WO2007086172A1

WO2007086172A1 - Constant velocity universal joint

Info

Publication number: WO2007086172A1
Application number: PCT/JP2006/321041
Authority: WO
Inventors: Shigemi Tanaka
Original assignee: Ntn Corporation
Priority date: 2006-01-30
Filing date: 2006-10-23
Publication date: 2007-08-02
Also published as: JP2007198569A

Abstract

A constant velocity universal joint in which an air breather is prevented from being released from a seal plate even if an axial force acts on the air breather. This constant velocity universal joint comprises an outer joint member (2), an inner joint member (1) having an inner diameter hole to which one end of a shaft (8) is connected, and a sealing device (10) closing the opening (34) of the outer joint member on the side opposite to the projected side of the shaft. The sealing device (10) includes a disk-like seal plate (13) fitted to the opening (34) of the outer joint member and an air breather (14) fitted to a fitting hole (32) at the center of the seal plate (13). The air breather (14) has a ring-like swelled part (19) on its inner surface side, and the fitting hole (32) of the seal plate (13) has a peripheral groove (23) opened to radial outward direction at its peripheral edge part. The swelled part (19) of the air breather (14) is fitted to the peripheral groove (23) from radial outside.

Description

Specification

Constant velocity universal joint

Technical field

[0001] The present invention relates to a constant velocity universal joint.

Background art

[0002] A constant velocity universal joint for a propeller shaft or the like includes, for example, an inner ring 101, an outer ring 102, a ball 103, and a cage 104 as main components as shown in FIG.

[0003] The inner ring 101 has a plurality of track grooves 106 formed on the outer peripheral surface thereof. A shaft 108 is inserted into the center hole (inner diameter hole) 105 of the inner ring 101 and is fitted with a spline, and the torque can be transmitted between the two by the spline fitting.

[0004] The outer ring 102 has the same number of track grooves 107 as the track grooves 106 of the inner ring 101 formed on the inner peripheral surface thereof. A plurality of balls 103 that transmit torque are incorporated between the track groove 107 of the outer ring 102 and the track groove 106 of the inner ring 101. A cage 104 is disposed between the inner ring 101 and the outer ring 102, and the ball 103 is held in a pocket 109 of the cage 104.

[0005] On the shaft protruding side, a paper structure having a boot fixing plate 111 and a rubber boot 112 is formed.

[0006] On the side opposite to the shaft protruding side, a sealing device 110 for closing the outer ring opening is mounted. The sealing device 110 allows ventilation to the outside, and is intended to prevent an increase in internal pressure, to prevent foreign matter such as dust from entering the joint, and to prevent leakage of grease sealed in the joint.

[0007] As shown in FIG. 9 and FIG. 10, the sealing device 110 used for the constant velocity universal joint for the propeller shaft is provided with a hole 114 in the center of the disk-shaped seal plate 113, and the hole 114 has a disk-shaped A seal structure with a rubber member (air breather) 115 is generally used (Patent Document 1, Patent Document 2).

As shown in FIG. 7, the air breather 115 is provided with a circumferential groove 116 on the outer peripheral surface, and the circumferential edge of the hole 114 of the seal plate 113 is fitted into the circumferential groove 116. That is, the air breather 115 is attached to the seal plate 113 by the compressive force in the inner diameter direction of the air breather 115. [0009] As shown in FIG. 8, a slit 117 is provided at the center of the air breather 115 to prevent a rise in internal pressure by allowing ventilation to the outside.

Patent Document 1: JP 2002-331804 A

Patent Document 2: Japanese Patent No. 3662050

Disclosure of the invention

Problems to be solved by the invention

[0010] In the sealing device 110 as described above, the air breather 115 is mounted with a compressive force in the inner diameter direction, so that the margin of tightening between the circumferential groove 116 of the air breather 115 and the hole 114 of the seal plate 113 is reduced. If tightened, the slit portion 117 of the air breather 115 deforms abnormally. For this reason, the function of allowing only air to pass through was prevented by preventing the intrusion of foreign substances and the leakage of grease, and the tightening force could not be tightened.

[0011] On the contrary, if the tightening margin is weak, the compressive force of the air breather 115 is reduced when handling or when the axial force is applied to the air breather 115 due to the negative pressure inside the joint. Therefore, there is a possibility that the air breather 115 is detached from the seal plate 113.

[0012] Conventionally, since the air breather 115 is in a state in which the force of the seal plate 113 protrudes, foreign matter may come into contact with the protruding portion. If such foreign matter comes into contact, the air breather 115 seals. There was also a problem when it became easy to come off the plate 113! For this reason, the air breather 115 must be handled in such a way that no foreign objects etc. hit it.

