Constant velocity universal joint and method for manufacturing same

Abstract

A grinding surface having a plurality of grinding ribs (P) is formed on the outer peripheral surface (24b) of the holder (24) and the outer peripheral surface (22b) of the inner joint member (22). The grinding surface has a removed part (R) formed by removing the front end of a convex part (Q) arranged at the boundary of the grinding rib (P).

Description

Technical Field

[0001] The invention relates to a constant velocity universal coupling and a manufacturing method thereof. Background Art

[0002] Generally speaking, the drive shaft of a motor vehicle is composed of a constant velocity universal coupling mounted on the outer side of the wheel, a constant velocity universal coupling mounted on the inner side of the differential gear, and an intermediate shaft connecting the two constant velocity universal couplings. Usually, for the constant velocity universal coupling on the outer side, a fixed constant velocity universal coupling is used, which can obtain a large working angle but does not cause axial displacement. On the other hand, for the constant velocity universal coupling on the inner side, a sliding constant velocity universal coupling is used, which has a small maximum working angle but can achieve an axial displacement while obtaining the working angle.

[0003] In recent years, with the low fuel consumption of automobiles, the drive shaft is required to be small and light, and the constant velocity universal joint provided therein is also required to be small and light. For example, the following patent documents 1 and 2 disclose a constant velocity universal joint that is small and light by setting the number of balls to 8.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 10-103365

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 10-73129 Summary of the invention

[0008] Problems to be solved by the invention

[0009] As mentioned above, although the constant velocity universal coupling has been miniaturized, the working angle, torque and rotation speed input to the constant velocity universal coupling have not changed, so the load applied to each component increases in accordance with the amount of miniaturization of each component. In this case, the heat generated at the contact portion between the components increases, which leads to a decrease in durability. In order to improve durability, it is necessary to reduce the resistance during the relative movement of the components in contact with each other. For example, the rolling resistance at the rolling portion (for example, the contact portion between the ball and the raceway groove) of the constant velocity universal coupling can be reduced by load distribution due to an increase in the number of balls, or an increase in the rolling rate, the use of a high-function lubricant, etc. On the other hand, for the sliding contact portion between the retainer and the outer coupling member and the inner coupling member, since there is no sliding contact of the rolling portion, there are fewer methods for reducing the sliding resistance.

[0010] Therefore, an object of the present invention is to reduce the sliding resistance at the sliding contact portions between a cage and an outer joint member and an inner joint member of a constant velocity universal joint, thereby improving the durability.

[0011] Solutions to Solve Problems

[0012] In order to solve the above-mentioned problem, the present invention provides a constant velocity universal joint, comprising: an outer coupling member having a plurality of rolling grooves formed on its inner circumferential surface; an inner coupling member having a plurality of rolling grooves formed on its outer circumferential surface; a plurality of balls arranged in a ball rolling path formed by the rolling grooves of the outer coupling member and the rolling grooves of the inner coupling member; and a retainer having a plurality of grooves for retaining the plurality of balls, the retainer being in sliding contact with the inner circumferential surface of the outer coupling member and the outer circumferential surface of the inner coupling member, wherein:

[0013] A processed surface having a plurality of processed ribs is provided on the outer peripheral surface of the retainer and the outer peripheral surface of the inner coupling member.

[0014] The processed surface has a removed portion formed by removing a tip of a convex portion provided at a boundary of the processed rib.

[0015] The above-mentioned fixed constant velocity universal joint can be manufactured through the following steps: machining the outer peripheral surface of the retainer and the outer peripheral surface of the inner coupling member; roller processing the outer peripheral surface of the retainer and the outer peripheral surface of the inner coupling member, thereby removing the front end of the convex portion of the boundary of the processing rib formed during the machining.

