JPS62268734A - Automobile power transmission device - Google Patents

Abstract

PURPOSE:To make a power transmission device smaller and compact, by changing a speed of engine power transmitted to a main speed change shaft and transmitting it through a wet type multi-disk main clutch and hydraulic speed change clutchs and accommodating the wet multi-disk main clutch in a separate chamber in a transmission case. CONSTITUTION:A transmission case has an input shaft 7, first and second main speed change shafts S1, S2, an auxiliary speed change shaft S3, a PTO shaft S4 and a front wheel drive shaft S5 disposed in parallel in it. A wet type multi- disk main clutch 17 is coaxially mounted on the first speed change shaft S1 which is accommodated in a separate chamber in a transmission case. The main clutch 17 transmits engine power from an input shaft 7 to a clutch shaft 20 supported by a bearing 19 in the transmission case 4 through a chain trained around sprockets 16, 18. The speed change shafts S1-S3 are provided with hydraulic speed change clutches 51, 52, 54, 39, respectively and the first speed change shaft S1 is associated with the clutch shaft 20.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power transmission device for a vehicle, and more particularly, to a power transmission device suitable as a power transmission device for a tractor for use in agriculture or the like.

In a one-pot agricultural tractor, the engine is usually mounted on the front of the vehicle body, and the transmission case is mounted on the rear. The output shaft of the engine is connected to a propeller shaft via a main clutch, and the propeller shaft extends rearward along the vehicle body and is connected to an input shaft pivotally supported by a transmission case.

A transmission mechanism is built in the transmission case, and engine power input to the input shaft is transmitted to an output shaft via the transmission mechanism, and the rear wheels are driven by the output shaft. In the case of four-wheel drive, the output shaft is further connected to the front wheel drive blower left, and the propeller shaft extends forward from the transmission case to drive the front wheels.

The transmission case is further provided with a PTO shaft, and the input engine power is also transmitted to this PTO shaft at variable speeds, and the power is transmitted to a working machine connected to the tractor via the PTO shaft.

Shito-. One object of the present invention is to improve the conventional power transmission device as described above, and to obtain a vehicle power transmission device that is small, compact, and convenient to operate.

For this reason, in the first aspect of the present invention, a wet multi-disc main clutch is connected to the main transmission shaft pivotally supported in the transmission case, and the main transmission shaft is connected to the main transmission shaft via the wet multi-disc main clutch. The engine power transmitted to the sewing machine is transmitted through a hydraulic transmission clutch built in the transmission case, and the wet multi-disc main clutch is provided in a separate chamber within the sewing machine case.

According to this invention, a hydraulic pump that generates oil pressure for lubricating various parts of the power transmission device and for clutch on/off is attached to the transmission case closer to the engine than the main clutch, so that it is driven by the engine regardless of whether the main clutch is engaged or disengaged. The hydraulic system can be simplified and the hydraulic piping can be shortened. In addition, the conventional main clutch housing of a tractor is eliminated, and a wet multi-disc main clutch is built into the transmission case, so the engine and transmission can be easily assembled or disassembled into the vehicle body.

Since the main clutch is a wet multi-plate type, its diameter is small and the device is compact.

In the second aspect of the present invention, a first main transmission shaft, a second main transmission shaft, and a PTO shaft are disposed in the mission case, and the second main transmission shaft is connected to the engine via a main clutch, and 2 between the first main transmission shaft and the second main transmission shaft, a gear connected to the shaft by a hydraulic clutch provided on one shaft, and a gear connected to the other shaft and meshed with the gear; A plurality of sets of hydraulic speed change clutch mechanisms are provided, and power is transmitted from the second main speed change shaft to the first main speed change shaft at a predetermined speed ratio by selectively operating these hydraulic speed change clutch mechanisms, and from the second main transmission shaft to the P
Power is transmitted to the TO shaft at a predetermined gear ratio via a plurality of gear transmission mechanisms that are selectively operated.

By doing so, it is possible to obtain a power transmission device with a small and simple structure that changes the speed and transmits the engine power to the running wheels of the vehicle and the work equipment connected to the vehicle, and also connects a wet multi-disc main clutch. Even if the vehicle is shifted for traveling while work is being performed via the PTO shaft, the shock to the vehicle is reduced and the shift operation is performed extremely smoothly.

