JPS6328007Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field The present invention is a transmission device for a tractor, etc., which has a plurality of built-in hydraulic clutches, and which is connected to a plurality of gears that are constantly engaged by selection using a hydraulic switching valve. This relates to a configuration in which one of the series is selected and the gear is changed.

(b) Prior Art Conventionally, as a technology equipped with a hydraulic clutch type transmission, a technology such as that disclosed in Japanese Utility Model Application Laid-open No. 53-147378 is known.

However, in the higher-level conventional technology, two walls were provided inside the transmission case at the front and back, making the case itself long. It was not possible to assemble the device externally and then insert it through the openings provided at the front and rear of the case, making assembly, repair and inspection troublesome.

(c) Problems to be solved by the invention By making the transmission case assembly 2 including the hydraulic clutch device into a small unit, this part can be assembled with high accuracy. This allows the assembly to be fixed to the sub-transmission case body 12 in an assembled state, thereby reducing assembly errors.

In addition, by combining the transmission case component 2 and the hydraulic clutch device, the gear pump 1
8, hydraulic clutch shaft 20, and seal case 71
All oil passages for this purpose are carved only in the mission case component 2, and there is no need to assemble highly accurate hydraulic parts in other cases. Furthermore, the gear pump 18 and the seal case 71 can be integrally assembled into the transmission case structure 2, and from this point of view as well, the hydraulic components can be concentrated and assembly and processing can be facilitated.

In addition, since the transmission case structure 2 and the sub-transmission case body 12 have a wall at the front and an open rear part, the mold can be formed into a punched shape, and they can be manufactured by aluminum die-casting. Therefore, accuracy can be improved and costs can be reduced.

As described above, in the present invention, only the hydraulic clutch type transmission is arranged in the transmission case structure 2, and parts related to oil passages such as the seal case, the support shaft of the hydraulic clutch, the hydraulic clutch, the hydraulic pump,
Hydraulic switching valves etc. can be assembled integrally,
In order to make the unit as small as possible, the sub-transmission device and the like are constructed separately from the sub-transmission case body.

(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.

The transmission case structure 2 that accommodates the hydraulic clutch type transmission A has a wall portion F at the front end and is open at the rear end, and the auxiliary transmission case body 12 that accommodates the gear sliding type auxiliary transmission B has a wall portion F at the front end. It has a wall portion 12a with an open rear end, and connects both back and forth, and furthermore, a rear axle housing 13 is fixed to the open rear end of the sub-transmission case body 12 to generate high pressure oil for operating a hydraulic clutch device. A gear pump 18, a high-pressure oil passage, and a seal case 71 for transmitting high-pressure oil to the hydraulic clutch shaft 20 are attached to the wall F of the transmission case structure 2, and the hydraulic clutch shaft 20 of the hydraulic clutch type transmission A is Supported by the wall F of the transmission case structure 2 and the front wall 12a of the sub-transmission case body 12,
The traveling drive shaft 22 that supports the gear sliding type sub-transmission device B is a bearing portion 2 provided at the rear end of the hydraulic clutch shaft 20.
0a and the front wall portion 13 of the rear axle housing 13
It is supported by a.

(E) Embodiment The purpose and structure of the present invention are as described above. Next, the structure of the embodiment shown in the attached drawings will be explained.

FIG. 1 is an overall side view of a tractor equipped with the hydraulic clutch type transmission of the present invention.

An engine 1 is contained within a bonnet 10, the rear end of the engine 1 is fastened to the front end of a main clutch housing 3, and a transmission case structure 2 is fixedly installed at the rear of the main clutch housing 3.

Further, a sub-transmission case body 12 and a rear axle housing 13 are fastened to the rear portion thereof, and the entire body is constituted.

A front wheel 4 is provided at the bottom of the bonnet 10, a rear wheel 5 is provided at the bottom of the rear axle housing 13, a three-point link hitch device for mounting a work machine is provided on the rear surface of the rear axle housing 13, a seat device 8 is provided on the top surface, and a fender 7 is provided on the side surface. will be established. A control device 9 is disposed above the main clutch housing 3. In particular, the main parts of the present invention are located inside the mission case structure 2 in FIG.

A main shift lever 14 projects upward from the upper part of the transmission case structure 2, and a sub-shift lever 15 projects upward from the sub-shift case body 12.

A muffler 11 is provided to protrude above the bonnet from the side of the engine 1.