[0016] If the outer peripheral surface of the retainer and the outer peripheral surface of the inner coupling member are machined, a Figure 6 The processing surface having a plurality of processing ribs P as shown in FIG. By performing roller processing on the processing surface, as shown in FIG. Fig. 9 As shown in FIG. 1 , the front end of the convex portion Q provided at the boundary of the adjacent processed ribs P is removed, and the surface texture of the processed surface becomes smooth. By setting such a smooth processed surface as the outer peripheral surface of the retainer and the outer peripheral surface of the inner coupling member, the sliding resistance at the contact portion where these surfaces contact the inner peripheral surface of the outer coupling member and the inner peripheral surface of the retainer can be reduced. In addition, since the concave processed ribs remain on the processed surface after the roller is processed, the processed ribs (concave portions) function as oil reservoirs, thereby further reducing the sliding resistance at the above-mentioned contact portions.

[0017] Effects of the Invention

[0018] As described above, according to the present invention, the sliding resistance at the sliding contact portions between the retainer and the outer and inner joint members of the constant velocity universal joint can be reduced, so that heat generation at the sliding contact portions can be suppressed and durability can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of the drive shaft.

[0020] Figure 2 It is a cross-sectional view of a sliding constant velocity universal coupling.

[0021] Figure 3 It is a cross-sectional view of a fixed constant velocity universal coupling.

[0022] Figure 4 1 is a flow chart showing the manufacturing process of the outer joint member.

[0023] Figure 5 This is a diagram (photograph) showing an enlarged view of a ground surface to which barrel processing has not been performed.

[0024] Figure 6 This is a cross-sectional view of a ground surface that has not been subjected to barrel processing.

[0025] Figure 7 1 is a flow chart showing the manufacturing process of the inner joint member.

[0026] Figure 8 This is a diagram (photograph) showing an enlarged view of a ground surface subjected to barrel processing.

[0027] Fig. 9 This is a cross-sectional view of a grinding surface subjected to roller processing.

[0028] Fig.10 1 is a flowchart showing the manufacturing process of the cage. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0030] [Basic structure of the drive shaft]

[0031] Figure 1The drive shaft 1 shown in the figure has a sliding constant velocity universal joint 2 provided on the inner side (right side in the figure), a fixed constant velocity universal joint 3 provided on the outer side (left side in the figure), and an intermediate shaft 4 connecting the two constant velocity universal joints 2 and 3. The sliding constant velocity universal joint 2 allows both axial displacement and angular displacement, and the fixed constant velocity universal joint 3 only allows angular displacement. The sliding constant velocity universal joint 2 on the inner side is connected to the differential gear, and the fixed constant velocity universal joint 3 on the outer side is connected to the wheel. The rotational driving force output from the engine is transmitted to the differential gear via the transmission and the transmission shaft, and is transmitted from the differential gear to the left and right wheels via the left and right drive shafts 1. The drive shaft 1 of this embodiment is a rear wheel drive shaft installed on the rear wheel of the motor vehicle.

[0032] The sliding type constant velocity universal joint 2 includes an outer coupling member 21, an inner coupling member 22, a plurality of (eight in this embodiment) balls 23 for transmitting torque between the outer coupling member 21 and the inner coupling member 22, and a retainer 24 for retaining the plurality of balls 23. The outer coupling member 21 is mounted on the differential gear, and the inner coupling member 22 is mounted on the inner end of the intermediate shaft 4.

[0033] like Figure 2 As shown, the outer coupling member 21 integrally includes a cup-shaped mouth 21a opened on the outer side and a rod 21b extending from the bottom of the mouth 21a to the inner side. A plurality of (eight in this embodiment) linear raceway grooves 21d extending in the axial direction are provided on the cylindrical inner circumferential surface 21c of the mouth 21a. A spline 21e inserted into the spline hole of the differential gear is provided on the outer circumferential surface of the inner side end of the rod 21b.

[0034] A spline hole 22a for inserting the intermediate shaft 4 is provided at the axial center of the inner joint member 22. A plurality of (eight in this embodiment) linear raceway grooves 22c extending in the axial direction are provided on the spherical outer peripheral surface 22b of the inner joint member 22.

[0035] The raceway grooves 21d of the outer joint member 21 and the raceway grooves 22c of the inner joint member 22 are opposed to each other in the radial direction to form a plurality of (eight in this embodiment) ball raceways. One ball 23 is arranged in each ball raceway.

