JP2006275241A - Constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure ventilation performance for restraining excessive deformation of boots, without impairing the seal action of the boots. <P>SOLUTION: This constant velocity universal joint has the boots 51 for partitioning the joint inside and outside by fitting to a power transmission shaft 22 having one end fitted to an outside joint member 10 and having the other end connected to an inside joint member 20. Air vents 22a1 and 22b1 for communicating the joint inside and outside are arranged in the power transmission shaft 22. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a constant velocity universal joint used in, for example, a propeller shaft and a drive shaft of an automobile or various industrial machines.

  One type of slidable constant velocity universal joint used for propeller shafts and drive shafts of automobiles is called a cross groove type shown in FIG. The constant velocity universal joint includes an outer joint member 10, an inner joint member 20, a plurality of (for example, six) balls 30 (rolling elements), a retainer 40, a boot 50 with an adapter, and an end cap 60 as main components. Provided (for example, see Patent Document 1).

  The outer joint member 10 is formed in a cylindrical shape and has a plurality of track grooves 11 on the inner peripheral surface. Bolt holes 12 are formed on the annular end surface of the outer joint member 10 at positions corresponding to each other between the track grooves 11. The inner joint member 20 has a plurality of track grooves 21 which are paired with the track grooves 11 of the outer joint member 10 formed on the outer peripheral surface. On the inner peripheral side of the inner joint member 20, a power transmission shaft 22 is fitted and integrated so as to be able to transmit torque. The track groove 11 of the outer joint member 10 and the track groove 21 of the inner joint member 20 form a space (ball track) for arranging the balls 30 one by one. The track groove 11 of the outer joint member 10 and the track groove 21 of the inner joint member 20 are formed to be inclined in opposite directions in the circumferential direction and intersect each other. Thereby, the axial direction relative movement of the outer joint member 10 and the inner joint member 20 is permitted. The cage 40 is disposed between the outer joint member 10 and the inner joint member 20 and holds the balls 30 one by one in a plurality of pockets 41 formed at predetermined intervals in the circumferential direction.

  On the other hand, in the above constant velocity universal joint, in order to reduce the frictional resistance between the outer joint member 10 and the inner joint member 20 and the ball 30, the inside of the joint is filled with a lubricant. If this lubricant leaks to the outside of the joint, or if foreign matter such as muddy water or sand dust enters from the outside, the frictional resistance increases and joint performance deteriorates. For this reason, the inside of the joint is formed by the adapter-equipped boot 50 that is airtightly fitted to the inner end of the outer joint member 10 and the power transmission shaft 22 and the end cap 60 that is attached to the outer end of the outer joint member 10. Sealed.

  The boot 50 with an adapter includes a boot 51 made of a rubber material or a flexible resin material and a metal adapter 52. The boot 51 is provided with a bellows-shaped bent portion 51 c between a small-diameter end 51 a that is fitted on the power transmission shaft 22 and a large-diameter end 51 b that is connected to the adapter 52. A small-diameter end 51 a of the boot 51 is fastened by a band 53 and fixed to the power transmission shaft 22. The adapter 52 includes a caulking portion 52 a that is caulked and fixed to the large-diameter end portion 51 b of the boot 51, and an annular flange 52 b that is fitted to the outer joint member 10. The annular flange 52 b of the adapter 52 has a plurality of bolt holes 52 c corresponding to the bolt holes 12 of the outer joint member 10. The bellows-shaped boot 51 may be directly attached to the outer joint member 10 without using the adapter 52. Further, the shape of the bent portion 51c of the boot 51 is not limited to the bellows shape. For example, as shown in FIG. 1 showing the embodiment of the present invention, there is a bent portion 51c having a U-shaped cross section.

  The end cap 60 includes a cup portion 61 that closes the other end opening of the outer joint member 10, and an annular flange 62 that is provided on the peripheral edge of the cup portion 61 and is fitted on the other end portion of the outer joint member 10. The annular flange 62 of the end cap 60 has a plurality of bolt holes 63 corresponding to the bolt holes 12 of the outer joint member 10.

  In the constant velocity universal joint, the adapter 52 and the end cap 60 are fitted to both ends of the outer joint member 10, and the bolt 71 is connected to the adapter 52, the outer joint member 10, the end cap 60, and the stub shaft 70. The bolts 52c, 12, 63 and 72 are inserted into the bolt holes 52 and integrated by tightening with nuts 73 from the stub shaft 70 side, while the other end (not shown) of the shaft 22 is connected to a shaft or joint (not shown) so that torque can be transmitted. By doing so, it is incorporated into a propeller shaft or the like.

