JP4602177B2 - Constant velocity universal joint - Google Patents

Description

  The present invention relates to a constant velocity universal joint, and particularly to a tripod type constant velocity universal joint.

  For example, as shown in FIG. 1, the tripod type constant velocity universal joint 30A has three tracks extending in the axial direction by connecting a tripod member 2 having three leg shafts 5 protruding in the radial direction to one shaft. A hollow cylindrical outer joint member 1 having a groove 3 is coupled to the other shaft, and a roller 20A fitted on the leg shaft 5 of the tripod member 2 is accommodated in the track groove 3 of the outer joint member 1 and rotated. Torque is being transmitted. This tripod type constant velocity universal joint is used, for example, as a joint for transmitting rotational force from an automobile engine to wheels at a constant speed.

  When the tripod type constant velocity universal joint transmits rotational torque while the outer joint member and the tripod member take an operating angle, when the roller and the roller guide surface are in an oblique state with the inclination of the leg shaft, Slip occurs between the two, and the smooth rolling of the roller is impeded and the induced thrust increases. Further, the sliding resistance when the outer joint member and the tripod member are relatively displaced in the axial direction is increased by the frictional force between the roller and the roller guide surface.

  Such induced thrust and slide resistance cause vibration and noise of the vehicle body when the constant velocity universal joint is used for, for example, a drive shaft or a propeller shaft of an automobile, and adversely affect the NVH performance of the automobile. In order to reduce such induced thrust and slide resistance, a tripod type constant velocity universal joint having a mechanism for allowing the roller 20A to freely tilt with respect to the leg shaft 5 has been proposed as shown in FIG.

  For example, those disclosed in Japanese Patent Laid-Open Nos. 2000-320563 and 2001-132766 have a roller assembly attached to a leg shaft of a tripod member. For example, as shown in FIG. 3, the roller assembly includes an outer ring 6, needle rollers 7 in a full roller state, a pair of snap rings 10, and an inner ring 8. The outer ring 6 is rotatably fitted on the outer periphery of the inner ring 8 via needle rollers 7.

  As for the combination of the inner ring 8 and the leg shaft, when the inner peripheral surface 8a of the inner ring 8 is formed into a convex curved surface as shown in FIG. 3, as shown in FIG. It is good to. As shown in FIG. 4, when the inner peripheral surface 8a of the inner ring 8 is a cylindrical surface, the outer peripheral surface 5a of the leg shaft 5 is preferably a true spherical surface as shown in FIG. In any of the combinations, since the leg shaft can swing freely with respect to the inner ring 8, it is possible to prevent the roller assemblies 20 </ b> A and 20 </ b> B from skewing with respect to the roller guide surface 4. As a result, the roller assemblies 20A and 20B can be smoothly rolled in a fixed posture with respect to the roller guide surface 4, and the above-described induced thrust and slide resistance can be reduced.

The needle roller 7 and the inner ring 8 in the full roller state are prevented from being pulled out by a pair of snap rings 10 as shown in FIGS. That is, a pair of snap ring grooves 9 having an inner width dimension U substantially corresponding to the length of the needle rollers 7 is formed on both sides in the width direction of the inner peripheral surface 6 a of the outer ring 6. The snap ring 10 is fitted. As shown in FIG. 6, the snap ring 10 is an ended ring in which slits 11 are formed obliquely, and is elastically reduced in diameter and attached to the snap ring groove 9 of the outer ring 6.
JP 2000-320563 A JP 2001-132766 A

  When the snap ring 10 is elastically reduced in diameter and attached to the snap ring groove 9 of the outer ring 6, the snap ring 10 is reduced in diameter while being elastically deformed in a spiral shape. At this time, the end portions 12 and 13 of the slit 11 interfere with each other. The workability of the assembly work may be poor.