In view of the above problems, an object of the present invention is to provide a constant velocity universal joint that can prevent the air breather from coming off the seal plate even when an axial force acts on the air breather.

Means for solving the problem

[0014] The constant velocity universal joint of the present invention includes an outer joint member, an inner joint member in which one end of the shaft is connected to the inner diameter hole, and a sealing device that closes the outer joint member opening on the opposite shaft protruding side. In the constant velocity universal joint, the sealing device includes a disc-shaped seal plate that is attached to the opening of the outer joint, and an air breather that is attached to the attachment hole in the center of the seal plate, and the air breather is provided on the inner surface. With a ring-shaped bulge on the side The mounting hole of the seal plate has a circumferential groove opened in the outer diameter direction at the peripheral edge thereof, and the bulging portion of the air breather is mounted in the circumferential groove from the outer diameter direction.

[0015] Therefore, the air breather can be attached to the seal plate by fitting the bulging portion of the outer diameter direction air breather into the circumferential groove of the seal plate. When an axial force is applied to the air breather during handling, etc., a tensile force acts on the bulging part in the inner diameter direction. However, since the bulging portion is fitted in the circumferential groove of the seal plate from the outer diameter direction, no detachment force acts on the bulging portion.

[0016] The air breather is attached to the seal plate in a state where a tensile force in the outer diameter direction is applied to the bulging portion. For this reason, in a state where no axial force is applied to the air breather, a force for reducing the diameter by the restoring force is generated in the bulging portion. In addition, even when an axial force is applied to the air breather, a further tensile force acts.

[0017] A groove opening on the inner diameter side is provided between the flat air breather main body portion of the air breather and the bulging portion, and the outer wall of the circumferential groove of the seal plate is fitted into this groove. For this reason, since the outer wall is interposed between the bulging portion and the main body portion, the air breather can ensure a stable mounting state even when an axial pressing force acts on the air breather.

[0018] When the air breather is mounted, the outer end surface of the seal plate and the outer end surface of the air breather are arranged to be flush with each other. That is, the air breather should not protrude outward from the seal plate.

The invention's effect

[0019] Even if an axial pressing force is applied to the air breather, a tensile force in the inner diameter direction is applied to the bulged portion, and the bulged portion can be more stably received by the circumferential groove. For this reason, the air breather can effectively exhibit the function of allowing only air to pass through, eliminating the intrusion of foreign matters that easily come off from the seal plate and the leakage of grease.

[0020] Since a force for reducing the diameter is generated in the bulge portion of the air breather, the bulge portion is fitted in a stable state in the circumferential groove of the seal plate.

[0021] By providing a groove that fits the outer wall of the circumferential groove of the seal plate on the inner peripheral side of the bulging portion, the mounting stability can be further improved even if an axial pressing force is applied to the air breather. This Togashi.

[0022] Since the outer end surface of the seal plate and the outer end surface of the air breather are arranged on substantially the same plane,

During handling, the air breather is less likely to come off from the seal plate where foreign objects are difficult to come into contact with. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to FIGS.

[0024] FIG. 1 is a cross-sectional view of a constant velocity universal joint showing an embodiment of the present invention. The constant velocity self-joint of the present invention includes an inner ring 1 as an inner joint member, an outer ring 2 as an outer joint member, a ball 3 and a cage 4 as main components.

The inner ring 1 has a plurality of track grooves 6 formed on its outer peripheral surface (convex spherical outer peripheral surface). A shaft 8 is inserted into the center hole (inner diameter hole) 5 of the inner ring 1 and is fitted with a spline, and the torque can be transmitted between the two by the spline fitting. The shaft 8 is secured against the inner ring 1 by a snap ring 15.

[0026] The outer ring 2 has the same number of track grooves 7 as the track grooves 6 of the inner ring 1 formed on its inner peripheral surface (cylindrical inner peripheral surface). A plurality of balls 3 for transmitting torque are incorporated between the track groove 7 of the outer ring 2 and the track groove 6 of the inner ring 1. A cage 4 is placed between the inner ring 1 and the outer ring 2, and the ball 3 is held in the pocket 9 of the cage 4!

[0027] One end of the outer ring 2 in the axial direction (opening on the shaft protruding side) is closed by a sealing device 16 including a boot 12 and an adapter 11. On the other hand, the outer ring opening on the non-shaft protruding side is closed by a sealing device 10 including a seal plate 13 and an air breather (a ventilation rubber member) 14. These sealing devices 10 and 16 prevent leakage of grease filled in the joint and prevent foreign substances from entering.