FIG. 2 is a power transmission diagram of the hydraulic clutch type transmission of the present invention.

The driving force from the engine 1 passes through the hydraulic clutch type transmission A to the auxiliary transmission B, and from the rear axle housing 13 to the rear shaft 5, and the other transmission system passes through the PTO transmission D to the PTO shaft 25. Used to drive work equipment.

The transmission system will be explained in order starting from the engine shown in FIG.

The rotation of the engine 1 is transmitted to the main clutch shaft 16 by the engagement and disengagement of the main clutch 14. The main clutch shaft 16 is connected to the pump shaft 17 by a coupling 15.
A gear pump 18 rotates on the pump shaft 17, which generates high pressure oil for operating the hydraulic clutch device.

The pump shaft 17 is transmission-coupled to the main shaft 19 by a spline through a coupling which also serves as a gear 18a of a gear pump 18.

18b is a pump gear of the gear pump 18.
The main shaft 19 passes through the sub-transmission device B and reaches the rear axle housing at the coupling 15.
It reaches the PTO gear shift shaft 23.

A PTO shaft 25 is installed parallel to the PTO speed change shaft 23, and between this PTO speed change shaft 23 and the PTO shaft 25,
PTO shifting is performed.

A hydraulic clutch shaft 20 is installed parallel to the lower part of the main shaft 19 in the hydraulic clutch type transmission A, and hydraulic clutch loose-fit gears 33, 34, 35, which are constantly engaged with drive gears 28, 29, 30, 31 on the main shaft. 36 loosely fit.

The drive gear 28 is a reverse gear, and the reverse gear 3
2 are installed from the front wall F of the transmission case structure 2 and are engaged with each other, then the reversing gear 32 is engaged with the loosely fitted gear 33. The combination of the drive gear 29 and the loose fit gear 34 is the first forward speed, the combination of the drive gear 30 and the loose fit gear 35 is the second forward speed, and the combination of the drive gear 31 and the loose fit gear 36 is the first forward speed. This is the third forward speed.

The loosely fitted gears 33, 34, 35, 36 are connected to drive friction plates 33a, 34a, 35a, 36a of hydraulic clutches 26a, 26b, 27a, 27b, respectively, and hydraulic pistons 33c, 34c, 35.
c, 36c, the driving friction plates 33a,
34a, 35a, 36a are driven friction plates 33b,
34b, 35b, and 36b, power is transmitted to the hydraulic clutch shaft 20 via the hydraulic cylinders 33d, 34d, 35d, and 36d.

The hydraulic cylinders 33d and 34d are integrally constructed back to back, and the hydraulic cylinders 35d and 36d are also integrally constructed back to back, which is effective in downsizing the hydraulic clutch device.

The sub-transmission device B includes sub-transmission gears 40, 41, 42, 4 loosely fitted onto a first shaft 19 protruding from the transmission case structure 2 into the sub-transmission case body 12.
3, and sliding gears 38, 39, 44, and 45 slidably disposed on the traveling drive shaft 22.

The traveling drive shaft 22 has its front end connected to the front wall portion 12.
a, the hydraulic clutch shaft 20 is supported by a bearing 20a protruding immediately behind the front wall 12a, and the rear end is supported by a bearing 20a of a front wall 13a provided at the front end of the rear axle housing 13. ing.

At the rear end of the hydraulic clutch shaft 20 protruding from the front wall portion 12a, a sub-transmission small-diameter gear 37 is attached together with a bearing portion 20a.
is disposed and is always in mesh with the large diameter gear 40 of the auxiliary transmission loosely fitted gears 40, 41, 42, 43 loosely fitted to the main shaft 17.

The auxiliary transmission loosely fitted gear 41 is a third-speed auxiliary transmission gear, and constitutes the third auxiliary transmission by meshing with the sliding gear 39 on the traveling drive shaft 22.

The auxiliary transmission loose fit gear 41 and the sliding gear 44 constitute a second auxiliary transmission speed, and the auxiliary transmission loose fit gear 42 and the sliding gear 45 constitute a auxiliary transmission first speed. Further, by directly connecting the sliding internal gear 38 to the auxiliary transmission small diameter gear 37, a fourth auxiliary transmission speed is constructed.

A bevel gear 46 is provided at the rear end of the traveling drive shaft 22, and the bevel gear 46 and the differential gear bevel gear 47 are connected to each other.
are engaged, and after being decelerated by travel reduction gears 49 and 50 via a differential device 48, power is transmitted to the rear wheels 5. A brake device 100 is provided outside the travel reduction gear 49.