In the constant velocity universal joint according to the present invention, in such a roller assembly, the snap ring is an ended ring in which a slit is formed obliquely with respect to the radial direction of the snap ring. The end that extends to the inner diameter side of the slit formed obliquely in the snap ring so that the end of the snap ring does not interfere when the snap ring is attached to the outer ring. It is characterized in that chamfering is performed on at least one of the corner on the outer diameter side and the corner on the inner diameter side of the end portion extending to the outer diameter side of the slit .

According to this constant velocity universal joint, the snap ring is an ended ring having a slit oblique to the radial direction , and is elastically reduced in diameter and attached to the outer ring, and the snap ring is attached to the outer ring. When mounting, the end of the snap ring formed on the outer diameter side of the slit and the outer diameter side of the slit extended to the inner diameter side of the slit so that the end of the snap ring does not interfere with each other . Since chamfering is applied to at least one of the corners on the inner diameter side of the end , the workability of the assembly work for mounting the snap ring on the outer ring is not deteriorated, and it is possible to reliably prevent the snap ring from being assembled incorrectly. And the occurrence of defective parts can be reduced.

  Hereinafter, a constant velocity universal joint according to an embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to drawing and the member and site | part which show | plays the same effect | action.

  As shown in FIGS. 1 and 2, the constant velocity universal joint 30A according to the first embodiment is mainly composed of the outer joint member 1 and the tripod member 2, and is configured with two shafts to be connected on the driving side and the driven side ( One of them is connected to the outer joint member 1 and the other is connected to the tripod member 2. The constant velocity universal joint 30A transmits rotational torque at a constant speed and allows relative displacement in the axial direction even when the two connected shafts take an operating angle θ as shown in FIG.

  The outer joint member 1 has a substantially cylindrical cup shape with one end opened and the other end closed (see FIG. 2). One shaft is integrally provided at the other end, and three shafts extending in the axial direction on the inner peripheral portion. Track grooves 3 are formed at intervals of 120 ° around the central axis. Each track groove 3 forms a pair of concave curved roller guide surfaces 4 in the axial direction on the side walls facing each other in the circumferential direction.

  The tripod member 2 has three leg shafts 5 protruding in the radial direction, and is held by serration (or spline) fitting on the other shaft. An outer ring 6 is attached to each leg shaft 5, and the outer ring 6 is accommodated in the track groove 3 of the outer joint member 1. The outer peripheral surface of the outer ring 6 has a convex curved surface shape that matches the roller guide surface 4. Specifically, the outer circumferential surface of the outer ring 6 is a convex curved surface having an arc having a center of curvature at a position away from the axis of the leg shaft 5 in the radial direction, and the cross-sectional shape of the roller guide surface 4 has two radii of curvature. Thus, the outer peripheral surface of the outer ring 6 and the roller guide surface 4 are brought into angular contact. In FIG. 1, the action line of two contact points which make an angular contact is indicated by a one-dot chain line a. Even if the cross-sectional shape of the roller guide surface 4 is tapered with respect to the outer circumferential surface of the convex curved surface of the outer ring 6, the angular contact between them can be realized.

  As shown in FIG. 3, an inner ring 8 is rotatably fitted to the inner peripheral surface 6 a of the outer ring 6 via needle rollers 7. The needle roller 7 and the inner ring 8 are restricted from being detached by a pair of snap rings 10. The snap ring 10 is fitted into a pair of snap ring grooves 9 formed on the inner peripheral surface 6 a of the outer ring 6 corresponding to the thickness of the needle roller 7 and the thickness width of the inner ring 8.

  Next, the constant velocity universal joint 30B which concerns on a 2nd form is demonstrated. The constant velocity universal joint 30B has the same basic configuration as the constant velocity universal joint 30A according to the first embodiment (see FIG. 1). explain.

