JP2006322549A - Tripod constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tripod constant velocity universal joint using a guide block for preventing a boot from being broken. <P>SOLUTION: In the tripod constant velocity universal joint, balls 9 are incorporated between each of raceway grooves 3 on both sides of a track groove 2 formed in the inner periphery of an outer ring 1 and each of raceway grooves 8 on both sides of the oscillatable guide block 6 supported by a leg shaft 5 of a tripod member 4. A large diameter cylinder portion 41 of the bellows boot 40 is fitted to the outer periphery of the opening end of the outer ring 1 and a small diameter cylinder portion 43 of the boot 40 is fitted to a torque transmission shaft 44 of the tripod member 4 to prevent the leakage of grease from the outer ring 1. The large diameter cylinder portion 41 of the boot 40 has a length such that an inward bent portion 46 ranging from the large diameter cylinder portion 41 is arranged outside of a slide region of the guide block 6. The large diameter cylinder portion 41 is kept in a straight cylinder shape by a supporting ring 47 fitted to the inside of the large diameter cylinder portion 41 to prevent the guide block 6 from interfering with the inward bent portion 46 of the boot 40 and prevent the boot 40 from being broken by the guide block 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tripod-type constant velocity universal joint that transmits torque between an outer ring having three track grooves on the inner periphery and a tripod member that is incorporated inside and moves in the axial direction.

  As this kind of tripod type constant velocity universal joint, what was described in patent document 1 is conventionally known. In this tripod type constant velocity universal joint, three track grooves are formed on the inner periphery of the outer ring, and a track groove extending in the outer ring axial direction is provided on a pair of side surfaces facing each other in the outer ring circumferential direction of each track groove. The tripod member incorporated inside has three leg shafts, and guide blocks supported by the respective leg shafts so as to be relatively swingable are accommodated in the track grooves, and are provided on both sides of the guide blocks. A ball is incorporated between the raceway groove and the outer raceway raceway groove, and torque is transmitted between the outer race and the tripod member via the ball.

  In the tripod type constant velocity universal joint, since the ball is assembled between the raceway groove of the outer ring and the raceway groove of the guide block, when the outer ring and the tripod member take torque and transmit torque, the guide block is always It reciprocates in the direction of the outer ring shaft while maintaining a constant posture. At this time, since the ball rolls by contact with the raceway groove, the occurrence of vibration and noise is extremely small, and it has a good NVH characteristic.

  In the tripod type constant velocity universal joint as described above, as shown in FIG. 12, a large-diameter cylindrical portion 62 at one end of an expandable bellows-like boot 61 is fitted to the outer periphery of the open end portion of the outer ring 60 to boot. The small diameter cylindrical portion 64 at the other end of the boot 61 is fitted to the outer periphery of the torque transmission shaft 66 connected to the tripod member 65 and is fixed by tightening the boot band 67. Accordingly, leakage of grease filled in the outer ring 60 is prevented, and foreign matters are prevented from entering the outer ring 60.

  In FIG. 12, reference numeral 68 denotes a leg shaft provided on the tripod member 65, and 69 denotes a guide block supported on the leg shaft 68 in a swingable manner. Reference numeral 70 denotes a cage for holding a ball (not shown).

  In the tripod type constant velocity joint to which the boot is attached, if the tripod member 65 comes out of the opening end of the outer ring 60 at the stage before assembly to the actual vehicle, it is necessary to reassemble the tripod member 65 in a groping state. It takes a lot of work.

In order to eliminate such inconvenience, a tripod constant velocity universal joint has been proposed in which a stopper ring 71 is attached to the open end of the outer ring 60 and the tripod member 65 is prevented from coming off by the stopper ring 71.
JP 2002-235769 A

  By the way, in the conventional tripod type constant velocity universal joint shown in FIG. 12, when the tripod member 65 slides to the opening end side of the outer ring 60, the outer ring 60 and the tripod member 65 take the operating angle and transmit torque. The guide block 69 and the retainer 70 slide to the position facing the outer side from the open end of the outer ring 60 as shown by a chain line (A) in FIG. On the other hand, a part of the inwardly bent portion 72 following the large-diameter cylindrical portion 62 of the boot 61 is deformed inward, and the end portion of the guide block 69 or the retainer 70 interferes with the inwardly bent portion 72. . Since this interference is repeated, there is a possibility that the inwardly bent portion 72 may be broken, and there remains a point to be improved in order to suppress a decrease in durability of the boot 61.

  An object of the present invention is to provide a tripod type constant velocity universal joint capable of preventing a boot from being damaged by interference of a guide block and a cage.

  In order to solve the above problems, in the first invention, three track grooves extending in the axial direction are formed on the inner periphery of the outer ring, and the side surfaces of each track groove facing each other in the outer ring circumferential direction are arranged in the outer ring axial direction. A linear track groove extending is provided, and the tripod member built inside the outer ring is provided with three leg shafts at positions opposed to the respective track grooves, and is supported by each leg shaft so as to be relatively swingable. The guide block is accommodated in the track groove, and a track groove facing the track groove is provided on both sides of the guide block, and a plurality of balls are assembled between the opposed track grooves, and the outer periphery of the opening end of the outer ring Fit the large-diameter cylindrical part at one end of the bellows-type boot that can be expanded and contracted, and fit the small-diameter cylindrical part at the other end of the boot to the outer periphery of the torque transmission shaft connected to the tripod member to cover the opening of the outer ring The tripod type constant velocity universal joint Extending the large-diameter cylindrical portion of the boot to a position where the inwardly bent portion following the large-diameter cylindrical portion is disposed axially outward from the slide region of the guide block. A configuration is adopted in which the end portion of the hard support ring that is fitted to the inner periphery and prevents the large-diameter cylindrical portion from being bent is press-fitted into the outer periphery of the opening end portion of the outer ring.

