JP2001227563A - Transmission of working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that it costs much to provide extra circuits and mechanism for working oil supply to forcibly lubricate a main clutch though reliability of a clutch is lowered in the case when lubrication of the main clutch is not sufficient, maintenance work and assembly work are troublesome as each shaft in a transmission is borne in a transmission case and it is hard to carry out shift change-over as confinement of torque takes place at speed- changing position of first speed of a sub-transmission in the case of constituting a spline cross-section shape of a spline collar to have stepped shapes in both sides. SOLUTION: Clutches 2, 3 are forcibly lubricated by drain oil of a power- steering mechanism by providing a synchromesh type reverser clutch 3 on a main shaft in such a constitution that engine output is transmitted to the main shaft 23 through the main clutch 2. Additionally, it is constituted to install a clutch case 20 to bear the main shaft, idling shafts 33, 35, etc., in a transmission case and one side of a cross-section shape of a spline 68a of a spline collar 68 is made in a tapered shape and the isde of the other side is made in a stepped shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for a work vehicle such as a tractor.

[0002]

2. Description of the Related Art Conventionally, in a working vehicle such as a tractor,
2. Description of the Related Art It is known that a transmission is configured by housing a main clutch for connecting and disconnecting an output from an engine, a main transmission, a sub transmission, a PTO clutch, a PTO transmission, and the like in a transmission case. In such a transmission, a wet clutch may be used for the main clutch and the like, and the transmission is lubricated with hydraulic oil in a transmission case. Further, the main shaft to which power is transmitted via the main clutch and other shafts are supported by bearings formed integrally with the transmission case. The spline collar which rotates integrally with the sub-transmission shaft of the sub-transmission is formed with a spline to be fitted to the shift slider. The gear slider has a stepped shape so that the shift slider is reliably locked at each shift position.

[0003]

However, in the above-mentioned conventional construction, the main clutch may not be sufficiently lubricated, and it is not possible to provide another hydraulic oil supply circuit or mechanism for positive lubrication. There is a cost problem. Further, in the above-described conventional configuration, since each shaft is supported by a bearing formed in the transmission case, it is necessary to take out each shaft separately during maintenance, which is troublesome. Also, the assembling work was complicated. Further, when the spline section of the spline collar is configured to have a stepped shape on both sides, there is a problem that torque is locked at the shift position of the first sub-speed, making it difficult to perform shift switching.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, according to the present invention, the engine output is transmitted to the main shaft in the transmission via the main clutch, and the main shaft is provided with a synchromesh type reverser clutch.

Further, the main clutch and the reverse clutch are forcibly lubricated by drain oil of a power steering mechanism.

According to a third aspect of the present invention, there is provided a clutch for turning on / off the transmission from the input shaft to the output shaft by sliding the clutch release on the output shaft. It is configured to extend to the clutch center side.

According to a fourth aspect of the present invention, a bearing for each shaft such as a main shaft and an idle shaft is formed in a clutch case for housing a main clutch, and the clutch case is mounted on a transmission case.

According to a fifth aspect of the present invention, a first speed gear is arranged on one side of a spline collar which rotates integrally with the speed change shaft, and a second speed gear is arranged on the other side. The spline and one of the transmission gears are engaged with each other via a shift slider to change the speed.The spline cross section of the spline collar has a tapered shape on one side and a spline cross section on the other side. Stepped shape.

Further, a PTO idle shaft for reversing the input rotation to the PTO shaft is provided with a PTO idle shaft.
The shift fork of the transmission is supported.

[0010]

Next, embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a first sectional view of a transmission (front end side) according to the present invention, FIG. 2 is a second sectional view of the transmission according to the present invention, and FIG. 3 is a transmission (rear end side) according to the present invention.
4 is a cross-sectional view of a synchromesh type reverser clutch, FIG. 5 is an enlarged cross-sectional view of a main part of a main clutch, FIG. 6 is a view showing a spline cross-sectional shape of a spline collar, and FIG. PTO on idle shaft mounted
FIG. 6 is an embodiment diagram supporting the shift fork of FIG.

First, the overall schematic structure of the transmission will be described with reference to FIGS. 1, 2 and 3. FIG. The transmission is entirely housed in a transmission case 1, and a first sectional view shown in FIG. 1 shows a front end side of the transmission. (In the following description, the left side of FIGS. 1 to 3 is the front of the transmission.) FIG. 2 is a second sectional view following the rear side of the first sectional view shown in FIG. 1, and FIG. FIG. 5 is a third sectional view following the rear side of the second sectional view indicated by, that is, a sectional view showing the rear end side of the transmission.