  When the above constant velocity universal joint is used for a propeller shaft of an automobile, the axial angular displacement (operation angle) of the outer joint member 10 and the inner joint member 20 is often small and used under high speed rotation. In such a constant velocity universal joint, the internal pressure rises as the temperature inside the joint rises during high-speed rotation, while the internal pressure fluctuates due to subsequent cooling to negative pressure. If the boot 51 is deformed excessively due to a change in the internal pressure of the joint, the durability of the boot 51 is lowered.

  The cross groove type constant velocity universal joint described above is a sliding type in which the outer joint member 10 and the inner joint member 20 are relatively moved in the axial direction, but other sliding type constant velocity universal joints (for example, tripod type). Even in the fixed type constant velocity universal joint in which the outer joint member 10 and the inner joint member 20 do not move relative to each other in the axial direction, the deformation of the boot due to the change in internal pressure is a common phenomenon. However, in the case of the sliding type, since the internal pressure also changes due to the change in the internal volume due to the relative movement of the outer joint member 10 and the inner joint member 20 in the axial direction, the durability of the boot 51 is reduced compared to the fixed type. It's easy to do.

  In order to solve the problem relating to the excessive deformation of the boot 51 due to the change in the internal pressure of the joint, as shown in FIGS. 7 and 8, a ventilation groove 51d is provided on the inner diameter side of the small diameter end portion 51a of the boot 51, and from the small diameter end portion 51a. There is a case in which a lip portion 51e to be brought into contact with the power transmission shaft 22 is extended and a plurality of discontinuous projections 51f are formed on the inner diameter side of the lip portion 51e. When the internal pressure rises, the lip portion 51e is expanded to the outer diameter side, and the joint inside and outside are communicated via the ventilation groove 51d. At the time of negative pressure, the base end side of the lip portion 51e is sucked inward with the projection 51f as a boundary, while the distal end side of the lip portion 51e is separated from the power transmission shaft 22, and the outside air flows from the gap between the projections 51f. By such an inflow / outflow action of the air inside and outside the joint (hereinafter referred to as a breathing action), the pressure difference between the inside and outside of the joint is reduced, so that excessive deformation of the boot 51 is suppressed, and the life of the boot is extended. Patent Document 2 discloses a ventilation structure for the boot 51 shown in FIGS. 7 and 8.

JP 2003-074580 A JP-A-8-28704

  In the case of Patent Document 2, although excessive deformation of the boot 51 is alleviated to some extent, as long as the boot 51 is made of a rubber material or a flexible resin material, an early decrease in the sealing action due to deterioration or breakage of the lip portion 51e can be prevented. Inevitable. The lip portion 51e can be opened and closed by being thin. However, since the lip portion 51e is thin, the lip portion 51e is cracked at the proximal end portion of the lip portion 51e or the proximal end portion of the protrusion 51f that serves as a fulcrum for the opening and closing operation. Is likely to occur. If the adhesion of the lip portion 51e to the stub shaft 22a is reduced due to the crack of the lip portion 51e, the original sealing action of the boot to prevent lubricant leakage and foreign matter intrusion is impaired, and the life of the boot 51 may be reduced instead. Concerned.

  The present invention was devised in view of such circumstances, and an object thereof is to provide a constant velocity universal joint that can enjoy a breathing action for suppressing excessive deformation of the boot without impairing the boot sealing action. There is to do.

  The constant velocity universal joint according to the present invention is engaged with the outer joint member, the inner joint member disposed so as to be swingable relative to the outer joint member, and the outer joint member and the inner joint member, A rolling element that transmits torque between the outer joint member and the inner joint member while allowing relative swinging of the outer joint member and the inner joint member, and one end connected to the inner joint member for torque transmission and the other end A solid stub shaft extending to the outside of the outer joint member, and a boot for fitting one end to the outer joint member and fitting the other end to the solid stub shaft to partition the inside and outside of the joint The constant velocity universal joint is characterized in that a vent hole is provided in the solid stub shaft to communicate the inside and outside of the joint.