  In the constant velocity universal joint 30B according to the second embodiment, as shown in FIG. 5, the outer peripheral surface of the leg shaft 5 of the tripod member 2 is a true spherical surface 5a, and the true spherical surface 5a is formed on the roller assembly 20B shown in FIG. The inner ring 8 is externally fitted so as to be swingable and slidable. The roller guide surface 4 of the outer joint member 1 is a partial cylindrical surface, and the outer peripheral surface of the outer ring 6 is a partial spherical surface. Further, a flange portion 1a is formed adjacent to the roller guide surface 4 of the outer joint member 1, and the outer ring 6 of the roller assembly 20B is guided toward the track groove 3 in a fixed posture by the flange portion 1a. The other configuration is the same as that of the constant velocity universal joint 30A (see FIG. 1) according to the first embodiment, in which the needle roller 7 of the roller assembly 20B includes the cylindrical outer peripheral surface of the inner ring 8 and the cylindrical shape of the outer ring 6. The roller is disposed between the inner peripheral surface and the inner peripheral surface in a full-roller state, and the both end surfaces of the needle roller 7 and the inner ring 8 are restricted by an annular snap ring 10.

  In the constant velocity universal joints 30A and 30B according to the first and second embodiments, the snap ring 10 is an end ring having an oblique slit, and is elastically reduced in diameter and attached to the outer ring 6. To do. Then, when the snap ring 10 is attached to the outer ring 6, at least one end of the snap ring 10 is chamfered so that the end of the snap ring 10 does not interfere.

  In this embodiment, as shown in FIG. 7, the snap ring 10 is chamfered on the outer diameter side corner 12a of the end portion 12 extending toward the inner diameter side of the slanted slit 11, and the snap ring 10 is When attaching to the ring 6, the end portions 12 and 13 on both sides of the slit 11 were prevented from interfering with each other.

  As a result, when the snap ring 10 is slightly helically reduced in diameter and attached to the outer ring 6, the end portions 12 and 13 on both sides of the slit 11 do not interfere with each other, so the snap ring 10 is attached to the outer ring 6. The workability at the time is good, assembly failure can be surely prevented, and occurrence of defective parts in the snap ring 10 can be prevented.

  As another embodiment, when the snap ring 10 is attached to the outer ring 6 by chamfering the inner diameter side corner 13a of the end 13 extending to the outer diameter side of the slit 11, as shown in FIG. In addition, the end portions 12 and 13 on both sides of the slit 11 may not interfere with each other. Also in this case, when the snap ring 10 is attached to the outer ring 6, the end portions 12 and 13 on both sides of the slit 11 do not interfere with each other, and the diameter can be reduced helically. The workability at the time of mounting on the rim is good, the assembly failure can be surely prevented, and the occurrence of defective parts in the snap ring 10 can be reduced.

  Note that the chamfering method is not limited to the above embodiment because the end portions 12 and 13 on both sides of the slit 11 do not interfere when the snap ring 10 is attached to the outer ring 6.

For example, in the above-described embodiment, the outer diameter side corner 12a of the end portion 12 extending to the inner diameter side of the slit 11 or the outer diameter side corner 13a of the end portion 13 extending to the outer diameter side of the slit 11 is defined as C. Although chamfered is illustrated, instead of chamfering such a portion, when the snap ring 10 is attached to the outer ring 6 by performing R chamfering, the end portions 12 and 13 on both sides of the slit 11 do not interfere with each other. It may be. Further, chamfering is performed on both the outer diameter side corner 12a of the end portion 12 extending to the inner diameter side of the slit 11 and the inner diameter side corner 13a of the end portion 13 extending to the outer diameter side of the slit 11, When attaching the snap ring 10 to the outer ring 6, the ends 12 and 13 on both sides of the slit 11 may be prevented from interfering with each other. When chamfering is performed , as in the reference example shown in FIG. 9, the outer diameter side corner 12 a of the end portion 12 extending to the inner diameter side of the slit 11 or the end portion extending to the outer diameter side of the slit 11 is used. Any one of the end portions 13a on the outer diameter side 13a (end portion 12 in FIG. 9) may be chamfered as a whole, and both end portions may be inclined at different angles.

  Thus, when the snap ring 10 is attached to the outer ring 6, the end portions 12 and 13 on both sides of the slit 11 do not interfere with each other, and the diameter of the snap ring 10 can be reduced helically. Workability at the time of mounting is good, assembly failure can be surely prevented, and occurrence of defective parts in the snap ring 10 can be reduced.