On the PTO transmission shaft 23, spline sliding gears 51 and 52 are slid on the front part, and loosely fitted gears 56 and 57 are loosely fitted on the rear half.

On the PTO shaft 25 are loosely fitted gears 53, 54, 55,
58, and sliding clutch pieces 60, 62 that are spline-fitted and slide on the PTO shaft. A fixed clutch piece 59 is provided at the base of the loosely fitted gear 55, and a fixed clutch piece 61 is provided at the base of the loosely fitted gear 58.
Loosely fitted gears 56, 57 on the PTO transmission shaft 23,
The loosely fitted gears 55 and 58 on the PTO shaft are always engaged.

The first stage of the PTO shift is made up of a sliding gear 51 and a loosely fitted gear 5
In the second stage of the PTO shift, the sliding gear 51 is engaged with the loose-fitting gear 53, and the sliding clutch piece 60 is engaged with the fixed clutch piece 54.
The third PTO speed change stage is when the sliding gear 52 is meshed with the loose-fit gear 54 and the sliding clutch piece 62 is meshed with the fixed clutch piece 61. The fourth PTO speed change stage is when the sliding gear 52 is meshed with the loose-fit gear 54 and the sliding clutch piece 60 is meshed with the fixed clutch piece 59.

The transmission system is as described above.

FIG. 3 is a side longitudinal cross-sectional view showing the main clutch housing 3, transmission case component 2, sub-transmission case body 12, rear axle housing 13, and hydraulic switching valve V portion.

The main part of the present invention is in the transmission case structure 2 shown in FIG. Tighten the rear axle housing 13.

In addition, a hydraulic switching valve V is provided in close contact with the upper surface of the transmission case structure 2. The hydraulic switching valve V includes an accumulator 101 for adjusting pressure, a valve case 66, a spool 65, a spool slide 6
The rear of the transmission case structure 2 is formed with an opening E, through which the hydraulic clutches 26a, 26b, 27a, 27b are inserted.
and drive gears 28, 29, 30, and 31 are inserted.
Thereafter, the pivot devices 77, 78 are attached in a manner that closes the opening in the front wall portion 12a of the auxiliary transmission case body 12. The other end portion, which is the front portion in this embodiment, is wall portion F, and other surfaces are made as large and flat as possible to provide holes for inserting the pivot devices 79, 80 and oil passages.

The oil passage is drilled when molding the mission case component 2 from a cast metal, and is provided in the form of a groove on the outer surface of the wall F. The groove-shaped oil passage is hermetically closed at the rear side surface of the clutch housing 3 to form an oil passage. If the transmission case component is manufactured by casting, machining is required in terms of finishing accuracy, but if die-cast aluminum is used, the surface precision can be improved, so no machining is required except for the oil passage drilled inside the wall F. It can be manufactured and helps reduce costs. A pump 18 and a seal case 71 are disposed in close contact with the outer surface of the wall F.

FIG. 4 is a detailed diagram of the PTO transmission D. FIG. 5 is an enlarged sectional view of part A of the hydraulic clutch type transmission, and FIG. 6 is a wall surface F of the transmission case structure 2.
It is a drawing showing an oil passage engraved on the outer surface of.

The high-pressure oil path for hydraulic clutch operation will be explained with reference to FIGS. 3, 5, and 6.

As shown in the oil filter installed at the bottom of the PTO transmission in Fig. 4, the lubricating oil in the transmission case is used as the hydraulic oil for the hydraulic clutch, and the hydraulic oil after filtering contaminants is passed through the pipe 8.
2, and enters the suction chamber 84 of the pump through the oil passage 83 in FIG. Pump gear 18 of pump 18
Due to the meshing of a and 18b, the oil enters the pump from the suction chamber and is subjected to high pressure, and enters the valve case 66 from the pressure chamber 85 through oil passages 86 and 86a. The high-pressure oil selected by the spool 65 within the valve case flows through oil passages 87a and 8 within the valve case.
Oil passages 87, 88, 89, and 90 are respectively carved into the wall F from 8a, 89a, and 90a, and after going around the pump part, the oil enters the wall F to enter the seal case 71, and is drilled. oil passage 87b,
88b, 89b, 90b through the oil passages drilled in the seal case 71 to the shaft oil passage 6 provided at the end of the hydraulic clutch shaft in the seal case 71 as shown in FIG.
7, 68, 69, 70 and holes 67a, 68a, 69a, 70a drilled in the respective shaft oil passages.
The oil passage (not shown) is drilled parallel to the axis within the shaft. The high-pressure oil that has passed through the oil passage in the shaft is transferred to hydraulic cylinders 33d, 34d, 35d, and 36d.
The oil enters through the oil passages 72, 73, 74, and 75, and generates a force that pushes the hydraulic pistons 33c, 34c, 35c, and 36c.