  The above constant velocity universal joint is provided with a vent hole for communicating the inside and outside of the joint with a solid stub shaft having one end connected to the inner joint member, and exerts a breathing action for suppressing excessive deformation of the boot through this vent hole. . The solid stub shaft is arranged on the innermost side inside the joint because the shaft center coincides with the rotation center O of the inner joint member and does not interfere with the outer joint member. Since the lubricant filled in the joint is unevenly distributed on the outer diameter side inside the joint by centrifugal force when the constant velocity universal joint rotates, it is difficult to adhere to the solid stub shaft. Even if the lubricant adheres to the solid stub shaft, the lubricant scatters to the outer diameter side inside the joint by centrifugal force when the constant velocity universal joint rotates, so the solid stub shaft It is hard to penetrate into the ventilation holes.

  One end of the vent hole of the solid stub shaft is opened inside the joint and the other end is opened outside the joint. The inside of the joint as used herein refers to a space defined by the outer joint member and the boot, and the outside of the joint is not limited to the atmosphere, but is a sealed space having a volume comparable to or larger than the inside of the joint (for example, FIG. 1). The inside of the hollow cylindrical intermediate shaft 22b connected to the solid stub shaft 22a as shown in FIG. When the other end of the vent hole is opened to the atmosphere, the other end portion of the vent hole is formed with a radial component of at least a solid stub shaft. Even if foreign matter enters from the other end of the vent hole, the foreign matter is discharged from the other end of the vent hole by centrifugal force when the constant velocity universal joint rotates. On the other hand, when the other end of the vent hole is opened to the sealed space, there is no foreign matter such as muddy water or dust in the sealed space, so that no foreign matter enters from the other end of the vent hole.

  When a vent hole is provided in the solid stub shaft in this way, a desired breathing action is performed while suppressing lubricant leakage and foreign substance intrusion, and the sealing action of the boot is not impaired at all by the breathing action by the vent hole. .

  On the other hand, the present invention can also be applied to a constant velocity universal joint using a hollow integrated power transmission shaft instead of a solid stub shaft. In this case, the inside of the joint can be opened to the atmosphere by providing a vent hole on the outer peripheral surface of the hollow integrated power transmission shaft extending outside the boot.

  According to the above configuration of the present invention, the solid stub shaft having one end connected to the inner joint member or the hollow integrated power transmission shaft is provided with the vent hole for communicating the inside and outside of the joint, and the vent hole allows excessive deformation of the boot. Since the breathing action for suppressing is performed, the sealing action of the boot is not impaired at all by the breathing action. Accordingly, the life of the boot can be further extended. Also, since the lubricant inside the joint and foreign matter outside the joint are less likely to enter the vent hole provided in the solid stub shaft or hollow integrated power transmission shaft, poor lubrication and deterioration of the joint performance due to foreign matter penetration are prevented. You can also

  Hereinafter, an embodiment of a constant velocity universal joint according to the present invention will be described with reference to the accompanying drawings. In addition, the constant velocity universal joint of this embodiment is used for the propeller shaft of a motor vehicle. However, the application is not limited to this, and it can be used for a drive shaft of an automobile and various industrial machines.

  FIG. 1 is a longitudinal sectional view showing a first embodiment of a constant velocity universal joint according to the present invention. As in the conventional example, the constant velocity universal joint includes an outer joint member 10, an inner joint member 20, a plurality of balls 30 (rolling elements), a cage 40, a boot 50 with an adapter, and an end cap 60 as main components. Prepare. The same parts as those in the conventional example shown in FIG. 6 are denoted by the same reference numerals, and the description thereof will be omitted.

  The constant velocity universal joint of the first embodiment is provided with a vent hole 22a1 that allows the inside and outside of the joint to communicate with a power transmission shaft 22 connected to the inner joint member 20 so as to be able to transmit torque. The power transmission shaft 22 has a solid stub shaft 22a whose one end is spline-fitted to the inner diameter side of the inner joint member 20, and a cylindrical intermediate shaft 22b connected to the other end of the stub shaft 22a.

  The solid stub shaft 22a has a desired shape by forging or turning a solid rod-shaped shaft material, for example, as shown in the figure, and has a small-diameter portion 22a2 fitted into the inner joint member 20 at one end. It is formed into a shape having a large diameter portion 22a3 joined to the intermediate shaft 22b at the end. A fitting portion 22a4 that is spline fitted to the inner joint member 20 is provided at the tip of the small diameter portion 22a2. A ring groove 22a5 is provided at the tip of the fitting portion 22a4, and a snap ring or circlip 23 is attached to the ring groove 22a5, whereby the solid stub shaft 22a is positioned and fixed in the axial direction of the inner joint member 20. . The large-diameter portion 22a3 is formed in a cup shape and is pressure-welded to one end of the intermediate shaft 22b.