The first sectional view shows a main clutch 2, a reverser clutch 3 and the like provided in the transmission.
In the second sectional view, the main transmission 4 provided in the transmission,
3 shows a creep transmission 5, an auxiliary transmission 6, a front wheel speed increasing clutch 7, and the like. In the third sectional view, the PTO drive transmission section 8 is shown. In the transmission configured as described above, after the output from the engine (not shown) is connected / disconnected by the main clutch 2 and the reversing clutch 3 switches between forward and reverse rotation (forward / backward), the main transmission 4,
The speed is shifted by the creep transmission 5 and the auxiliary transmission 6, and the engine output after the transmission is transmitted into the rear axle case 10 to drive the rear wheels. Further, the engine output after the sub-shift is transmitted to the front axle case (not shown) through the front wheel speed increasing clutch 7 to drive the front wheels (4WD),
The front wheel speed increasing drive is configured. Further, the engine output is transmitted to the rear side in the transmission, and is taken out from a PTO shaft 84 provided at the rear end of the transmission case 1.

Next, a detailed configuration of the transmission according to the present invention will be described. As shown in FIG. 1, the rotation output of an engine (not shown) is input into the transmission case 1 from an engine output shaft 22. A first pipe shaft 23, which is a main shaft that rotates on the same axis as the engine output shaft 22, is provided on the outer periphery of the engine output shaft 22, and between the engine output shaft 22 and the first pipe shaft 23, A main clutch 2 is provided. The main clutch 2 is a wet-type multi-plate clutch, and includes a drive plate 2a that rotates integrally with the engine output shaft 22, a clutch center 2b that rotates integrally with the first pipe shaft 23, a clutch release 2c, and the like. The main clutch 2 is connected and disconnected by sliding the clutch release 2c on the first pipe shaft 23. When the main clutch 2 is in the connected state, the clutch center 2b and the clutch release 2c are connected and rotated with the drive plate 2a, and the rotational driving force of the engine output shaft 22 is transmitted to the first pipe shaft 23.

On the first pipe shaft 23, a reverser clutch 3 is provided behind the main clutch 2. As shown in FIG. 4, the reverser clutch 3 is a synchromesh clutch, and the synchronizer sleeve 3b is moved to gradually push the synchronizer rings 3c, 3c against the reverse gear 31 or the forward gear 32. And synchronizer ring 3c
Is fitted to one of the gears, so that the rotation output of the synchronizer hub 3a that rotates integrally on the first pipe shaft 23 is
It is alternatively transmitted to the reverse gear 31 or the forward gear 32.

Also, as shown in FIG.
Substantially parallel to the first idle shaft 33 and the second idle shaft 3
The reverse gear 34 that rotates integrally with the first idle shaft 33 is meshed with the reverse gear 31.
The second idle shaft 35 is provided with two gears 36 and 37 that rotate integrally with the second idle shaft 35,
The gear 36 meshes with the reverse gear 34, and the gear 37 meshes with the forward gear 32. With such a configuration, by operating the synchronizer sleeve 3b toward the reverse gear 31, the synchronizer hub 3a
Is transmitted from the reverse gear 31 to the forward gear 32 after the rotation direction is reversed via the reverse gear 34 and the gears 36 and 37. On the other hand, the synchronizer sleeve 3b
Is operated to the forward gear 32 side, whereby the rotational output of the first pipe shaft 23 is transmitted to the forward gear 32 while keeping the same direction.

As described above, in the transmission of the present invention,
Since the synchromesh type reversing clutch 3 is provided on the first pipe shaft (main shaft) 23 to which the engine output is input via the main clutch 2, it is possible to reduce the shock at the time of switching between forward and backward. Also, the transmission can be made compact.

