JP2007113614A - Fixed constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixed constant velocity universal joint capable of preventing damage to a boot, and the like due to nipping by avoiding the boot from being nipped between an adapter and a shaft. <P>SOLUTION: This fixed constant velocity universal joint has an outer race 22 forming a track groove 27 axially extending on an inner peripheral surface, an inner race 21 forming a track groove 26 axially extending on an outer peripheral surface and connecting one end of the shaft 28 to an inner diameter hole, a ball 23 interposing between the track grooves 26 and 27 of these inner-outer races 21 and 22, a cage 24 for holding the ball 23 and a sealing device 30 for blocking up an outer race opening part on the shaft projecting side. The sealing device 30 has the metallic cylindrical adapter 33 having one end part 33a fitted to the outer race 22, and the boot 31 composed of a flexible material having a large diameter part 31a connected to the other end part 33b of the adapter 33 and a small diameter part 31b fitted to the shaft 28. The inner race 21 is provided with an angle restraining mechanism 40 preventing the boot from being nipped between the shaft 28 and the adapter 33 by regulating a joint allowable angle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fixed type constant velocity universal joint, and more particularly to a fixed type constant velocity universal joint used in a propeller shaft that transmits a rotational driving force from a transmission to a differential in a 4WD vehicle, an FR vehicle, or the like.

  A fixed type constant velocity universal joint for a propeller shaft includes, for example, an inner ring 1, an outer ring 2, a ball 3 and a cage 4 as main components as shown in FIG.

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

  The outer ring 2 has the same number of track grooves 7 as the track grooves 6 of the inner ring 1 formed on the inner peripheral surface thereof. 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 disposed between the inner ring 1 and the outer ring 2, and the ball 3 is held in a pocket 9 of the cage 4.

  A sealing device 10 is mounted between the outer ring 2 and the shaft 8 on the shaft protruding side. The sealing device 10 is intended to prevent foreign matter such as dust from entering the joint and to prevent leakage of grease sealed in the joint.

  The sealing device 10 includes a boot 11 made of a flexible material such as a rubber material or a resin material, and a metal adapter 13. The boot includes a large-diameter portion 11a, a small-diameter portion 11b, and a bent portion 11c having a substantially U-shaped cross section that connects the large-diameter portion 11a and the small-diameter portion 11b. The adapter 13 has a substantially cylindrical shape, and one end 13a is press-fitted and crimped to the outer peripheral surface of the end of the outer ring 2 via a seal member 14 such as an O-ring, and the other end 13b is caulked to the large-diameter portion 11a of the boot 11. Is held at. Further, the boot 11 has a small-diameter portion 11 b fitted on the shaft 8 and fastened with a boot band 14.

  The bent portion 11c of the boot 11 is inserted into a space between the inner peripheral surface of the adapter 13 and the outer peripheral surface of the shaft 8, and repeats a bending and stretching operation in the radial direction when the joint rotates at an operating angle. Become.

  However, if the shaft axis is greatly bent with respect to the joint axis, the boot 11 is sandwiched between the adapter 13 and the shaft 8. If it is pinched, the boot 11 may be damaged or torn.

  Therefore, a constant velocity universal joint having a structure for preventing such damage to the boot has been proposed (Patent Documents 1 and 2).

  In the device described in Patent Document 1, the other end portion 13b of the adapter 13 is surrounded by the large-diameter portion 11a of the boot 11 as shown in FIG. Further, the axial length L1 of the bonding portion 16a bonded to the inner peripheral surface of the other end portion 13b is made longer than the axial length L2 of the bonding portion 16b bonded to the outer peripheral surface of the other end portion 13b. ing.

  Therefore, in the structure shown in FIG. 7, the buffer portion 16 prevents the other end portion 13 b of the adapter 13 from coming into direct contact with the boot 11 to prevent damage to the boot 11. Further, the axial length L1 of the bonding portion 16a bonded to the inner peripheral surface of the other end portion 13b is made longer than the axial length L2 of the bonding portion 16b bonded to the outer peripheral surface of the other end portion 13b. Thus, when the bent portion 11c (intermediate flexible portion) of the boot 11 is expanded outward (in the axial direction), the intermediate flexible portion becomes the other end edge (free end) of the adapter 13. I try not to reach it. As a result, the boot 11 is prevented from being damaged.