[0036] The retainer 24 has a plurality of (eight in this embodiment) grooves 24a for retaining the balls 23. The grooves 24a are all of the same shape and are arranged at equal intervals in the circumferential direction. The outer peripheral surface of the retainer 24 is provided with a spherical portion 24b that is in sliding contact with the cylindrical inner peripheral surface 21c of the outer coupling member 21 and a conical portion 24c that extends in the tangential direction from both axial ends of the spherical portion 24b. The conical portion 24c functions as a stopper that is in line contact with the inner peripheral surface 21c of the outer coupling member 21 when the sliding constant velocity universal joint 2 takes the maximum working angle to limit the further increase of the working angle. The inclination angle θ of the conical portion 24c relative to the axis of the retainer 24 is set to a value of 1 / 2 of the maximum working angle of the sliding constant velocity universal joint 2. The inner peripheral surface of the retainer 24 is provided with a spherical portion 24d that is in sliding contact with the spherical outer peripheral surface 22b of the inner coupling member 22. The spherical portion 24 b of the outer peripheral surface of the retainer 24 slides in the axial direction with the cylindrical inner peripheral surface 21 c of the outer joint member 21 , thereby allowing axial displacement between the outer joint member 21 and the inner joint member 22 .

[0037] The center of curvature O24b of the spherical portion 24b of the outer peripheral surface of the retainer 24 and the center of curvature O24d of the spherical portion 24d of the inner peripheral surface of the retainer 24 (i.e., the center of curvature of the spherical outer peripheral surface 22b of the inner coupling member 22) are offset by equal distances to the opposite axial sides relative to the joint center O(s). In the example shown in the figure, the center of curvature O24b of the spherical portion 24b of the outer peripheral surface of the retainer 24 is offset to the inner side (joint inner side) relative to the joint center O(s), and the center of curvature O24d of the spherical portion 24d of the inner peripheral surface of the retainer 24 is offset to the outer side (joint opening side) relative to the joint center O(s). As a result, at any working angle, the ball 23 retained by the retainer 24 is always arranged in a plane that bisects the working angle to ensure the uniform velocity between the outer coupling member 21 and the inner coupling member 22.

[0038] The sliding constant velocity universal joint 2 of this embodiment is made compact and lightweight by being used exclusively for the rear wheel drive shaft. Specifically, the maximum working angle is 25° or more in conventional products, but in this embodiment, the maximum working angle is limited to 20° or less by being used exclusively for the rear wheel drive shaft.

[0039] like Figure 1 As shown, the fixed constant velocity universal joint 3 includes an outer coupling member 31 mounted on the wheel, an inner coupling member 32 mounted on the outer side end of the intermediate shaft 4, a plurality of (eight in this embodiment) balls 33 for transmitting torque between the outer coupling member 31 and the inner coupling member 32, and a retainer 24 for retaining the plurality of balls 23.

[0040] like Figure 3 As shown, the outer coupling member 31 integrally includes a cup-shaped mouth 31a opened on the inner side and a rod 31b extending outward from the bottom of the mouth 31a. A plurality of (eight in this embodiment) arc-shaped rolling grooves 31d extending in the axial direction are formed on the spherical inner peripheral surface 31c of the mouth 31a. A spline 31e inserted into the spline hole on the wheel side is provided on the outer peripheral surface of the rod 31b.

[0041] A spline hole 32a for inserting the intermediate shaft 4 is provided at the axial center of the inner joint member 32. A plurality of (eight in this embodiment) arc-shaped rolling grooves 32c extending in the axial direction are provided on the spherical outer peripheral surface 32b of the inner joint member 32.

[0042] The ball rolling grooves 31 d of the outer joint member 31 and the ball rolling grooves 32 c of the inner joint member 32 are opposed to each other in the radial direction to form a plurality of (eight in this embodiment) ball rolling paths. One ball 33 is arranged in each ball rolling path.

