JP2024011917A - Speed changer - Google Patents

Abstract

To solve the problem that in an operation structure of a speed changer, two mechanical mechanisms are provided between a gearshift lever and first and second shifting gear mechanisms, so the operation structure is complicated to increase costs and to cause speed changing operation trouble due to backlash of the respective mechanical mechanisms.SOLUTION: A speed changer includes: first and second shifting gear mechanisms 21, 22; a first switching mechanism 31 selectively switching power transmission due to the first shifting gear mechanism 21; a second switching mechanisms 32 selectively switching power transmission by the second shifting gear mechanism 22; and a single switch shaft 60 which interlocks with operation of a single speed change tool 14 and rotates around the shaft or slides in the shaft direction. To the speed change tool 14, a base end part of the switching shaft 60 is interlockingly coupled. At an end part of the switching shaft 60, a selection member 72 uniformly selecting the first switching mechanism 31 and the second switching mechanisms 32 is provided.SELECTED DRAWING: Figure 2

Description

The present invention relates to a transmission device mounted on a work vehicle such as an agricultural work machine such as a tractor or a special work machine such as a crane truck.

BACKGROUND ART Conventionally, it is well known that work vehicles such as agricultural machines have a main transmission mechanism and a sub-transmission mechanism as a transmission (see, for example, Patent Document 1). Patent Document 1 discloses an example of an operation structure for this type of transmission.

In the transmission device of Patent Document 1, the first link mechanism that switches and operates the first clutch of the first auxiliary transmission gear mechanism and the second link mechanism that switches and operates the second clutch of the second auxiliary transmission gear mechanism are on the horizontal axis. is linked to. A first change arm for selecting the first link mechanism and a second change arm for selecting the second link mechanism are attached to the base of the sub-shift lever that can be rotated about the horizontal axis. They are placed opposite each other. The lever portion of the sub-shift lever is configured to be selectively engageable and detachable from the engaging portion formed on each change arm. By operating the sub-shift lever along the guide groove of the lever guide and selecting and rotating each change arm, the first or second clutch is switched via the corresponding link mechanism, resulting in sub-shift power. can be shifted to 4 speeds.

Japanese Patent Application Publication No. 2001-199253

However, in the configuration of Patent Document 1, it is necessary to provide two mechanical mechanisms, a first link mechanism and a second link mechanism, between the auxiliary shift lever and the first and second auxiliary shift gear mechanisms. There was a problem in that the structure became complicated and the cost increased. Further, since there is a relatively long distance from each change arm selectively selected by the sub-shift lever to the corresponding clutch, each link mechanism must be configured to be long. In this case, there is a problem in that the auxiliary gear shifting operation is hindered due to the rattling of each link mechanism.

The technical object of the present invention is to provide a transmission device that has been improved by considering the above-mentioned current situation.

The transmission device of the present invention includes first and second transmission gear mechanisms, a first switching mechanism that selectively switches power transmission by the first transmission gear mechanism, and a first switching mechanism that selectively switches power transmission by the second transmission gear mechanism. It is equipped with a second switching mechanism for switching, and a single switching shaft that rotates around the axis or slides in the axial direction in conjunction with the operation of the single speed change operation tool, and the speed change operation tool includes The base end of the switching shaft is interlocked and connected, and the distal end of the switching shaft is provided with a selection member that selectively selects the first switching mechanism and the second switching mechanism. It is something.

The transmission of the present invention further includes a transmission case that accommodates both of the transmission gear mechanisms and both of the switching mechanisms, the switching shaft is pivotally supported by the transmission case, and the base end of the switching shaft is The switching shaft may be located outside the transmission case, and the tip of the switching shaft and the selection member may be located inside the transmission case.

In the transmission of the present invention, the switching shaft is configured to slide in an axial direction in conjunction with a selection operation of the speed change operating tool, and rotate around the axis in conjunction with a shift operation of the speed change operating tool. It may be.

In the transmission of the present invention, the switching shaft slides in the axial direction by a selection operation of the speed change operation tool, and the selection member connects or disconnects from the first or second switching mechanism. may be configured.

In the transmission device of the present invention, the switching shaft is rotated about the axis by a shift operation on the neutral side of the speed change operating tool, and the selection member is moved to a position where it can be connected to the first or second switching mechanism. may be configured to move.

In the transmission device of the present invention, the switching shaft rotates around the axis by a shift operation on the speed change side of the speed change operation tool, and the selection member selects the first or second switching mechanism for the corresponding speed change. A configuration may be adopted in which the power transmission by the gear mechanism is operated so as to be selectively switched.

