JPH08145075A - Gear transmission device - Google Patents

Abstract

PURPOSE: To prevent gear noise, and also prevent unauthorized sliding resistance following power loss. CONSTITUTION: A first rotary member (clutch hub) 26 which rotates integratedly with an output shaft 22, and a second rotary member 32 which is rotatably supported at a prescribed angle opposing to the first rotary member 26, are arranged so as to be brought in contact with each other on the output shaft 22. The opposing surface of the first rotary member 26 and the second rotary member 32 is provided with a surface which is in parallel with the output shaft 22 and an inclining surface at a prescribed angle opposing to the parallel surface, and a friction member 33 is arranged between a driven gear (a first gear) 25 and the second rotary member 32. Only when rotary speed of an input shaft 20 is higher than that of the output shaft 22, sliding resistance is applied on the driven gear 25 which is loosely fitted to the output shaft 22, and thereby, it is possible to prevent gear noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle gear transmission, and more particularly to a gear transmission configured to prevent gear meshing noise and gear rattle noise.

[0002]

2. Description of the Related Art The basic structure of a general vehicle manual transmission will be described with reference to FIG. 11, which is disclosed in Japanese Utility Model Publication No. 62-15558, in which an output shaft 1 is provided with a clutch hub 2. Driven gears 3 and 4 which are spline-fitted and which are in mesh with the drive gear that rotates integrally with an input shaft (not shown) are rotatably disposed on both left and right sides of the clutch hub 2. Spline pieces 5 and 6 are spline-fitted to portions of the driven gears 3 and 4 on the clutch hub 2 side. Of these spline pieces 5 and 6, taper cone portions 7 and 8 are formed on the outer periphery of a boss portion that extends toward the clutch hub 2 side, and synchronizer rings 9 and 10 are formed in the taper cone portions 7 and 8 in the axial direction. It is movably fitted with a predetermined size. A hub sleeve 11 is engaged with the outer peripheral portion of the clutch hub 2 via a shifting key 13 biased by a key spring 12 so as to be movable only in the axial direction. A chamfer is formed on each of the parts, a chamfer is formed on the outer periphery of each of the synchronizer rings 9 and 10, and splines 14 and 15 that engage with the hub sleeve 11 are formed on the outer periphery of each of the spline pieces 5 and 6. ing.

In the vehicle manual transmission constructed as described above, when the hub sleeve 11 is moved to one of the driven gears 3 and 4, the synchronizer rings 9 and 10 are pushed by the keys. Spline piece 5,
Move to side 6. As a result, the synchronizer ring 9,
10 is engaged with the spline pieces 5, 6 by the tapered cone portions 7, 8 and starts to rotate synchronously. Hub sleeve 11
When the chamfers of the synchronizer ring 9 and the chamfers of the synchronizer rings 9 and 10 come into contact with each other, the hub sleeve 11 is further moved.
0 chamfers are pushed apart to move forward, and engage with the splines 14 and 15 of the spline pieces 5 and 6.

The synchronizer rings 9 and 10 act when the hub sleeve 11 is engaged with the spline pieces 5 and 6 on the driven gears 3 and 4, and are in the neutral state shown in FIG. 11 or a gear not shown. In the state where the predetermined shift speed is set, the synchronizer rings 9 and 10 are stopped or rotated together with the clutch hub 2. On the other hand, the above-mentioned input shaft and drive gear are rotating at different speeds including rotation fluctuations of the engine, and the driven gears 3 and 4 which can idle on the output shaft 1 are drive gears. It meshes with and rotates. At this time, backlash occurs between the driving gear and the driven gears 3 and 4 due to the fluctuation of the rotation of the engine, and the teeth are struck by the amount of this backlash, and abnormal noise (teeth rattling noise) is generated.

