Tripod-type constant-velocity joint

Abstract

The present invention is a tripod-type constant-velocity joint 1 in which three arc-shaped large diameter portions 22 and three arc-shaped small diameter portions 23 are alternately provided in the joint circumferential direction Z on the inner-diameter surface 21 of an outer joint member 2, a track groove 5 is formed inside of each large diameter portion 22, the large diameter portions 22 and the small diameter portions 23 are connected via roller guide surfaces 6, and rollers are retained by means of a clip 10 mounted in a cup part 20. The clip 10 protrudes from the roller guide surfaces 6 at both joint-circumferential direction-Z ends of each clip mounting groove 25, retaining portions 10c capable of coming into contact with the outer-diameter surfaces of the rollers are provided at portions of the clip 10 located outside of the clip mounting grooves 25, and each retaining portion 10c extends in parallel with the axis of a leg shaft 32 and is disposed to follow a roller guide surface 6.

Description

Tripod type constant velocity universal joint

[0001] This invention relates to a tripod-type constant velocity universal joint.

[0002] A constant velocity universal joint connects two shafts, a drive shaft and a driven shaft, and has a structure that allows torque to be transmitted at a constant velocity even when these two shafts are at an operating angle (relative angular displacement). This constant velocity universal joint is broadly classified into a fixed type that allows only relative angular displacement of the two shafts, and a sliding type that allows both relative angular displacement and axial displacement of the two shafts. For example, in a drive shaft used to transmit power output from a drive source such as an engine or motor mounted on the chassis of an automobile to the drive wheels, a sliding type constant velocity universal joint is provided on the inboard side (drive source side), and a fixed type constant velocity universal joint is provided on the outboard side (drive wheel side).

[0003] As a sliding constant velocity universal joint, the tripod type constant velocity universal joint is well known. The tripod type constant velocity universal joint comprises an outer joint member having a bottomed cylindrical cup portion with one end open in the joint axial direction (the direction along the axis of the constant velocity universal joint), and three track grooves extending in the joint axial direction formed on the inner circumference of the cup portion; rollers housed in each track groove that roll along a pair of opposing roller guide surfaces in the joint circumferential direction (the circumferential direction of a circle centered on the axis of the constant velocity universal joint); and a tripod member having three leg shafts that rotatably support the rollers. This tripod type constant velocity universal joint has a retaining structure to prevent the rollers (internal joint components including the rollers and the tripod member that rotatably supports the rollers) inserted into the track grooves from coming out. For example, in the tripod type constant velocity universal joint described in Patent Document 1 below, the rollers are prevented from coming out by attaching a clip as a retaining part to the open end of the cup portion.

[0004] The outline of the conventional roller retaining structure disclosed in Patent Document 1 will be described based on FIG. 6. First, on the inner diameter surface of the cup portion 100A of the outer joint member 100, three arc-shaped large-diameter portions 101 and small-diameter portions 102 extending in the joint circumferential direction Z are alternately provided in three each in the joint circumferential direction Z. The large-diameter portion 101 and the small-diameter portion 102 are connected via a roller guide surface 103 that guides the outer diameter surface of the roller 121. In the formation region of the small-diameter portion 102 among the opening-side end portions of the cup portion 100A, a chamfer (first chamfer) 104 is formed to allow relative angular displacement between the outer joint member 100 and the tripod member 120 (to avoid interference of the shaft connected to the tripod member 120), and second chamfers 105 are formed on both sides of the first chamfer 104 in the joint circumferential direction Z. An arc-shaped clip mounting groove 106 extending in the joint circumferential direction Z is provided in the first chamfer 104, and the circumferential end portion of this clip mounting groove 106 opens to the second chamfer 105.

