JPH0519670U - Clutch type speed change mechanism - Google Patents

Abstract

(57) [Summary] [Purpose] To have a simple structure with a small number of parts, to enable smooth gear shifting, and to cope with sudden gear shifting. [Structure] A clutch inner ring 2 and a clutch outer ring 3 are provided that are loosely fitted to each other so as to be axially movable and rotatable. The clutch inner ring 2 is provided with axial grooves 11 having an arcuate cross section at a plurality of circumferential positions on the outer diameter surface, and the clutch outer ring 3 is provided with circumferential grooves 7 on the inner diameter surface. The axial groove 11 has a different axial cross section, and the shallow groove portion 1 for generating a wedge effect by the ball 4 is formed.
1c and the deep groove portion 11a that does not generate the wedge effect are formed. The ball 4 together with the clutch inner ring 2 is provided with an axial groove 11
By moving the clutch wheels 2 and 3, the clutch wheels 2 and 3 are locked and unlocked.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a clutch type speed change mechanism used for transmissions in automobiles and agricultural machines.

[0002]

[Prior Art]

 2. Description of the Related Art Conventionally, in a transmission for an automobile, a synchronization mechanism using a synchronizer ring is generally used in order to achieve smooth gear shifting. The outline of an example thereof will be briefly described with reference to FIG. 7.

This mechanism includes a clutch hub 52 connected to a shaft 51, a sleeve 54 spline-connected to the outer periphery of the clutch hub 52 and axially moved by an operation of a shift lever 53, and a spring 55. The synchronizer key 56 biased to the inner circumference, the clutch gear 57 rotatably supported on the outer circumference of the shaft 51, and the synchronizer ring 58 slidably arranged on the outer circumference of the cone portion 57a of the clutch gear 57 are provided. I have it.

Now, as shown in FIG. 1B, when the clutch gear 57 and the shaft 51 are rotating at different rotational speeds, if the shift lever 53 moves the sleeve 54 to the clutch gear 57 side, Then, the synchronizer ring 58 is pressed against the cone portion 57a of the clutch gear 57 by being pushed by (). Therefore, a frictional force is generated on the conical friction surface of the cone portion 57a, and the speed difference between the shaft 51 that rotates together with the synchronizer ring 58 and the clutch hub 52 and the clutch gear 57 is reduced.

By the time the sleeve 54 moves further to the left, the clutch gear 57 and the shaft 51 are in synchronization with each other, and the spline teeth 54 a of the sleeve 54 are synchronized with each other in this manner. The parts 58a and 57b are engaged with each other ((F) in the figure). Therefore, smooth meshing is performed. (A), (C) and (E) of the same figure show the meshing process corresponding to (B), (D) and (F) of the same figure, respectively.

[0006]

[Problems to be solved by the device]

 However, in the above configuration, since the synchronizer ring 58 is used, there are problems that the number of parts is large and the structure is complicated.

Further, it takes time to synchronize the synchronizer ring 58, it is difficult to perform a sufficiently smooth shift, a large shift force is required, a sudden shift cannot be supported, and meshing can be performed before synchronization is completed. There is also a nature.

The problem at the time of shifting can be alleviated by using a lubricating oil having a large friction coefficient. That is, when the friction coefficient increases, the synchronization time is shortened, which improves the smoothness of the shift and enables a rapid shift. However, if the friction coefficient of oil increases, the wear of the meshing parts of the bearings and gears will increase, and the service life will decrease. Therefore, it is difficult to change the lubricating oil.

An object of the present invention is to provide a clutch-type speed change mechanism that has a small number of parts, has a simple structure, can perform a smooth speed change, and can cope with a sudden speed change.

[0010]

[Means for Solving the Problems]

 A clutch type speed change mechanism of the present invention is provided with a clutch inner ring and a clutch outer ring that are loosely fitted to each other so as to be axially movable and rotatably, forming an axial groove on the outer diameter surface of the clutch inner ring and a circumferential groove on the clutch outer ring. Is formed, and a locking ball is interposed between both grooves. The axial groove of the clutch inner ring is provided at a plurality of circumferential positions on the outer diameter surface. Further, in these axial grooves, a deep groove portion having a small radius of curvature that does not cause the wedge effect of the ball and a shallow groove portion having a large radius of curvature that causes the wedge effect are formed.