[0005]

Therefore, in the conventional manual transmission for a vehicle, a spring 14 for axially urging the synchronizer rings 9 and 10 is fitted into the clutch hub 2 to insert the synchronizer rings 9 and 10 into a tapered cone portion. The noises are prevented from occurring by lightly pressing them against 7, 8 to give drag resistance to the spline pieces 5, 6 (driven gears 3, 4). However, drag resistance is always generated in the tapered cone portions 7 and 8, so that the service lives of the synchronizer rings 9 and 10 are shortened, and the operating force and power loss at the time of gear shift operation are increased. In the vehicle manual transmission described in Japanese Utility Model Publication No. 62-15558, the spring 14 is made of a shape memory alloy, and the operation of the spring 14 is controlled by temperature. However, except when abnormal noise must be prevented. Similarly, drag resistance occurred.

The present invention has been made in view of the above circumstances, and it is possible to effectively prevent generation of abnormal noise between the output shaft and the driven gear and to prevent unnecessary dragging resistance accompanied by power loss. An object of the present invention is to provide a gear transmission capable of achieving the above.

[0007]

In order to achieve the above object, the present invention provides a second rotary member which is dragged by an input shaft to a first rotary member which rotates integrally with an output shaft and is about to rotate. Based on the relative rotation speed, that is, the magnitude relation between the rotation speed of the input shaft and the rotation speed of the output shaft, drag resistance is applied to the driven gear to prevent generation of abnormal noise.

More specifically, the invention described in claim 1 is a drive gear which rotates integrally with an input shaft, and a driven gear which is always meshed with the drive gear and is rotatably supported by the output shaft. A clutch hub that rotates integrally with the output shaft; a hub sleeve that is axially movably engaged with the outer peripheral portion of the clutch hub; and the hub sleeve that moves with the axial movement of the hub sleeve. In a gear transmission including a synchronizer ring that applies drag resistance to the driven gear and rotates synchronously with the driven gear, a first rotating member that rotates integrally with the output shaft, and the first rotating member on the output shaft. A second rotating member, which is supported so as to be rotatable relative to the rotating member by a predetermined angle, is arranged to face each other on the output shaft, and the driven gear and the second rotating member are Is provided with a friction transmission portion for transmitting torque, and is operated by rotation of the second rotating member relative to the first rotating member in one predetermined direction. A separating mechanism for separating the two rotating members from each other in the axial direction is provided between the first rotating member and the second rotating member, and the second rotating member and the synchronizer ring are provided on the output shaft. Are arranged so as to face each other.

According to a second aspect of the present invention, there is provided a drive gear which rotates integrally with the input shaft, a driven gear which is always meshed with the drive gear and is rotatably supported by the output shaft, and the output shaft. A clutch hub that rotates integrally with the hub hub, a hub sleeve that is movably engaged with the outer peripheral portion of the clutch hub in the axial direction, and the hub sleeve and the driven gear as the hub sleeve moves in the axial direction. In a gear transmission including a synchronizer ring that applies drag resistance to and to rotate synchronously, a first rotating member that rotates integrally with the output shaft, and the output shaft with respect to the first rotating member. A second rotating member supported so as to be rotatable relative to a predetermined angle is disposed so as to face the output shaft, and torque transmission is performed between the driven gear and the second rotating member. Friction transmission unit is provided to perform, it is operated by the relative rotation of the predetermined direction of the second rotating member with respect to the first rotary member, these first
A separating mechanism for separating the rotating member and the second rotating member from each other in the axial direction is provided between the first rotating member and the second rotating member, and the second rotating member and the driven gear. And are arranged to face each other on the output shaft.

[0010]

According to the above construction, the first rotating member rotates integrally with the output shaft, while the second rotating member rotates while transmitting torque with the driven gear (input shaft). Further, a separating mechanism is provided which separates the first rotating member and the second rotating member in the axial direction by the relative rotation speed of the second rotating member with respect to the first rotating member.
Therefore, only when the rotation speed of the driven gear (input shaft) and the rotation speed of the output shaft, for example, the rotation speed of the driven gear (input shaft) is higher than the rotation speed of the output shaft, The member and the second rotating member are separated from each other.