The air breather 14 is a rubber molded product, and includes a circular flat plate-like main body portion 17 and a thick portion 18 provided on the outer peripheral edge portion of the main body portion 17 as shown in FIG. That is, the thick part 18 has the bulging part 19 provided continuously through the continuous part 30 in which the groove 21 opened on the inner diameter side is formed. Further, on the outer diameter side of the thick portion 18, a flange portion 20 having a tongue-like cross section is provided so as to protrude in the outer diameter direction along the circumferential direction. Thus, the groove 21 is formed between the main body portion 17 and the bulging portion 19 in the air breather 14. The inner part of the joint of the flange 20 A tapered surface 31 is provided which expands in diameter from the part side to the outside side.

In addition, a radial slit 22 is provided at the center of the main body 17 of the air breather 14 as shown in FIG. As a result, when the pressure inside the joint rises, the rise in the internal pressure of the slit 22 is released to the outside to prevent the pressure inside the joint from rising. On the other hand, when the pressure inside the joint drops, the drop in the internal pressure is sucked in from the slit 22 to prevent the pressure drop inside the joint.

[0030] The seal plate 13 is provided with a mounting hole 32 for mounting the air breather 14 at the center. As shown in FIG. 4, the peripheral portion (outer peripheral portion) of the mounting hole 32 has an outer diameter direction. It has a circumferential groove 23 that is open at the bottom. That is, the outer peripheral edge portion of the mounting hole 32 of the seal plate 13 has a cross-section fishhook shape, and the tapered wall portion 24 that inclines toward the inner side of the joint sequentially from the outer diameter side toward the inner diameter side. The radial wall 33 extending from the inner diameter end to the inner diameter side, the axial wall 25 extending outward from the inner diameter end of the radial wall 33, and the outer end force of the axial wall 25 is also directed to the outside of the joint. It consists of an outer wall portion 26 that gradually expands with force. Therefore, a circumferential groove 23 opened in the outer diameter direction is formed in the outer peripheral edge portion of the mounting hole 32. For example, the seal plate 13 is formed by pressing an SPC material (cold rolled steel plate) with a press, and the air blender 14 is formed by an injection method using a rubber material, for example.

Then, as shown in FIG. 5, the air breather 14 is mounted in the mounting hole 32 of the seal plate 13 by fitting the bulging portion 19 of the air breather 14 into the circumferential groove 23 of the seal plate 13. The At this time, the outer wall portion 26 of the seal plate 13 is fitted into the groove 21 of the air breather 14, and the tapered surface 31 of the flange portion 20 of the air breather 14 is in contact with the taper wall portion 24 of the seal plate 13.

By the way, φ a (inner diameter of the bulging portion 19 in the free state) is φ A (diameter of the axial wall portion 25 of the circumferential groove 23). Thereby, the air breather 14 is held by the seal plate 13 in a state where the bulging portion 19 is pulled in the outer diameter direction. That is, as shown in FIG. 5, in order to mount the air breather 14 in the mounting hole 32 provided in the central portion of the seal plate 13, the seal portion 13 is pulled with the thick portion 18 of the air breather 14 pulled in the outer diameter direction. A part of the bulging portion 19 may be fitted into the circumferential groove 23 of the plate 13 and then continuously fitted in the circumferential direction. In addition, when the air breather 14 is mounted, the outer end surface 29 of the seal plate 13 It arrange | positions so that the outer end surface 28 of the breather 14 may become flush | level. In other words, the circumferential groove 23 of the seal plate 13 is provided at a recessed position on the inner side so that the air breather 14 does not protrude from the seal plate 13 outward in the axial direction. Here, the flush surface includes not only completely the same, but also includes a state where the outer end surface 28 of the air breather 14 is slightly inwardly or outwardly displaced with respect to the outer end surface 29 of the seal plate 13.

A mounting portion 35 is formed on the outer peripheral edge of the seal plate 13 to be mounted in the opening 34 on the side opposite to the shaft protruding from the outer ring 2. The mounting portion 35 includes a tapered wall 36 that gradually increases in diameter from the inner diameter side toward the inside of the joint, a radial wall portion 37 that extends from the outer peripheral edge of the tapered wall 36 in the outer diameter direction, and the radial wall. It comprises an axial wall 38 extending from the outer periphery of the portion 37 to the outside of the joint. When the seal plate 13 is attached to the opening 34 on the non-shaft protruding side of the outer ring 2, the axial wall 38 is in pressure contact with the inner diameter surface.

[0034] In the constant velocity universal joint configured as described above, the seal plate 13 is attached to the air breather 14 by fitting the bulging portion 19 of the air breather 14 to the circumferential groove 23 of the seal plate 13 with the outer diameter direction force. can do. When an axial force is applied to the air breather 14 during handling or the like, a force that reduces the diameter in the inner diameter direction acts on the bulging portion 19. However, since the bulging portion 19 is also fitted with the outer radial force in the circumferential groove 23 of the seal plate 13, the detaching force does not act on the bulging portion 19.