According to the transmission of the present invention, the transmission device includes a single switching shaft that rotates around the axis or slides in the axial direction in conjunction with the operation of a single speed change operating tool, and the base end of the switching shaft is interlocked and connected to the speed change operation tool, and a selection member for selectively selecting the first switching mechanism and the second switching mechanism is provided at the tip of the switching shaft, so that the two switching mechanisms ( The two transmission gear mechanisms can be selectively selected using a selection member provided at the tip of a single switching shaft, eliminating the need for two long link mechanisms as in Patent Document 1. Therefore, the number of parts related to the speed change operation system can be reduced, and costs can be suppressed.

In addition, since the selection member is provided at the tip of the switching shaft, the selection member can be placed near the two switching mechanisms (two speed change gear mechanisms), eliminating the problem of rattling caused by the presence of long link mechanisms. . Therefore, the operability of the gear shift operation system is improved.

FIG. 2 is a schematic perspective view of a tractor. FIG. 3 is a schematic perspective view showing the operation structure of the sub-shift lever. FIG. 3 is an enlarged perspective view of the operation structure of the sub-shift lever seen from another direction. FIG. 3 is a schematic front view showing the operation structure of the sub-shift lever. FIG. 3 is a schematic front view when the sub-shift lever is at a first neutral position. FIG. 6 is a schematic front view when the sub-shift lever is at a second neutral position. FIG. 6 is a schematic front view when the sub-shift lever is in a third neutral position. FIG. 7 is a schematic front view when the sub-shift lever is at a fourth neutral position.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described based on the drawings. The embodiment disclosed below is a case where the transmission device of the present invention is applied to a tractor 1 as a work vehicle. In the following description, words such as front and back, left and right, and up and down are used to specify directions and positions, but these terms are based on the direction of the operator sitting on the tractor 1. These terms are used for convenience of explanation and are not intended to limit the technical scope of the present invention.

First, the general structure of the tractor 1 will be explained with reference to FIG. As shown in FIG. 1, the tractor 1 includes a traveling body 2. As shown in FIG. The traveling body 2 is supported by a pair of left and right front wheels 3 and a pair of left and right rear wheels 4. An engine 5 is mounted on the front part of the traveling body 2. By driving the rear wheels 4 and front wheels 3 with the power of the engine 5, the tractor 1 travels forward and backward.

A front axle case 6 that protrudes outward from the left and right is attached to a lower part in front of the engine 5 in the traveling body 2. Front wheels 3 are attached to both left and right sides of a front axle case 6 so as to be steerable. A transmission case 7 is disposed at the rear of the traveling body 2 to appropriately change the speed of the power of the engine 5 and transmit it to both rear wheels 4 and both front wheels 3. The mission case 7 is located below a control seat 12, which will be described later. A rear axle case 8 is provided on the left and right outer surfaces of the transmission case 7 to protrude outward. A rear wheel 4 is attached to the left and right outer ends of each rear axle case 8.

An engine 5 located at the front of the traveling body 2 is covered with a bonnet 9. A control column 10 is arranged at the rear of the hood 9. A steering handle 11 for changing the steering angle of both the left and right front wheels 3 is arranged on the upper surface side of the steering column 10. A control seat 12 is arranged behind the control column 10. Side columns 13 are provided on both the left and right sides of the pilot seat 12. One side column 13 (left side column 13 in the embodiment) is provided with a sub-shift operation tool that sets and maintains the shift output of the sub-transmission mechanism 20 (see FIGS. 2 to 8) within the mission case 7 within a predetermined range. A speed change lever 14 is arranged.

As shown in FIGS. 2 to 8, the auxiliary transmission mechanism 20 housed in the mission case 11 is a mechanical type that changes the output in multiple stages via a hydraulic continuously variable transmission (not shown) or the like driven by the power of the engine 5. It is composed of a creep transmission gear mechanism 21 and a traveling sub-transmission gear mechanism 22. The creep transmission gear mechanism 21 corresponds to a first transmission gear mechanism, and the traveling sub-transmission gear mechanism 22 corresponds to a second transmission gear mechanism.

In the embodiment, an auxiliary transmission output shaft 23 extending in the longitudinal direction is rotatably supported within the mission case 11. A creep gear 24 and a sub-transmission first speed gear 25 are rotatably fitted onto the rear side of the sub-transmission output shaft 23 in order from the rear side. A creep slider 26 is fitted between the creep gear 24 and the auxiliary first speed gear 25 on the auxiliary transmission output shaft 23 so that the creep slider 26 is not relatively rotatable and is slidable in the axial direction.