[0005] On the other hand, the clip 110 integrally has an arc portion 111 arranged along the large-diameter portion 101 described above, a mounting portion 112 fitted into the clip mounting groove 105, and a retaining portion 113 provided between the arc portion 111 and the mounting portion 112. In this case, while arranging the arc portion 111 of the clip 110 along the large-diameter portion 101 of the cup portion 100A and fitting the mounting portion 112 of the clip 110 into the clip mounting groove 106 of the cup portion 100, the retaining portion 113 is arranged so as to overlap a part of the roller 121 inserted into the track groove (large-diameter portion 101) when viewed from the joint axis direction. Thereby, when the roller 121 moves to the opening side of the cup portion 100A, the outer diameter surface of the roller 121 contacts the retaining portion 113 of the clip 110, so that the joint internal components including the roller 121 are retained.

[0006] The above-described retaining structure offers the following advantages: • Since the second chamfer 105 is provided on both sides of the first chamfer 104 in the circumferential direction of the joint, the circumferential dimensions of the first chamfer 104 and the clip mounting groove 106 provided therein can be shortened. This improves the machinability of the clip mounting groove 106 and the ease of mounting the clip 110 to the clip mounting groove 106. • The presence of the second chamfer 105 improves the ease of inserting the roller 121 into the roller guide surface 103 (ease of assembling internal joint components into the cup portion 100A).

[0007] Furthermore, in the case of the retaining structure described above, which is provided with the second chamfer 105, the clip 110 contacts the cup portion 100A at point P1. In this case, the retaining portion 113 of the clip 110 is positioned at the location shown by the solid line in Figure 6. On the other hand, when the second chamfer 105 is not provided, the clip 110 contacts the cup portion 100A at point P2. In this case, the retaining portion 113 of the clip 110 is positioned at the location shown by the dashed line in Figure 6, that is, closer to the rotation center of the roller 121 than when the second chamfer 105 is provided. Therefore, in the case of the retaining structure provided with the second chamfer 105, the roller 121 interferes with the retaining portion 113 of the clip 110 when the amount of protrusion of the roller 121 from the opening of the cup portion 100A (the amount of protrusion in the joint axial direction) becomes larger compared to when the second chamfer 105 is not provided. Therefore, it is also possible to enjoy the advantage of being able to secure a large amount of sliding of the roller 121 in the axial direction of the joint (the allowable axial displacement of the tripod-type constant velocity universal joint).

[0008] Japanese Patent Publication No. 2002-168262

[0009] To provide the second chamfer 105 described above, for example, additional machining such as cutting could be performed during the manufacturing process of the outer joint member 100, but this would inevitably lead to increased costs due to a deterioration in product yield and an increase in the number of processes. The second chamfer 105 can also be formed by plastic deformation such as cold forging (paragraph 0025 of Patent Document 1), but in this case, it would be necessary to manufacture and possess a large number of punches corresponding to the shape of the second chamfer 105 and the axial length of the cup portion 100A, which would increase equipment (mold) costs.

[0010] Therefore, the present invention aims to ensure the required roller retention force and sliding amount in the axial direction of the joint while suppressing the cost increase of tripod-type constant velocity universal joints.

[0011] The present invention, devised to achieve the above objective, comprises an outer joint member having a bottomed cylindrical cup portion with one end open in the joint axial direction, and three track grooves extending in the joint axial direction formed on the inner circumference of the cup portion at equal intervals in the joint circumferential direction, a tripod member having three leg shafts that rotatably support the rollers, wherein the inner diameter surface of the cup portion is provided with three large-diameter portions and three small-diameter portions alternatingly in the joint circumferential direction, track grooves are formed on the inside of the large-diameter portions in the joint radial direction, the large-diameter portions and small-diameter portions are connected via roller guide surfaces, and a clip mounting groove extending in the joint circumferential direction is formed at the opening end of the portion of the cup portion where the small-diameter portion is provided, and the rollers are prevented from coming off by clips mounted in these clip mounting grooves, wherein the clips protrude from the roller guide surfaces at both ends of the clip mounting groove in the joint circumferential direction, The clip is characterized in that a retaining portion is provided on the part of the clip located outside the clip mounting groove, which can come into contact with the outer diameter surface of the roller, and this retaining portion extends parallel to the axis of the leg shaft and is arranged along the roller guide surface.

