JP2009085380A - Constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify lay-out of elements for assembling a constant velocity universal joint. <P>SOLUTION: This constant velocity universal joint comprises an outer ring 10 having an opening in one end thereof and an inner ring 20 for transmitting torque, allowing a change in angle between the outer ring 10. A shaft 50 is pressed into a shaft hole 26 of the inner ring 20, and a boot 60 is provided to seal an opening of the outer ring 10. A cylindrical portion 64 fitted on the shaft 50 is provided in the boot 60, and a loose end 66 of the cylindrical portion 64 is fixed to the shaft hole 26 of the inner ring 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fixed or sliding type constant velocity universal joint used in a power transmission system of an automobile or various industrial machines, for example, incorporated in a drive shaft or a propeller shaft of an automobile. The present invention relates to a boot mounting structure that prevents leakage of lubricant from the inside of a joint.

  For example, in a 4WD vehicle, an FR vehicle, or the like, a propeller shaft that transmits a rotational driving force from a transmission to a differential is used. The propeller shaft is disposed between the transmission and the differential in the front-rear direction of the automobile using a fixed constant velocity universal joint and a sliding constant velocity universal joint as a coupling joint.

  This type of propeller shaft has a structure that can respond to changes in length and angle due to changes in the relative positions of the transmission and the differential. The above-mentioned sliding type constant velocity universal joint has a function of absorbing movement in the longitudinal direction of a power plant system such as an engine. As this sliding type constant velocity universal joint, a cross-groove type constant velocity universal joint that is light in weight and has good rotational balance and vibration characteristics is used from the viewpoint of reducing the weight of the entire vehicle (for example, Patent Document 1). reference).

  As shown in FIG. 7, the constant velocity universal joint disclosed in Patent Document 1 includes a main part including an outer ring 110 as an outer joint member, an inner ring 120 as an inner joint member, a ball 130, and a cage 140. It has a structure in which a shaft 150 and a boot 160 with an adapter are attached.

  The outer ring 110 is a cup-shaped molded body having an opening 115 at one end, and a plurality of linear track grooves 114 extending in the axial direction are formed on a cylindrical inner peripheral surface 112 thereof. A hollow pipe (not shown) is pressed against the other end of the outer ring 110 by resistance welding or the like, and the hollow pipe is connected to a differential. On the other hand, the inner ring 120 is located on the inner periphery of the outer ring 110, and a plurality of track grooves 124 extending in the axial direction are formed on the spherical outer peripheral surface 122 corresponding to the track grooves 114 of the outer ring 110.

  The track groove 114 of the outer ring 110 and the track groove 124 of the inner ring 120 are angled in opposite directions with respect to the axis. A ball 130 is incorporated at the intersection of the track groove 114 of the outer ring 110 and the track groove 124 of the inner ring 120 that form a pair. The cage 140 is disposed in an annular space between the cylindrical inner peripheral surface 112 of the outer ring 110 and the spherical outer peripheral surface 122 of the inner ring 120, and the balls 130 are accommodated in the pockets 142 of the cage 140 and are equidistant in the circumferential direction. Is held by.

  The shaft 150 is press-fitted into the shaft hole 126 of the inner ring 120, and torque can be transmitted by fitting with splines 128 and 152 formed on the inner diameter of the shaft hole 126 and the outer diameter of the shaft 150. An annular concave groove 154 is formed in the shaft end portion of the shaft 150, and a circular circlip 156 fitted in the annular concave groove 154 is formed in an annular concave portion 121 formed in the shaft hole opening edge of the inner side end surface 123 of the inner ring 120. The shaft 150 is prevented from coming off from the inner ring 120 by being fitted to the inner ring 120.

  A rubber boot 160 is installed between the opening 115 of the outer ring 110 and the shaft 150 extending from the inner ring 120 to prevent intrusion of foreign matter from the outside of the joint and leakage of the lubricant sealed inside the joint. 110 opening 115 is closed. In the case of a constant velocity universal joint for a propeller shaft, the large-diameter end 162 of the boot 160 is fixed to the outer ring 110 via a metal adapter 170 in order to prevent expansion during high-speed rotation.

