WO2012098959A1 - Sliding constant-velocity universal joint - Google Patents

Abstract

A sliding constant-velocity universal joint, the interior of which houses a coil spring for exerting an urging force on a torque transmission shaft, wherein a compact spring bearing member is used, and this spring bearing member is prevented from falling into a step part of a roller end face even in the case of a high operating angle. The sliding constant-velocity universal joint comprises an outside joint member (11), a slidable inside joint member (12), a torque transmission shaft (13) fitted in the center of the inside joint member (12), a spring bearing member (15), and a coil spring (14) interposed between the spring bearing member (15) and the inside bottom face of the outside joint member (11), wherein the joint can be made more compact by forming the spring bearing member (15) in a dish shape, and wherein the size of the pitch of the coil spring (14) is set such that a roller (28) does not readily enter an inter-pitch gap even in a case where the coil spring (14) interferes with the roller (28).

Description

Sliding constant velocity universal joint

The present invention relates to a constant velocity universal joint used for power transmission devices such as automobiles and various industrial machines, and more particularly to a sliding type constant velocity universal joint.

2. Description of the Related Art A driving force transmission structure is known in which a pair of sliding constant velocity universal joints are interposed between respective driving shafts between a vehicle differential gear and left and right wheels with an intermediate shaft interposed therebetween. In the sliding type constant velocity universal joint in this case, since the intermediate shaft is freely displaced in the axial direction and its position is not fixed, one end portion of the intermediate shaft hits the inner end surface of the outer joint member of one constant velocity universal joint. Abnormal noise and vibration may occur.

In order to prevent the generation of the noise and vibration, a coil spring is interposed between the inner end of the outer ring joint member of the other constant velocity universal joint and the other end of the intermediate shaft in a compressed state, and the intermediate shaft is A configuration is adopted in which the one constant velocity universal joint is urged and one end of the intermediate shaft is pressed against a receiving member provided on the inner end face of the outer joint member (Patent Documents 1 and 2).

The tripod type sliding constant velocity universal joint disclosed in Patent Document 1 described above will be described with reference to FIG. This constant velocity universal joint is constituted by a combination of an outer joint member 111, an inner joint member 112, a torque transmission shaft (the intermediate shaft) 113, a coil spring 114 and a spring receiving member 115.

The outer joint member 111 is formed with a cup-shaped mouth portion 116 having one end opened, and a stem portion 117 is provided on the opposite surface of the mouth portion 116. An axial guide groove 118 is provided at a circumferentially equally divided position of the inner peripheral surface of the mouse portion 116, and a spring receiving recess 119 is provided at the center of the inner bottom surface.

The inner joint member 112 is provided with a journal shaft protruding in a radial direction at a position equally divided into three parts around the boss 123, a so-called trunnion shaft 124. A roller 128 having needle rollers 127 interposed between an inner ring 125 and an outer ring 126 is fitted to the trunnion shaft 124 so as to be swingable with a margin in the radial direction. A roller 128 is slidably fitted into the guide groove 118.

The torque transmission shaft 113 has a spline shaft portion 130 formed at the tip thereof, and the tip surface of the spline shaft portion 130 is a convex spherical surface 131. The spline shaft portion 130 is fitted into the spline hole 122 of the inner joint member 112, and is prevented from coming off by a retaining ring 132. The convex spherical surface 131 protrudes from the spline hole 122 to the inside of the mouse portion 116.

The spring receiving member 115 is a cup-shaped member including a bottom plate 133 formed on a concave spherical surface that contacts the convex spherical surface 131 and a cylindrical portion 134 that rises from the peripheral edge of the bottom plate 133 toward the spring receiving concave portion 119. is there. The rising height of the cylindrical portion 134 is formed such that the cylindrical portion 134 can contact the outer ring 126 when the torque transmission shaft 113 takes a large operating angle θ. The coil spring 114 is interposed between the spring receiving recess 119 and the spring receiving member 115 in a compressed state.

In the case of Patent Document 2 shown in FIGS. 5 and 6, the configuration is substantially the same as that of Patent Document 1, but the spring receiving member 115 has a cylindrical portion 134 whose height is higher than that of Patent Document 1. The difference is that it is a low-shaped dish.

