detachably attached to the gear case section 3b so that it can be handled as a separate component from the section 3b.

[Another example]

When the charge pump is installed inside the partition wall 24, a configuration may be adopted in which the pump casing is also fitted into the partition wall 24.

[Brief explanation of the drawing]

The drawings show an embodiment of the transmission device for an agricultural tractor according to the present invention, and FIG. 1 is a sectional view of the transmission;
Figure 2 is a sectional view of the charge oil passage, Figure 3 is a sectional view of the charge pump discharge side oil passage, Figure 4 is a hydraulic circuit diagram of the continuously variable transmission, and Figure 5 is a side view of the operation structure of the continuously variable transmission. , FIG. 6 is a side view of the entire agricultural tractor. 3...Gear transmission case, 3a...Continuously variable transmission case part, 3b...Gear case part, 1
0...Hydraulic pump, 11...Hydraulic motor, 12...
...Continuously variable transmission, 24...Partition wall, 32...
Charge pump, 33, 35...Oil passage, A...Transmission storage space, B...Gear transmission storage space.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A continuously variable transmission device 12 consisting of a hydraulic pump 10 and a hydraulic motor 11 is connected to a gear transmission case 3.
A transmission device for an agricultural tractor, which is equipped with a charge pump 32 that supplies lubricating oil contained in the transmission case 3 to the continuously variable transmission 12 as hydraulic oil, the transmission device comprising: The partition wall portion 24 between the stepped transmission storage space A and the gear transmission storage space B, and the continuously variable transmission case portion 3a forming the continuously variable transmission storage space A of the transmission case 3 are The charge pump 32 is detachably attached to the gear case portion 3b forming the gear transmission storage space B of the mission case 3, and the charge pump 32 is fitted into an assembly hole provided in the partition wall 24. An oil passage 33 connecting the gear transmission storage space B, and the charge pump 32 and the continuously variable transmission 12.
A transmission device for an agricultural tractor in which oil passages 35 connecting the two are provided in the partition wall 24. 2 The charge pump 32 is connected to the partition wall 2
4. The transmission device according to claim 1, wherein the transmission device is fitted in a state in which the part 4 is also used as a pump casing.