JPH0747643Y2 - Gear change device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a speed change device suitable for a vehicle speed change mechanism.

2. Description of the Related Art Conventionally, various speed change devices have been used in a vehicle speed change mechanism. For example, a drive shaft and a driven shaft into which a plurality of passive gears are rotatably fitted are arranged on the same axis. The intermediate shaft, which is arranged in a fixed manner with the drive gear that meshes with the passive gear, is arranged with an axis parallel to the drive shaft and the driven shaft to transmit power from the drive shaft to the intermediate shaft and to form a coupling mechanism. Therefore, there is a speed change device that selectively connects the passive gear and the driven shaft.

Problems to be Solved by the Invention In such a speed change device, power transmission from the drive shaft to the intermediate shaft is performed by meshing a gear provided on the drive shaft with a gear provided on the intermediate shaft. There is. For this reason, there are drawbacks that the number of gears used is large and the cost is high, and the noise generated at the meshing portion of the gears is large.

Means for Solving the Problems A drive shaft 2 and a driven shaft 3 are arranged on the same axis, and an intermediate shaft 9 is arranged with an axis parallel to the drive shaft 2 and the driven shaft 3, Drive gears with different diameters on the intermediate shaft 9
12, 13 are fixedly provided, a passive gear 19 meshing with the drive gear 12 and a first rotating body 16 meshing with the drive gear 13 are rotatably fitted on the driven shaft 3 and the driven shaft 3 A second rotating body 24 is rotatably fitted on the upper side, and a power transmission disconnecting portion 23 for connecting and disconnecting power is provided between the passive gear 19 and the second rotating body 24. A clutch claw 25, which is located between 16 and the second rotary body 24 and is biased toward the first rotary body 16, is slidably spline-fitted onto the driven shaft 3 as well as the clutch. A cam claw body 36 is rotatably fitted to the side of the first rotating body 16 of the claw body 25, and a second clutch claw 39 is formed on the inner peripheral side of the side end surface of the first rotating body 16. A second sloped cam claw 40 is formed on the outer peripheral side, and a first clutch claw 34 that meshes with the second clutch claw 39 in an axially disengageable manner is formed. Serial clutch pawl
25, and when driven from the side of the second rotating body 24, the cam claw body 36 is axially moved together with the clutch claw body 25 by meshing with the second sloped cam claw 40 having a sloped surface. Then, when driven from the side of the first rotary body 16, a cam bevel 37 having a first slope is formed on the cam pawl 36, which is fixedly engaged in the rotational direction, and is projected to the outer peripheral direction of the clutch pawl 25. A second convex portion 38 is formed by forming the first convex portion 32 and extending in the outer circumferential direction on the cam claw body 36, and the second convex portion 38 is fixedly fitted and the second convex portion 38 is formed. Power transmission part 30 that fits into one convex part 32 rotatably within a set angle
Is provided on the second rotating body 24, and a joint body 14 that rotates integrally with the drive shaft 2 is provided on the drive shaft 2.
A first meshing joint portion 15 is provided on 14 and a second meshing joint portion 22 that meshes with the first meshing joint portion 15 is formed on the side end surface of the first rotating body 16.

Action One drive gear in which the first rotary body 16 fixedly provided on the intermediate shaft 9 is rotatably fitted onto the driven shaft 3 and acts as a passive gear selectively connected to the driven shaft 3. By engaging with the second meshing joint portion 22 provided on the first rotating body 16 and the first meshing joint portion 15 of the joint body 14 provided on the drive shaft 2 while meshing with 13, Drive shaft 2
Power can be transmitted from the drive shaft 2 to the intermediate shaft 9 without providing a dedicated gear for transmitting power from the drive shaft 2 to the intermediate shaft 9. Therefore, the number of gears to be used can be reduced to achieve cost reduction. In addition, it is possible to reduce the size of the entire device, and further reduce the number of meshing portions of the gears to reduce noise generated at the meshing portions of the gears.