  Further, a vent hole 17 is provided on the inner peripheral surface of the small-diameter portion 11b of the boot 11 so that when the internal pressure rises, the internal pressure is released to avoid expansion of the boot 11 due to the increase in internal pressure, and damage to the boot 11 or the like. Trying to prevent.

  As shown in FIG. 8, the device described in Patent Document 2 is provided with a branch portion 18 branched from a bent portion 11 c, and this branch portion 18 extends along the inner surface of the radial wall 13 c of the adapter 13. And this branch part 18 is clamped by the radial direction wall 13c of the adapter 13, and an outer ring | wheel end surface. For this reason, even if the bent portion 11c of the boot 11 tries to expand outward in the axial direction, the branch portion 18 prevents this expansion. Thereby, even if it receives the centrifugal force accompanying high-speed rotation, it tries to avoid the outward damage in the axial direction and prevent the boot 11 from being damaged.

Moreover, the sealing chamber 19 is provided between the branch part 18 and the adapter 13, and it is trying to prevent expansion | swelling of the bending part 11c (intermediate flexible part) by this.
JP-A-8-284972 Japanese Patent Laid-Open No. 8-296662

  In the thing of patent document 1, when the big operating angle is taken, the adapter 13 will contact | win the boot 11 via the buffer part 16. FIG. However, the other end 13 b of the adapter 13 is accommodated in the buffer portion 16. For this reason, the boot 11 is sandwiched between the other end portion 13b and the shaft 8, and damage to the boot 11 cannot be prevented. In addition, the other end portion 13b of the adapter 13 must be surrounded by the large diameter portion 11a of the boot 11, which is inferior in assemblability.

  Moreover, in the thing of patent document 2, like the sealing device shown in FIG. 6, the other end 13b of the adapter 13 is exposed to the outside, and the boot 11 is sandwiched between the adapter 13 and the shaft 8. It cannot be avoided.

  In view of the above problems, the present invention provides a fixed type constant velocity universal joint that can prevent the boot from being pinched between the adapter and the shaft and prevent the boot from being damaged by the pinching. For the purpose.

  The fixed type constant velocity universal joint of the present invention includes an outer ring in which a plurality of track grooves extending in the axial direction are formed on the inner peripheral surface, a plurality of track grooves extending in the axial direction on the outer peripheral surface, and one end of the shaft in the inner diameter hole. A plurality of balls that transmit torque by being interposed between the track grooves of the inner and outer rings, a cage that is held between the outer ring and the inner ring to hold the balls, and an outer ring opening on the shaft protruding side A sealing device that closes a portion, and the sealing device includes a metal cylindrical adapter whose one end is fitted to the outer ring, a large diameter portion connected to the other end of the adapter, and a small diameter portion In a constant velocity universal joint having a boot made of a flexible material fitted to the shaft, an angle restraining mechanism for preventing the pinching of the boot between the shaft and the adapter by restricting the joint allowable angle on the inner ring. Provided .

  By providing the inner ring with an angle suppression mechanism that regulates the joint allowable angle, it is possible to avoid a bent state where the boot between the shaft and the adapter is pinched, and prevent damage to the boot due to this pinching. can do.

  The angle suppression mechanism includes a ring-shaped body that fits in a circumferential groove provided on the outer circumferential surface of the inner ring, and the shaft is bent when the shaft axis is bent at a predetermined angle with respect to the joint axis. The ring-shaped body abuts to restrict bending over the predetermined angle.

  The ring-shaped body of the angle suppression mechanism can be disposed on the inner ring opening side on the anti-boot side or on the inner ring opening side on the boot side.

  Since the constant velocity universal joint used for the propeller shaft of the automobile has a small operating angle (ordinary angle), the fixed type constant velocity universal joint is optimally used for the propeller shaft.

  By providing the inner ring with an angle suppression mechanism for restricting the joint allowable angle, a bent state in which the boot between the shaft and the adapter is sandwiched can be avoided, and the boot can be prevented from being pinched. Thus, the boot can be prevented from being damaged or cracked, and the sealing device can perform its function for a long time. In addition, since it is not necessary to surround the other end of the adapter with the large diameter portion of the boot, the assemblability can be improved.

  The angle suppression mechanism includes a ring-shaped body that fits in a circumferential groove provided on the outer peripheral surface of the inner ring, and does not have a complicated configuration and is excellent in workability. In addition, when the shaft axis is bent at a predetermined angle with respect to the joint axis, the ring-shaped body comes into contact with the ball and the bending beyond the predetermined angle is regulated, and the angle regulation is reliably performed. Can be made. For this reason, the reliability of prevention of pinching of boots is improved.