An oil passage 22r is formed in the shaft of the engine output shaft 22 in the axial direction.
r extends to near the rear end of the engine output shaft 22.
Then, the drain oil of the power steering mechanism (not shown) is configured to flow into the oil passage 22r via the oil passage 24 provided at the rear end of the oil passage 22r shown in FIG. (The flow path of the hydraulic oil is indicated by arrow A.) On the other hand, the engine output shaft 22 has three oil passages 22a, 22b, and 22c branched from the oil passage 22r as shown in FIGS.
Are formed, and the oil passage 22r communicates with the outside of the shaft through the oil passages 22a, 22b, and 22c. In such a configuration, the drain oil of the power steering mechanism is supplied to the main clutch 2 via the oil passage 22r → the oil passage 22a to forcibly lubricate the main clutch 2, and the drain oil is supplied to the oil passage 22r. → Oil passages 22b and 23
c, and is supplied to the reverser clutch 3 to forcibly lubricate the reverser clutch 3. As described above, in the present invention, the main clutch 2 and the reversing clutch 3 are forcibly lubricated by the drain oil of the power steering mechanism, so that the respective parts can be efficiently and reliably lubricated. . Also, since the hydraulic oil is supplied from the hydraulic circuit of the power steering mechanism, which is an existing facility, no new components are required, and the clutch can be reliably lubricated at low cost.

Although the main clutch 2 is lubricated by the drain oil of the power steering mechanism as described above, when the main clutch 2 is in the connected state, the clutch release 2c and the clutch center 2b
There is a problem that the lubricating oil escapes into the transmission case from the gap 2d because the gap between them is wide. Therefore, in the present invention, as shown in FIG. 5, the outer periphery of the clutch release 2c is bent to extend toward the clutch center 2b. With this configuration, the working oil sufficiently stays inside the main clutch 2 and the lubricating oil can be efficiently supplied to the clutch center 2b side. The performance and durability were improved.

As shown in FIG. 1, in the transmission case 1, the main clutch 2 is covered with a clutch case 20, and the front side of the clutch case 20 is covered with a clutch cover 21 so that the main clutch 2 Are accommodated. In the present invention, a bearing portion is provided on the clutch case 20, and the first pipe shaft (main shaft) 23 and the first and second idle shafts 33
The first idle shaft 33 is displaced due to a development view in FIG. 1, but is actually supported by the clutch case 20 in FIG. The clutch case 20 is mounted and fixed to the transmission case 1 with bolts or the like.

With such a configuration, by removing the clutch case 20, the respective shafts such as the main shaft 22 and the idle shaft can be integrally removed. became.
Further, at the time of assembly, the clutch case 20, the main clutch 2, and the first pipe shaft 23 can be handled integrally, so that the structure is easy to assemble.

The rear end of the engine output shaft 22 is connected to a connecting shaft 42, and a second pipe shaft 43 is provided on the outer periphery of the connecting shaft 42. And the forward gear 3
The rear end of the second pipe shaft 43 is spline-fitted to the front end of the second pipe shaft 43, and the rotation output transmitted to the forward gear 32 through forward / reverse rotation (forward / backward) by the operation of the reverser clutch 3 is transmitted to the second gear. The power is transmitted to the pipe shaft 43. The connecting shaft 42
Rotates integrally with the engine output shaft 22.

As shown in FIG. 2, the second pipe shaft 43 is provided with four gears 43a, b, c, and d having different diameters. Further, the main transmission shaft 4 is substantially parallel to the second pipe shaft 43.
And a main variable first speed gear 44a, a main variable second speed gear 44b, and a main variable third speed gear 4 loosely fitted to the main speed change shaft 44.
4c, the main variable fourth speed gear 44d is
-It rotates at different rotation speeds by meshing with b, c, and d.
The main transmission shaft 44 has shift sliders 45 and 46.
A main transmission 4 is provided, and the shift sliders 45 and 46 are operated by operating a shift fork (not shown).
By sliding the main transmission gears 44a and 44
The rotation output of any of the gears b, 44c, and 44d is transmitted to the main transmission shaft 44.

A gear 47 is provided at the rear end of the main transmission shaft 44 so as not to rotate relatively. The gear 47 meshes with the creep input gear 52. Creep input gear 52
Is a creep shaft 51 provided substantially parallel to the main transmission shaft 44.
The creep shaft 51 is provided with a creep output gear 53 at the rear end thereof. A creep output shaft 54 is connected to the rear end of the main transmission shaft 44 so as to be relatively rotatable.
4 is provided with a slide gear 55 that cannot rotate relatively and is slidable in the axial direction of the creep output shaft 54.