Embodiment An embodiment of the present invention will be described with reference to the drawings. One end of an input shaft 2 that is a drive shaft that is connected to an engine (not shown) extends in the mission case 1 of the tractor, and an output shaft 3 that is a driven shaft that is connected to front wheels (not shown). Has one end extended, and the input shaft 2 and the output shaft 3 are arranged on the same axis. Then, the cylindrical protrusion 4 formed at the tip of the input shaft 2 is inserted into the recess 5 formed at the tip of the output shaft 3, and the outer peripheral surface of the cylindrical protrusion 4 and the inner periphery of the recess 5 are inserted. A bearing 6 is interposed between the surface and the surface. The input shaft 2 is supported by a bearing 7 mounted on the mesh case 1 and another bearing (not shown), and the output shaft 3 is supported by the bearing 8 mounted on the mesh case 1 and the bearing 8. It is supported by the bearing 6. Further, an intermediate shaft 9 having an axis parallel to the axes of the input shaft 2 and the output shaft 3 is supported by bearings 10 and 11 in the mesh case 1, and the number of teeth on the intermediate shaft 9 is different. Large and small drive gears 12, 13 are integrally formed.

A joint body 14 is spline-fitted to an end portion on the input shaft 2, and a first meshing joint portion is formed on an outer peripheral portion of the joint body 14.
15 are formed. A passive gear 16 that is a first rotating body that meshes with the drive gear 13 is rotatably supported on the output shaft 3 via bearings 17 and 18, and a passive gear 19 that meshes with the drive gear 12 is provided. It is rotatably supported via a bearing 20. A coupling mechanism 21 for selectively coupling the passive gears 16 and 19 to the output shaft 3 is provided on the output shaft 3. Where the passive gear
A second meshing joint portion 22 that meshes with the first meshing joint portion 15 is formed on one side end surface of 16.

Next, the connection mechanism 21 will be described. First, a wet friction clutch 23 that acts as a power transmission disconnecting portion that connects and disconnects power transmission through the passive gear 19 and a cylindrical transmission component 24 as a second rotating body are rotatably mounted on the output shaft 3. The clutch claw 25, which is fitted and is located between the cylindrical transmission component 24 and the passive gear 16, has the output shaft 3.
It is fitted with a spline slidably on top. The cylindrical transmission part 24 is formed with a meshing joint portion 27 that meshes with a meshing joint portion 26 formed on the wet friction clutch 23, and is further formed between a plurality of convex portions 28 and these convex portions 28. A power transmission portion 30 including a groove portion 29 and a protrusion portion 31 for holding one end of a spring, which will be described later, is formed. The clutch claw 25 has a first protrusion 32 protruding in the outer peripheral direction, a protrusion 33 further protruding from the tip of the first protrusion 32, and a first protrusion facing the passive gear 16 side. Clutch claws 34 are formed. Then, the first convex portion 32 extends into the groove portion 29, the first convex portion
A clearance of a predetermined size is provided between the side surface of 32 and the side surface of the convex portion 28 so that the clutch claw 25 and the cylindrical transmission component 24 can relatively rotate within a set angle. . In addition, a spring 35 is stretched between the protrusion 33 and the protrusion 31 in the rotational direction of the cylindrical transmission component 24. Further, a cam pawl 36 is rotatably fitted to the clutch pawl 25, and a first sloped cam pawl 37 facing the side of the passive gear 16 is formed on the cam pawl 36. At the same time, a second protrusion 38 extending into the groove 29 is formed. Both side surfaces of the second convex portion 38 in the rotation direction are always in contact with the side surfaces of the convex portion 28. Here, on the other side end surface of the passive gear 16, there is provided a second clutch pawl 39 which engages with the first clutch pawl 34 in a disengageable manner,
A second sloped cam pawl 40 meshing with the first sloped cam pawl 37 engageably and disengageably is formed. A spring 41 that urges the clutch pawl 25 together with the cam pawl 36 toward the passive gear 16 is provided between the cylindrical transmission component 24 and the clutch pawl 25.