[0012] In the tripod-type constant velocity universal joint according to the present invention, clips for preventing the roller (and the tripod member that rotatably supports it) from coming off protrude from the roller guide surface at both ends of the clip mounting groove in the joint circumferential direction. This means that both ends of the clip mounting groove in the joint circumferential direction are open to the roller guide surface, and the outer joint member does not have a portion corresponding to the second chamfer 105 (see Figure 6) provided in the conventional tripod-type constant velocity universal joint (Patent Document 1). In this case, additional processing such as cutting or forming punches that would be necessary when additionally providing a second chamfer are not required, so processing costs can be reduced. Furthermore, if there is no portion corresponding to the second chamfer, the groove length of the clip mounting groove and, consequently, the contact area of ​​the clip with the clip mounting groove (outer joint member) can be increased, so the roller retention force can be increased.

[0013] Furthermore, the retaining portion of the clip, located outside the clip mounting groove and capable of contacting the outer diameter surface of the roller, extends parallel to the axis of the leg shaft and is positioned along the roller guide surface. With this configuration, it is possible to increase the amount of roller protrusion from the open end face of the outer joint member (cup portion), thereby ensuring a larger amount of roller sliding in the joint axial direction.

[0014] The retaining portion of the clip is preferably in contact with the outer diameter surface of the roller at the end in the torque transmission direction when the roller is viewed from the coupling axis direction. This allows the amount of sliding of the roller in the coupling axis direction to be maximized.

[0015] Based on the above, the present invention makes it possible to realize a tripod-type constant velocity universal joint that can sufficiently secure the roller's retaining force and sliding amount while suppressing the cost increase of the tripod-type constant velocity universal joint.

[0016] This is a longitudinal cross-sectional view of a tripod-type constant velocity universal joint according to one embodiment of the present invention in the state of operating angle 0°. This is a left side view of Figure 1 (front view of the tripod-type constant velocity universal joint). This is a partially enlarged view of Figure 1 as seen from the direction of arrow A in the same figure. This is a plan view of the clip in the free state. This figure shows the state in which the roller is in contact with the clip in the tripod-type constant velocity universal joint of this embodiment. This figure shows the state in which the roller is in contact with the clip in a conventional tripod-type constant velocity universal joint. This is an enlarged view showing a part of the roller retention structure used in a conventional tripod-type constant velocity universal joint.

[0017] The embodiments of the present invention will be described below based on the drawings (Figures 1 to 5). In the following description, the direction along the axis of the tripod-type constant velocity universal joint 1 will be referred to as the "joint axis direction," and the radial and circumferential directions of the circle centered on the axis of the tripod-type constant velocity universal joint 1 will be referred to as the "joint radial direction" and the "joint circumferential direction," respectively. In Figure 1, etc., the joint axis direction, joint radial direction, and joint circumferential direction are indicated by arrows X, Y, and Z, respectively. The joint circumferential direction Z is also the torque transmission direction of the tripod-type constant velocity universal joint 1.

[0018] Figure 1 is a longitudinal cross-sectional view of a tripod-type constant velocity universal joint 1 according to one embodiment of the present invention in the state of operating angle 0°, Figure 2 is a left side view (front view) of Figure 1, and Figure 3 is a view of a part of Figure 1 from the direction of arrow A in the same figure. The tripod-type constant velocity universal joint 1 shown in Figure 1, etc., is a type of sliding constant velocity universal joint that allows angular displacement and axial displacement of two axes, the drive side and the driven side, and constitutes a drive shaft by being connected to a fixed constant velocity universal joint (not shown) via a shaft 8 (see dashed line in Figure 1). The drive shaft is mounted, for example, on an automobile and transmits rotational torque output from a drive source such as an engine or electric motor mounted on the chassis to the drive wheels. In this drive shaft, the tripod-type constant velocity universal joint 1 is located on the drive source side (inboard side), and the fixed constant velocity universal joint is located on the drive wheel side (outboard side). In Figure 1, the left side of the paper is the drive wheel side, and the right side of the paper is the drive source side.