A second sub-speed gear 27 and a third sub-speed gear 28 are rotatably fitted onto the front side of the sub-transmission output shaft 23 in order from the rear side. A sub-transmission slider 29 is fitted between the sub-transmission second speed gear 27 and the sub-transmission third speed gear 28 on the sub-transmission output shaft 23 so as to be non-rotatable relative to each other and slidable in the axial direction.

As shown in FIGS. 2 to 8, the transmission case 11 includes a first switching mechanism 31 that selectively switches the power transmission by the creep transmission gear mechanism 21, and a first switching mechanism 31 that selectively switches the power transmission by the traveling auxiliary transmission gear mechanism 22. A second switching mechanism 32 for switching is housed therein.

The first switching mechanism 31 has a creep operation shaft 33 that extends parallel to the sub-transmission output shaft 23 . Similarly, the second switching mechanism 32 has a sub-shift operation shaft 34 that extends parallel to the sub-shift output shaft 23 and the creep operation shaft 33. Both the creep operation shaft 33 and the sub-shift operation shaft 34 are supported within the mission case 11 so as to be slidable along the axial direction.

A creep fork 36 that engages with the creep slider 26 is fixed to the creep operation shaft 33. Furthermore, a sub-shift fork 39 that engages with the sub-shift slider 29 is fixed to the sub-shift operating shaft 34 . The creep fork 36 is provided with a first arm piece 37 that projects upward. On the upper end side of the first arm piece 37, a first engaging pin shaft 38 extending laterally and extending parallel to a switching shaft 60, which will be described later, is projectingly provided. The auxiliary transmission fork 39 is provided with a second arm piece 40 that projects upward. A second engagement pin shaft 41 extending horizontally and extending parallel to the switching shaft 60 and the first engagement pin shaft 38 projects from the upper end side of the second arm piece 40 .

Although the details will be described later, when the creep fork 36 is moved in the direction of the creep operation shaft 33 based on the operation of the sub-shift lever 14, the creep slider 26 is slid along the sub-shift output shaft 23, and the creep gear 24 and the sub-shift A first gear 25 is alternatively connected to the sub-transmission output shaft 23. As a result, the rotational power of the creep gear 24 and the sub-transmission first speed gear 25 is transmitted to the sub-transmission output shaft 23.

Further, when the sub-transmission slider 29 is slid along the sub-transmission output shaft 23 by the movement of the sub-transmission fork 39 in the direction of the sub-transmission operating shaft 34 based on the operation of the sub-transmission lever 14, the sub-transmission second speed gear 27 A sub-transmission third speed gear 28 is alternatively connected to the sub-transmission output shaft 23. As a result, the rotational power of the sub-transmission second speed gear 27 and the sub-transmission third speed gear 28 is transmitted to the sub-transmission output shaft 23.

Although a detailed explanation will be omitted, in the forks 36 and 39 of the embodiment, when the creep fork 36 is moved, the auxiliary transmission fork 39 is prevented from moving, and when the auxiliary transmission fork 39 is moved, the creep fork 36 is prevented from moving. The structure is designed to prevent the movement of

As shown in FIGS. 2 to 8, the sub-shift lever 14 disposed on the left side column 13 has a fulcrum block 44 at its lower end (base end). A lever select shaft 46 extending in the front-rear direction is attached to a pedestal 45 disposed below the left side column 13. The lever select shaft 46 passes through the fulcrum block 44 of the sub-shift lever 14. Therefore, the sub-shift lever 14 is configured to be rotatable in the left-right direction (select direction) about the lever select shaft 46.

Lever shift pin shafts 47 projecting outward from the left and right are provided on both left and right side surfaces of the fulcrum block 44. The lever shift pin shaft 47 is rotatably inserted into and attached to the base end of the sub-shift lever 14. Therefore, the sub-shift lever 14 is configured to be rotatable in the longitudinal direction (shift direction) around the lever shift pin shaft 47. That is, the sub-shift lever 14 of the embodiment is configured to be rotatable both in the front-rear direction (shift direction) and in the left-right direction (select direction).