In such a structure, FIG. 1 shows a low speed transmission state, and the wet friction clutch 23 is not operating. Further, the clutch pawl 25 and the cam pawl 36 are slid toward the passive gear 16 side by the urging force of the spring 41, and as shown in FIG. 4 (a), the first and second clutch pawls 34 are formed. , 39 and the first and second sloped cam claws 37, 40 are in mesh with each other. When the input shaft 2 is rotated by the power from the engine in this state, the joint body 14 is rotated integrally with the input shaft 2, and the passive gear 16 is caused by the meshing of the first and second meshing joint portions 15 and 22. Rotate integrally with the joint body 14.

Here, the rotation of the passive gear 16 is transmitted to the drive gear 13 to rotate the intermediate shaft 9, and is further transmitted from the drive gear 12 to the passive gear 19 to rotate the passive gear 19. However, since the wet friction clutch 23 is not operating, the passive gear 19 is idling. On the other hand, the rotation of the passive gear 16 is transmitted to the clutch claw body 25 by the meshing of the first and second clutch claws 34 and 39, and by the meshing of the first and second beveled cam claws 37 and 40. The clutch claw body 25 and the cam claw body 36 are transmitted to the cam claw body 36 to rotate integrally with the passive gear 16. Then, the clutch pawl 25 and the output shaft 3 rotate integrally to transmit power to the front wheels.

As shown in FIG. 3 (a), the side surface on the front side in the rotation direction of the first convex portion 32 formed on the clutch claw body 25 is in contact with the side surface on the rear side in the rotation direction of the convex portion 28, and the cylindrical shape The transmission component 24 receives the force from the first protrusion 32 and rotates integrally with the clutch claw 25. Then, since the wet friction clutch 23 is not operating, the meshing joint portion 26 of the wet friction clutch 23 meshing with the meshing joint portion 27 of the cylindrical transmission component 24 idles integrally with the cylindrical transmission component 24. There is.

Next, FIG. 2 shows a high-speed transmission state in which the wet friction clutch 23 is operating. Note that the passive gear 16 continues to rotate integrally with the joint body 14 due to the engagement of the first and second meshing joint portions 15 and 22, and the passive gear 16 and the drive gear 13
The intermediate shaft 9 is rotationally driven by meshing with the.
When the wet friction clutch 23 is operated, the rotation of the passive gear 19 is transmitted to the meshing joint portion 26, and further, the meshing joint portions 26, 27
The cylindrical transmission component 24 is rotationally driven by the mutual engagement. Then, since the second convex portion 38 of the cam pawl 36 is fixedly fitted between the convex portions 28 of the cylindrical transmission component 24, the cam pawl 36 is integrated with the cylindrical transmission component 24. Rotate. Then, due to the difference between the rotational speed of the cam pawl 36 and the rotational speed of the passive gear 16 at this time, the cam pawl 36 receives a force in a direction away from the passive gear 16 and is shown in FIG. 4 (b). As described above, when the cylindrical transmission component 24 advances by 25 ° with respect to the passive gear 16, the engagement between the first and second sloped cam pawls 37, 40 is released.
Further, the clutch claw 25 pushed by the cam claw 36 also slides in the direction away from the passive gear 16, and the first and second clutch claws 34, 39 mesh with each other as shown in FIG. 4 (b). Is also canceled. Then, when the cylindrical transmission component 24 that rotates at a higher speed than the passive gear 16 advances by a set angle (30 °) with respect to the passive gear 16, as shown in FIG.
The front side surface in the rotational direction of the abutting contact the rear side surface in the rotational direction of the first convex portion 32, and thereafter, the clutch claw 25 is a cylindrical transmission component.
By receiving the force from 24, it is rotationally driven integrally with the cylindrical transmission component 24 as shown in FIGS. 3 (d) to (g). And
The output shaft 3 rotates integrally with the clutch claw 25, and the front wheels are rotationally driven at high speed. Therefore, the speed change from the low speed transmission state to the high speed transmission state can be easily and smoothly performed only by the operation of operating the wet friction clutch 23. In this high-speed transmission state, the projection 31 of the cylindrical transmission component 24 is maintained in a state of advancing the set angle with respect to the projection 33 of the clutch claw body 25, so that it is shown in FIG. 5 (b). The spring 35 has been stretched.