[0019] As shown in Figures 1 to 3, the tripod-type constant velocity universal joint 1 (hereinafter also simply referred to as "constant velocity universal joint 1") comprises an outer joint member 2, a tripod member 3 as an inner joint member, a roller unit 4 as a torque transmission member, and a clip 10 as a retaining part.

[0020] The outer joint member 2 has a bottomed cylindrical cup portion 20 with one end open in the joint axis direction X and the other end closed. Three linear track grooves 5 extending in the joint axis direction X are formed on the inner diameter surface 21 of the cup portion 20 at equal intervals in the joint circumferential direction Z. In this embodiment, the inner diameter surface 21 of the cup portion 20 is formed in a flower shape with three alternating arc-shaped large diameter portions 22 extending in the joint circumferential direction Z and three arc-shaped small diameter portions 23 located inside the joint radial direction Y from the large diameter portion 22, and the groove bottom surface of the track groove 5 is composed of the above-mentioned large diameter portion 22. Each track groove 5 extends in the joint axis direction X and has a pair of roller guide surfaces 6 arranged opposite each other in the joint circumferential direction Z, and the above-mentioned large diameter portion 22 and small diameter portion 23 are continuous via the roller guide surfaces 6. In this embodiment, the outer diameter surface of the cup portion 20, like the inner diameter surface 21, has a flower-like shape in which three arc-shaped large-diameter portions extending in the joint circumferential direction Z and three arc-shaped small-diameter portions located inside the joint radial direction Y from the large-diameter portions are alternately provided in the joint circumferential direction Z.

[0021] The tripod member 3 integrally comprises a body portion 31 having a central hole 30, and three leg shafts 32 that protrude outward in the joint radial direction Y from three equal divisions in the joint circumferential direction Z on the outer diameter surface of the body portion 31, with their tip surfaces facing the groove bottom surface (large diameter portion 22) of the track groove 5 via a small gap in the joint radial direction Y. A female spline is formed in the central hole 30 of the body portion 31, and the tripod member 3 and the shaft 8 are coupled in a torque-transmitting manner by fitting a male spline formed on the shaft 8 into this female spline. Although not shown in the figure, a retaining ring is attached to the outer circumference of the shaft 8, and the shaft 8 is prevented from coming out of the tripod member 3 by locking this retaining ring onto the tripod member 3 in the direction of withdrawal of the shaft 8.

[0022] There are a total of three roller units 4, each individually housed in a track groove 5 of the three outer joint members 2. In this embodiment, the pair of roller guide surfaces 6 provided in the track groove 5 are formed as a concave curved surface, with the approximately central part in the joint radial direction Y slightly recessed relative to the axis of the opposing leg shaft 32 in the joint circumferential direction Z compared to both ends in the joint radial direction Y. The outer diameter surface of the roller unit 4 (outer diameter surface 15 of the outer ring 11) facing this roller guide surface 6 is formed as a convex curved surface that makes angular contact with the concave curved roller guide surface 6. As a result, when an axial force in the joint axial direction X acts on the outer joint member 2 or the shaft 8, the roller unit 4 housed in the track groove 5 rolls along the roller guide surface 6.