A lever guide 48 is arranged above the pedestal 45 on the left side column 13. The sub-shift lever 14 passes through grooves 49 to 51 formed in the lever guide 48 and projects upward from the left side column 13. The sub-shift lever 14 can be rotated forward, backward, left and right along the grooves 49 to 51 of the lever guide 48. The presence of these grooves 49 to 51 restricts the rotational operation range of the sub-shift lever 14.

The lever guide 48 is formed with two shift grooves 49 and 50 that extend in the front-rear direction (shift direction) and a neutral groove 51 that has an inverted U-shape in plan view and connects the shift grooves 49 and 50. The creep shift groove 49 and the sub-transmission shift groove 50 are formed in a straight line in the front-rear direction (shift direction).

A first neutral position (N1) is provided between the creep position (C) of the creep shift groove 49 and the sub-shift first speed position (first speed). A fourth neutral position (N4) is provided between the auxiliary transmission 2nd speed position (2nd speed) and the auxiliary transmission 3rd speed position (3rd speed) of the auxiliary transmission shift groove 50. The front corner portion of the neutral groove 51 is configured at a second neutral position (N2). The rear corner portion of the neutral groove 51 is configured at a third neutral position (N3).

A first neutral position (N1) of the creep shift groove 49 and a fourth neutral position (N4) of the auxiliary transmission shift groove 50 communicate with each other via a neutral groove 51 that has an inverted U-shape in plan view. That is, the sub-shift lever 14 is configured to be movable between the creep shift groove 49 and the sub-shift groove 50 via the neutral groove 51.

The sub-shift lever 14 is interlocked and connected via a shift link mechanism 58 and a select link mechanism 59 to the base end of a single horizontally elongated switching shaft 60 that rotates around the axis and slides in the axial direction. has been done. The switching shaft 60 is rotatably supported by the mission case 11 so as to be rotatable around the shaft and slidable in the axial direction.

As shown in FIG. 4 , the base end portion (left end portion in the embodiment) of the switching shaft 60 projects to the outside of the mission case 11 . The switching shaft 60 is located inside the mission case 11 from the middle to the tip (right end). A relay bracket 61 is attached to one of the left and right side surfaces (in the embodiment, the left side surface) of the mission case 11. The base end side (left end side) of the switching shaft 60 passes through one left and right side of the mission case 11 and the relay bracket 61.

As described above, two link mechanisms 58 and 59 are provided between the sub-shift lever 14 and the switching shaft 60. Of the link mechanisms 58 and 59, the shift link mechanism 58 is a mechanism that rotates the switching shaft 60 around the axis in conjunction with the longitudinal rotation operation (shift operation) of the sub-shift lever 14.

In the embodiment, the upper end side of the shift rod 63 is connected to a projecting arm 62 that projects diagonally downward and forward from the lower end (base end) of the sub-shift lever 14 . The lower end side of the shift rod 63 is connected to a link arm 64 fixed to the base end side of the switching shaft 60. When the sub-shift lever 14 is rotated in the longitudinal direction (shift direction) around the lever shift pin shaft 47, the shift rod 63 moves up and down in conjunction with this, and the link arm 64 is rotated around the switching shaft 60. As a result, the switching shaft 60 rotates around the axis.

The select link mechanism 59 is a mechanism that slides the switching shaft 60 in the axial direction in conjunction with a left-right rotation operation (select operation) of the sub-shift lever 14. In the embodiment, the upper end of the select rod 66 is connected to a rotating arm 65 fixed to the rear end of the lever select shaft 46 . A pivot shaft 67 facing forward and backward is rotatably supported on the relay bracket 61 . The lower end of the select rod 66 is connected to a relay arm 68 fixed to the rear end of the pivot shaft 67 . A locking pin 70 protruding forward from a linking arm 69 fixed to the front end side of the pivot shaft 67 is inserted into a locking groove 71 formed along the outer periphery of the base end of the switching shaft 60.

When the sub-shift lever 14 is rotated in the left-right direction (select direction) around the lever select shaft 46, the select rod 66 moves up and down in conjunction with this, and the relay arm 68 and eventually the link arm 69 are rotated around the pivot shaft 67. Rotate it. As a result, the locking pin 70 fitted into the locking groove 71 of the switching shaft 60 slides the switching shaft 60 in the axial direction.

That is, in the embodiment, by interposing the shift link mechanism 58 and the select link mechanism 59, the single switching shaft 60 can be rotated around the single switching shaft 60 by rotating the single sub-shift lever 14 in the front, back, right, and left directions. It is possible to rotate it or slide it in the axial direction. The sub-shift lever 14 and the switching shaft 60 are configured in a one-to-one relationship.