In the present invention, even if an axial pressing force is applied to the air breather 14, a tensile force in the inner diameter direction acts on the bulged portion 19, and the bulged portion 19 is further stabilized by the circumferential groove 23. Can be received. For this reason, the air breather 14 can effectively exert the function of allowing only air to pass through by eliminating the intrusion of foreign matters that easily come off from the seal plate 13 and the leakage of grease.

The air breather 14 is attached to the seal plate 13 by applying a tensile force in the outer diameter direction to the bulging portion 19. For this reason, in the state where no axial force is applied to the air breather 14, the bulging portion 19 has a force to reduce its diameter by its restoring force. For this reason, the bulging portion 19 is fitted in the circumferential groove 23 of the seal plate 13 in a stable state.

[0037] Between the flat air breather main body portion 17 of the air breather 14 and the bulging portion 19, a groove 21 opened to the inner diameter side is provided, and the outer wall of the circumferential groove 23 of the seal plate 13 is provided in the groove 21. 26 fits. For this reason, since the outer wall 26 is interposed between the bulging portion 19 and the main body portion 17, when an axial pressing force acts on the air breather 14, the outer wall 26 becomes a catching force, and the air breather 14 is stabilized. The mounted state can be secured, and the mounting stability can be further improved.

[0038] Since the outer end face 29 of the seal plate 13 and the outer end face 28 of the air breather 14 are disposed on substantially the same plane, the handle is detached from the seal plate 13 where foreign matter hardly comes into contact with the air breather 14 during handling. The fear is reduced.

As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the bulging portion 19 of the air breather 14 does not have a ring shape. In addition, a plurality may be arranged at a predetermined pitch along the circumferential direction. Further, the air breather 14 may or may not have the flange portion 20 or may have the flange portion 20 or may not have the tapered surface 31. Further, the cross-sectional shape of the circumferential groove 23 of the seal plate 13 can be various as long as the bulging portion 19 can be fitted, and conversely the cross-sectional shape of the bulging portion 19 is also the circumferential direction of the seal plate 13. Anything that fits into groove 23 is acceptable. Further, the outer end surface 29 of the air breather 14 does not have to be on the same plane as the outer end surface 29 of the seal plate 13 and the outer end surface 28 of the air breather 14 are attached to the inside from the outer end surface 29 of the seal plate 13. Anyway.

[0040] The material of the air breather 14 is not limited to rubber, but can be adapted to the environment in which this constant velocity universal joint is used. Can be used.

[0041] The constant velocity universal joint is not limited to the fixed type constant velocity universal joint as in the embodiment, and may be a sliding type universal joint.

Brief Description of Drawings

FIG. 1 is a cross-sectional view of a constant velocity universal joint showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the air breather.

FIG. 3 is a front view of the main part of the air breather.

FIG. 4 is an enlarged cross-sectional view of a main part of a seal plate.

FIG. 5 is a cross-sectional view of a principal part showing a state where the air breather is mounted. FIG. 6 is a cross-sectional view of a conventional constant velocity universal joint.

FIG. 7 is an enlarged cross-sectional view of a main part of a conventional air breather.

FIG. 8 is a front view of a conventional air breather.

FIG. 9 is an enlarged cross-sectional view of a main part of a conventional seal plate.

[10] FIG. 10 is a cross-sectional view of a main part showing a conventional air breather mounted state.

Claims

The scope of the claims

[1] A constant velocity universal joint comprising an outer joint member, an inner joint member having one end of the shaft connected to the inner diameter hole, and a sealing device for closing the outer joint member opening on the anti-shaft protruding side! The sealing device includes a disc-shaped seal plate mounted on the outer joint opening, and an air breather mounted in a mounting hole in the center of the seal plate, and the air breather is ring-shaped on the inner surface side. The mounting hole of the seal plate has a circumferential groove opened in the outer diameter direction at the peripheral edge thereof, and the bulging part of the air breather extends from the outer diameter direction into the circumferential groove. A constant velocity universal joint that is mounted.

[2] The constant velocity universal joint according to claim 1, wherein the air breather is attached to a seal plate in a state in which a tensile force in an outer diameter direction acts on the bulging portion.

[3] A groove opening on the inner diameter side is provided between the flat air breather main body portion of the air breather and the bulging portion, and an outer wall of a circumferential groove of the seal plate is fitted into the groove. The constant velocity universal joint according to claim 1 or 2.

[4] The constant velocity according to any one of claims 1 to 3, wherein when the air breather is mounted, the outer end surface of the seal plate and the outer end surface of the air breather are flush with each other. Universal joint.