The adapter 170 is attached to the large-diameter end 162 of the boot 160 by caulking the small-diameter end 172, and is mounted by fitting the large-diameter end 174 to the outer peripheral surface of the outer ring 110 by press fitting. . A small-diameter end 164 that is bent from the large-diameter end 162 of the boot 160 and extends in the axial direction is fixed to the outer peripheral surface of the shaft 150 by caulking the tightening band 166.
JP 2003-56590 A

  By the way, the constant velocity universal joint disclosed in Patent Document 1 is assembled in the following manner.

  First, an assembly body in which the inner ring 120, the ball 130, and the cage 140 are assembled is accommodated in the outer ring 110, and a lubricant such as grease is injected from the opening 115 of the outer ring 110. Extrapolate the small diameter end 164. An adapter 170 is attached in advance to the large-diameter end 162 of the boot 160.

  Thereafter, the shaft end of the shaft 150 is press-fitted into the shaft hole 126 of the inner ring 120. At this time, the inner end 120 of the inner ring 120 is brought into contact with the bottom surface 116 of the outer ring 110 as shown in FIG. With the outer ring 110 supported in the axial direction, the shaft end of the shaft 150 is press-fitted into the shaft hole 126 of the inner ring 120. The shaft 150 is prevented from coming off when a circular circlip 156 mounted in advance in the annular groove 154 at the end of the shaft is engaged with the annular recess 121 on the inner side end surface 123 of the inner ring 120.

  In order to prevent the shaft end portion of the shaft 150 protruding from the inner end surface 123 of the inner ring 120 from interfering with the bottom surface 116 of the outer ring 110, the bottom surface 116 of the outer ring 110 has a recess 118 as a relief of the shaft end portion of the shaft 150. Is formed.

  Thereafter, the small-diameter end 164 of the boot 160 is fixed to the outer peripheral surface of the shaft 150 by caulking the tightening band 166, and the large-diameter end 174 of the adapter 170 is press-fitted and fixed to the outer peripheral surface of the outer ring 110. In this way, the assembly of the constant velocity universal joint is completed.

  As described above, in the conventional constant velocity universal joint, after the lubricant such as grease is injected into the outer ring 110 in which the assembly body is accommodated, the small diameter end 164 of the boot 160 is fixed to the outer peripheral surface of the shaft 150. Prior to this, a step of press-fitting the shaft end portion of the shaft 150 into the shaft hole 126 of the inner ring 120 is necessary. Therefore, there has been a problem that the layout of the equipment for assembling the constant velocity universal joint is complicated.

  Therefore, the present invention has been proposed in view of the above-described problems, and the object of the present invention is to provide a constant velocity universal joint having a structure capable of simplifying the layout of equipment for assembling the constant velocity universal joint. It is to provide.

  As technical means for achieving the above object, the present invention includes an outer joint member having an opening at one end, and an inner joint member that transmits torque while allowing angular displacement between the outer joint member and the outer joint member. A constant velocity universal joint having a structure including a boot that press-fits the shaft into the shaft hole of the inner joint member and closes the opening of the outer joint member, and has a cylindrical portion extrapolated to the shaft. It is provided in the boot, and the free end portion of the cylindrical portion is fixed to the shaft hole of the inner joint member.

  The cylindrical portion in the present invention can be formed integrally with the same material as the boot, for example, vulcanized rubber, or can be manufactured as a metal ring attached separately to the end of the boot.

  In the present invention, the cylindrical portion extrapolated to the shaft is provided in the boot, and the free end portion of the cylindrical portion is fixed to the shaft hole of the inner joint member. The step of press-fitting into the shaft hole can be the final step.

  That is, in the assembly of the constant velocity universal joint according to the present invention, the assembly body assembled with the internal parts including the inner joint member is accommodated in the outer joint member, and a lubricant such as grease is injected from the opening of the outer joint member. Then, the boot is attached to close the opening of the outer joint member. In attaching the boot, the free end portion of the cylindrical portion is pressed into the shaft hole of the inner joint member and fixed.