[0043] The curvature center O31d of the raceway groove 31d of the outer coupling member 31 and the curvature center O32c of the raceway groove 32c of the inner coupling member 32 are offset by equal distances to the opposite axial sides relative to the joint center O(f). In the example shown in the figure, the curvature center O31d of the raceway groove 31d of the outer coupling member 31 is offset to the inner side (joint opening side) relative to the joint center O(f), and the curvature center O32c of the raceway groove 32c of the inner coupling member 32 is offset to the outer side (joint inner side) relative to the joint center O(f). Thus, at any working angle, the balls 33 held by the retainer 34 are always arranged in a plane that bisects the working angle to ensure the uniform velocity between the outer coupling member 31 and the inner coupling member 32.

[0044] The retainer 34 has a plurality of (eight in the present embodiment) grooves 34a for retaining the balls 33. The grooves 34a are all of the same shape and are arranged at equal intervals in the circumferential direction. The spherical outer peripheral surface 34b of the retainer 34 is in sliding contact with the spherical inner peripheral surface 31c of the outer coupling member 31. The spherical inner peripheral surface 34c of the retainer 34 is in sliding contact with the spherical outer peripheral surface 32b of the inner coupling member 32. The center of curvature of the outer peripheral surface 34b of the retainer 34 (i.e., the center of curvature of the spherical inner peripheral surface 31c of the outer coupling member 31) and the center of curvature of the inner peripheral surface 34c (i.e., the center of curvature of the spherical outer peripheral surface 32b of the inner coupling member 32) are respectively consistent with the joint center O (f).

[0045] The fixed constant velocity universal joint 3 of this embodiment is made compact and lightweight by being used exclusively for the rear wheel drive shaft. Specifically, the maximum working angle is 45° or more in conventional products, but in this embodiment, the maximum working angle is limited to 20° or less by being used exclusively for the rear wheel drive shaft.

[0046] like Figure 1 As shown, the intermediate shaft 4 can use a hollow shaft having a through hole in the axial direction. The spline 41 at the inner side end of the intermediate shaft 4 is inserted into the spline hole 22a of the inner coupling member 22 of the sliding constant velocity universal joint 2. As a result, the intermediate shaft 4 and the inner coupling member 22 are connected in a torque-transmitting manner by spline engagement. Between the outer peripheral surface of the outer coupling member 21 of the sliding constant velocity universal joint 2 and the outer peripheral surface of the intermediate shaft 4, a bellows-shaped protective cover 25 is fixed by a protective cover belt. Grease as a lubricant is enclosed in the inside of the joint (the space sealed by the outer coupling member 21 and the protective cover 25).

[0047] The spline 42 at the outer end of the intermediate shaft 4 is inserted into the spline hole 32a of the inner coupling member 32 of the fixed constant velocity universal joint 3. Thus, the intermediate shaft 4 and the inner coupling member 32 are connected in a torque-transmitting manner by spline engagement. Between the outer peripheral surface of the outer coupling member 31 of the fixed constant velocity universal joint 3 and the outer peripheral surface of the intermediate shaft 4, a bellows-shaped protective cover 35 is fixedly mounted via a protective cover belt. Grease as a lubricant is enclosed in the inside of the joint (a space sealed by the outer coupling member 31 and the protective cover 35).

[0048] Next, a method for manufacturing each component of the sliding type constant velocity universal joint 2 will be described.

[0049] [Manufacturing method of outer coupling member]

[0050] like Figure 4 As shown, the outer joint member 21 is manufactured through a forging process, a turning process, a spline processing process, a heat treatment process, and a machining process (a grinding process in the present embodiment).

[0051] In the forging step, the shaft-shaped blank is subjected to forging to form a blank having substantially the same shape as the outer joint member 21. In the present embodiment, a blank having the mouth portion 21a and the rod portion 21b integrally formed therein is formed.

[0052] In the turning step, the blank is turned to improve the dimensional accuracy of the outer peripheral surface of the mouth portion 21 a and the outer peripheral surface of the rod portion 21 b , and a protective cover mounting groove is formed on the outer peripheral surface of the mouth portion 21 a .