  The power transmission shaft 22 of this embodiment is provided with a vent hole 22a1 in the solid stub shaft 22a, and a vent hole 22b1 that communicates the inside and outside of the intermediate shaft 22b on the peripheral surface of the cylindrical intermediate shaft 22b. is there. The vent hole 22a1 is fitted in the inner joint member 20, and is drilled in the axial direction of the stub shaft 22a from the distal end surface of the small diameter portion 22a2 facing the inner surface of the end cap 60 to the cup-shaped inner surface of the large diameter portion 22a3. The inside communicates with the inside of the intermediate shaft 22b. In the drawing, for easy understanding, the diameters of the air holes 22a1 of the stub shaft 22a and the air holes 22b1 of the intermediate shaft 22b are shown to be relatively large. The size and shape of each of the vent holes 22a1 and 22b1 are not particularly limited, but a size and shape necessary for entering and exiting a slight amount of air (for example, a circular hole having a diameter of about 1 mm) is sufficient and does not need to be so large.

  As described above, the constant velocity universal joint of the first embodiment is opened to the atmosphere through the vent hole 22a1 of the stub shaft 22a and the vent hole 22b1 of the intermediate shaft 22b. Even if the internal temperature of the joint changes, such as when the internal temperature of the joint rises due to high-speed rotation of the constant velocity universal joint, or the temperature inside the joint decreases due to cooling, the inside and outside of the joint are connected via the vent holes 22a1 and 22b1. The air can enter and exit freely. As a result, the internal pressure of the joint hardly changes, so that the excessive deformation of the boot 51 due to the change of the internal pressure of the joint does not occur, and the sealing action of the boot 51 is not impaired, so the life of the boot 51 is extended.

  On the other hand, the axis of the stub shaft 22a coincides with the rotation center O of the inner joint member 20, and is disposed on the innermost side inside the joint. Since the lubricant filled in the joint is unevenly distributed on the outer diameter side inside the joint by centrifugal force when the constant velocity universal joint rotates, it is difficult to adhere to the stub shaft 22a. Even if the lubricant adheres to the stub shaft 22a inside the joint, the lubricant scatters to the outer diameter side inside the joint due to centrifugal force when the constant velocity universal joint rotates, so that it is difficult for the lubricant to enter the vent hole 22a1. . Therefore, if the vent hole 22a1 is provided in the stub shaft 22a, it is possible to prevent the lubricant inside the joint from leaking.

  On the other hand, since the vent hole 22a1 of the stub shaft 22a is opened at or near the rotation center O on the cup-shaped inner surface of the large diameter portion 22a3, foreign matter such as muddy water or dust should be in the vent hole 22b1 of the intermediate shaft 22b. Even if it enters the inside of the intermediate shaft 22b from the inside, it is difficult to enter the vent hole 22a1 of the stub shaft 22a. In addition, since the air hole 22b1 of the intermediate shaft 22b is provided on the peripheral surface, the foreign matter in the intermediate shaft 22b is unevenly distributed on the outer diameter side of the intermediate shaft 22b by centrifugal force when the constant velocity universal joint rotates. Easily discharged from 22b1 to the outside.

  As described above, the constant velocity universal joint according to the first embodiment is provided with the air hole 22a1 in the stub shaft 22a to ensure the air permeability inside and outside the joint while suppressing the leakage of the lubricant and the entry of the foreign matter. The breathing action necessary for extending the life of the boot 51 can be enjoyed without impairing the sealing action of the boot 51.

  FIG. 2 is a longitudinal sectional view showing a second embodiment of the constant velocity universal joint according to the present invention. This constant velocity universal joint is different from the first embodiment in that the power transmission shaft 22 is a hollow integrated type. Since other configurations are the same as those in the first embodiment, the same portions are denoted by the same reference numerals, and the description thereof will be omitted. Hereinafter, differences from the first embodiment will be mainly described. To do.

  In the constant velocity universal joint of the second embodiment, a hollow integrated power transmission shaft 22 connected to the inner joint member 20 so as to be able to transmit torque is provided with a vent hole 22a1 for communicating the inside and outside of the joint. The hollow-integrated power transmission shaft 22 has a desired shape by drawing a tubular shaft material, for example, as shown in the drawing, and has a small-diameter portion 22a2 fitted into the inner joint member 20 at least at one end. The portion is molded into a shape having a large diameter portion 22a3. The vent hole 22a1 is formed on the peripheral surface of the large diameter portion 22a3 extending to the outside of the boot 51.