US 2010/0022314 A1 specification and drawings Japanese Utility Model Publication No. 6-12258 (Fig. 2)

In the constant velocity universal joint of Patent Document 1 shown in FIG. 4, when the operating angle θ becomes a certain high angle, the spring receiving member 115 is displaced from the convex spherical surface 131 at the tip of the torque transmission shaft 113, and the inclination increases. The cylindrical portion 134 interferes with the outer ring 126 of the roller 128. In this case, in order to avoid a problem that the edge 137 of the cylindrical portion 134 falls into the width surface stepped portion 138 of the roller 128, the rising height of the cylindrical portion 134 is adjusted to the size of the roller 128, and the contact position with the roller at the time of interference is determined. It is necessary to set the size in consideration.

In particular, the roller 128 that swings freely on the trunnion shaft 124 has a complicated structure with a step on its width surface, so the rising height of the cylindrical portion 134 matches the size and model of the constant velocity universal joint. There is a hassle that must be set. Further, since the rising height of the cylindrical portion 134 is increased, there is a problem that the spring receiving member 115 as a part is increased in size.

On the other hand, the spring receiving member 115 in the case of Patent Document 2 shown in FIG. 5 and FIG. 6 has a dish shape in which the cylindrical portion 134 is formed to be relatively low, so that it is more compact than the above case, and press There is an advantage that it can be easily manufactured by processing. However, when the operating angle θ increases, the coil spring 114 bends and tilts and directly interferes with the roller 128, and a part of the roller 128 may enter the gap between the pitches of the coil spring 114 (see FIG. 6).

When the roller 128 enters the gap between the pitches, the inclination angle of the coil spring 114 and the spring receiving member 115 is further increased, and the end edge 137 of the spring receiving member 115 falls into the stepped portion 138 of the width surface of the roller 128, allowing constant velocity. Problems that affect the operability of the joint occur.

Therefore, the present invention aims to make the spring receiving member compact in the sliding type constant velocity universal joint, while preventing the edge of the spring receiving member from falling into the stepped portion of the roller width surface. The objective is to improve the performance.

In order to solve the above problems, the present invention provides an outer joint member, an inner joint member slidable with respect to the outer joint member, a radial trunnion shaft provided on the inner joint member, and a neck on the trunnion shaft. A roller fitted in a swingable manner, a torque transmission shaft fitted in the center of the inner joint member, a spring receiving member having a concave spherical surface contacting the convex spherical surface at the tip of the torque transmission shaft, and the spring receiving member and A sliding type constant velocity universal joint comprising a coil spring interposed between the inner bottom surface of the outer joint member and transmitting torque between a stem portion provided on the outer joint member and the torque transmission shaft. In this case, the spring receiving member is formed in a dish shape having a relatively low cylindrical portion, and the pitch of the coil spring is such that even when the coil spring interferes with the roller, a part of the roller is It was set configured to enter the gap hardly magnitude between pitch.

By setting the pitch of the coil spring as described above, even if the joint takes a large operating angle and the coil spring part bends or tilts and interferes with the roller, the coil spring Part of the roller is prevented from entering the gap between the pitches. As a result, since the inclination of the coil spring does not increase any more and the inclination of the spring receiving member does not increase any more, the problem that the spring receiving member falls into the stepped portion of the roller width surface can be prevented. .

The specific height of the cylindrical portion of the spring receiving member refers to a height that accepts about two rounds of the end of the coil spring. The pitch of the coil spring is specifically set to be not less than the wire diameter of the coil spring wire and not more than twice the wire diameter. The case where the pitch of the coil spring is equal to the wire diameter of the coil spring wire means that the gap between the pitches is zero (contact state). Moreover, the case where the pitch is twice as large as the wire diameter means that the gap between the pitches is equal to the diameter of the wire.

The pitch does not necessarily need to be set to a constant size over the entire length of the coil spring, but is set to the size in a range from the end of the coil spring on the spring receiving member side to a portion that interferes with the roller. However, it is general to adopt a configuration in which the other ranges are formed at a relatively large pitch. In this case, the coil spring has a relatively small pitch range, that is, a small pitch range, and a relatively large pitch range, that is, a large pitch range.

As described above, in the sliding type constant velocity universal joint according to the present invention, the coil spring interposed between the inner bottom surface of the outer joint member and the torque transmission shaft has a pitch size of the coil spring. Even when it interferes with the roller, a part of the roller is set to a pitch that does not easily enter the gap between the pitches. It is prevented from entering the gap between the pitches. As a result, since the inclination of the coil spring and the spring receiving member that supports the coil spring is also restricted, the problem that the spring receiving member falls into the stepped portion of the roller is prevented, and the operability of the constant velocity universal joint is improved. .