[0053] In the spline processing step, the outer peripheral surface of the rod portion 21 b is subjected to rolling to form the splines 21 e.

[0054] In the heat treatment step, heat treatment is applied to necessary parts of the blank. In this embodiment, heat treatment is applied to the inner circumferential surface 21c of the mouth portion 21a, the raceway groove 21d, and the spline 21e of the rod portion 21b. For example, high-frequency quenching and tempering or carburizing quenching and tempering can be applied as heat treatment.

[0055] In the grinding step, grinding is performed on necessary parts of the blank. In the present embodiment, grinding is performed on the rod portion 21b.

[0056] [Manufacturing method of inner coupling member]

[0057] like Figure 7 As shown, the inner joint member 22 is manufactured through a forging process, a turning process, a spline processing process, a heat treatment process, a machining process (a grinding process in the present embodiment), and a barrel processing process.

[0058] In the forging step, a cylindrical blank is forged to form a blank having substantially the same shape as the inner joint member 22 .

[0059] In the turning process, the outer peripheral surface and both end surfaces in the axial direction of the blank are turned to improve their dimensional accuracy.

[0060] In the spline processing step, the inner peripheral surface of the blank is subjected to broaching or the like to form the spline hole 22 a .

[0061] In the heat treatment step, heat treatment is applied to necessary parts of the blank. In the present embodiment, heat treatment is applied to the outer peripheral surface 22b, the raceway groove 22c, and the spline hole 22a of the blank. For example, carburizing, quenching, and tempering are applied as heat treatment.

[0062] In the grinding process, the necessary parts of the blank are ground. In this embodiment, the spherical outer peripheral surface 22b and the rolling groove 22c of the blank are ground. Figure 5 The grinding surface is as shown. Figure 6 As shown in FIG. 1 , a plurality of grinding ribs P are formed on the grinding surface. A pointed convex portion Q is formed at the boundary between adjacent grinding ribs P. The grinding ribs P and the convex portion Q extend along the machining direction.

[0063] In the roller processing step, the blank is subjected to roller processing. The so-called roller processing refers to the following method: a workpiece (blank) and a medium are put into a container (drum), and the container is moved to process the workpiece by utilizing the mutual friction between the workpiece and the medium. As roller processing, rotary roller processing, vibrating roller processing, centrifugal roller processing, fluid roller processing, etc. are known. Although any roller processing can be used, vibrating roller processing and fluid roller processing are particularly preferred. Specifically, for the retainer, vibrating roller processing is most preferred, and for the inner ring coupling component, fluid roller processing is most preferred.

[0064] Regarding the roller processing, since the medium easily collides with the outer peripheral surface of the workpiece, the roller processing is mainly performed on the outer peripheral surface 22b and the raceway groove 22c of the blank. Figure 8 Specifically, Fig. 9 As shown in FIG. 1 , the front end of the convex portion Q is removed due to the collision of the medium with the convex portion Q provided at the boundary of the grinding rib P, thereby forming a removed portion R. By removing the front end of the convex portion Q in this way to form a smooth removed portion R, the entire grinding surface can be smoothly finished. In addition, the convex portion Q is not completely removed by the roller processing, and the concave grinding rib P remains on the grinding surface.

[0065] [Method for manufacturing retainer]

[0066] like Fig.10 As shown, the cage 24 is manufactured through a press forming step, a turning step, a groove punching step, a heat treatment step, a machining step (a grinding step in the present embodiment), and a barrel machining step.

[0067] In the press forming step, the cylindrical blank is press formed to form a barrel-shaped blank having substantially the same shape as the retainer 24 .

[0068] In the turning process, the outer peripheral surface and the inner peripheral surface of the blank are turned to improve their dimensional accuracy.

[0069] In the recess punching step, a barrel-shaped blank is punched in a radial direction by a die, thereby forming a plurality of recesses 24 a.

[0070] In the heat treatment step, heat treatment is applied to necessary parts of the blank. In the present embodiment, heat treatment is applied to the inner surface of the concave groove 24a of the blank. For example, carburizing, quenching and tempering are applied as heat treatment.