A selection arm 72 as a selection member that selectively selects the first switching mechanism 31 and the second switching mechanism 32 is provided at the tip (right end) of the switching shaft 60 to protrude downward. The selection arm 72 is fixed to rotate integrally with the switching shaft 60. The selection arm 72 is formed with a guide slot 73 extending along its longitudinal direction. Needless to say, the selection arm 72 is located inside the mission case 11.

The selection arm 72 (the guide slot 73 thereof) is rotated about the switching shaft 60 in a state in which the selection arm 72 (its guide slot 73) is disengaged from the first engagement pin shaft 38 and the second engagement pin shaft 41 to prevent creep. It can be rotated to a position facing the first engagement pin shaft 38 of the fork 36 and the second engagement pin shaft 41 of the sub-transmission fork 39 (which can also be called a position where it can be connected, see FIGS. 6 and 7). It has become. Further, the selection arm 72 (the guide slot 73 thereof) is configured to be able to engage and disengage from the first engagement pin shaft 38 and the second engagement pin shaft 41 by sliding movement of the switching shaft 60 in the axial direction. (See Figures 5 to 8).

In the above configuration, when the sub-shift lever 14 is in the first neutral position (N1) shown in FIG. are doing. In this state, when the sub-shift lever 14 is rotated in the longitudinal direction (shift direction) along the creep shift groove 49 (corresponding to a shift operation on the transmission side), the shift rod 63 moves up and down in conjunction with this. Then, the link arm 64 is rotated around the switching shaft 60, and the switching shaft 60 is rotated around the axis.

Then, in this state, since the first engagement pin shaft 38 of the creep fork 36 is engaged with the guide slot 73 of the selection arm 72, the creep operation shaft is The creep fork 36 moves in the 33 direction, and the creep slider 26 engaged with the creep fork 36 slides along the sub-shift output shaft 23. As a result, the creep gear 24 and the sub-transmission first speed gear 25 are selectively connected to the sub-transmission output shaft 23, and the rotational power of the creep gear 24 and the sub-transmission first speed gear 25 is transmitted to the sub-transmission output shaft 23.

When the sub-shift lever 14 is in the fourth neutral position (N4) shown in FIG. 8, the second engagement pin shaft 41 of the sub-shift fork 39 is engaged with the guide slot 73 of the selection arm 72. In this state, when the sub-shift lever 14 is rotated in the longitudinal direction (shift direction) along the sub-shift shift groove 50, the shift rod 63 moves up and down in conjunction with this, and the link arm 64 is switched. The switch shaft 60 is rotated around the shaft 60, and the switching shaft 60 is rotated around the shaft.

Then, in this state, since the second engagement pin shaft 41 of the sub-transmission fork 39 is engaged with the guide slot 73 of the selection arm 72, the sub-shift The auxiliary transmission fork 39 moves in the direction of the transmission operation shaft 34, and the auxiliary transmission slider 29 engaged with the auxiliary transmission fork 39 slides along the auxiliary transmission output shaft 23. As a result, the auxiliary transmission 2nd speed gear 27 and the auxiliary transmission 3rd speed gear 28 are selectively connected to the auxiliary transmission output shaft 23, and the rotational power of the auxiliary transmission 2nd speed gear 27 and the auxiliary transmission 3rd speed gear 28 is transmitted to the auxiliary transmission output. The signal is transmitted to the shaft 23.

When the sub-shift lever 14 is in the first neutral position (N1) shown in FIG. When the shift rod 63 is moved to the second neutral position (N2) shown in (corresponding to the select operation), the shift rod 63 does not move, but the select rod 66 moves up and down in conjunction with this, and the relay arm 68 and the linking arm 69 is rotated around the pivot shaft 67, and the locking pin 70 fitted into the locking groove 71 of the switching shaft 60 slides in the direction of pushing out the switching shaft 60. Then, the selection arm 72 moves away from the first engagement pin shaft 38, and the first engagement pin shaft 38 of the creep fork 36 is disengaged from the guide slot 73 of the selection arm 72 (Fig. 6 reference).

Then, when the sub-shift lever 14 is rotated in the front-back direction (shift direction) along the front-rear midway part of the neutral groove 51 and moved to the third neutral position (N3) shown in FIG. Since the guide slot 73 of the selection arm 72 is in a free state, the selection arm 72 (the guide slot 73 of the selection arm 72) moves in conjunction with the rotation of the switching shaft 60 around the axis (corresponding to a shift operation). (See FIG. 7).