Also, it is not necessary to set the rising height of the cylindrical portion of the spring receiving member of the coil spring large, and the height may be a low dish shape that allows the coil spring to be seated stably. Thereby, the spring receiving member can be made compact.

FIG. 3 is a cross-sectional view of the sliding type constant velocity universal joint according to Embodiment 1 when the operating angle is 0 °. It is an expanded sectional view of the spring receiving member of FIG. 1A. It is an expanded sectional view of the coil spring of FIG. 1A. It is sectional drawing at the time of taking the fixed operating angle of FIG. 1A. It is a partially expanded sectional view of FIG. It is sectional drawing of the state which took the operating angle of the sliding type constant velocity universal joint of the prior art example. It is sectional drawing of the state which took the operating angle of the sliding type constant velocity universal joint of another prior art example. It is a partially expanded sectional view of FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
[Embodiment 1]
The tripod type sliding constant velocity universal joint according to the first embodiment shown in FIGS. 1A to 3 is a combination of an outer joint member 11, an inner joint member 12, a torque transmission shaft 13, a coil spring 14 and a spring bearing member 15. Consists of.

The outer joint member 11 is composed of a cup-shaped mouth portion 16 having one end opened, and a stem portion 17 projecting coaxially opposite to the mouth portion 16 at the center of the outer surface of the closed end. An axial guide groove 18 is provided at a position of the inner peripheral surface of the mouse portion 16 in three circumferential directions, and a spring receiving recess 19 is provided at the center of the inner bottom surface. The stem portion 17 is provided with a spline (including serration) 21.

The inner joint member 12 is provided with a so-called trunnion shaft 24, which is a journal shaft protruding in the radial direction at a position equally divided into three around the boss 23. A spline hole 22 is provided at the center of the boss 23. The trunnion shaft 24 has a cross-sectional shape that is cylindrical or elliptical, and a roller 28 is fitted to the trunnion shaft 24 so as to be swingable with a margin in the radial direction. The roller 28 is configured by interposing a needle roller 27 between the inner ring 25 and the outer ring 26.
The trunnion shaft 24 may be formed in a spherical shape.

The inner ring 25 and the needle rollers 27 are integrated with the outer ring 26 by retaining rings 29a and 29b interposed between the inner and outer end faces of the outer ring 26. The outer ring 26 of the roller 28 is slidably fitted into the guide groove 18. A stepped portion 38 (see FIG. 3) exists between the width surface of the outer ring 26 on the boss portion 23 side and the retaining ring 29a.

The torque transmission shaft 13 has a spline shaft portion 30 formed at the tip portion, and the tip surface of the spline shaft portion 30 is a convex spherical surface 31. The spline shaft portion 30 is fitted into the spline hole 22 of the inner joint member 12 and is prevented from coming off by a retaining ring 32. The convex spherical surface 31 protrudes from the spline hole 22 to the inside of the mouse portion 16.

As shown in FIG. 1B, the spring receiving member 15 includes a bottom plate 33 formed on a concave spherical surface that contacts the convex spherical surface 31, and a low cylindrical portion that rises from the peripheral edge of the bottom plate 33 toward the spring receiving concave portion 19. 34 in the shape of a dish. A corner portion between the peripheral portion of the inner bottom surface of the bottom plate 33 and the rising portion of the inner peripheral surface of the cylindrical portion 34 is a seating portion 35 of the coil spring 14.

The rising height of the cylindrical portion 34 is set to a height sufficient to allow the end portion of the coil spring 14 to be seated stably at the seating portion 35. Specifically, it is set to a height of about two rounds of the portion of the coil spring 14 in the small pitch range C (see FIG. 1C) described later.

Since the spring receiving member 15 has a plate shape, it can be easily manufactured by pressing a metal plate. In addition, it can be formed of a sintered body.

The coil spring 14 is interposed between the spring receiving recess 19 and the spring receiving member 15 in a compressed state. When intervened in the compressed state, the pitch P of the coil spring 14 (see FIG. 1C) is a relatively large pitch range on the spring receiving recess 19 side, that is, a large pitch range S. The range of several turns from the end on the side is a relatively small pitch range, that is, a small pitch range C.

The length of the small pitch range C is set to the length from the end portion on the spring receiving member 15 side to the portion where the coil spring 14 interferes with the roller 28. In the case of the first embodiment, the small pitch range C is a range of four turns from the end. The size of the pitch P in the small pitch range C is set in the range of d to 2d (d is the diameter of the wire), that is, d ≦ P ≦ 2d.