Husband 1JI Hereinafter, the present invention will be described with reference to illustrated embodiments.

FIG. 1 is a side view of an agricultural tractor to which the present invention is applied.
1 is the front wheel, and 2 is the front wheel. An engine 3 is mounted on the front part of the vehicle body, and a transmission case 4 is mounted on the rear part. The output shaft of the engine 3 is connected to a propeller seat 71-6 via a reduction gear 5, and the propeller shaft 6 extends rearward from the lower part of the vehicle body and is connected to an input shaft 7 of the mission case 4. The transmission case 4 is fixed to a vehicle body frame 8, a part of which is shown in fragmentary form, and has a built-in power transmission device, which will be described later. The engine power input to the human power shaft 7 is outputted to the rear vehicle IN19, the PTO shaft S4, and the front wheel drive shaft S5 after being appropriately changed in speed through the power transmission device. The PTO shaft S4 transmits power to a working machine such as a rotary work machine connected to the rear of the tractor. Front wheel drive shaft S5 is front wheel drive propeller shaft 1
0 to the front wheels 2. Reference numeral 11 denotes a hydraulic cylinder which lowers the working machine 4 times via a lift arm 12.

13 is a seat, and 14 is a handle.

FIG. 2 is a sectional view showing the power transmission device inside the mission case 4, and as shown in the figure, the input +l17, the first main shift shaft S1, the second main shift shaft S2, the sub-shift shaft S3, and the PTO@s
4. Front wheel drive shaft S5 (7) Arranged parallel to each shaft. However, these axes are not arranged one above the other in one plane as shown in FIG. Fig. 3 shows the actual arrangement of the respective axes. For example, the first main transmission shaft S1 and the second main transmission shaft S2 are arranged side by side at almost the same height, and the auxiliary transmission shaft The first main transmission shaft S1 and the second main transmission shaft S3 and the front wheel drive shaft S5 are also at approximately the same height.
They are arranged side by side slightly to the lower left of the main transmission shaft S2. And P T O@S 4 is arranged at the uppermost position.

The input shaft 7 is connected to the propeller shaft 6 as described above.
is rotatably supported by a transmission case 4 and a clutch housing 15 fixed thereto via a bearing, and a sprocket 16 is fixed to this input shaft 7. The input shaft 7 transmits engine power to a sprocket 18 provided in a main clutch 11 of a warm type multi-disc type via a chain.

The main clutch 11 has a clap shaft 20 that is pivotally supported to the transmission case 4 via a ball bearing 19, and the sprocket 18 is relatively rotatably supported on the clutch shaft 20 via a needle bearing 21. There is.

Sprocket 18 has Iiii when the clutch is connected! ! II
A cylindrical drive member 23 with a bottom is fixed to the drive member 23 via a spring member 22 in order to absorb the vibration, and a plurality of drive clutch plates 24 are displaceable in the axial direction via splines on the inner peripheral surface of the drive member 23. Accepted. The clutch shaft 20 also includes
A cylindrical driven member 25 with a bottom is integrally fixed. A plurality of driven clutch plates 26 are received on the outer circumferential surface of the driven member 25 via splines so as to be displaceable in the axial direction, and these driven clutch plates 26 and the driving clutch plates 24 are arranged alternately. Arranged. A disc-shaped pressure contact plate 27 having approximately the same diameter as the flange 25a provided at the end of the driven member 25 is provided so as to rotate integrally with the driven member 25 and to be relatively displaceable in the axial direction. ing.

The press plate 27 has a boss 28 that protrudes through a hole provided in the bottom wall of the driven member 25, and a lifter plate 29 is fixed to the end surface of the boss 28. A coil spring 30 is sandwiched between the ivy plate 29 and the bottom wall surface of the driven member 25, and normally the flange 25a of the driven member 25 and the pressure contact plate 27 are moved in a direction that is driven A biasing force is applied in a direction to press the clutch plate 24 and the driven clutch plate 26 together. The lifter plate 29 is received from behind by an actuating piece 32 via a ball bearing 31, and the actuating piece 32 is pressed against the coil spring 30 by a lever 33 to press the plate 27.
By pushing it toward the side along the clutch shaft 20, the pressure plate 27 moves away from the flange 25a of the driven member 25, and the pressed state between the driving clutch plate 24 and the driven clutch plate 26 is released. That is, the main clutch 17 is in a disengaged state.