  Accordingly, it is possible to manufacture a joint unit in which an assembly body in which an internal part including an inner joint member is assembled is accommodated in an outer joint member and a boot for closing an opening of the outer joint member is attached. In this way, by making it possible to produce a joint unit in which a boot is attached to a constant velocity universal joint in advance, the storage space can be reduced during handling such as transportation.

  Then, the assembly of the constant velocity universal joint is completed by press-fitting the shaft end of the shaft into the shaft hole of the inner joint member in the joint unit. As described above, a process for press-fitting the shaft end portion of the shaft into the shaft hole of the inner joint member of the joint unit after the joint unit in which the boot is previously attached to the constant velocity universal joint can be set. As a result, it becomes easy to simplify the layout of the equipment for assembling the constant velocity universal joint.

It is desirable that the cylindrical portion in the present invention has a structure in which the cylindrical portion is prevented from being detached from the inner joint member. By this locking means, the cylindrical portion can be surely prevented from coming off from the inner joint member, so that the reliability of the constant velocity universal joint can be improved and the life can be extended.
As the locking means, an annular groove is formed in the inner diameter of the opening of the shaft hole of the inner joint member, and an annular groove is formed on the outer periphery of the cylindrical portion of the boot so as to correspond to the annular groove of the inner joint member. A structure in which a retaining ring is fitted into the annular groove of the inner joint member and the annular groove of the cylindrical portion is preferable. With such a structure, it is possible to easily prevent the cylindrical portion of the boot from coming off from the inner joint member.

  In the present invention, it is desirable to have a structure in which a sealing means is interposed between the outer peripheral surface of the shaft and the inner peripheral surface of the cylindrical portion of the boot. If such a sealing means is interposed between the outer peripheral surface of the shaft and the inner peripheral surface of the cylindrical portion of the boot, entry of foreign matter from the outside of the joint and leakage of the lubricant from the inside of the joint can be reliably prevented. The sealing performance can be improved.

  As the sealing means, a structure in which an annular groove is formed on the outer peripheral surface of the shaft and an O-ring is fitted into the annular groove is suitable. With such a structure, a seal between the outer peripheral surface of the shaft and the inner peripheral surface of the cylindrical portion of the boot can be easily realized.

  Moreover, in this invention, it is desirable to set it as the structure which attached the cap which obstruct | occludes the axial hole of the inner joint member to the non-shaft press-fit side edge part of an inner joint member. If such a structure is adopted, leakage of the lubricant from the shaft hole of the inner joint member can be prevented by the cap.

  According to the present invention, the cylindrical portion extrapolated to the shaft is provided in the boot, and the free end portion of the cylindrical portion is fixed to the shaft hole of the inner joint member. A joint unit in which boots are attached to the joint in advance can be manufactured, and the storage space can be reduced during handling such as transportation. In addition, since a joint unit in which a boot is previously attached to a constant velocity universal joint can be manufactured, a process for press-fitting the shaft end of the shaft into the shaft hole of the inner joint member of the joint unit can be set. The process of press-fitting into the shaft hole of the member can be the final process, and the equipment layout can be simplified easily.

  Embodiments of the present invention are described in detail below. In addition, although the following embodiment illustrates the case where it applies to the cross groove type constant velocity universal joint (LJ) which is one of the sliding type constant velocity universal joints used as a coupling joint in a propeller shaft, The present invention can also be applied to other sliding constant velocity universal joints such as an offset type constant velocity universal joint (DOJ) and a tripod type constant velocity universal joint (TJ). Furthermore, the present invention is also applicable to fixed type constant velocity universal joints such as a Barfield type constant velocity universal joint (BJ) and an undercut free type constant velocity universal joint (UJ).

  The constant velocity universal joint in the embodiment shown in FIG. 1 is composed mainly of an outer ring 10 as an outer joint member, an inner ring 20 as an inner joint member, a ball 30 and a cage 40, and a shaft 50 and a boot 60 with an adapter. It has an attached structure.