In the above configuration, when the slide gear 55 is slid forward (to the left in FIG. 2) and fitted to the gear 47 at the rear end of the main transmission shaft 44, the rotation of the main transmission shaft 44 The output is transmitted directly to the creep output shaft 54. On the other hand, when the slide gear 55 is slid rearward (to the right in FIG. 2), the slide gear 55 meshes with the creep output gear 53. Accordingly, the rotational output of the main transmission shaft 44 is transmitted to the creep output shaft 54 after being reduced through the gear 47, the creep input shaft 52, the creep output shaft 53, and the slide gear 55.

At the rear end of the creep output shaft 54, a transmission shaft 6
1 is connected, and the rotation output of the creep output shaft 54 is transmitted to the transmission shaft 61 as it is. The transmission shaft 61 is provided with three gears 61a, 61b, and 61c having different diameters, and rotates integrally with the transmission shaft 61. The transmission shaft 61 is provided with a sub-transmission shaft 62 substantially parallel to the transmission shaft 61.
The second variable speed gear 62a and the second variable speed gear 62
b, the sub variable third speed gear 62c
b and 61c and are rotating at different rotational speeds.
The sub-transmission shaft 62 is provided with a sub-transmission 6 composed of shift sliders 63 and 64 and the like. By operating a shift fork (not shown) to slide the shift sliders 63 and 64, The auxiliary transmission gears 62a, 62b
The rotation output of one of the gears 62c is transmitted to the auxiliary transmission shaft 62.

Here, a detailed configuration of the auxiliary transmission 6 will be described. As shown in FIGS. 2 and 6, a spline collar 68 is provided between the sub-transmission first-speed gear 62a and the sub-transmission second-speed gear 62b so that the sub-transmission shaft 62 cannot rotate relatively. The spline collar 68 is a cylindrical member inserted and fitted on the outer periphery of the auxiliary transmission shaft 62, and a spline 68 a is engraved on the outer peripheral surface of the spline collar 68. A shift slider 63 is provided on the outer periphery of the spline collar 68. A spline 63a on the inner periphery of the shift slider 63 and a spline 68a on the outer periphery of the spline collar 68 are fitted. It is configured to be non-rotatable and slidably supported in the axial direction.

In such a configuration, the switching operation between the first speed and the second speed in the auxiliary transmission 6 causes the shift slider 63 fitted to the spline collar 68 to slide in the axial direction of the auxiliary transmission shaft 62. Thus, the shift is performed by fitting the shift slider 63 to one of the auxiliary first and second speed gears 62a and 62b. At this time, the shift slider 63 is locked at each shift position, and It is necessary to be configured to maintain the shift position.

In the present invention, as shown in FIG. 6, the sectional shape of the spline 68a is
The side 2a has a tapered shape, and the side of the sub-transmission second speed gear 62b has a stepped shape. By adopting such a configuration, it is possible to prevent slippage of the first-speed and second-speed sub-transmissions, but to switch from the first-speed sub-speed shift position to the second-speed second-speed shift position with a tapered spline. 68a, the switching resistance is relatively small, and it is possible to prevent the torque from being locked in the state of the first shift position of the sub-shift, so that it is difficult to perform the shift switching from the shift position of the first sub-shift. Such a problem was solved, and a structure excellent in operability was obtained. In the present embodiment, the shape of the spline 68a according to the present invention has been described for the auxiliary transmission 6, but the spline 68a can be applied to the main transmission as well, and has the same effect. .

In this manner, the engine output shifted through the main transmission 4, the creep transmission 5, and the subtransmission 6 is transmitted from the bevel gear 67 provided at the rear end of the subtransmission shaft 62 to the rear axle case 10. It is input and drives the rear wheels.

At the front end of the auxiliary transmission shaft 62, front wheel output gears 65 and 66 are provided. A front wheel transmission shaft 71 is provided substantially parallel to the auxiliary transmission shaft 62, and gears 72 and 73 loosely fitted to the front wheel transmission shaft 71 mesh with front wheel output gears 65 and 66, respectively, to provide different rotations. Spinning by number. The front wheel transmission shaft 71 is provided with a hydraulic front wheel speed increasing clutch 7.
By this operation, the rotational output of one of the gears 72 and 73 is transmitted to the front wheel transmission shaft 71. And the gear 65
When power is transmitted via the gear 72, the rotational output of the front wheel transmission shaft 71 is taken into the front axle case via a shaft, gears and the like (not shown), and the front wheel can be accelerated. .