[0023] The roller unit 4 is a so-called double roller type and comprises an outer ring 11 as a "roller" forming an annular shape around the axis of the leg shaft 32, an annular inner ring 12 arranged on the inner circumference of the outer ring 11 and fitted onto the outer circumference of the leg shaft 32, and rolling elements interposed between the outer ring 11 and the inner ring 12. In this embodiment, a large number of needle-shaped rollers 13 in a full-roller configuration without cages are used as rolling elements. The needle-shaped rollers 13 are arranged to roll freely between the inner diameter surface of the cylindrical outer ring 11, which serves as the outer raceway surface, and the outer diameter surface of the cylindrical inner ring 12, which serves as the inner raceway surface. Therefore, the outer ring 11 and the inner ring 12 can rotate relative to each other via the large number of needle-shaped rollers 13. Snap rings 14 are arranged on the outer and inner sides of the needle-shaped rollers 13 in the joint radial direction Y, respectively. This snap ring 14 prevents unintended disassembly of the roller unit 4 (falling off the needle rollers 13).

[0024] As shown in Figure 3, the outer diameter surface (cross-sectional shape) of the leg shaft 32 is elliptical with the coupling axis direction X as the minor axis and the coupling circumferential direction (torque transmission direction) Z as the major axis, while the inner diameter surface of the inner ring 12 fitted to the outer circumference of the leg shaft 32 is formed in an arc-shaped convex cross section. Therefore, the outer diameter surface of the leg shaft 32 contacts the inner diameter surface of the inner ring 12 at both ends in the direction perpendicular to the coupling axis direction X (coupling circumferential direction Z), and a gap G in the coupling axis direction X is formed between it and the inner diameter surface of the inner ring 12. Furthermore, as described above, the roller unit 4 is an assembly in which the inner ring 12 and the outer ring 11 can rotate relative to each other via a number of needle rollers 13. With the above configuration, the outer ring 11 and the inner ring 12 (including the roller unit 4) are movable in the axial direction of the leg shaft 32 (coupling radial direction Y) and are also pivotable relative to the leg shaft 32. In other words, the axes of the outer ring 11 and the inner ring 12 can be inclined with respect to the axis of the leg shaft 32 within a plane that includes the axis of the leg shaft 32.

[0025] Therefore, when the constant velocity universal joint 1 takes an operating angle, the axis of the tripod member 3 is inclined with respect to the axis of the outer joint member 2, but it is possible to avoid the outer ring 11 (including the roller unit 4) and the roller guide surface 6 being at an oblique angle. As a result, a low-vibration constant velocity universal joint 1 can be realized with reduced induced thrust (axial force induced by friction between internal joint components) and sliding resistance.

[0026] The following describes the roller retention structure, which is a characteristic feature of the present invention. In short, the outer ring 11 (including the roller unit 4) as a roller is retained from coming off by a clip 10 attached to the opening end of the cup portion 20 of the outer joint member 2.

[0027] As shown in Figures 1 and 2, chamfers 24 are formed in the region where three small-diameter portions (arc-shaped small-diameter inner diameter surfaces) 23 are provided at intervals in the circumferential direction Z of the joint, on the opening end of the cup portion 20 of the outer joint member 2. That is, the cup portion 20 has a tapered surface that slopes downward from its opening end face toward the small-diameter portions 23. The primary function of the chamfers 24 is to prevent the shaft 8 connected to the tripod member 3 from interfering with the outer joint member 2 when the constant velocity universal joint 1 takes a predetermined operating angle (when the outer joint member 2 and the tripod member 3 are relatively angularly displaced).

[0028] Each chamfer 24 has an arc-shaped clip mounting groove 25 extending in the joint circumferential direction Z, and one end and the other end of the clip mounting groove 25 in the joint circumferential direction Z open to the roller guide surfaces 6 on both sides of the small diameter portion 23 (chamfer 24) in the joint circumferential direction Z. The outer joint member 2 of this embodiment does not have the second chamfer 105 (or a corresponding portion) that was provided on the conventional outer joint member 100 shown in Figure 6.

[0029] The clip 10 shown in Figure 4 has an arc portion 10a, a mounting portion 10b, and a retaining portion 10c that extends substantially parallel to the axis of the leg shaft 32 (joint radial direction Y) to connect the arc portion 10a and the mounting portion 10b. The clip 10 is a metal part obtained by bending and folding a single metal wire, and a dividing portion 10d is provided at one location in the joint circumferential direction Z (in this case, one of the three mounting portions 10b provided) to make the clip 10 discontinuous in the joint circumferential direction Z. Due to the presence of this dividing portion 10d, the clip 10 as a whole can be elastically deformed to reduce its diameter.