A gear G13 is integrally formed at the end of the clutch shaft 20 that protrudes into the transmission case 4. The end of the first main transmission shaft S1 is also supported coaxially and relatively rotatably via a needle bearing 34 at this end. The first main transmission shaft S1 extends back and forth within the mission case 4, with its other end and intermediate portion supported by ball bearings 35, 35, . . . , respectively.

A second main transmission shaft S2 is disposed adjacent to and parallel to the first main transmission shaft S1. The second main transmission shaft $2 is rotatably supported by the front wall of the transmission case 4 and a bearing wall 36 provided in the transmission case 4 via ball bearings 37 and 38, respectively. At the front end of the second main transmission shaft S2, there is a gear G that constantly meshes with the gear G of the clutch shaft 20.
23 is fixed. Gear G 1 and gear G 23 have the same diameter, so when the main clutch 17 is engaged, the second main transmission shaft S 2 moves from the clutch shaft 20 to gear G 13 . It is rotationally driven at the same rotational speed as the clutch shaft 20 via G23. A low speed (1st speed) speed change clutch 39 is provided at the other end of the second main speed change shaft S2, that is, the end that penetrates the bearing wall 36 and projects rearward, in close proximity to the bearing wall 36. As shown in more detail in FIG. 4, the three low-speed hydraulic transmission clutches include a right bottom cylindrical drive member 40 fixed to the second main transmission @S2, and an annular shaped drive member 40 on the open end surface of the drive member 40. A plate 41 is fixed to the receiver. Then, on the inner circumferential surface, the support is opposite to the plate 41, and the drive clutch plate 24 for connecting the main clutch 17 to the J3
A plurality of similar drive clutch plates 42 are axially displaceably received via splines. Drive member 40
An annular cylinder portion 43 is formed by the peripheral wall portion 40a1, the bottom wall portion 40b, and the boss portion 40c fitted to the second main transmission @s2, and the actuating member 44 is fitted into the cylinder portion 43 in the shape of a piston. is mounted and urged toward the bottom wall portion 40b by a spring 45. An oil passage 46 is provided in the boss portion 40c so that hydraulic pressure can be supplied between the operating member 44 and the bottom wall portion 40b of the drive member 40, and this oil passage 46 is formed in the second main transmission @S2. It communicates with a clutch oil passage 47 that is supplied with oil from an oil pump via a control valve. A low speed change drive gear G21 is mounted on the second main speed change shaft S2 adjacent to the drive member 40 and is connected to the needle bearing 4.
It is rotatably mounted via 8. A driven member 49 of the low-speed hydraulic transmission clutch 39 is integrally formed with the gear G21, and enters into the cylinder portion 43 of the drive member 40. A plurality of driven clutch plates 50 are received on the outer peripheral surface of the driven member 49 via splines so as to be displaceable in the axial direction.
0 and the drive clutch plates 42 are arranged alternately.

Since the low-speed hydraulic shift clutch 39 is configured as described above, oil flows through the clutch oil passage 47 and the clutch oil passage 47 during the shift operation.
When the oil is supplied behind the actuating member 44 through the oil passage 46, the actuating member 44 is pushed forward by the hydraulic pressure, and the driving clutch plate 42 and the driven clutch plate 50 are pressed against each other.

Therefore, the rotation of the second main transmission shaft S2 is caused by the rotation of the drive member 40. Drive clutch plate 42, driven clutch plate 50, driven member 49
is transmitted to the gear G21 via the gear G21, and the gear G21 rotates integrally with the second main transmission shaft S2. Since the teeth 11G21 mesh with the low speed change driven gear G11 fixed to the first main speed change shaft S1, the engagement of the low speed hydraulic speed change clutch 39 causes the first main speed change shaft S1 to shift between the gear G21 and the gear G11. Rotationally driven with a reduction ratio according to the tooth number ratio. When the low-speed hydraulic transmission clutch 39 is disengaged, the gear G21 is the gear G.
11 from the first main transmission shaft S1 side and rotates freely around the second main transmission shaft S2.