[0011]

[Action]

 According to this structure, with the ball loosely fitted in the deep groove portion in the axial groove of the clutch inner ring, the ball freely rolls in the circumferential groove of the clutch outer ring, and the clutch outer ring and the clutch inner ring restrain the rotation from each other. It rotates at different rotation speeds without being rotated. When the inner clutch wheel is moved in the axial direction relative to the outer clutch wheel, the balls move to the shallow groove portion in the axial groove. In the shallow groove, the clearance between the ball and the inner and outer rings of the clutch is small, and the radius of curvature of the groove cross-section is large and the contact angle is small, so the wedge effect occurs and the inner and outer clutch rings are locked. To be done. Therefore, the clutch inner wheel and the clutch outer wheel rotate integrally.

[0012]

【Example】

 An embodiment of the present invention will be described with reference to FIGS. This clutch type speed change mechanism includes a clutch inner ring 2 that rotates together with a shaft 1, a pair of clutch outer rings 3 and 3 rotatably supported by a shaft 1 through a needle bearing 4, and a pair of clutch outer rings 3 and 2. It is mainly composed of a locking ball 4. The shaft 1 corresponds to the input shaft or main shaft of the transmission.

The clutch inner ring 2 is spline-engaged with the outer periphery of the clutch hub 5 coupled to the serration portion of the shaft 1 and is movable back and forth in the axial direction of the shaft 1. The clutch inner ring 2 is engaged with a selector 6 such as a shift lever in an annular engagement groove provided at an axially intermediate position, and is moved in the axial direction by a driver's operation of moving the selector 6. The selector 6 is not rotating and is in sliding contact with the engagement groove of the clutch inner ring 2. The clutch inner ring 2 is formed symmetrically.

The clutch outer ring 3 serves as a gear for power transmission, and has a gear portion (not shown) integrally formed on the outer periphery thereof. The pair of clutch outer rings 3 and 3 are different in the number of teeth of the outer gears from each other, and are selectively transmitted in rotation by the movement of the clutch inner ring 2, and are formed symmetrically with respect to each other except for the gears. ..

The clutch outer ring 3 has a U-shaped cross section, and the clutch inner ring 2 is loosely fitted in the inner space of the clutch outer ring 3, and the ball 4 can roll on the inner diameter surface of the outer peripheral flange portion. The groove 7 is formed. The circumferential groove 7 is opened in the width surface of the clutch inner ring 2 on the insertion side, and the opening surface is covered with a side ring 8 to prevent the ball 4 from protruding. The side ring 8 is detachably fixed with a bolt 12. A spring member 9 for urging the ball 4 toward the side ring 8 is provided in the circumferential groove 7, and a push ring 10 for stably transmitting the urging force of the spring member 9 to the ball 4 is provided. ..

The clutch inner race 2 is provided with axial grooves 11 each having a circular arc shape for guiding the ball 4 at a plurality of circumferential positions on the outer diameter surfaces of the sleeve portions on both sides. The axial groove 11 has different cross-sectional shapes along the axial direction as shown in FIGS. 4 (A) to 4 (C) for the cross section of each portion of FIG. 3, and the deep groove portion 11a and the transition groove portion are sequentially provided from the tip side. 11b and the shallow groove portion 11c.

The deep groove portion 11a is a groove having a small radius of curvature and a large groove depth as shown in FIG. 4A, and the shallow groove portion 11c has a large radius of curvature and a groove depth as shown in FIG. 4C. It is a shallow groove. The transition groove portion 11b is formed as a taper groove in which the curvature and the groove depth are gradually changed so that the deep groove portion 11a can smoothly continue to the shallow groove portion 11c. FIG. 5 is an explanatory diagram emphasizing the shape changes of the groove portions 11a to 11c.

The operation of the above configuration will be described. The operating state of FIGS. 6A and 6B is a neutral state, and the ball 4 is positioned in the deep groove portion 11a of FIG. 4A. At this time, since a gap C is formed between the bottom surface of the groove and the bottom surface of the groove, the ball 4 comes into contact with the bottom surface of the circumferential groove 7 of the clutch outer ring 3 and the opening edge of the deep groove portion 11a of the clutch inner ring 2 at two points a and b. At this time, the wedge angle α formed by the tangent line between the contact point a and the contact point b is more than twice the friction angle β at the contact point a and the contact point b (steel-to-steel friction angle is β). The wedge effect cannot be obtained because the angle becomes. Therefore, even if the relative rotation occurs between the clutch outer wheel 3 and the clutch inner wheel 2, the ball 4 is not locked.

When the selector 6 is moved to the left side of the drawing from the neutral state as shown by the white arrow in FIG. 6D, the shift completion state of FIG. 6F is passed through the state of FIG. 6D. Move on to.