Therefore, in the invention described in claim 1,
A second rotating member that performs a separating operation with respect to the first rotating member is arranged so as to face a synchronizer ring that synchronously rotates the output shaft and the driven gear. for that reason,
With the movement (separation operation) of the second rotating member, the synchronizer ring is pressed by the driven gear, and drag resistance acts on the driven gear.

Further, in the invention described in claim 2, the second rotating member for performing the separating operation with respect to the first rotating member is
It is arranged so as to face the driven gear. for that reason,
Due to the movement of the second rotating member, drag resistance acts such that the driven gear is pressed.

Here, gear rattling noise in a general gear transmission is a problem when the input shaft and the output shaft are not connected, that is, when the engine is idling and the gear is in a neutral state. That is, when the rotation speed of the input shaft is higher than that of the output shaft. Therefore, when the rotation speed of the input shaft is higher than the rotation speed of the output shaft, the separating mechanism is configured to separate the first rotating member and the second rotating member, so that the gear teeth at the time of neutral are geared. The generation of sound is prevented.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the invention described in claim 1 will be explained based on a first embodiment shown in FIGS. This first
In the embodiment, for convenience of description, for example, the invention described in claim 1 is adopted as the 1st gear of a gear transmission for performing a 5-speed gear shift for a vehicle. In FIG. 1, this gear transmission is similar to a conventional device in that a drive gear 21 that rotates integrally with an input shaft 20 is constantly meshed with the drive gear 21, and a thrust bearing portion 23 and a radial bearing 23 are provided on an output shaft 22. 1 rotatably fitted through the bearing 24
The st gear 25 is provided.

On the other hand, a clutch hub 26 is attached to the output shaft 22.
Is spline-fitted, and a hub sleeve 27 is fitted on the outer peripheral portion of the clutch hub 26 so as to be movable only in the axial direction. A boss portion projecting to the clutch hub 26 side is formed on the 1st gear 25, and a spline piece 28 is spline-fitted to the boss portion.
The spline piece 28 has a spline that engages with the hub sleeve 27 on the outer peripheral portion and a tapered surface that becomes smaller in diameter as it approaches the clutch hub 26. A synchronizer ring 29 configured to rotate integrally with the clutch hub 26 is loosely fitted on the outer peripheral side of the tapered surface.

A taper surface corresponding to the taper surface of the spline piece 28 is formed on the inner peripheral surface of the synchronizer ring 29, and these taper surfaces come close to each other while being pressed, whereby the spline piece 28 and the synchronizer ring. 29, that is, the 1st gear 25 and the output shaft 22 which are rotated by meshing with the drive gear 21.
The drag resistance is generated between the clutch hub 26 and the clutch hub 26 that rotate together with the 1st gear 25 and the output shaft 22 to rotate in synchronization with each other.

Therefore, in the first embodiment, the output shaft 22
The annular clutch hub 26, which is spline-fitted to, is used as the first rotating member. In FIG. 2, the clutch hub 26 is provided with keys 30 slidably in the axial direction at a plurality of locations (for example, three locations at equal intervals) on the outer circumference side, and these keys 30 are located on the inner circumference side. The key spring 31 disposed on the outer circumference (hub sleeve 27) side is pressed.

The portion of the clutch hub 26 where the key 30 and the key spring 31 are not disposed, the synchronizer ring 29, and the spline piece 28.
Between the second and the annular second section having a substantially U-shaped cross section.
The rotary member 32 is loosely fitted. Specifically, one protrusion of the second rotating member 32 having a substantially U-shaped cross section is arranged so as to face the synchronizer ring 29 in the axial direction, and the other protrusion has friction. Member 3
It is arranged so as to face and contact the spline piece 28 in the radial direction via 3 (see FIG. 3). That is, the second rotating member 33 is arranged independently of the clutch hub 26 and the synchronizer ring 29 that rotate integrally with the output shaft 22 by a predetermined angle, that is, the key 30 and the key spring 31 in the clutch hub 26 are arranged. Spline piece 28 to the extent that it does not interfere with the installed part
(Input shaft 20, 1st gear 25) is supported so as to be dragged and rotated.