[0030] The clip 10 is attached to the outer joint member 2 by first applying pressure in the diameter-reducing direction to the clip 10, which is in a state of elastic diameter-reduced deformation, and then positioning it on the inner circumference of the cup portion 20. After that, the pressure is released to cause elastic diameter-expanding deformation, and each mounting portion 10b of the clip 10 is fitted into the corresponding clip mounting groove 25. For this reason, the "part of the clip located outside the clip mounting groove" as referred to in this invention is the part other than the mounting portion 10b.

[0031] When the clip 10 is attached to the outer joint member 2, as shown in Figure 2, the arc portion 10a is positioned close to the inside of the large diameter portion 22 in the joint radial direction Y along the large diameter portion 22 of the cup portion 20, and the retaining portion 10c is positioned close to the inside of the roller guide surface 6 (the side closer to the axis of the leg shaft 32) along the roller guide surface 6. In this embodiment, the outer joint member 2 is not provided with a portion corresponding to the conventional second chamfer 105 (see Figure 6), and one end and the other end of the clip mounting groove 25 in the joint circumferential direction Z open to the roller guide surfaces 6 on both sides of the chamfer 24 in the joint circumferential direction Z. As a result, the clip 10 attached to the outer joint member 2 protrudes from the roller guide surface 6 toward the track groove 5 at both ends of the clip mounting groove 25 in the joint circumferential direction Z.

[0032] As described above, in the tripod-type constant velocity universal joint 1 of this embodiment, the clip 10 for preventing the roller unit 4 from coming off protrudes from the roller guide surface 6 at both ends of the clip mounting groove 25 in the joint circumferential direction Z. This means that one end and the other end of the clip mounting groove 25 in the joint circumferential direction Z are open to the roller guide surface 6, and the outer joint member 2 does not have a portion corresponding to the second chamfer 105 shown in Figure 6. In this case, additional processing such as cutting and forming punches that would be required when the second chamfer is added to the outer joint member 2 are unnecessary, so the processing cost of the outer joint member 2 and, consequently, the manufacturing cost of the constant velocity universal joint 1 can be reduced. Furthermore, if there is no portion corresponding to the second chamfer, the groove length of the clip mounting groove 25 and, consequently, the contact area of ​​the clip 10 with the outer joint member 2 on which the clip mounting groove 25 is provided can be increased, thereby increasing the anti-dislodgement force of the roller unit 4.

[0033] Furthermore, as shown in the lower view of Figures 2 and 5A, the retaining portion 10c (the entire portion) of the clip 10, which is located outside the clip mounting groove 25 of the outer joint member 2 and is capable of contacting the outer diameter surface of the roller unit 4 (outer roller 11), extends parallel to the axis of the leg shaft 32 (joint radial direction Y) and is positioned along the roller guide surface 6. In particular, in this embodiment, the entire retaining portion 10c of the clip 10 is positioned close to the roller guide surface 6 so that the retaining portion 10c of the clip 10 contacts the outer diameter surface of the roller unit 4 at the end in the torque transmission direction when the roller unit 4 is viewed from the joint axis direction.

[0034] With this configuration, compared to, for example, the case where a different configuration from the present invention is adopted, such as the lower view of Figure 5B (in this case, a configuration using a clip 10' with the retaining portion inclined with respect to the radial direction Y of the joint), the contact point between the roller unit 4 and the retaining portion 10c of the clip 10 can be shifted closer to the roller guide surface 6, thereby increasing the amount of protrusion of the roller (roller unit 4) from the open end face of the outer joint member 2. In other words, the amount of protrusion D shown in the upper view of Figure 5A is greater than the amount of protrusion D' shown in the upper view of Figure 5B (D > D'). As a result, the amount of sliding of the internal joint components, including the roller unit 4, in the joint axis direction X, or in other words, the relative displacement amount between the outer joint member 2 and the internal joint components in the joint axis direction X can be increased.