A connecting shaft 42 connected to the engine output shaft 22 extends rearward in the transmission case 1. The connecting shaft 42 is connected to the PTO clutch 80 via a PTO clutch 80.
It is connected to the TO transmission shaft 81. As shown in FIG. 3, the PTO transmission shaft 81 has three gears 81a and 81b having different diameters.
81c is provided so as not to rotate relatively.

The PT transmission shaft 81 is substantially parallel to the PT transmission shaft 81.
An O transmission shaft 82 is provided, and a PTO first speed gear 82a, a PTO second speed gear 82b, P
The third gear 82c is composed of gears 81a, 81b,
81c and rotates at different rotational speeds. The PTO transmission shaft 82 is provided with a PTO transmission 87 including a shift slider 86 and the like.
The rotation output of any one of the transmission gears 82a, 82b, 82c is transmitted to the PTO transmission shaft 82.

A gear 82d is provided at the rear end of the PTO speed change shaft 82.
The gear 82d meshes with a gear 83d of a transmission shaft 83 provided substantially parallel to the PTO speed change shaft 82.
The gear 83d is provided with a gear P substantially parallel to the transmission shaft 83.
It meshes with the gear 84d of the TO shaft 84. With the above configuration, after the engine output is shifted in three stages by the PTO transmission 87, it is taken out from the PTO shaft 84,
It drives various working machines attached to the work vehicle.

Next, the configuration of the PTO transmission drive unit 8 is as follows.
An embodiment in which a PTO idler shaft is added (an embodiment in which PTO reverse rotation is enabled) will be described. As shown in FIG. 7, a PTO idler shaft 88 is provided substantially parallel to the PTO transmission shaft 81 of the present embodiment. PTO idler shaft 88
A reverse gear 88a is provided at the front end of the PTO transmission shaft 81. The reverse gear 88a meshes with a gear 81r on the PTO transmission shaft 81.

The PTO transmission shaft 81 has a PT
An O transmission shaft 82 is provided, and the PTO first speed gear 82a and the PTO second speed gear 82b loosely fitted to the PTO transmission shaft 82 mesh with the gears 81a and 81b, respectively, and the PTO reverse gear 82r meshes with the reverse gear 88a to achieve different rotational speeds. , Rotating in the direction of rotation. The PTO transmission shaft 82 is provided with a PTO transmission 87 composed of a shift slider 86 and the like. When the shift slider 86 is slid to the first or second speed, the PTO transmission gear 82a
The rotational output of any one of the gears 82b
2 is transmitted. When the shift slider 86 is slid toward the PTO reverse gear 82r, the PTO
The rotation output of the transmission shaft 81 is represented by a gear 81r and a reverse gear 88.
a, the rotation direction is reversed through the PTO reverse rotation gear 82r, and then transmitted to the PTO speed change shaft 82.

In the present invention, a shift fork 89 for sliding the shift slider 86 is provided.
Is supported on the PTO idle shaft 88.
As described above, the PTO drive transmission unit 8 is configured such that the shaft supporting the shift fork 89, which is a component of the PTO transmission 87, and the PTO idle shaft 88, which is a component of the reverse rotation mechanism of the PTO, are also used. Can be made compact, and the entire transmission can be made compact.

[0037]

As described above, the present invention has the following advantages. That is, the engine output is transmitted to the main shaft in the transmission via the main clutch, and the main shaft is provided with the synchromesh type reverser clutch, so that the forward / reverse switching can be performed. The shock at the time can be reduced, and the transmission can have a compact configuration.

Also, the main clutch and the reverse clutch are forcibly lubricated by the drain oil of the power steering mechanism, so that the respective parts can be efficiently and reliably lubricated. became. Also, since the hydraulic oil is supplied from the hydraulic circuit of the power steering mechanism, which is an existing facility, no new components are required, and the clutch can be reliably lubricated at low cost.

According to a third aspect of the present invention, there is provided a clutch for switching the transmission from the input shaft to the output shaft by sliding the clutch release on the output shaft. With the structure extending to the clutch center side, the hydraulic oil sufficiently stays inside the clutch, and it is possible to supply the lubricating oil to the clutch center side efficiently. The durability was improved.