  The outer ring 10 is a cup-shaped molded body having an opening 15 at one end, and a plurality of linear track grooves 14 extending in the axial direction are formed on the cylindrical inner peripheral surface 12 thereof. A hollow pipe (not shown) is pressed against the other end of the outer ring 10 by resistance welding or the like, and the hollow pipe is connected to a differential. On the other hand, the inner ring 20 is located on the inner periphery of the outer ring 10, and a plurality of track grooves 24 extending in the axial direction are formed on the spherical outer peripheral surface 22 corresponding to the track grooves 14 of the outer ring 10.

  An annular concave groove 11 is formed on the inner peripheral surface of the opening 15 of the outer ring 10, and a retaining ring 13 is fitted into the annular concave groove 11 to restrict the axial movement of the ball 30. 30, the inner part composed of the inner ring 20 and the cage 40 is prevented from jumping out of the outer ring 10.

  The track groove 14 of the outer ring 10 and the track groove 24 of the inner ring 20 are angled in opposite directions with respect to the axis. A ball 30 is incorporated at the intersection of the track groove 14 of the outer ring 10 and the track groove 24 of the inner ring 20 that form a pair. A cage 40 is disposed in an annular space between the cylindrical inner peripheral surface 12 of the outer ring 10 and the spherical outer peripheral surface 22 of the inner ring 20, and the balls 30 are accommodated in pockets 42 of the cage 40 and are equidistant in the circumferential direction. Is held by. The number of balls 30 is eight or ten, but other numbers may be used.

  The shaft end of the shaft 50 is press-fitted into the shaft hole 26 of the inner ring 20, and torque can be transmitted by fitting with splines 28 and 52 formed on the inner diameter of the shaft hole 26 and the outer diameter of the shaft 50. In addition, the inner ring 20 and the shaft 50 may be other uneven fitting capable of transmitting torque in addition to the above-described spline fitting.

  The opposite shaft end portion side of the shaft 50 is connected to the transmission. An annular groove 54 is formed in the shaft end of the shaft 50, and a circular circlip 56 fitted in the annular groove 54 is formed in the annular recess 21 formed in the shaft hole opening edge of the inner side end face 23 of the inner ring 20. The shaft 50 is prevented from coming off from the inner ring 20 by being fitted to the inner ring 20.

  A boot 60 with an adapter is installed between the opening 15 of the outer ring 10 and the shaft 50 extending from the inner ring 20 to prevent intrusion of foreign matters from the outside of the joint and leakage of the lubricant sealed inside the joint. The opening 15 is closed. The boot 60 is made of rubber, and its large-diameter end 62 is fixed to the outer ring 10 via a metal adapter 70 in order to prevent expansion during high-speed rotation in the case of a constant velocity universal joint for a propeller shaft. .

  The adapter 70 is attached to the large-diameter end portion 62 of the boot 60 by caulking the small-diameter end portion 72, and is attached by fitting the large-diameter end portion 74 to the outer peripheral surface of the outer ring 10. . On the small-diameter side that is bent from the large-diameter end portion 62 of the boot 60 and extends in the axial direction, a cylindrical portion 64 that is extrapolated to the shaft 50 is integrally formed of vulcanized rubber.

  The free end portion 66 of the cylindrical portion 64 of the boot 60 integrally molded with this vulcanized rubber is press-fitted into the shaft hole 26 of the inner ring 20 and fixed. On the other hand, a fixed portion 25 into which the free end portion 66 of the cylindrical portion 64 of the boot 60 is press-fitted is formed at the opening end portion of the shaft hole 26 of the inner ring 20.

  The fixed portion 25 has an inner diameter larger than the outermost diameter of the spline 52 of the shaft 50, and a tapered position restricting portion 27 that is reduced in diameter toward the spline 28 is formed between the fixed portion 25 and the spline 28 of the inner ring 20. Has been. The inner diameter of the fixed portion 25 is such that the free end portion 66 of the cylindrical portion 64 of the boot 60 can be press-fitted, and the free end portion 66 of the cylindrical portion 64 of the boot 60 is pushed by the position restricting portion 27 due to press-fitting. Regulated and positioned.