  The ring-shaped body of the angle suppression mechanism can be disposed on the inner ring opening side on the anti-boot side or on the inner ring opening side on the boot side. For this reason, since the arrangement | positioning site | part of a ring-shaped body may be on the anti-boot side or the boot side, workability can be improved.

  Since the constant velocity universal joint used for the propeller shaft of an automobile has a small operating angle (ordinary angle), the fixed type constant velocity universal joint is optimally used for the propeller shaft. If a quick universal joint is used, a stable function can be exhibited over a long period of time.

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

  The fixed type constant velocity universal joint according to the first embodiment of the present invention includes an inner ring 21, an outer ring 22, a ball 23, and a cage 24 as main components.

  The inner ring 21 has a plurality of track grooves 26 formed on its outer peripheral surface (convex spherical outer peripheral surface). A shaft 28 is inserted into the center hole (inner diameter hole) 25 of the inner ring 21 and is spline-fitted, and torque can be transmitted between the two by the spline fitting. The shaft 28 is prevented from coming off from the inner ring 21 by a snap ring 32.

  The outer ring 22 has the same number of track grooves 27 as the track grooves 26 of the inner ring 21 formed on its inner peripheral surface (cylindrical inner peripheral surface). A plurality of balls 23 for transmitting torque are incorporated between the track groove 27 of the outer ring 22 and the track groove 26 of the inner ring 21. A cage 24 is disposed between the inner ring 21 and the outer ring 22, and the ball 23 is held in a pocket 29 of the cage 24.

  An end cap 50 is fitted on one end of the outer ring 22 in the axial direction (an opening on the opposite shaft protruding side), and the outer ring opening on the shaft protruding side is closed by a sealing device 30. The end cap 50 and the sealing device 30 prevent leakage of grease filled in the joint and prevent entry of foreign matter.

  The sealing device 30 is the same as the conventional sealing device 10 shown in FIG. 6 and includes a boot 31 made of a flexible material such as a rubber material or a resin material, and a metal adapter 33. The boot 31 connects (connects) a large-diameter portion 31a fixed to the outer ring 22 via the adapter 33, a small-diameter portion 31b fixed to the shaft 28 by a boot band 35, and the large-diameter portion 31a and the small-diameter portion 31b. And a bent portion 31c having a substantially U-shaped cross section.

  One end portion 33a of the adapter 33 is press-fitted through a seal member 34 such as an O-ring on the outer peripheral surface of the end portion of the outer ring 22 in order to secure sealing performance and pull-out strength with respect to the outer ring 22, and then subjected to crimping by rolling caulking or the like. Tightened and fixed. The other end portion 33 b of the adapter 33 holds and holds the large diameter portion 31 a of the boot 31. In other words, the large diameter portion 31 a of the boot 31 is surrounded by the other end portion 33 b of the adapter 33.

  An annular recess 37 is formed on the outer peripheral surface of the shaft 28, and a small-diameter portion 31 b of the boot 31 is fitted on the annular recess 37 and fastened with a boot band 35. Further, a circumferential groove 38 is formed on the outer peripheral surface of the small diameter portion 31 b, and the boot band 35 is fitted in the circumferential groove 38.

  The end cap 50 includes a disc-shaped main body 50a and a small cap 50b attached to the axial center of the main body 50a. The main body 50 a includes a flat plate-like central portion 51 and a fitting portion 52 on the outer peripheral side of the central portion 51. And the fitting part 52 is fitted by the large diameter part 53 of the outer ring | wheel opening part by the side of anti-boots.

  The inner ring 21 is provided with an angle suppression mechanism 40 that restricts the joint allowable angle and prevents the boot 28 from being pinched between the shaft 28 and the adapter 33.

  As shown in FIG. 2, a circumferential groove 41 is provided on the outer circumferential surface on the outer ring opening side on the anti-boot side, and a ring-shaped body 42 is fitted into the circumferential groove 41, whereby the angle suppression mechanism 40 is arranged. Is configured. The circumferential groove 41 is provided with a notch 43 on the outer ring opening side on the anti-boot side, and is formed on the notch bottom surface 44 of the notch 43.