On the other hand, the lubricating oil is contained in the valve case 66 as surplus oil in the lubricating oil passage 91a of the valve case.
The lubricating oil enters the tip of the clutch shaft 20 of the seal case 71 through oil passages 91 and 91b in the wall, and from there through another lubricating oil passage in the clutch shaft 20 to each hydraulic cylinder 33d, 34d, 35d, and 36d. Accompanied by the centripetal force caused by the rotation of the shaft, they come out from holes 76c, 76b, 76a, and 76 opened at the ends of the keyway.

FIG. 6 is a front view of the wall portion F of the mission case structure 2. FIG.

Most of the oil passages are formed by the sealing surface between the groove carved in the front of the wall and the mounting surface at the rear end of the clutch housing.
8 and a transfer oil passage 83 into the seal case 71,
87, 88b, 89b, 90b, 87b, 91b
is composed of a hole drilled from the side surface of the wall F and a hole drilled from the front surface of the wall F. Of course, the hole opened from the side is closed with a blind plug.

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

First, by making the transmission case component 2 including the hydraulic clutch device into a small unit, this part can be assembled with high precision separately, and the sub-transmission case component 12 can be assembled in an assembled state. Since it can be fixed, assembly errors can be avoided.

Second, by combining the transmission case structure 2 and the hydraulic clutch device, it is possible to use the gear pump 18, the hydraulic clutch shaft 20, and the seal case 7.
All the oil passages for the transmission case 1 are carved only in the transmission case component 2, and there is no need to assemble highly accurate hydraulic parts in the other cases. Furthermore, the gear pump 18 and the seal case 71 can be integrally assembled into the transmission case structure 2, which also makes it possible to centralize the hydraulic components and facilitate assembly and processing.

Thirdly, since the transmission case structure 2 and the sub-transmission case body 12 are constructed with a wall at the front and an open rear part, the mold can be formed into a punched shape, and the mold can be formed by aluminum die casting. Since it can be manufactured, accuracy can be improved and costs can be reduced.

[Brief explanation of the drawing]

Figure 1 is an overall side view of a tractor equipped with a hydraulic clutch type transmission, Figure 2 is a transmission line diagram of the hydraulic clutch type transmission, Figure 3 is a side vertical sectional view showing the whole, and Figure 4 is a PTO transmission. A detailed view of device D, FIG. 5 is an enlarged sectional view of section A of the hydraulic clutch type transmission, and FIG. 6 is a drawing showing an oil passage carved on the outer surface of wall F. A... Hydraulic clutch type transmission, B... Sub-transmission, 1... Engine, 2... Mission case structure, 12... Sub-transmission case body, 12a... Front wall portion.

Claims (1)

[Scope of utility model registration request] The transmission case structure 2 that accommodates the hydraulic clutch type transmission A has a wall portion F at the front end and is open at the rear end, and the auxiliary transmission case body 12 that accommodates the gear sliding type auxiliary transmission B has a wall portion F at the front end. It has a wall portion 12a with an open rear end, and connects both back and forth, and furthermore, a rear axle housing 13 is fixed to the open rear end of the sub-transmission case body 12 to generate high pressure oil for operating a hydraulic clutch device. A gear pump 18, a high-pressure oil passage, and a seal case 71 for transmitting high-pressure oil to the hydraulic clutch shaft 20 are attached to the wall F of the transmission case structure 2, and the hydraulic clutch shaft 20 of the hydraulic clutch type transmission A is Supported by the wall F of the transmission case structure 2 and the front wall 12a of the sub-transmission case body 12,
The traveling drive shaft 22 that supports the gear sliding type sub-transmission device B is a bearing portion 2 provided at the rear end of the hydraulic clutch shaft 20.
0a and the front wall portion 13 of the rear axle housing 13
A hydraulic clutch type transmission, characterized in that it is supported by a.