The second rotating member 32 and the clutch hub 26 are separated from each other between the clutch hub 26 and the second rotating member 32 only when the rotating speed of the input shaft 20 is higher than that of the output shaft 22. A separating mechanism is provided to allow it. Specifically, the contact surface in the axial direction between the second rotating member 32 and the clutch hub 26 has an inclined surface (hatched portion by dotted line) 34 inclined in the circumferential direction at a predetermined angle α and the circumferential direction. On a flat surface (flat surface) 35
Are alternately formed, and the boundary between the inclined surface 34 and the flat surface 35 is constituted by a surface 36 (a surface parallel to the axial direction) perpendicular to the flat surface 35 (FIG. 4 and FIG. 5).

The operation of the first embodiment will be described below. First, when the input shaft 20 is connected to the idling engine through a clutch and the gear is stopped in the neutral state (see FIG. 4), the output shaft 2
2, the clutch hub 26, and the synchronizer ring 29 are stopped, but the input shaft 20 and the 1st gear 2
5 and spline piece 28 are rotating. Here, since the friction member 33 is interposed between the spline piece 28 and the second rotating member 32, a minute torque T1 is transmitted from the spline piece 28 to the second rotating member 32. This minute torque T1 causes the second rotary member 32 to rotate so as to slide on the inclined surface 34 formed on the clutch hub 26 and the second rotary member 32, so that the direction away from the clutch hub 26 in the axial direction. Move to. The load F1 in the axial direction is calculated by the following formula.

F1 = T1. (1-μs.tan α) /
rs. (μs + tan α) where μs: friction coefficient of inclined surface rs: equivalent radius of inclined surface.

The load F1 for moving the second rotating member 32 in the axial direction is the synchronizer ring 29.
Is pressed toward the spline piece 28. This load F
1 is synchronizer ring 29 and spline piece 2
On the taper surface with 8, the drag resistance is amplified by the drag resistance T2 to prevent generation of rattling noise.

T2 = μgrgF1 / sin β where μg: friction coefficient on tapered surface rg: equivalent radius of tapered surface β: taper angle

Next, description will be made on the case of traveling in the 1st gear. In this case, the rotation speed of the output shaft 22 (the clutch hub 26 and the synchronizer ring 29) and the input shaft 20 (1s
Since the rotation speeds of the t-gear 25 and the second rotating member 32) are equal, drag resistance does not occur in any part.

Further, a description will be given of the case of traveling in the 2nd to 5th gears (see FIG. 5). In this case, the output shaft 22, the clutch hub 26, and the synchronizer ring 29 are rotating at a higher speed with respect to the input shaft 20, the 1st gear 25, and the spline piece 28. Therefore, the clutch hub 26 and the second rotating member 32 are engaged with each other on the vertical surface 36 and integrally rotate. At this time, the second
Rotating member 32 and spline piece 28 (1st gear 2
5. A slight drag resistance T1 is generated between the input shaft 20 and the input shaft 20) via the friction member 33. However, since this drag resistance T1 is not amplified, it hardly affects the torque transmission efficiency. .

In the first embodiment, in order to reduce the rotating mass on the output shaft, the clutch hub 2 is used as the first rotating member.
However, since the first rotating member may rotate integrally with the output shaft, naturally, the first rotating member can be configured separately from the clutch hub 26. Also,
With the movement of the second rotating member 32 in the axial direction, the synchronizer ring 29 moves the 1st gear 25 (spline piece 2
As long as the second rotary member 32 indirectly presses the synchronizer ring 29, a suitable member can be arranged between them so that the second rotary member 32 can be pressed against the synchronizer ring 29.