  In the above embodiment, the chamfering applied to the end portions 12 and 13 of the snap ring 10 is related to the outer ring 6, the inner ring 8, and the needle rollers 7 when the snap ring 10 is attached to the outer ring 6. This is performed to the extent that the original function of the snap ring 10 is not impaired.

  Although the constant velocity universal joint according to one embodiment of the present invention, particularly the snap ring, has been described above, the constant velocity universal joint according to the present invention is not limited to the above embodiment.

For example, a conventional snap ring 10, as shown in FIG. 10, in which cross section the corners 10a at substantially rectangular, 10b, 10c, and 10d, uniformly, respectively (e.g., ro in) chamfered. In the present invention, similarly, the snap ring 10 having a substantially rectangular cross section and chamfering each corner can be employed.

  However, in assembling the roller assembly, the snap ring 10 is slightly reduced in diameter and is inclined and mounted in the direction of the arrow b toward the snap ring groove 9 of the outer ring 6 as shown in FIG. However, the groove width W of the snap ring groove 9 is not so large with respect to the thickness t of the snap ring 10.

  This is for suppressing the play of the snap ring 10 itself, and hence the play of the inner ring 8 and the needle rollers 7. For this reason, when the snap ring 10 is inserted into the snap ring groove 9, the outer edge portion 9a of the snap ring groove 9 comes into contact with the outer surface of the snap ring 10 and rubs. It may be difficult to insert and may take time to assemble.

  Therefore, as described above, when the snap ring 10 is attached to the outer ring 6, at least one of the end portions 12 and 13 of the snap ring 10 is chamfered so that the end portion of the snap ring 10 does not interfere. As shown in FIG. 12, at the outer peripheral edge 16 of the snap ring 10, the corner 10a located on the side opposite to the inner ring 8 (the side that becomes the outer side when attached to the outer ring 6), as shown in FIG. When the snap ring 10 is inserted into the snap ring groove 9, the chamfering amount of the snap ring 10 may be increased to such an extent that the frictional resistance of the snap ring 10 against the outer edge portion 9a of the snap ring groove 9 is reduced. Here, the “chamfering amount” is the length of one side of two orthogonal sides of a portion cut out by R chamfering or C chamfering.

  Another problem with the snap ring 10 is that the attached state of the snap ring 10 becomes unstable depending on the degree of axial load. That is, FIG. 13 shows the inclination of the snap ring 10 slightly exaggerated. However, when an axial load is applied from the inner ring 8 toward the snap ring 10 as indicated by an arrow c, for example, the snap ring 10 10 bends outward (deflection amount δ). At this time, the inner corner portion 10b rubs against the inner side surface 9b of the snap ring groove 9 at the outer peripheral edge 16 of the snap ring 10, so that the amount of deflection in the outer direction of the snap ring 10 is suppressed to some extent. However, when the chamfered amount of the corner portion 10b is too large, the deflection amount δ increases, and the mounting state of the snap ring 10 becomes unstable depending on the degree of the axial load.

  Therefore, when the snap ring 10 is attached to the outer ring 6, the snap ring 10 is chamfered on at least one end so that the end of the snap ring 10 does not interfere with the outer periphery of the snap ring 10. The chamfering amount of the corner 10b located on the inner ring side (the inner side when the outer ring 6 is attached) may be reduced at the peripheral edge 16.

  Thereby, as shown in FIG. 14, when an axial load is applied from the inner ring 8 to the snap ring 10, the inner side surface 9b of the snap ring groove 9 and the corner portion 10b of the snap ring 10 are brought into contact with each other with a small amount of deflection. The state where the snap ring 10 is attached to the outer ring 6 is stabilized.