[0071] In the grinding process, the necessary parts of the blank are ground. In this embodiment, the inner surface of the groove 24a, the spherical surface 24b of the outer peripheral surface, and the spherical surface 24d of the inner peripheral surface of the blank are ground. Thus, the inner surface of the groove 24a, the spherical surface 24b of the outer peripheral surface, and the spherical surface 24d of the inner peripheral surface are formed. Figure 5 The grinding surface is as shown. Figure 6 As shown in FIG. 1 , a plurality of grinding ribs P are formed on the grinding surface. A pointed convex portion Q is formed at the boundary between adjacent grinding ribs P. The grinding ribs P and the convex portion Q extend along the machining direction.

[0072] In the roller processing step, the blank is subjected to roller processing. The details of the roller processing are the same as the roller processing of the inner coupling member 22 described above, so the description is omitted. By roller processing, the surface (mainly the outer peripheral surface) of the blank of the retainer 24 is formed with Figure 8 , 9 Smooth ground surface as shown.

[0073] As described above, the inner peripheral surface 21c of the outer joint member 21 of the sliding type constant velocity universal joint 2 is formed with a ground surface having a convex portion Q with a sharp tip (see Figure 6 On the other hand, the spherical portion 24b of the outer peripheral surface of the retainer 24 is formed with a grinding surface having a smooth removed portion R formed by removing the tip of the convex portion Q from the boundary of the grinding rib P (see Fig. 9 ). By making the spherical portion 24b of the outer peripheral surface of the retainer 24 a smooth ground surface in this way, the sliding resistance at the sliding contact portion that slides with the inner peripheral surface 21c of the outer coupling member 21 can be reduced. In addition, since the concave grinding ribs P remain on the spherical portion 24b of the outer peripheral surface of the retainer 24, the grinding ribs P function as oil reservoirs, thereby further reducing the sliding resistance at the sliding contact portion that slides with the inner peripheral surface 21c of the outer coupling member 21.

[0074] In addition, a spherical portion 24d of the inner peripheral surface of the retainer 24 of the sliding type constant velocity universal joint 2 is formed with a ground surface having a convex portion Q with a sharp tip even after the roller processing (see Figure 6 On the other hand, a grinding surface having a smooth removed portion R formed by removing the front end of the convex portion Q from the boundary of the grinding rib P is formed on the outer peripheral surface 22b of the inner coupling member 22 (see Fig. 9). By making the outer circumferential surface 22b of the inner coupling member 22 a smooth ground surface in this way, the sliding resistance at the sliding contact portion that slides with the spherical portion 24d of the inner circumferential surface of the retainer 24 can be reduced. In addition, since the concave grinding ribs P remain on the outer circumferential surface 22b of the inner coupling member 22, the grinding ribs P function as oil reservoirs, thereby further reducing the sliding resistance at the sliding contact portion that slides with the spherical portion 24d of the inner circumferential surface of the retainer 24.

[0075] As described above, in the sliding type constant velocity universal joint 2, by reducing the sliding resistance at the sliding contact portion between the components, it is possible to suppress the heat generation of the sliding type constant velocity universal joint 2 during the rotation of the drive shaft 1, thereby improving the durability.

[0076] The manufacturing method of the fixed constant velocity universal joint 3 is the same as that of the sliding constant velocity universal joint, so the detailed description is omitted. In the fixed constant velocity universal joint 3, a grinding surface having a convex portion Q with a sharp tip is formed on the inner peripheral surface 31c of the outer coupling member 31 (see Figure 6 ), on the other hand, on the outer peripheral surface 34b of the retainer 34, a grinding surface having a smooth removed portion R formed by removing the tip of the convex portion Q is formed at the boundary of the grinding rib P (refer to Fig. 9 ). In addition, a ground surface having a convex portion Q with a sharp tip even after roller processing is formed on the inner circumferential surface 34c of the retainer 34 (see Figure 6 ), on the other hand, on the outer peripheral surface 32b of the inner coupling member 32, a grinding surface having a smooth removed portion R formed by removing the front end of the convex portion Q is formed at the boundary of the grinding rib P (refer to Fig. 9 ). As a result, the sliding resistance at each sliding contact portion can be reduced, so that the heat generation of the fixed constant velocity universal joint 3 during the rotation of the drive shaft 1 can be suppressed, thereby improving the durability.