A 2-speed hydraulic transmission clutch 51 is located at the front end of the first main transmission shaft S1.
and a three-speed hydraulic transmission clutch 52. These hydraulic speed change clutches 51, 52 are all constructed in exactly the same way as the low speed hydraulic speed change clutch 39. However, the drive members 51a and 52b of these clutches are integrated, and each cylinder portion is formed back to back on this integrated drive member. 2-speed hydraulic gear shift clutch 51
Covered by I! ! ! The moving member 49a is integrated with a gear G12 rotatably mounted on the first main transmission shaft S1 via a needle bearing 53, and the gear G12 meshes with a gear G22 fixed to the second main transmission shaft 82. There is. When the second-speed hydraulic transmission clutch 51 is engaged in the manner described for the low-speed hydraulic transmission clutch 39, the rotation of the second main transmission @S2 is caused by gear G, gear G12, driven member 49a, and drive member 51a.
is transmitted to the first main transmission shaft S1 through the first main transmission shaft S1.
1 rotates at a gear ratio according to the tooth ratio of gear G1 and gear G12. Strictly speaking, regarding the clutches 51 and 52, the drive member 51a1 and the drive member 52b are the members on the driven side, and the driven member 49a and the driven member 49b are the members on the drive side. Speed change clutch 39
It is called this way to match it.

The driven member 49b of the third-speed hydraulic transmission clutch 52 is formed integrally with the gear G13, and when the clutch 52 is engaged, the rotation of the clutch shaft 20 is caused to rotate through the gear G13, the driven member 49b1, and the driving member 51b. It is transmitted to the main transmission shaft S1, and the first main transmission shaft S1 is rotationally driven at a rotational speed equal to that of the second main transmission shaft S2 and in a direction connected to the second main transmission shaft S2.

A 4-speed/rear hydraulic transmission clutch 54 having the same configuration as each of the hydraulic transmission clutches 39, 51, and 52 is also located in the middle of the second main transmission shaft S2, and its driving member is attached to the second main transmission shaft $2. It is provided. The driven member of the clutch 54 is formed integrally with a gear G24 rotatably mounted on the second main transmission shaft S2 via a needle bearing 55. Gear G
24 is also integrated with the reverse drive gear "2R. On the other hand, the first main transmission shaft S1 has a gear Q1 that meshes with the gear G24.
4 is rotatably mounted via a needle bearing 56, and a reverse driven gear "In" which engages with gear G2R via an idle gear 57 (FIG. 3) is attached to a needle bearing 58.
It is rotatably attached via the The gear G14 and the gear G1R have boss portions facing each other and having the same diameter, and a connecting member 59 which is sandwiched between these boss portions and forms an annular shape having the same diameter.
is provided, and the connecting member 59 is connected to the first main distal axis S1.
It is fixed so that it rotates integrally with this. Both gears G14. Splines are carved on the outer circumferential surface of each of the boss portions of the GlR and on the outer circumferential surface of the connecting member 59, and these splines are fitted to connect both boss portions and the connecting member 5.
An annular selector 60 is provided that can be slid back and forth on 9. In a position where the selector 60 is located between the gear G14 and the connecting member 59, the gear G14 is connected to the first main transmission shaft S1 via the connecting member 59, and the selector 60 is located between the tooth 1iG1R and the connecting member 59. When in the straddling position, the gear G1R is connected to the first main transmission shaft S1.

Further, when the selector 60 is on the connecting member 59, both the gear G and the gear G1R can freely rotate relative to the first main shift @S1.

Therefore, when the selector 60 is moved to the gear G14 side and the clutch 54 is engaged, the rotation of the second main transmission shaft S2 is changed between the clutch 54, the gear G24, the gear G14, and the selector 6.
0, the speed is increased through the connecting member 59 and transmitted to the first main transmission shaft S1. When the selector 60 is moved to the gear G1R side and the clutch 54 is engaged, the rotation of the second main transmission shaft S2 causes the clutch 54, the gear G24, the gear G2l1, the idle gear 57, the gear G11l' selector 60, and the connecting member 59 to rotate. The first main shift shaft $1 is transmitted to the first main shift shaft @S1 through the drive shaft S1, and the first main shift shaft $1 is rotationally driven in the reverse direction.