According to a fourth aspect of the present invention, a bearing for each shaft such as a main shaft and an idle shaft is formed in a clutch case for housing a main clutch, and the clutch case is mounted on a transmission case. By removing the clutch case, each shaft such as the main shaft and the idle shaft can be integrally removed, resulting in a configuration excellent in maintainability.
Further, at the time of assembly, the clutch case, the main clutch, and the first pipe shaft can be integrally handled, so that the structure is easy to assemble.

According to a fifth aspect of the present invention, a first speed gear is disposed on one side of a spline collar that rotates integrally with the speed change shaft, and a second speed gear is disposed on the other side. The spline and one of the transmission gears are engaged with each other via a shift slider to change the speed.The spline cross section of the spline collar has a tapered shape on one side and a spline cross section on the other side. Since the stepped shape is employed, the shift from the first-speed shift position to the second-speed shift position only needs to pass through the tapered spline, even though the first-speed and second-speed gears can be prevented from being disengaged. The switching resistance is relatively small, the torque can be prevented from being locked in the first shift position, and the problem of difficulty in shifting from the first shift position can be solved. It became an excellent structure.

Further, the PTO idle shaft for reversing the input rotation to the PTO shaft is provided with a PTO idle shaft.
Because it was configured to support the shift fork of the transmission,
The shaft that supports the shift fork, which is a component of the PTO transmission, and the PTO idle shaft, which is a component of the PTO reversing mechanism, are also used, so that the transmission can be made more compact.

[Brief description of the drawings]

FIG. 1 is a first sectional view of a transmission according to the present invention.

FIG. 2 is a second sectional view of the transmission according to the present invention.

FIG. 3 is a third sectional view of the transmission according to the present invention.

FIG. 4 is a sectional view of a synchromesh type reverser clutch.

FIG. 5 is an enlarged sectional view of a main part of the main clutch.

FIG. 6 is a diagram showing a spline sectional shape of a spline collar.

FIG. 7 is an embodiment diagram in which a PTO shift fork is supported on an idle shaft on which a reverse gear is fitted.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transmission case 2 main clutch 3 reverser clutch 4 main transmission 6 auxiliary transmission 8 PTO drive transmission unit 20 clutch case 21 clutch cover 22 engine output shaft 22r oil passage 22a, b, c oil passage 23 first pipe shaft (main shaft) ) 24 oil passage 33 first idle shaft 35 second idle shaft 62a auxiliary first speed gear 62b auxiliary second speed gear 63 shift slider 68 spline collar 68a spline 88 PTO idle shaft

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) F16D 11/00 F16D 11/00 A 13/74 13/74 Z F16H 63/02 F16H 63/02 63/30 63/30 F-term (reference) 3D039 AA02 AA04 AA12 AA15 AB12 AC03 AC14 AC15 AC38 AC45 AC64 AC70 AC80 AC85 AC86 AD06 AD23 3D043 AA06 AB12 BA06 BC03 BC05 BC09 BC11 BD03 BE01 3J056 AA22 BA01 BA03 BB15 BB21 GA04 AC05 3 AC51 AC53 EA90 FB01 FB33 FB81 FB83 GA14

Claims (6)

[Claims] An engine output is transmitted to a main shaft in a transmission via a main clutch, and a synchromesh type reverser clutch is provided on the main shaft. apparatus. 2. The transmission according to claim 1, wherein the main clutch and the reverser clutch are forcibly lubricated by drain oil of a power steering mechanism. 3. A clutch for turning on / off transmission from an input shaft to an output shaft by sliding a clutch release on an output shaft, wherein an outer peripheral portion of the clutch release extends toward a clutch center. A transmission for a work vehicle, wherein the transmission is configured. 4. A work vehicle according to claim 1, wherein a bearing portion for each shaft such as a main shaft and an idle shaft is formed in a clutch case for housing the main clutch, and the clutch case is mounted on a transmission case. Transmission. 5. A first-speed gear is disposed on one side of a spline collar that rotates integrally with a transmission shaft, and a second-speed gear is disposed on the other side.
A speed gear is disposed, and the speed is changed by fitting the spline of the spline collar and any of the transmission gears via a shift slider, and the spline cross-sectional shape of the spline collar is such that one side is A transmission for a working vehicle, wherein the transmission has a tapered shape and a stepped shape on the other side. 6. A transmission for a work vehicle, wherein a shift fork of the PTO transmission is supported on a PTO idle shaft for reversing an input rotation to the PTO shaft.