  As shown in FIG. 1, when the joint axis (the axis of the outer ring 22) O and the axis O1 of the shaft 28 coincide with each other, the axis O1 of the shaft 28 is the axis of the outer ring 22, as shown in FIG. If it bends with respect to the center O and it will be in a predetermined bending state, as shown in FIG. 3 and FIG. 4, the ring-shaped body 42 will contact | abut to the ball | bowl 23 of the anti-bending direction side. Here, the predetermined bent state is a bent state that is required for the portion where the fixed type constant velocity universal joint is used.

  Thus, if the ring-shaped body 42 contacts the ball 23, the bending in this direction is further restricted. That is, if this angle suppression mechanism 40 is not provided, the shaft 28 bends to the position of the axis indicated by O2 in FIG. If it is bent to this position, the other end portion 33b of the adapter 33 comes into contact with the boot 31, and this contact portion is sandwiched between the other end portion 33b of the adapter 33 and the shaft 28. The part is damaged or torn.

  However, the angle suppression mechanism 40 does not bend until a part of the boot 31 is sandwiched between the other end 33 b of the adapter 33 and the shaft 28.

  In the present invention, by providing the inner ring 21 with the angle suppression mechanism 40 that restricts the joint allowable angle, it is possible to avoid a bent state in which the boot between the shaft 28 and the adapter 33 is sandwiched. This can be prevented. As a result, the boot 31 can be prevented from being damaged or cracked, and the sealing device 30 can exhibit its function over a long period of time. Moreover, since it is not necessary to surround the other end portion 33b of the adapter 33 with the large-diameter portion 11a of the boot 11, the assemblability can be improved.

  The angle suppression mechanism 40 includes a ring-shaped body 42 that fits in a circumferential groove 41 provided on the outer peripheral surface of the inner ring 21, and does not have a complicated configuration and is excellent in workability. Further, when the shaft axis O1 is bent at a predetermined angle with respect to the joint axis O, the ring-shaped body 42 is brought into contact with the ball 23 to restrict the bending beyond the predetermined angle. It can be done reliably. For this reason, the reliability of prevention of pinching of boots is improved.

  FIG. 5 shows the inner ring 21 of the second embodiment. In this case, the circumferential groove 41 of the angle suppression mechanism 40 is provided on the outer peripheral surface of the boot side on the inner ring opening side. A ring-shaped body 42 is fitted in the circumferential groove 41. The circumferential groove 41 is provided with a notch 45 on the inner ring opening side on the boot side and is formed on the notch bottom surface 46 of the notch 45.

  Therefore, as shown in FIG. 5, the ring-shaped body 42 of the angle suppression mechanism 40 can be arranged on the inner ring opening side of the boot side to regulate the joint allowable angle. It is possible to avoid a bent state where the boots are sandwiched between them, and to prevent the boots from being pinched.

  That is, as shown in FIG. 3, when the axis O1 of the shaft 28 is bent with respect to the joint axis O, and the bending angle reaches a predetermined angle, the ring-shaped body 42 contacts the ball 23 on the bending direction side. Touch. As a result, the joint allowable angle can be regulated.

  Thus, in the present invention, the ring-shaped body 42 of the angle suppression mechanism 40 can be disposed on the inner ring opening side on the anti-boot side or on the inner ring opening side on the boot side. For this reason, since the arrangement | positioning site | part of a ring-shaped body may be on the anti-boot side or the boot side, workability can be improved.

  In addition, since the constant velocity universal joint used for the propeller shaft of an automobile has a small operating angle (ordinary angle), the fixed type constant velocity universal joint of the present invention is optimally used for the propeller shaft. If this fixed type constant velocity universal joint is used, a stable function can be exhibited over a long period of time.

  As described above, the fixed type constant velocity universal joint of the present invention is preferably used for a propeller shaft of an automobile, but it can of course be used for other than the propeller shaft.

  Further, the predetermined angle of the angle restriction by the angle suppression mechanism 40 can be variously changed according to the outer diameter of the large diameter portion 31a of the boot 31, the outer diameter of the small diameter portion 31b, and the like. That is, the predetermined angle may be in a range that can prevent bending of the boot and can be bent in a usage environment.

  In the first embodiment, the circumferential groove 41 is disposed on the inner ring opening side on the anti-boot side, and in the second embodiment, the circumferential groove 41 is disposed on the inner ring opening side on the boot side. The circumferential grooves 41 may be arranged on the inner ring opening side on the side and the inner ring opening side on the boot side. That is, the ring-shaped body 42 that restricts the joint allowable angle may be disposed on both opening portions of the inner ring 21.