Here, when power is transmitted at a high speed through the wet friction clutch 23, the cam pawl 36 is rotating with a set angle advanced from the clutch pawl 25. Therefore, as shown in FIG. 4 (f), the cylindrical transmission component 24 advances 120 degrees from the passive gear 16 and faces the first and second inclined surface cam pawls 37, 40 so that they can mesh with each other. In this case, the first and second clutch claws 34 and 39 are opposed to each other in a non-meshed state, and the cam claw body 36 slides toward the passive gear 16 side together with the clutch claw body 25 by the biasing force of the spring 41. Without the first and second beveled cam pawls 37,4
Zero meshing does not occur. Further, as shown in FIG. 4 (g), when the cylindrical transmission component 24 advances from the passive gear 16 by 150 ° and the first and second clutch pawls 34, 39 face each other in a meshable manner. , The first and second sloped cam claws 37, 40 are opposed to each other in a non-meshed state, and the clutch claw 25 slides together with the cam claw 36 toward the passive gear 16 by the biasing force of the spring 41. Therefore, the first and second clutch claws 34, 39 do not mesh with each other. Therefore, the first and second beveled cam pawls 37, 40 and the first and second clutch pawls 34, 39 do not generate noise or wear due to repeated meshing, and the output shaft 3 can operate at high speed. Continue rotation in the transmission state.

When the operation of the wet friction clutch 23 is stopped, the driving force for rotating the cylindrical transmission component 24 disappears, and the cylindrical transmission component 24 becomes rotatable. Then, due to the urging force of the spring 35, the cylindrical transmission component 24 is returned in the direction opposite to the direction in which it was rotated. As a result, the cam claw 36 is also returned in the direction opposite to the direction in which the cam claw 36 is rotated by the convex 28 of the cylindrical transmission component 24, and the side surface of the convex 28 is the first convex of the clutch claw 25.
When the cam claw 36 is returned to the position where it abuts against the front side surface of the rotation direction 32, the advance state of the cam claw 36 with respect to the clutch claw 25 is canceled, and the first claw 34 and the cam claw 36 of the clutch claw 25 are released. The phase is the same as that of the first sloped cam claw 37. Therefore, when the first and second clutch claws 34 and 39 face each other in a meshable state, the first and second sloped cam claws 3
7, 40 also face each other so that they can mesh with each other. At this time, the clutch claw 25 slides together with the cam claw 36 toward the passive gear 16 by the urging force of the spring 41, and the cams with the first and second slopes. The claws 37, 40 and the first and second clutch claws 34, 39 mesh with each other. Then, the rotation of the input shaft 2 is transmitted to the output shaft 3 via the joint body 14, the passive gear 16, and the clutch claw body 25, and the low speed transmission state is restored. Therefore, the speed change from the high speed transmission state to the low speed transmission state can be easily and smoothly performed only by the operation of stopping the operation of the wet friction clutch 23.

It should be noted that, in the present embodiment, the transmission in which the high speed transmission state is set when the wet friction clutch 23 is operated and the low speed transmission state is set when the wet friction clutch 23 is stopped is described. The transmission may be a low speed transmission state when the wet friction clutch 23 is operated by changing the number of teeth 12 and 13.