[0077] For example, in the above-mentioned embodiment, the number of balls 23 and 33 of the constant velocity universal joints 2 and 3 is eight, but the number of balls is not limited thereto and may be six, for example.

[0078] In addition, in the above-mentioned embodiment, grinding is shown as the machining process before the roller processing, but it is not limited to this, and the machining process before the roller processing can also be set as cutting processing. In this case, the cross section after the cutting processing shows the same Figure 6 The same shape, the cross section after the roller processing shows Fig. 9 Same form.

[0079] In the above-mentioned embodiment, the constant velocity universal joints 2 and 3 dedicated to the rear wheel drive shaft are shown, but the present invention is not limited to this, and the present invention can also be applied to existing constant velocity universal joints that can also be used as front wheel drive shafts.

[0080] In addition, the types of constant velocity universal joints to which the present invention can be applied are not limited to those described above, and for example, the present invention can also be applied to a cross groove type constant velocity universal joint.

[0081] Description of Reference Numerals

[0082] 1 Drive shaft

[0083] 2 Sliding constant velocity universal coupling

[0084] 3 Fixed constant velocity universal coupling

[0085] 4 Intermediate shaft

[0086] 21 Outer coupling member

[0087] 22 Inner coupling member

[0088] 23 Ball

[0089] 24 Retainer

[0090] 25 Protective cover

[0091] 31 Outer coupling member

[0092] 32 Inner coupling member

[0093] 33 Ball

[0094] 34 Retainer

[0095] 35 Protective cover

[0096] P Grinding ribs (processing ribs)

[0097] Q convex part

[0098] R removal part.

Claims

1. A constant velocity universal coupling, comprising: An outer coupling member having a plurality of raceway grooves formed on an inner peripheral surface thereof; An inner coupling member having a plurality of raceway grooves formed on an outer peripheral surface thereof; a plurality of balls arranged in a ball rolling path formed by the rolling path groove of the outer joint member and the rolling path groove of the inner joint member; and a retainer having a plurality of grooves for retaining the plurality of balls, the retainer being in sliding contact with the inner peripheral surface of the outer coupling member and the outer peripheral surface of the inner coupling member, in, A processed surface having a plurality of processed ribs is provided on the outer peripheral surface of the retainer and the outer peripheral surface of the inner coupling member. The processed surface has a removed portion formed by removing a tip of a convex portion provided at a boundary of the processed rib.

2. The constant velocity universal joint according to claim 1, wherein: The constant velocity universal joint is a sliding type constant velocity universal joint that allows both axial displacement and angular displacement between the outer coupling member and the inner coupling member. The number of the balls is 8.

3. A drive shaft, wherein: The drive shaft has the constant velocity universal joint according to claim 1 or 2.

4. A method for manufacturing a constant velocity universal coupling, The constant velocity universal coupling comprises: An outer coupling member having a plurality of raceway grooves formed on an inner peripheral surface thereof; An inner coupling member having a plurality of raceway grooves formed on an outer peripheral surface thereof; a plurality of balls arranged in a ball rolling path formed by the rolling path groove of the outer joint member and the rolling path groove of the inner joint member; and a retainer having a plurality of grooves for retaining the plurality of balls, the retainer being in sliding contact with the inner peripheral surface of the outer coupling member and the outer peripheral surface of the inner coupling member, in, The manufacturing method of the constant velocity universal coupling comprises the following steps: Mechanically processing the outer peripheral surface of the retainer and the outer peripheral surface of the inner coupling member; The outer peripheral surface of the retainer and the outer peripheral surface of the inner joint member are subjected to roller processing to remove the tip of the convex portion at the boundary of the processing rib formed by the machining.

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