  Here, the outermost diameter of the spline 52 of the shaft 50 means the outer diameter of the tooth tip of the spline 52. Further, the position restricting portion 27 may have a step shape other than the tapered shape.

  Further, an O-ring 58 as a sealing means is interposed between the outer peripheral surface of the shaft 50 and the inner peripheral surface of the cylindrical portion 64 of the boot 60. That is, an annular groove 51 is formed on the outer peripheral surface of the shaft 50, and an O-ring 58 is fitted into the annular groove 51. With such a simple structure, entry of foreign matter from the outside of the joint and leakage of the lubricant from the inside of the joint can be reliably prevented, and the sealing performance can be improved.

  The constant velocity universal joint is assembled in the following manner. First, an assembly body in which the inner ring 20, the ball 30, and the cage 40 are assembled is accommodated in the outer ring 10, a lubricant such as grease is injected from the opening of the outer ring 10, and a boot 60 with an adapter is attached to the outer ring 10. Close the opening. The boot 60 with an adapter is obtained by connecting a large-diameter end 62 of the boot 60 and a small-diameter end 72 of the adapter 70 by crimping the small-diameter end 72 of the adapter 70.

  As shown in FIG. 2, the adapter-equipped boot 60 is fixed by press-fitting the large-diameter end portion 74 of the adapter 70 into the outer peripheral surface of the outer ring 10. The tip of the large-diameter end 74 of the adapter 70 is securely fixed by fitting it into the concave groove 53 on the outer peripheral surface of the outer ring 10 by caulking. Further, the O-ring 57 is fitted into the annular groove 55 on the outer peripheral surface of the outer ring 10 so as to ensure the sealing performance. On the other hand, the free end portion 66 of the cylindrical portion 64 provided in the boot 60 is press-fitted into the shaft hole 26 of the inner ring 20 and fixed. The free end portion 66 of the cylindrical portion 64 is press-fitted into the fixed portion 25 of the shaft hole 26 of the inner ring 20 and is positioned by the position restricting portion 27.

  As a result, it is possible to manufacture a joint unit in which the assembly body assembled with the internal parts including the inner ring 20 is accommodated in the outer ring 10 and the boot 60 with an adapter for closing the opening 15 of the outer ring 10 is attached. In this manner, by making it possible to manufacture a joint unit in which the boot 60 with an adapter is attached in advance to the assembly body, it is possible to reduce the storage space during handling such as transportation.

  Further, as described above, the cylindrical portion 64 is provided in the boot 60, and the free end portion 66 of the cylindrical portion 64 is fixed to the shaft hole 26 of the inner ring 20, so that the shaft 50 is connected to the inner ring 20 in the assembly of the constant velocity universal joint. The step of press-fitting into the shaft hole 26 can be the final step.

  After the manufacture of the joint unit in which the adapter-equipped boot 60 is attached in advance to the assembly body, the shaft end of the shaft 50 is inserted into the cylindrical portion 64 of the boot 60 as shown in FIG. 3 to the shaft hole 26 of the inner ring 20 in the joint unit. The assembly of the constant velocity universal joint is completed by press-fitting. At this time, the inner end 20 of the inner ring 20 is brought into contact with the bottom surface 16 of the outer ring 10 and the inner ring 20 is supported by the outer ring 10 in the axial direction, and the shaft end of the shaft 50 is inserted into the shaft hole 26 of the inner ring 20. Press fit. The shaft 50 is prevented from coming off when a circular circlip 56 mounted in advance in the annular groove 54 at the axial end of the shaft 50 is engaged with the annular recess 21 on the inner side end face 23 of the inner ring 20.

  In order to prevent the shaft end portion of the shaft 50 protruding from the inner end surface 23 of the inner ring 20 from interfering with the bottom surface 16 of the outer ring 10, the bottom surface 16 of the outer ring 10 has a recess 18 as a relief of the shaft end portion of the shaft 50. Is formed.