  Further, as another problem of the snap ring 10, there is a problem of fatigue of the snap ring 10 due to an axial load. That is, as shown in FIG. 13, when an axial load is applied from the inner ring 8 to the inner surface of the snap ring 10 in the outer direction as indicated by an arrow, the snap ring 10 is moved outward as described above. Deflection. At this time, the outer corner portion 10c has a large amount of deformation at the inner peripheral edge of the snap ring 10, and a maximum tensile stress is generated in the vicinity of the corner portion 10c. Since this maximum tensile stress is repeatedly generated by the rotation of the joint, the vicinity of the corner portion 10c tends to cause metal fatigue.

Therefore, when attaching the snap ring 10 to the outer ring 6, as shown in FIG. 14 , in addition to chamfering at least one end of the snap ring 10 so that the end of the snap ring 10 does not interfere. In addition, the chamfering amount of the corner portion 10c may be increased. Thereby, when an axial load is applied to the snap ring 10, the maximum tensile stress generated in the corner portion 10c of the snap ring 10 can be reduced, and metal fatigue at the portion can be reduced.

  Another problem with the snap ring 10 is that the rotational force transmitted from the snap ring 10 to the inner ring 8 is reduced. That is, as shown in FIG. 15, when the outer ring 6 rotates, the rotational force is transmitted mainly to the inner ring 8 through the snap ring 10, but at the inner peripheral edge 17 of the snap ring 10, the inner corner 10 d. When the amount of chamfering is too large, the catching margin S between the inner ring 8 and the snap ring 10 is reduced, so that the frictional force at this portion is reduced and the rotation transmitted from the snap ring 10 to the inner ring 8 is reduced. The power will be reduced. When the rotational force of the inner ring 8 decreases, the relative rotational amount of the outer ring 6 and the inner ring 8 increases, and the life of the inner ring 8 and the needle roller 7 may be reduced. Such an event is not preferable in order not to lower the value.

  Therefore, when attaching the snap ring 10 to the outer ring 6, as shown in FIG. 16, in addition to chamfering at least one end of the snap ring 10 so that the end of the snap ring 10 does not interfere. Moreover, it is preferable to reduce the chamfering amount of the corner 10d. As a result, the catching margin S of the snap ring 10 in contact with the inner ring 8 increases, so that the torque transmitted from the outer ring 6 to the inner ring 8 via the snap ring 10 increases, and the outer ring 6 and the inner ring 8 It is possible to prevent the relative rotation amount of the shaft from being reduced and the durability of the constant velocity universal joint from being lowered.

  As described above, the end surface of the snap ring 10 has a corner portion located on the inner ring 8 side by increasing the chamfering amount of the corner portion 10 a located on the opposite side of the inner ring 8 at the outer peripheral edge 16 of the snap ring 10. It is preferable to reduce the chamfering amount of 10b. Further, at the inner peripheral edge 17 of the snap ring 10, the chamfering amount of the corner portion 10c on the opposite side to the inner ring 8 may be increased, and the chamfering amount of the corner portion 10d on the inner ring side may be decreased. Therefore, at the outer peripheral edge 16 of the snap ring 10, when the chamfering amount of the corner portion 10b on the inner ring 8 side is A and the chamfering amount of the corner portion 10a opposite to the inner ring 8 is B, A < A configuration that satisfies B is preferable. In the inner peripheral edge 17 of the snap ring, when the chamfering amount of the corner portion 10d on the inner ring 8 side is A and the chamfering amount of the corner portion 10c opposite to the inner ring 8 is B, A <B It is recommended that the configuration satisfies the above.

  The end face of the snap ring 10 can be variously modified without being limited to the above-described embodiment. For example, as shown in FIG. 17, four corners 10a, 10b, 10c, and 10d are applied. The chamfering may be either R chamfering or C chamfering, and these chamfering may be combined arbitrarily. In the above-described embodiment, an arc or a straight line is exemplified as a typical shape of the R chamfering or C chamfering. However, the R chamfering arc is not necessarily a strict meaning arc, and is substantially a curve close to the arc. The chamfer may be formed by a curve close to a straight line. In addition, the chamfering amount of the R chamfering or C chamfering is within the range in which the above-described effects can be obtained, the inner and outer diameters of the outer ring 6 and inner ring 8 of the constant velocity universal joint that actually uses the snap ring 10, or The snap ring groove 9 can be appropriately changed according to the position where the snap ring groove 9 is formed.