Next, the invention described in claim 2 will be described with reference to FIG.
A description will be given based on the second embodiment shown in FIGS. In the second embodiment, similarly to the first embodiment described above, the drive gear 21 that rotates integrally with the input shaft 20, and the first gear that is constantly meshed with the drive gear 21 and is rotatably supported by the output shaft 22. 25, a clutch hub 26 that rotates integrally with the output shaft 22, and a hub sleeve 2 that is engaged with the outer peripheral portion of the clutch hub 26 so as to be movable only in the axial direction.
7 and a synchronizer ring 29 that imparts drag resistance to the 1st gear 25 and the hub sleeve 27 as the hub sleeve 27 moves in the axial direction.

In the second embodiment, the 1st gear 2
The thrust bearing portion 23, which supports the output shaft 5 on the output shaft 22, is composed of a first rotating member 37 and a second rotating member 38. That is, the ring member that rotates integrally with the output shaft 22 via the ball member 39 that is fitted in the recess formed in the output shaft 22 is provided in the axial direction so that the first rotating member 37 and the second rotating member 38 are provided. It is configured by dividing. Hereinafter, a specific description will be given.

The first rotating member 37 is formed in an annular shape and is provided with a concave portion on its inner peripheral side that substantially fits with the ball member 39. On the other hand, the second rotating member 3
8 is configured in an annular shape like the first rotating member 37,
A concave portion that fits with the ball member 39 is provided on the inner peripheral side thereof, and the concave portion of the second rotating member 38 is formed larger than the concave portion of the first rotating member 37 in the circumferential direction. That is, the first rotating member 37 is configured to rotate integrally with the output shaft 22, while the second rotating member 38 is configured to be rotatable relative to the first rotating member within a predetermined range. (See Figure 7).

The second rotating member 38 is arranged on the 1st gear 25 side, and the first rotating member 3
7 and the second rotating member 38 are arranged so as to contact each other in the axial direction. Therefore, like the first embodiment, the first
The separating mechanism between the rotating member 37 and the second rotating member 38 of
By forming an inclined surface 34 inclined in the circumferential direction at a predetermined angle α, a vertical surface 36 (a surface parallel to the axial direction) and a flat surface 35 in the circumferential direction alternately on these contact surfaces. It is configured.

The outer peripheral portion of the second rotating member 38 is formed in a tubular shape so as to cover the outer peripheral portion of the first rotating member 37 (see FIG. 8). 1st
A friction member 33 is arranged between the outer peripheral portion of the second rotating member 38 and the inner peripheral portion of the 1st gear 25 so that torque is transmitted to and from the gear 25.

The operation of the second embodiment will be described below. First, when the input shaft 20 is connected to the engine in the idling state via a clutch and the vehicle is stopped in the neutral state (see FIG. 9), the output shaft 2
2 is stopped, but the input shaft 20 and the 1st gear 25
Is spinning. In the second embodiment, a minute torque T1 is transmitted between the second rotating member 38 and the 1st gear 25, and the second rotating member 38 contacts the first rotating member 37 (inclined surface 34). Since it rotates in a sliding manner, an axial load F1 is generated and the first rotating member 37 and the second rotating member 38 operate so as to be separated from each other, as in the first embodiment.

In the second embodiment, the first rotating member 37
Since the second rotary member 38 and the second rotary member 38 form the thrust bearing portion 23, the thrust bearing portion 23 operates so as to close the axial clearance of the thrust bearing portion 23. Here, since the second rotating member and the clutch hub 26 are configured to face each other via the 1st gear 25, when the second rotating member 38 further moves, the 1st gear 25 is rotated by the second rotating member. Inserted between the member 38 and the clutch hub 26, the 1st
The axial clearance of the gear 25 is also reduced. Therefore, the amplified drag resistance T3 acts on the contact surface between the 1st gear 25 and the second rotating member 38 and the contact surface between the 1st gear 25 and the clutch hub 26, and the clearance that causes the rattling noise is generated. Disappear.