As can be seen from the above, engine power is transmitted to the second main transmission shaft S2 via the main clutch 17, and by selectively engaging the hydraulic transmission clutches 39, 51, and 54, the engine power is transmitted to the second main transmission shaft S2 at a predetermined transmission ratio. It is transmitted from the second main shift shaft S2 to the first main shift shaft S1. In addition, when the 3rd speed hydraulic transmission clutch 52 is engaged, power is directly transmitted from the clutch shaft 20 to the first main transmission shaft S1 via the gear "13", and the power is transmitted directly to the 4th speed/rear hydraulic transmission clutch 54 and the gear G2R' idle. It is also possible to drive the first main transmission shaft S1 in the reverse direction from the second main transmission shaft S2 at a predetermined reduction ratio through the gear 57 and the gear G1Re, and in this way, the first main transmission shaft S1 has four forward speeds. , one reverse gear speed change rotation is provided.

The rotation of the first main transmission shaft S1 is further transmitted to the sub-transmission shaft S3 at three gear ratios. Therefore, the first main transmission shaft S1
Three gears G61, 62, and 63 are fixed to. The gear G61 meshes with the gear G31 rotatably mounted on the sub-transmission shaft S3 via the needle bearing as described above, and the gear G63 meshes with the gear G33 similarly rotatably mounted on the sub-transmission shaft S3. They mesh together. Gear G62 has teeth I by a spline mechanism similar to the selector 60.
j! Boss part of G31, sub-shift f*S3 and gear G
Teeth 11IG3 that can slide back and forth across 33 bosses
It is now possible to mesh with □. Gear G32
When is meshing with gear G62 as shown in the figure, the rotation of the first main transmission shaft S1 is caused by the rotation of gear G through teeth G3□.
If the deceleration is transmitted to the first main shift shaft S3, and the gear G disengages from gear G62 and moves to a position where it straddles the gear G31 and the n1 shift shaft S3, the rotation of the first main shift shaft S1 will be the same as that of the gear G6.
1. Speed increase is transmitted to the sub-shift shaft S3 through the gear G31.

If the gear G moves to the gear G33 side, the first main shift shaft S
1 rotation is through gear G 1 gear G33 and secondary variable axis S3
The deceleration is transmitted to. The sub-transmission shaft S3 is connected to the rear axle 9 (Fig. 1) via a differential gear device and a final reduction gear device (not shown).
This provides 12 forward speeds and 3 reverse speeds.

As can be seen from FIG. 3, the front wheel drive shaft S5 is arranged adjacent to the auxiliary transmission shaft S3, and a gear G34 fixed to the auxiliary transmission shaft S3 is rotatable on the front wheel drive shaft S5 via a needle bearing. It meshes with gear G5 attached to. Gear G5
is the front wheel drive shaft S by sliding the selector 61.
5, it can be freely connected and disconnected. The front end of the front wheel drive shaft S5 is connected to the front wheel 2 via the front wheel drive propeller shaft 10 as described above. Operate selector 61 to select gear G
5 to and from the front wheel drive shaft S5, the traveling drive of the tractor can be switched to four-wheel drive using the front and rear wheels or drive using only the rear wheels at an appropriate time.

As explained with reference to Fig. 3, the PTO@S4 is placed at the uppermost position within the mission case 4, and its rear end protrudes outward from the mission case 4 so that it can be connected to the drive system of the work machine. ing. This PTO@S
4, three gears G41, G42, and G43 are rotatably mounted via twenty-one dollar bearings in the same manner as the gears described above. The gear G41 is integral with the gear G22 fixed to the second main transmission shaft S2 and has a smaller diameter than the gear G22.
2° and always mesh. Gear "41" is selector 62
Gl:) PTO'Nl51m is engaged and disengaged, but gear G
41, gear G22. Since the 4th speed/reverse hydraulic transmission clutch 54 is disposed close to the clutch 54, in order to avoid the clutch 54, the boss 63 of the gear "41 is
4, and is adapted to be engaged with and disengaged from a boss 63 at a position in contact with the bearing wall 36 by a PTO shaft S axis alignment 4 rector 62. In this position, the gear G2R with a relatively small diameter is attached to the second main transmission shaft S2, so that the engagement mechanism 1112 by the selector 62 can be accommodated with plenty of room. The gear G42 and the gear G43 are always in mesh with the gear G22 and the gear G23, respectively. These gears G42 and ``43 selectively adjust the PTO axis S axis alignment 4 by moving the selector 64 back and forth.
can be tied. With this configuration, PTCI
S4 has 3 types of low, medium, and high by connecting gears G41, G42, or G43 to the PTO shaft S axis.
It can be driven by the engine power via the second main transmission shaft S2 at step rotational speeds.