In the state of FIG. 6 (F), the ball 4 is at the position of the transition groove portion 11b of FIG. 4 (B), the gap C (FIG. 4 (A)) gradually decreases, and the radius of curvature also gradually. As the contact point b increases, the contact point b moves toward the groove bottom of the axial groove 11.

In the shift completed state of FIG. 6 (F), the ball 4 is positioned in the shallow groove portion 11c of FIG. 4 (C), the clearance C becomes zero, and two points of contact points a ′ and b ′ are obtained. Contact with. At this time, the wedge angle α ′ formed by the contact points a ′ and b ′ is less than twice the friction angle β of the contact points a ′ and b ′. Therefore, when the wedge effect is obtained and relative rotation occurs between the clutch outer ring 3 and the clutch inner ring 2, the ball 4 is locked and the power of the shaft 1 is transmitted from the clutch inner ring 2 to the clutch outer ring 3. This rotation transmission can be performed in any rotation direction.

In this way, the shift, that is, the shift is completed. In this case, the frictional resistance between the clutch inner wheel 2, the ball 4 and the clutch outer wheel 3 increases, and the shift is completed while the crank inner and outer wheels 2 and 3 are synchronized. Therefore, a smooth shift can be performed. In this embodiment, since the transition groove portion 11b formed of a tapered groove is provided, the above-mentioned friction resistance is gradually increased, and a smoother shift can be performed.

Further, since this clutch type speed change mechanism does not engage the teeth, but transmits the rotation by the locking action of the wedge effect of the ball 4 as described above, the smoothness of the shift is ensured. It does not easily depend on the properties of the lubricating oil, and can handle sudden shifts. Moreover, since this clutch type speed change mechanism is composed of the clutch inner and outer wheels 2 and 3 and the ball 4, it has an advantage that the number of parts is small and the structure is simple as compared with the conventional speed change mechanism using the synchronizer ring.

Although the tapered groove-shaped transition groove portion 11b is formed in the axial groove 11 of the clutch inner ring 2 in the above embodiment, the transition groove portion 11b may not be necessarily provided. Further, although the deep groove portion 11a and the shallow groove portion 11c are each formed in a cylindrical surface shape in the above-described embodiment, the entire axial groove 11 is formed as a taper groove in which the groove depth and the curvature gradually change, and a part thereof is formed in the deep groove portion. 11a and the shallow groove portion 11c may be used.

[0025]

[Effect of the device]

 In the clutch type speed change mechanism of the present invention, a ball is interposed between an axial groove formed on the inner ring of the clutch and a circumferential groove formed on the outer ring of the clutch to generate a wedge effect formed on the axial groove. The ball is moved between the shallow groove and the deep groove for idling to lock and unlock the clutch wheels, so the number of parts is small and the structure is simple. The smoothness of the shift is unlikely to be affected by the nature of, and there is an effect that smooth shifts can always be performed and sudden shifts can be dealt with.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view of a clutch type speed change mechanism according to an embodiment of the present invention.

FIG. 2 is a partial transverse sectional view thereof.

FIG. 3 is a sectional view of the inner ring of the clutch.

4 (A) to (C) of FIG. 4 are lines AA of FIG. 3, respectively.
It is an expanded sectional view of a BB line and a C-C line.

5A to 5C are a perspective view, a plan view, and a cross-sectional view, respectively, showing a schematic shape of an axial groove of a clutch inner ring.

FIG. 6 is an explanatory diagram of the same operation.

FIG. 7 is an operation explanatory diagram of a conventional example.

[Explanation of symbols]

1 ... Shaft, 2 ... Clutch inner ring, 3 ... Clutch outer ring,
4 ... Ball, 6 ... Selector, 7 ... Circumferential groove, 11 ... Axial groove, 11a ... Deep groove part, 11b ... Progressive groove part, 11c ... Shallow groove part

Claims (1)

[Scope of utility model registration request] 1. A clutch inner ring and a clutch outer ring which are axially movable and rotatably fitted to each other, wherein the clutch inner ring has an axial groove having an arcuate cross section at a plurality of circumferential positions on an outer diameter surface thereof. The outer ring has a circumferential groove on the inner diameter surface, and a ball movable in the axial groove is interposed between both grooves. A deep groove portion having a small radius of curvature and a large radius of curvature are provided in each axial groove. A clutch type speed change mechanism in which a shallow groove portion is formed apart from each other in the axial direction.