The longitudinal cross-sectional view which shows the tripod type constant velocity universal joint which concerns on a 1st form. The cross-sectional side view which shows the tripod type constant velocity universal joint which concerns on a 1st form. Sectional drawing which shows the roller assembly of the tripod type | mold constant velocity universal joint which concerns on a 1st form. Sectional drawing which shows the roller assembly of the tripod type | mold constant velocity universal joint which concerns on a 2nd form. The longitudinal cross-sectional view which shows the tripod type constant velocity universal joint which concerns on a 2nd form. The figure which shows the snap ring used for a roller assembly. The figure which shows the snap ring of the constant velocity universal joint which concerns on one Embodiment of this invention. The figure which shows the snap ring of the constant velocity universal joint which concerns on other embodiment of this invention. The figure which shows the snap ring of the constant velocity universal joint which concerns on a reference example . Sectional drawing which shows the snap ring used for a roller assembly. Sectional drawing which shows the state at the time of attaching a snap ring to an outer ring. Sectional drawing which shows the state at the time of attaching a snap ring to an outer ring regarding the snap ring of the constant velocity universal joint which concerns on one Embodiment of this invention. Sectional drawing which shows the use condition of the snap ring of a constant velocity universal joint. Sectional drawing which shows the state of use of the snap ring of the constant velocity universal joint which concerns on one Embodiment of this invention. Sectional drawing which shows the state of use of the snap ring of the constant velocity universal joint which concerns on one Embodiment of this invention. Sectional drawing which shows the state of use of the snap ring of the constant velocity universal joint which concerns on one Embodiment of this invention. Sectional drawing which shows the snap ring of the constant velocity universal joint which concerns on one Embodiment of this invention.

Explanation of symbols

1 outer joint member 2 tripod member 3 track groove 4 roller guide surface 5 leg shaft 6 outer ring 6a inner peripheral surface 8 inner ring 8a inner peripheral surface 9 snap ring groove 9b inner side surface 9a outer edge portion 10 snap rings 10a to 10d corner portion 10e Inner side surface 11 Slit 12 End portion 13 extending toward the inner diameter side End portion 16 extending toward the outer diameter side Outer peripheral edge 17 Inner peripheral edge 20A, 20B Roller assembly 30A, 30B Constant velocity universal joint

Claims (3)

An outer joint member having a track groove formed on the inner periphery, a tripod member having a leg shaft projecting radially toward the track groove of the outer joint member, and an inner ring externally fitted to each leg shaft of the tripod member The inner ring is pivotally supported and attached to the outer ring inserted into the track groove of the outer joint member and the snap ring groove formed on the inner peripheral surface of the outer ring to restrict the axial movement of the inner ring. In a constant velocity universal joint equipped with a snap ring
The snap ring is an end ring having a slit formed obliquely with respect to the radial direction of the snap ring , and is elastically reduced in diameter and attached to the snap ring groove of the outer ring. In order to prevent the end of the snap ring from interfering with the outer ring when attached to the outer ring, the outer diameter side corner of the end extending to the inner diameter side of the slit formed obliquely of the snap ring and the outer diameter side of the slit A constant velocity universal joint characterized by chamfering at least one of the corners on the inner diameter side of the end portion extending to the end .   At the outer peripheral edge of the snap ring, when the chamfering amount at the corner on the inner ring side is A and the chamfering amount at the corner opposite to the inner ring is B, A <B is satisfied. The constant velocity universal joint according to claim 1.   At the inner periphery of the snap ring, when the chamfering amount at the corner on the inner ring side is A and the chamfering amount at the corner opposite to the inner ring is B, A <B is satisfied. The constant velocity universal joint according to claim 1.

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