T3 = μgrgF1 where μg: Friction coefficient on tapered surface rg: Equivalent radius of tapered surface Note that the rotational speed of the output shaft 22 is equal to the rotational speed of the input shaft 20 during the 1st gear running. Therefore, as in the first embodiment, drag resistance does not occur in any part. When the second to fifth gears are running (see FIG. 10), the first rotating member 37 and the second rotating member 38 engage with each other on the vertical surface 36 and rotate together to rotate the first gear 25 and the first gear 25. A minute drag resistance T1 is formed between the second rotating member 38 and the second rotating member 38.
However, similarly to the first embodiment, since the drag resistance T1 is not amplified, it hardly affects the torque transmission efficiency.

In the second embodiment, as in the first embodiment, in order to reduce the rotating mass of the output shaft 22, the thrust bearing portion 2 is used.
Although the first rotating member 37 and the second rotating member 38 are configured by using the ring member of No. 3, naturally, the first rotating member and the second rotating member independent of the thrust bearing portion 23 are formed. Can be provided. In addition, the second rotating member 38
It is sufficient that the second rotating member 38 indirectly presses the 1st gear 25 to provide the drag resistance because the second rotating member 38 is configured to provide the drag resistance to the 1st gear 25 with the movement of the first gear 25 in the axial direction. You can also do it.

The first embodiment and the second embodiment described above
Similar to the conventional gear transmission shown in FIG. 11, when the hub sleeve 27 is moved in the axial direction, the gear shift operation according to the embodiment causes the key 30 to move in the axial direction together with the hub sleeve 27, thereby causing the synchronizer ring 29 to move. The taper surface is pressed in the axial direction, and as a result, the taper surface on the inner peripheral side comes into contact with the taper surface of the corresponding spline piece 28, and both start rotating synchronously. Then, the chamfer of the hub sleeve 27 and the chamfer of the synchronizer ring 29 come into contact with each other, and the hub sleeve 27 further moves in the axial direction, so that the chamfer of the synchronizer ring 29 is pushed and the hub sleeve 27 moves to the spline piece 28 side. Finally, the spline is engaged, and the shift operation is completed.

Further, the first embodiment and the second embodiment described above
In the embodiment, when the driving force is cut off while the input shaft 20 and the output shaft 22 are connected in the idling state, when the driving force is disconnected by a so-called clutch, the rotational mass of the input shaft 20 and Since the difference in the rotational mass of the output shaft 22 (usually, the rotational mass of the input shaft 20 <the rotational mass of the output shaft 22) causes the rotation of the output shaft 22 to decrease first,
Drag resistance T2 is given to the 1st gear 25, and the rotation speed of the input shaft 20 is rapidly reduced. Therefore, even if the reverse synchromesh mechanism is abolished, the reverse gear shift operation can be smoothly performed.

Further, in the first and second embodiments described above, for convenience of explanation, the spline piece 28 or the spline piece 28 is provided at the portion of the 1st gear 25 depending on the relative rotation direction of the input shaft 20 with respect to the output shaft 22. 1st gear 2
5 is configured to give a drag resistance to prevent gear rattling noise, but of course, at all shift speeds (2nd to 5t).
It is possible to apply to h).

[0039]

As described above, according to the gear transmission of the present invention, only when the rotation speed of the input shaft is higher than that of the output shaft, specifically, the prime mover is in the idling state, and When the input shaft and the output shaft are not coupled, drag resistance is given to the driven gear that is loosely fitted to the output shaft, so there is no power loss during traveling, It is possible to effectively prevent the generation of rattling noise. Further, when the driving force is cut off to the input shaft that is rotating in the idling state, specifically, when the clutch is operated to perform the reverse speed change operation, the rotational speed of the input shaft decreases, Since the reverse synchromesh mechanism is not required and the structure of the transmission can be simplified, the structure can be remarkably advantageous in terms of cost and reliability.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of the invention described in claim 1.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged view of a part III in FIG. 1;

FIG. 4 is a diagram showing the input shaft rotation speed in the embodiment shown in FIG.
It is a schematic diagram which shows operation | movement of a 1st rotating member (clutch hub) and a 2nd rotating member in case of an output shaft rotation speed.