[0035] In this case, even if the length of the cup portion 20 of the outer joint member 2 in the joint axis direction X is shortened, the required relative displacement amount can be secured. Therefore, it becomes possible to realize a lightweight and compact tripod-type constant velocity universal joint 1 in which the outer joint member 2 is shortened in the joint axis direction X.

[0036] The above describes a tripod-type constant velocity universal joint 1 according to one embodiment of the present invention, but the embodiments of the present invention are not limited thereto.

[0037] For example, the tripod-type constant velocity universal joint 1 described above employs a double-roller type roller unit 4 equipped with an outer ring 11 and an inner ring 12 that rotate relative to each other via a large number of needle-shaped rollers 13. However, the present invention can also be applied to a tripod-type constant velocity universal joint 1 employing a single-roller type roller unit. Although not shown in the figures, the single-roller type roller unit is a type of unit in which the inner ring 12 of the double-roller type is omitted, and comprises, for example, a roller fitted on the outer circumference of the leg shaft 32 and a large number of rolling elements (needle-shaped rollers) arranged between the roller and the leg shaft 32.

[0038] Furthermore, although the outer joint member 2 described above has a so-called flower-shaped outer diameter surface of the cup portion 20, the present invention can also be applied to a tripod-type constant velocity universal joint 1 using an outer joint member 2 in which the outer diameter surface of the cup portion 20 is formed in a cylindrical shape (without irregularities).

[0039] Furthermore, the tripod-type constant velocity universal joint 1 of this embodiment, as described above, can be used not only in drive shafts for automobiles but also in power transmission paths for industrial machinery and the like.

[0040] 1. Tripod type constant velocity universal joint 2. Outer joint member 3. Tripod member 4. Roller unit 5. Track groove 6. Roller guide surface 10. Clip 10a. Arc portion 10b. Mounting portion 10c. Retaining portion 11. Outer ring (roller) 20. Cup portion 22. Large diameter portion 23. Small diameter portion 24. Chamfer 25. Clip mounting groove 32. Leg shaft X: Axial direction of joint Y: Radial direction of joint Z: Circumferential direction of joint (torque transmission direction)

Claims

1. A tripod-type constant velocity universal joint comprising: an outer joint member having a bottomed cylindrical cup portion with one end open in the axial direction of the joint, with three track grooves extending in the axial direction of the joint formed on the inner circumference of the cup portion at equal intervals in the circumferential direction of the joint; a roller housed in each track groove and rolling along a pair of opposing roller guide surfaces in the circumferential direction of the joint; and a tripod member having three leg shafts that rotatably support the rollers, wherein the inner diameter surface of the cup portion has three alternating large-diameter portions and three small-diameter portions extending in the circumferential direction of the joint, the track grooves are formed on the inside of the large-diameter portions in the radial direction of the joint, and the large-diameter portions and the small-diameter portions are connected via the roller guide surfaces, and a clip mounting groove extending in the circumferential direction of the joint is formed at the open end of the portion of the cup portion where the small-diameter portions are provided, and the rollers are prevented from coming off by clips mounted in these clip mounting grooves, wherein the clips protrude from the roller guide surfaces at both ends of the clip mounting groove in the circumferential direction of the joint, A tripod-type constant velocity universal joint, characterized in that a retaining portion is provided in the part of the clip located outside the clip mounting groove, which is capable of contacting the outer diameter surface of the roller, and this retaining portion extends parallel to the axis of the leg shaft and is arranged along the roller guide surface.

2. The tripod-type constant velocity universal joint according to claim 1, wherein the retaining portion of the clip contacts the outer diameter surface of the roller at the end in the torque transmission direction when the roller is viewed from the joint axis direction.

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