  On the other hand, the hollow integrated power transmission shaft 22 is filled with a filler 24 made of a foam (for example, a porous resin material such as urethane foam). The filler 24 is formed with a vent 24a extending in the axial direction from the end surface on the small diameter portion 22a2 side and branching in the axial direction and the radial direction in the large diameter portion 22a3. The vent hole 24a branches in the radial direction within the large-diameter portion 22a3 and continues to the vent hole 22a1 provided on the peripheral surface of the hollow integrated power transmission shaft 22.

  In the constant velocity universal joint of the second embodiment, as described above, the power transmission shaft 22 is filled with the filler 24 made of a foam, and the ventilation hole 24a is formed in the filler 24. Since 22a1 and the vent hole 24a of the filler 24 are communicated with each other, the inside of the joint is opened to the atmosphere via these vent holes 22a1 and 24a. Thereby, the breathing action for suppressing the excessive deformation of the boot 51 can be enjoyed without impairing the sealing action of the boot 51.

  On the other hand, since the filler 24 is made of a foam, a large number of small holes (not shown) are formed on the inner surface of the vent hole 24a. Even if a lubricant inside the joint or a foreign matter outside the joint enters the vent hole 24a, the lubricant or the foreign matter is captured by the small hole and the movement in the vent hole 24a is suppressed.

  Although the embodiments of the constant velocity universal joint according to the present invention have been described above, the present invention is not limited to the first and second embodiments, and various modifications can be made. In the first embodiment, the air hole 22b1 is formed on the peripheral surface of the intermediate shaft 22b and the inside of the joint is opened to the atmosphere. However, the air hole 22b1 may not be formed on the peripheral surface of the intermediate shaft 22b. I do not care. For example, as shown in FIG. 3, the air holes 22 a 1 formed in the axial direction from the end surface of the small-diameter portion 22 a 2 of the solid stub shaft 22 a are formed in the axial direction and the radial direction at the outer portion of the stub shaft 22 a extending to the outside of the boot 51. And is opened at the peripheral surface of the outer portion of the stub shaft 22a. As described above, when the inside of the joint is opened to the atmosphere only by the vent hole 22a1 provided in the solid stub shaft 22a, the vent hole 22b1 may not be formed in the intermediate shaft 22b. In FIG. 3, the vent hole 22a1 is also communicated with the inside of the intermediate shaft 22b. However, the vent hole 22a1 need not be communicated with the intermediate shaft 22b. As shown in FIG. 3, when the air hole 22a1 communicates with the inside of the intermediate shaft 22b, even if a foreign object enters from the air hole 22a1 opened on the peripheral surface of the outer portion of the stub shaft 22a, Enters either the joint inner side or the intermediate shaft 22b side from the branch point of the vent hole 22a1. Further, if the branch point of the vent hole 22a1 is biased to the intermediate shaft 22b side rather than the inside of the joint, foreign matter can easily enter the intermediate shaft 22b rather than the inside of the joint, and entry of foreign matter into the joint can be suppressed. . Further, by forming the air holes 22a1 in the stub shaft 22a that is thicker than the thin intermediate shaft 22b, the strength reduction of the power transmission shaft 22 can be minimized.

  Further, in the first embodiment, the internal space surrounded by the cup-shaped inner surface of the large-diameter portion 22a3 of the stub shaft 22a and the cylindrical inner surface of the intermediate shaft 22b is emptied, but as shown in FIG. The internal space 22c may be filled with the filler 24 as in the second embodiment, and the air holes 24a may be communicated with the air holes 22a1 of the stub shaft 22a and the air holes 22b1 of the intermediate shaft 22b.

  In the second embodiment, the vent hole 22a1 is formed in the large diameter portion 22a3 of the hollow integrated power transmission shaft 22. However, as shown in FIG. 5, the vent hole 22a1 is formed in the small diameter portion 22a2. It doesn't matter.

  In the first and second embodiments, the vent holes 22a1 and 24a are opened at the end face on the small diameter portion 22a2 side in order to facilitate the processing of the vent holes 22a1 and 24a. Can be opened to the peripheral surface of the power transmission shaft 22 inside the joint.