  Thus, since the joint unit in which the adapter-equipped boot 60 is attached in advance to the assembly body can be manufactured, the step of press-fitting the shaft end of the shaft 50 into the shaft hole 26 of the inner ring 20 of the joint unit can be set. It becomes easy to simplify the layout of the equipment for assembling the constant velocity universal joint.

  The cylindrical portion 64 in the above-described embodiment has been described with respect to the case where it is integrally formed of the same material as the boot 60, that is, vulcanized rubber, but the present invention is not limited to this, and the structure as shown in FIG. It is also possible.

  In the embodiment of FIG. 4, a metal ring 80 as a cylindrical portion is separately attached to the small diameter end portion 68 of the boot 60. One end 82 of the metal ring 80 is connected to the small-diameter end 66 of the boot 60 by caulking, and the other free end 84 is press-fitted into the fixed portion 25 of the shaft hole 26 of the inner ring 20.

  Thus, by using the metal ring 80 as the cylindrical portion, a harder material is used than when the cylindrical portion 64 is integrally formed of vulcanized rubber as in the embodiment of FIG. The work of press-fitting the free end portion 84 of the ring 80 into the shaft hole 26 of the inner ring 20 is facilitated.

  Regarding the structure and assembly of the constant velocity universal joint in the embodiment of FIG. 4, the same or corresponding parts as those of the embodiment of FIG.

  Further, the constant velocity universal joint in the embodiment shown in FIG. 5 is the same as that in the embodiment shown in FIG. 1 (form in which the cylindrical portion 64 of the boot 60 is integrally formed of vulcanized rubber). 20 with a retaining ring 96 as locking means.

  In the locking means, an annular groove 92 is formed on the inner diameter of the fixed portion 25 of the shaft hole 26 of the inner ring 20, and an annular groove 94 is formed on the outer periphery of the cylindrical portion 64 of the boot 60 with the annular groove 92 of the inner ring 20. The retaining ring 96 is fitted to the annular groove 92 of the inner ring 20 and the annular groove 94 of the cylindrical portion 64. In this way, the cylindrical portion 64 of the boot 60 can be reliably prevented from coming off from the inner ring 20 with a simple structure by the retaining ring 96, so that the reliability of the constant velocity universal joint can be improved and the life can be extended. I can plan.

  Note that the structure in which the cylindrical portion 64 of the boot 60 is prevented from coming off by the retaining ring 96 with respect to the inner ring 20 is also applicable to the embodiment of FIG. 4 (the configuration in which the cylindrical portion of the boot 60 is a metal ring 80). In addition, regarding the structure and assembly of the constant velocity universal joint in the embodiment of FIG. 5, the same or corresponding parts as those of the embodiment of FIG.

  Furthermore, the constant velocity universal joint in the embodiment shown in FIG. 6 is the same as that in the embodiment shown in FIG. 1 (form in which the cylindrical portion 64 of the boot 60 is integrally formed of vulcanized rubber). And a structure in which a cap 98 for closing the shaft hole 26 of the inner ring 20 is attached. With such a structure, the cap 98 can prevent the lubricant from leaking from the shaft hole 26 of the inner ring 20.

  Since this cap 98 has a U-shaped cross section having a flange portion 91 at the periphery, it is larger than the outer diameter of the shaft 50 (the outermost diameter of the spline 52) at the inner opening end edge of the shaft hole 26 of the inner ring 20. A recess 93 having an inner diameter is provided, and the flange portion 91 of the cap 98 is press-fitted into the recess 93 and fixed.

  Further, since the shaft hole 26 of the inner ring 20 is closed by the cap 98, the shaft end portion of the shaft 50 is fitted into the annular concave groove 54 of the shaft 50 so as not to protrude from the rear end surface 23 of the inner ring 20. The retaining ring 56 is retained by being engaged with the annular recess 21 of the inner ring 20.