Effect of the Invention As described above, the present invention has the first rotating body 16 on the intermediate shaft 9 that is rotatably fitted onto the driven shaft 3 and that acts as a passive gear selectively connected to the driven shaft 3. Is engaged with one drive gear 13 fixedly provided on the first rotary body 16 and the second meshing joint portion 22 and the drive shaft 2 provided on the first rotary body 16.
By engaging with the first meshing joint portion 15 of the joint body 14 provided above, the drive shaft 2 to the intermediate shaft 9 can be provided without providing a dedicated gear for transmitting power from the drive shaft 2 to the intermediate shaft 9.
Power can be transmitted to the gears. Therefore, the number of gears to be used can be reduced and the cost can be reduced, the size of the entire device can be reduced, and the number of meshing parts between the gears can be reduced. By reducing the amount, it is possible to reduce the noise generated at the meshing portion of the gears.

[Brief description of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is a vertical sectional side view showing a low speed transmission state, Fig. 2 is a vertical sectional side view showing a high speed transmission state, and Fig. 3 is a passive gear of a cylindrical transmission part. FIG. 4 is an explanatory view showing an advanced angle state with respect to the passive gear of the cylindrical transmission component and an explanatory view showing a positional relationship between the cam pawls and the clutch pawls at that time, and FIG. 5 is a low speed transmission state. FIG. 3 is an explanatory diagram showing a state of expansion and contraction of a spring in a high speed transmission state. 2 ... drive shaft, 3 ... driven shaft, 9 ... intermediate shaft, 12 ... drive gear, 13 ... drive gear, 14 ... joint, 15 ... first meshing joint, 16 ... passive Gear, 19 ... Passive gear, 21 ...
Coupling mechanism, 22 ... Second mesh joint

Claims (1)

[Scope of utility model registration request] 1. A drive shaft 2 and a driven shaft 3 are arranged on the same axis, and an intermediate shaft 9 is arranged with an axis parallel to the drive shaft 2 and the driven shaft 3. Driving gears 12 and 13 having different diameters are fixedly provided on the driven shaft 3, and a passive gear 19 meshing with the driving gear 12 and a first rotating body 16 meshing with the driving gear 13 are rotatably fitted on the driven shaft 3. The second rotating body 24 is rotatably fitted on the driven shaft 3 and the power transmission connecting / disconnecting portion 23 for connecting / disconnecting the power is provided between the passive gear 19 and the second rotating body 24. , The first rotating body
A clutch claw 25, which is located between 16 and the second rotary body 24 and is biased toward the first rotary body 16, is slidably spline-fitted onto the driven shaft 3 as well as the clutch. A cam claw body 36 is rotatably fitted to the side of the first rotating body 16 of the claw body 25, and a second clutch claw 39 is formed on the inner peripheral side of the side end surface of the first rotating body 16. A second sloped cam claw 40 is formed on the outer peripheral side, and a first clutch claw 34 that meshes with the second clutch claw 39 in an axially disengageable manner is formed on the clutch claw body 25 and the second claw 34 is formed. When driven from the side of the rotary member 24, the second rotary cam 16 is engaged with the second cam cam 40 with a slope to move the cam pawl 36 together with the clutch pawl 25 in the axial direction, and the first rotary member 16 is moved. When driven from the side, a first sloped cam claw 37 that is fixedly meshed in the rotational direction is formed on the cam claw body 36, The clutch claw body 25 is formed so as to project in the outer peripheral direction to form a first convex portion 32, and the cam claw body 36 is formed to extend in the outer circumferential direction to form a second convex portion 38. The drive shaft 2 is provided with a power transmission portion 30 fixedly fitted to the portion 38 and fitted to the first convex portion 32 so as to be rotatable within a set angle.
The joint body 14 that rotates integrally with the drive shaft 2 is provided on the top,
This joint body 14 is provided with a first meshing joint portion 15 and a second meshing joint portion 22 that meshes with the first meshing joint portion 15 is formed on a side end surface of the first rotating body 16. Gear change device.