Next, when the sub-shift lever 14 is rotated in the left-right direction (select direction) along the rear part of the neutral groove 51 and moved to the fourth neutral position (N4) shown in FIG. 8 (corresponding to a select operation). , the shift rod 63 does not move, but the select rod 66 moves up and down in conjunction with this, causing the relay arm 68 and the linking arm 69 to rotate around the pivot shaft 67 and to engage the locking groove 71 of the switching shaft 60. The fitted locking pin 70 slides the switching shaft 60 in the direction of pulling it back.

Then, the selection arm 72 moves toward the second engagement pin shaft 41, and the second engagement pin shaft 41 of the auxiliary transmission fork 39 engages with the guide slot 73 of the selection arm 72 (Fig. 8). When operating the sub-shift lever 14 from the fourth neutral position (N4) to the first neutral position (N1), operate the sub-shift lever 14 from the first neutral position (N1) to the fourth neutral position (N4) as described above. The flow is opposite to that of .

According to the above configuration, the single switching shaft 60 is provided which rotates around the shaft or slides in the axial direction in conjunction with the operation of the single sub-shift lever 14, and the base end of the switching shaft 60 This is because a selection arm 72 is provided at the tip of the switching shaft 60 to selectively select between the first switching mechanism 31 and the second switching mechanism 32. , the two switching mechanisms 31, 32 (two speed change gear mechanisms 21, 22) can be selectively selected by a selection arm 72 provided at the tip of a single switching shaft 60, Two long linkages are no longer required. Therefore, the number of parts related to the speed change operation system can be reduced, and costs can be suppressed.

Further, since the selection arm 72 is provided at the tip of the switching shaft 60, the selection arm 72 can be placed near the two switching mechanisms 31 and 32 (the two transmission gear mechanisms 21 and 22), and the long link mechanism The problem of rattling caused by its presence is eliminated. Therefore, the operability of the gear shift operation system is improved.

Note that the configuration of each part in the present invention is not limited to the illustrated embodiment, and various changes can be made without departing from the spirit of the present invention. For example, the transmission device is not limited to the operating structure associated with the sub-shift lever 14 of the embodiment, but may be employed in an operating structure associated with a main shift lever, a PTO shift lever, etc. used in agricultural machinery, etc.

1 Tractor 7 Mission case 13 Side column 14 Sub-shift lever (shift operating tool)
21 Creep transmission gear mechanism (first transmission gear mechanism)
22 Travel sub-transmission gear mechanism (second transmission gear mechanism)
31 First switching mechanism 32 Second switching mechanism 36 Creep fork 38 First engagement pin shaft 39 Sub-transmission fork 41 Second engagement pin shaft 58 Shift link mechanism 59 Select link mechanism 60 Switch shaft 72 Selection arm (selection member)
73 Guide slot

Claims (6)

first and second transmission gear mechanisms, a first switching mechanism that selectively switches power transmission by the first transmission gear mechanism, and a second switching mechanism that selectively switches power transmission by the second transmission gear mechanism; It is equipped with a single switching shaft that rotates around the shaft or slides in the axial direction in conjunction with the operation of a single speed change operating tool.
A base end of the switching shaft is interlocked and connected to the speed change operation tool, and a selection member is provided at the distal end of the switching shaft for selectively selecting between the first switching mechanism and the second switching mechanism. is provided,
gearbox. further comprising a transmission case that accommodates both of the transmission gear mechanisms and both of the switching mechanisms;
The switching shaft is pivotally supported by the transmission case, a base end of the switching shaft is located outside the transmission case, and a distal end of the switching shaft and the selection member are located inside the transmission case. ing,
A transmission according to claim 1. The switching shaft is configured to slide in an axial direction in conjunction with a selection operation of the speed change operating tool, and rotate around the axis in conjunction with a shift operation of the speed change operating tool.
The transmission according to claim 2. The switching shaft slides in the axial direction by a selection operation of the speed change operation tool, and the selection member connects or disconnects from the first or second switching mechanism.
The transmission according to claim 3. The switching shaft rotates around the axis by a shift operation on the neutral side of the speed change operation tool, and the selection member moves to a position where it can be connected to the first or second switching mechanism.
The transmission according to claim 3. The switching shaft rotates around the axis by a shift operation on the speed change side of the speed change operation tool, and the selection member selects the first or second switching mechanism and the power transmission by the corresponding speed change gear mechanism. operate so as to switch between
The transmission according to claim 3.

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