  Note that the structure in which the shaft hole 26 of the inner ring 20 is closed by the cap 98 is also applicable to the embodiment of FIG. 4 (a configuration in which the cylindrical portion of the boot 60 is a metal ring 80). In addition, regarding the structure and assembly of the constant velocity universal joint in the embodiment of FIG. 6, the same or corresponding parts as those of the embodiment of FIG.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

1 is a longitudinal sectional view showing a constant velocity universal joint having a structure in which a cylindrical portion of a boot is integrally formed of vulcanized rubber in an embodiment of the present invention. FIG. 2 is a longitudinal cross-sectional view illustrating a manner of assembling the constant velocity universal joint of FIG. 1 and illustrating a state in which a boot with an adapter is assembled to an assembly body. FIG. 2 is a longitudinal cross-sectional view illustrating how to assemble the constant velocity universal joint of FIG. 1 and illustrating a state in which a shaft is assembled to a joint unit in which a boot with an adapter is assembled to an assembly body. In other embodiment of this invention, it is a longitudinal cross-sectional view which shows the constant velocity universal joint of the structure which used the cylindrical part of the boot as a separate metal ring. In the constant velocity universal joint of FIG. 1, it is a longitudinal cross-sectional view which shows embodiment which added the structure which stopped the cylindrical part of the boot with the latching means with respect to the inner ring | wheel. In the constant velocity universal joint of FIG. 1, it is a longitudinal cross-sectional view which shows embodiment which added the structure which attached the cap which obstruct | occludes the axial hole of the inner ring | wheel to the inner side end part of the inner ring | wheel. It is a longitudinal cross-sectional view which shows the prior art example of a constant velocity universal joint. FIG. 8 is a longitudinal cross-sectional view illustrating a manner of assembling the constant velocity universal joint of FIG. 7 and illustrating a state in which a boot with an adapter is assembled after a shaft is press-fitted into an assembly body.

Explanation of symbols

10 Outer joint member (outer ring)
20 Inner joint member (inner ring)
26 Shaft hole 50 Shaft 51 Annular groove 53 Sealing means (O-ring)
60 Boot 64 Cylindrical portion 66 Free end portion 80 Metal ring 92, 94 Annular groove 96 Locking means (retaining ring)
98 cap

Claims (9)

  A constant velocity universal joint comprising: an outer joint member having an opening at one end; and an inner joint member that transmits torque while allowing angular displacement between the outer joint member and the shaft of the inner joint member A structure having a boot for press-fitting the shaft into the hole and closing the opening of the outer joint member is provided in the boot with a cylindrical portion extrapolated to the shaft, and the free end portion of the cylindrical portion is disposed on the inner side. A constant velocity universal joint characterized by being fixed to a shaft hole of a joint member.   The constant velocity universal joint according to claim 1, wherein the cylindrical portion is integrally formed of the same material as the boot.   The constant velocity universal joint according to claim 2, wherein the cylindrical portion is integrally formed of vulcanized rubber.   The constant velocity universal joint according to claim 1, wherein the cylindrical portion is a metal ring attached separately to an end portion of a boot.   The constant velocity universal joint according to any one of claims 1 to 4, wherein the cylindrical portion is secured to the inner joint member by a locking means.   The locking means forms an annular groove on the inner diameter of the opening of the shaft hole of the inner joint member, and forms an annular groove on the outer periphery of the cylindrical portion of the boot so as to correspond to the annular groove of the inner joint member. The constant velocity universal joint according to claim 5, wherein a retaining ring is fitted into the annular groove of the inner joint member and the annular groove of the cylindrical portion.   The constant velocity universal joint as described in any one of Claims 1-6 which interposed the sealing means between the outer peripheral surface of the said shaft, and the internal peripheral surface of the cylindrical part of a boot.   The constant velocity universal joint according to claim 7, wherein the sealing means has an annular groove formed on an outer peripheral surface of the shaft, and an O-ring is fitted into the annular groove.   The constant velocity universal joint as described in any one of Claims 1-8 which attached the cap which obstruct | occludes the shaft hole of the inner joint member to the non-shaft press-fit side edge part of the inner joint member.

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