  As the cross-sectional shape of the circumferential concave groove 41, it was semicircular in each embodiment, but various shapes such as other semi-ellipses and trapezoids can be adopted, and the cross-sectional shape of the ring-shaped body 42 is also as follows. It can be changed within a range that can be fitted in the circumferential groove 41.

  As long as the ring-shaped body 42 can be fitted in the circumferential groove 41, the ring-shaped body 42 may be endless or may have a notch in part. Therefore, the material of the ring-shaped body 42 can cope with the environment in which this fixed type constant velocity universal joint is used, and the joint allowable angle can be restricted when the ball 23 abuts on the ring-shaped body 42. If possible, various materials such as rubber, resin, metal and the like can be used.

  The constant velocity universal joint of the present invention can also be applied to various fixed constant velocity universal joints such as a Rzeppa type and an undercut free type.

It is sectional drawing of the fixed type constant velocity universal joint which shows 1st Embodiment of this invention. It is an expanded sectional view of the inner ring of the fixed type constant velocity universal joint. It is sectional drawing which shows the angle suppression state of the said fixed type constant velocity universal joint. It is a principal part enlarged view which shows the angle suppression mechanism of the said fixed type constant velocity universal joint. It is an expanded sectional view of the inner ring | wheel of the fixed type constant velocity universal joint which shows 2nd Embodiment of this invention. It is sectional drawing of the conventional fixed type constant velocity universal joint. It is sectional drawing of the other sealing device used for the conventional fixed type constant velocity universal joint. It is sectional drawing of another sealing device used for the conventional fixed type constant velocity universal joint.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 3 Ball 4 Cage 6, 7 Track groove 8 Shaft 9 Pocket 10 Sealing device 11 Boot 11a Large diameter part 11b Small diameter part 11c Bending part 13 Adapter 13a One end part 13b Other end part 13c Radial wall 14 Seal member 14 Boot Band 16 Buffer portion 16a, 16a Adhesion portion 17 Vent hole 18 Branch portion 19 Sealing chamber 21 Inner ring 22 Outer ring 23 Ball 24 Cage 26, 27 Track groove 28 Shaft 29 Pocket 30 Sealing device 31 Boot 31a Large diameter portion 31b Small diameter portion 31c Bending portion 32 Snap ring 33 Adapter 33a One end 33b Other end 34 Seal member 35 Boot band 37 Annular recess 38 Circumferential groove 40 Angle restraining mechanism 41 Circumferential concave groove 42 Ring-shaped body 43, 45 Notch 44, 46 Notch bottom 50 End cap 50a Main body 50b Small cap Flop 51 the central portion 52 fitting portion 53 large diameter portion O joint axis O1 shaft axis

Claims (5)

  An outer ring having a plurality of track grooves extending in the axial direction on the inner peripheral surface, an inner ring having a plurality of track grooves extending in the axial direction on the outer peripheral surface and having one end of the shaft connected to the inner diameter hole, A plurality of balls interposed between the track grooves for transmitting torque; a cage held between the outer ring and the inner ring for holding the balls; and a sealing device for closing the outer ring opening on the shaft protruding side; A device is a metal cylindrical adapter with one end fitted to the outer ring, and a flexible material with a large diameter connected to the other end of the adapter and a small diameter fitted to the shaft. A fixed type constant velocity universal joint having a boot made of a fixed type characterized in that the inner ring is provided with an angle suppression mechanism for restricting the joint allowable angle and preventing the boot from being caught between the shaft and the adapter. Constant speed universal connection . The angle suppression mechanism includes a ring-shaped body that fits in a circumferential groove provided on the outer circumferential surface of the inner ring, and the shaft is bent when the shaft axis is bent at a predetermined angle with respect to the joint axis. The fixed constant velocity universal joint according to claim 1, wherein the ring-shaped body abuts to restrict bending of the predetermined angle or more. The fixed type constant velocity universal joint according to claim 2, wherein the ring-shaped body of the angle suppression mechanism is arranged on the inner ring opening side on the anti-boot side. 3. The fixed type constant velocity universal joint according to claim 2, wherein the ring-shaped body of the angle suppression mechanism is disposed on the inner ring opening side on the boot side. The fixed type constant velocity universal joint according to claim 1, wherein the fixed type constant velocity universal joint is used for a propeller shaft of an automobile.

Images