Mission case 4 has each of the above @7, 20°Sl...
- In addition to S5, a pump shaft SP is arranged parallel to each of the above-mentioned axes. A gear G is fixed to the pump shaft SP, and the gear G is always meshed with the gear G7 fixed to the input shaft 7.

The iyr end of the pump shaft SP is connected to an oil pump 65 formed of, for example, a gear pump, which is fixed to the transmission case 4, and the pump 65 is driven by the pump@SP. The oil discharged from the oil pump 65 passes through an appropriate passage provided along each wall of the transmission case 4, and then passes through a lubricant provided in the axial direction at the center of each shaft S1...S5, etc. The oil is fed under pressure to the passage 66 and the clutch oil passage 67. The oil passes through oil passages branching from these passages 66 and 67 to lubricate the bearing portions such as the needle bearings or the clutch plate portions of the hydraulic transmission clutches, or to operate the operating members of the hydraulic transmission clutches. . As shown by the oil level in FIG. 3, the lubricated oil stored in the transmission case 4 passes through the oil filter 68, returns to the suction vibro 9, is sucked into the oil pump 65, and is recirculated.

The rear end of the pump shaft SP extends rearward through the transmission case 4 and is connected to a hydraulic pump (not shown) for lifting and lowering the working machine.

The configuration of the illustrated embodiment has been described in detail above, but in this embodiment, the clutch @2° of the main clutch 17 and the second main gear shift Ir! ll52 are connected through gear G13 and gear "23 at a speed ratio of 1:1, so clutch shaft 2
0 and the second main transmission shaft S2 are equal, and the main clutch 17 can also be directly connected to the second main transmission shaft S2 as it is. Therefore, regardless of whether the input shaft 7 rotates clockwise or counterclockwise, the PTO shaft S axis alignment depends on whether the main clutch 17 is installed on the first main transmission shaft S1 side or the second main transmission shaft S2 side. The four-turn direction can be set to "clockwise as seen from the rear" as per the standard.

Furthermore, in this embodiment, since the main clutch 17 is provided between the input shaft 7 to the transmission case 4 and the main transmission shaft S1 or S2 inside the transmission case 4,
Compared to conventional systems in which the main clutch is installed between the front engine output shaft and the propeller shaft, the main clutch is located closer to the driver and is often operated together with the main clutch. It is also close to the location of the mechanism.

Therefore, it is easy to operate and the structure of the operating system is also simplified.

An oil pump that supplies oil for lubricating and operating various parts of the power transmission system is generally connected to the engine power transmission system closer to the engine than the main clutch, and must be driven by the engine regardless of whether the main clutch is engaged or disengaged. However, in this embodiment, as described above, the main clutch 17 is provided between the input shaft 7 and the main transmission @$1, S2, so the oil pump 65 is connected to the input shaft 7 and the oil pump 65 can be provided in the mission case 4, and therefore the hydraulic system from the oil pump 65 to each part in the mission case 4 can be shortened and simplified.

Furthermore, in this embodiment, the first main shift lll1llS1, the second main shift shaft S
2. A plurality of sets of hydraulic transmission clutch mechanisms (low-speed hydraulic transmission clutch 39, 2-speed hydraulic transmission clutch 51.3 (speed hydraulic transmission clutch 52, 4 speed/reverse hydraulic transmission clutch 54, etc.) and the PTO from the second main transmission shaft S2.
A gear transmission mechanism (G
22. and G41, ``22 and G42, and G23 and G43) are skillfully arranged, so that a power transmission device with a small and simple configuration is obtained, and the gear shifting operation is performed extremely smoothly.