“The pitch P is d” means that the gap between the pitches is zero, that is, the wires are in contact with each other. In any case, the pitch P of the large pitch range S is set larger than each case of the small pitch range C.

It should be noted that it is desirable that the first and second circumferential portions of the free end portion of the small pitch range C be fitted to the seating portion 35 of the spring receiving member 15 with a required tightening margin in order to stabilize the coil spring 14.

2 and 3 show an operating state in which a constant operating angle θ (15 ° in the case of illustration) is taken. In this state, the spring receiving member 15 may be tilted in a direction opposite to the tilt direction of the torque transmission shaft 13. Along with the inclination, the end portion on the spring receiving side of the coil spring 14 also moves, and is bent and inclined in a dogleg shape at the boundary portion between the large pitch range S and the small pitch range C.

Due to this deformation, a part of the small pitch range C of the coil spring 14 interferes with the width surface of the outer ring 26 of the roller 28 (see FIGS. 2 and 3). However, since the pitch P is set to be relatively small, a part of the outer ring 26 of the roller 28 cannot enter between the gaps. For this reason, since the inclination angle of the coil spring 14 and the spring receiving member 15 does not increase any more, the edge 37 of the cylindrical portion 34 of the spring receiving member 15 is prevented from falling into the stepped portion 38 (FIG. 3). reference).

P Pitch C Small pitch range S Large pitch range d Wire diameter 11 Outer joint member 12 Inner joint member 13 Torque transmission shaft 14 Coil spring 15 Spring receiving member 16 Mouse part 17 Stem part 18 Guide groove 19 Spring receiving concave part 21 Spline 22 Spline hole 23 Boss 24 Trunnion shaft 25 Inner ring 26 Outer ring 27 Needle roller 28 Roller 29a, 29b Retaining ring 30 Spline shaft part 31 Convex spherical surface 32 Retaining ring 33 Bottom plate 34 Cylindrical part 35 Seating part 37 Edge 38 Step part

Claims (10)

1. An outer joint member, an inner joint member slidable with respect to the outer joint member, a radial trunnion shaft provided on the inner joint member, a roller fitted to the trunnion shaft so as to swing freely, the inner joint member And a spring receiving member having a concave spherical surface contacting a convex spherical surface at the tip of the torque transmission shaft, and a spring receiving member interposed between the spring receiving member and the inner bottom surface of the outer joint member In a sliding type constant velocity universal joint comprising a coil spring and transmitting torque between a stem portion provided on the outer joint member and the torque transmission shaft, a cylindrical portion in which the spring receiving member is relatively low The pitch of the coil spring is set so that it is difficult for a part of the roller to enter the gap between the pitches even when the coil spring interferes with the roller. Sliding type constant velocity universal joint, characterized in that it is.
2. The sliding type constant velocity universal joint according to claim 1, wherein the height of the cylindrical portion of the spring receiving member is about two rounds of the end portion of the coil spring.
3. The sliding type constant velocity universal joint according to claim 1 or 2, wherein the size of the pitch is not less than the wire diameter of the wire material of the coil spring and not more than twice the wire diameter.
4. The range of the pitch is set to a range extending from the end of the coil spring on the spring receiving member side to a portion that interferes with the roller, and the other range is formed to have a relatively large pitch, thereby reducing the pitch. The sliding constant velocity universal joint according to any one of claims 1 to 3, wherein a range and a large pitch range are formed.
5. The sliding type constant velocity universal joint according to any one of claims 1 to 4, wherein the spring receiving member has a seat portion for receiving an end portion of the coil spring.
6. The sliding type constant velocity according to any one of claims 1 to 5, wherein an end of the coil spring is fitted to a cylindrical portion inner diameter surface of the spring receiving member with a predetermined tightening allowance. Universal joint.
7. The sliding constant velocity universal joint according to any one of claims 1 to 6, wherein an axial cross-sectional shape of the trunnion shaft is either a circle or an ellipse.
8. The sliding constant velocity universal joint according to any one of claims 1 to 6, wherein the trunnion shaft is formed in a spherical shape.
9. The sliding constant velocity universal joint according to any one of claims 1 to 8, wherein the spring receiving member is manufactured by press working.
10. The sliding constant velocity universal joint according to any one of claims 1 to 8, wherein the spring receiving member is formed of a fired body.

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