FIG. 5 shows the output shaft rotation speed in the embodiment shown in FIG.
It is a schematic diagram which shows operation | movement of a 1st rotating member and a 2nd rotating member in case of an input shaft rotation speed.

FIG. 6 is a schematic sectional view showing an embodiment of the invention described in claim 2.

7 is a sectional view taken along the line VII-VII in FIG.

FIG. 8 is a diagram schematically showing the side surface of FIG.

FIG. 9 is a diagram showing the input shaft rotation speed in the embodiment shown in FIG.
It is a schematic diagram which shows operation | movement of a 1st rotating member and a 2nd rotating member in case of an output shaft rotation speed.

10 is a schematic diagram showing the operation of the first rotating member and the second rotating member when the output shaft rotational speed> the input shaft rotational speed in the embodiment shown in FIG.

FIG. 11 is a schematic sectional view showing an example of a conventional gear transmission.

[Explanation of symbols]

20 Input Shaft 22 Output Shaft 25 1st Gear (Driven Gear) 26 Clutch Hub (First Rotation Member, First Embodiment) 32 Second Rotation Member (However, First Embodiment) 33 Friction Member 34 Inclined Surface 36 Vertical Surface (surface parallel to output shaft) 37 First rotating member (provided in the second embodiment) 38 Second rotating member (provided in the second embodiment)

Claims (2)

[Claims] 1. A drive gear which rotates integrally with an input shaft, a driven gear which is always meshed with the drive gear and is rotatably supported by an output shaft, and a clutch hub which rotates integrally with the output shaft. A hub sleeve engaged with the outer peripheral portion of the clutch hub so as to be movable in the axial direction, and with the movement of the hub sleeve in the axial direction, drag resistance is imparted to the hub sleeve and the driven gear to synchronously rotate. In a gear transmission including a synchronizer ring, a first rotating member that rotates integrally with the output shaft, and the output shaft are supported to be rotatable relative to the first rotating member by a predetermined angle. A second rotary member is disposed so as to face the output shaft, and a friction transmission unit that transmits torque between the driven gear and the second rotary member is provided. A separating mechanism that is operated by rotation of the second rotating member relative to the first rotating member in one predetermined direction to separate the first rotating member and the second rotating member from each other in the axial direction. Is provided between the first rotating member and the second rotating member, and the second rotating member and the synchronizer ring are arranged to face each other on the output shaft. Gear transmission. 2. A drive gear which rotates integrally with the input shaft, a driven gear which is constantly meshed with the drive gear and is rotatably supported by the output shaft, and a clutch hub which rotates integrally with the output shaft. A hub sleeve engaged with the outer peripheral portion of the clutch hub so as to be movable in the axial direction, and with the movement of the hub sleeve in the axial direction, drag resistance is imparted to the hub sleeve and the driven gear to synchronously rotate. In a gear transmission including a synchronizer ring, a first rotating member that rotates integrally with the output shaft, and the output shaft are supported to be rotatable relative to the first rotating member by a predetermined angle. A second rotary member is disposed so as to face the output shaft, and a friction transmission unit that transmits torque between the driven gear and the second rotary member is provided. A separating mechanism that is operated by rotation of the second rotating member relative to the first rotating member in one predetermined direction to separate the first rotating member and the second rotating member from each other in the axial direction. Is provided between the first rotating member and the second rotating member, and the second rotating member and the driven gear are arranged to face each other on the output shaft. Gear transmission that does.