As described above, according to the present invention, the power can be distributed between the PTO shaft and the traveling shaft with a small and compact transmission, and it is convenient for operation, especially for agricultural tractors. A vehicle power transmission device with a transmission that generates suitable low-speed high torque can be obtained. In addition, when servicing the transmission, there is no need to remove the case of the wet multi-plate main clutch.
Maintenance work is facilitated because it is only necessary to remove the transmission from the vehicle body, and it is also easy to disassemble and assemble the engine for maintenance.

[Brief explanation of the drawing]

Fig. 1 is a side view of an agricultural tractor to which the present invention is applied, Fig. 2 is a sectional view showing the power transmission device of the same tractor, and Fig. 3 is a drawing showing the actual arrangement relationship of each shaft of the power transmission device. FIG. 4 is an end view of the device viewed from the front to the rear.
It is a partially enlarged view of the figure. 1... Rear wheel, 2... Front wheel, 3... Engine, 4...
...Mission case, 5.Reduction gear, 6.Propeller shaft, 7.Input shaft, 8.Vehicle frame, 9.Rear axle, 10.Front wheel drive propeller shaft, 11 ...Hydraulic cylinder, 12...Lift arm, 13...Seat, 14...Handle, 15...
Clutch housing, 16... Sprocket, 17...
...Main clutch, 18...Sprocket, 19...
Ball bearing, 20...Clutch shaft, 21...Needle bearing, 22...Spring member, 23...Drive member, 24...
... Drive clutch plate, 25... Driven member, 26...
- Driven clutch plate, 27... Pressure contact plate, 28... Boss, 29... Lifter plate, 30... Coil spring, 31... Ball bearing, 32... Operating part, 33...・・・
lever, 34... needle bearing, 35... ball bearing,
36...Bearing wall, 37.38...Ball bearing, 39...
・Low speed hydraulic transmission clutch, 40... Drive member, 41・
...Brace is plate, 42...Drive clutch plate, 43...Cylinder section, 44...Fll' moving member, 45...Spring, 46...Oil passage, 47...Clutch ura passage , 48... Needle bearing, 49... Driven member, 5
0... Driven clutch plate, 51... 2nd speed hydraulic transmission clutch, 52... 3rd speed hydraulic transmission clutch, 53...
Needle bearing, 54... 4-speed/return hydraulic transmission clutch, 55.56... Needle bearing, 57... Idle gear, 58... Needle bearing, 59... Connection member,
60.61.62...Selector, 63...Boss,
64...Selector, 65...Oil pump, 6G
...Lubrication passage, 67...Clutch ura passage, 68...
・Oil filter, 69...Suction pipe, Sl
...First main shift shaft, SP...Second main shift shaft, S3.
...Sub-shift shaft, S4...PTO axis, S5...Front wheel drive shaft, G...gear, SP...pump shaft.

Claims (2)

[Claims] (1) A wet multi-disc main clutch is connected to the main transmission shaft supported in the transmission case, and the engine power transmitted to the main transmission shaft via the wet multi-disc main clutch is transmitted to the main transmission shaft built in the transmission case. What is claimed is: 1. A power transmission system for a vehicle, which transmits speed through a hydraulic speed change clutch, and wherein the wet multi-plate main clutch is provided in a separate chamber within a transmission case. (2) A first main transmission shaft, a second main transmission shaft and a PTO shaft are arranged in the mission case, the second main transmission shaft is connected to the engine via a wet multi-disc main clutch, and the first main transmission shaft is connected to the engine via a wet multi-disc main clutch. A hydraulic speed change clutch, which is located between the speed change shaft and the second main speed change shaft, and includes a gear connected to the shaft by a hydraulic clutch provided on one shaft, and a gear connected to the other shaft and meshed with the gear. A plurality of sets of mechanisms are provided, and power is transmitted from the second main transmission shaft to the first main transmission shaft at a predetermined transmission ratio by selectively operating these hydraulic transmission clutch mechanisms; A power transmission device for a vehicle, characterized in that power is transmitted from a main transmission shaft to the PTO shaft at a predetermined transmission ratio via a plurality of gear transmission mechanisms that are selectively operated.