  Moreover, in the said 1st and 2nd embodiment, although it is not set as the structure which performs a respiration action with the small diameter edge part 51a of the boot 51, as shown in FIG.7 and FIG.8, this invention is the small diameter edge part 51a. It can also be applied to a constant velocity universal joint that exhibits a breathing action. When the boot 51 and the power transmission shaft 22 exert a breathing action, the air permeability of the joint is improved, so that excessive deformation of the boot 51 can be suppressed and the life of the boot 51 can be extended. Further, if the power transmission shaft 22 is ensured to have air permeability, the opening operation of the lip portion 51e can be suppressed small. Since the load acting on the base end portion of the lip portion 51e and the base end portion of the protrusion 51f when the lip portion 51e is opened is reduced, the durability of the lip portion 51e can be improved.

  As described above, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of maintaining the same inventive concept as defined in the claims.

1 is a longitudinal sectional view showing a first embodiment of a constant velocity universal joint according to the present invention. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the constant velocity universal joint which concerns on this invention. It is a longitudinal cross-sectional view which shows the 1st modification of the constant velocity universal joint which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the 2nd modification of the constant velocity universal joint which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the modification of the constant velocity universal joint which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows an example of the conventional constant velocity universal joint. It is a principal part expansion longitudinal cross-sectional view which shows an example of the conventional ventilation structure of a constant velocity universal joint, Comprising: It is a figure which shows the fitting structure of the small diameter end part of a boot, and the stub shaft of an inner side coupling member. It is XX arrow directional cross-sectional view of FIG.

Explanation of symbols

10 Outer joint member 11 Track groove 12 Bolt hole 20 Inner joint member 21 Track groove 22 Power transmission shaft 22a Stub shaft 22a1 Vent hole 22a2 Small diameter portion 22a3 Large diameter portion 22a4 Fitting portion 22a5 Ring groove 22b Intermediate shaft 22b1 Vent hole 22c Internal space 23 Circlip 24 Filler 24a Vent 30 Ball 40 Cage 41 Pocket 50 Boot with Adapter 51 Boot 51a Small Diameter End 51b Large Diameter End 51c Bent 51d Vent Groove 51e Lip 51f Projection 52 Adapter 52a Clamping 52b Annular Flange 52c Bolt hole 53 Band 60 End cap 61 Cup part 62 Annular flange 63 Bolt hole 70 Hollow shaft 71 Bolt 72 Screw hole

Claims (7)

  The outer joint member, the inner joint member disposed so as to be swingable relative to the outer joint member, and the outer joint member and the inner joint member are engaged with each other, and the outer joint member and the inner joint member are relatively engaged with each other. A rolling element that transmits torque between the outer joint member and the inner joint member while permitting proper swinging, and one end connected to the inner joint member to transmit torque and the other end extended to the outside of the outer joint member In a constant velocity universal joint comprising a solid stub shaft and a boot that fits one end to an outer joint member and the other end to a solid stub shaft to partition the inside and outside of the joint, a solid stub A constant velocity universal joint characterized in that a vent hole is provided in the shaft for communicating the inside and outside of the joint.   A power transmission shaft is formed by connecting a cylindrical intermediate shaft to the other end of the solid stub shaft, and a vent hole is opened at the axially outer end surface of the solid stub shaft extending from the inside of the joint to the outside of the boot. The constant velocity universal joint according to claim 1, wherein the inside of the joint and the inside of the cylindrical intermediate shaft are communicated with each other through a vent hole of a solid stub shaft.   The constant velocity universal joint according to claim 2, wherein a vent hole for communicating the inside and outside of the cylindrical intermediate shaft is provided on a peripheral surface of the cylindrical intermediate shaft.   The constant velocity universal joint according to claim 1, wherein a vent hole is opened at a peripheral surface of an outer portion of a solid stub shaft extending from the inside of the joint to the outside of the boot.   The outer joint member, the inner joint member disposed so as to be swingable relative to the outer joint member, and the outer joint member and the inner joint member are engaged with each other, and the outer joint member and the inner joint member are relatively engaged with each other. A rolling element that transmits torque between the outer joint member and the inner joint member while permitting proper swinging, and one end connected to the inner joint member to transmit torque and the other end extended to the outside of the outer joint member In a constant velocity universal joint comprising a hollow integrated power transmission shaft, and a boot that fits one end to an outer joint member and fits the other end to a hollow integrated power transmission shaft to partition the inside and outside of the joint, A constant velocity universal joint characterized in that a vent hole for communicating the inside and outside of the joint is provided on the peripheral surface of a hollow integrated power transmission shaft.   6. The power transmission shaft is filled with a filler, and a ventilation hole is formed in the filler, so that the ventilation hole of the power transmission shaft communicates with the ventilation hole of the filler. The constant velocity universal joint described.   The constant velocity universal joint according to claim 6, wherein the filler is made of a foam.

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