  Here, if the support ring is simply fitted inside the large-diameter cylindrical portion, the support ring and the large-diameter cylindrical portion move relatively relative to each other due to expansion / contraction or bending of the boot, so Since the inner periphery of the large-diameter cylindrical portion may be damaged by the contact, it is preferable to fix the support ring to the large-diameter cylindrical portion.

  For fixing the support ring, a band may be wound around the outer periphery of the large-diameter cylindrical portion and tightened, or the support ring may be bonded to the inner diameter surface of the large-diameter cylindrical portion. Band tightening and adhesion may be used in combination.

  When the support ring is fixed by tightening the band, if an engagement groove extending in the circumferential direction is provided on the outer periphery of the band tightening portion of the support ring, the large-diameter cylindrical portion is deformed inward by tightening the band. Since the engaging ring is engaged, the support ring can be more firmly fixed.

  Here, if a circular arc surface is provided on the outer periphery of the tip of the support ring, the large-diameter cylindrical portion can be more effectively prevented from being damaged.

  In order to solve the above problems, in the second invention, three track grooves extending in the axial direction are formed on the inner periphery of the outer ring, and the track grooves extend in the outer ring axial direction on the side surfaces facing each other in the outer ring circumferential direction. A straight track groove is provided, and the tripod member built inside the outer ring is provided with three leg shafts at positions facing the track grooves, and is supported by each leg shaft so as to be relatively swingable. A guide block is accommodated in the track groove, and a track groove facing the track groove is provided on both sides of the guide block, and a plurality of balls are assembled between the opposed track grooves, on the outer periphery of the opening end of the outer ring. Fit the large-diameter cylindrical part at one end of the expandable bellows-like boot and fit the small-diameter cylindrical part at the other end of the boot to the outer periphery of the torque transmission shaft connected to the tripod member to cover the opening of the outer ring Tripod type constant velocity universal joint The large-diameter cylindrical portion of the boot is extended to a position where an inwardly bent portion following the large-diameter cylindrical portion is disposed axially outward from the slide region of the guide block, and the large-diameter cylindrical portion is extended to the outer ring. And a tripod member adopting a thick structure capable of maintaining a straight cylinder shape in a torque transmission state in which an operating angle is taken.

  In the tripod type constant velocity universal joint according to the first aspect of the present invention, the inward bent portion that follows the large-diameter cylindrical portion fitted to the outer periphery of the outer ring opening end of the boot is the guide block. Since the support ring is provided inside the large-diameter cylindrical portion to prevent bending of the large-diameter cylindrical portion, the outer ring and tripod member are The guide block does not interfere with the inwardly bent portion of the boot in the torque transmission state that takes the operating angle, and the boot can be prevented from being damaged by the guide block.

  Further, in the tripod member according to the second invention, as in the first invention, the inward bent portion of the large-diameter cylindrical portion of the boot following the large-diameter cylindrical portion is more axial than the slide region of the guide block. Since it extends to the position where it is arranged outward, its large-diameter cylindrical part is thickened and has a waist, so that it can maintain a straight cylindrical shape even when the outer ring and tripod member take operating angles and transmit torque The guide block does not interfere with the bent portion of the boot and can prevent the boot from being damaged.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, three track grooves 2 extending in the axial direction are formed on the inner periphery of the outer ring 1 at intervals of 120 °, and a pair of track grooves 2 facing each other in the outer ring circumferential direction. A linear track groove 3 extending in the axial direction is provided on the side surface of the shaft.

  A tripod member 4 incorporated inside the outer ring 1 is provided with three leg shafts 5 at positions corresponding to the track grooves 2, and a guide block 6 is supported by each leg shaft 5. When supporting the guide block 6, here, a spherical surface 5 a is formed on the leg shaft 5, and the spherical surface 5 a is inserted into a cylindrical hole 7 provided in the guide block 6, and the leg shaft 5, the guide block 6, Is relatively swingable.

  A pair of linear track grooves 8 facing the track grooves 3 on both sides of the outer ring track groove 2 are formed on both side surfaces of the guide block 6, and a plurality of balls 9 are assembled between the facing track grooves 3, 8. ing.

  On both sides of the guide block 6, a plurality of balls 9 arranged in the axial direction of the outer ring 1 are held by a cage 10. The cage 10 is a pair of plates disposed between the side surface of the guide block 6 and the side surface of the track groove 2 on both sides of the plate body portion 10 a disposed between the outer wall inner surface 11 of the track groove 2 and the outer surface 12 of the guide block 6. A holding plate portion 10b is provided, and a pocket 10c for accommodating the ball 9 is formed in each holding plate portion 10b.

  As described above, by incorporating a plurality of balls 9 between the raceway grooves 3 formed on both side surfaces of the track groove 2 and the raceway grooves 8 provided on both side surfaces of the guide block 6, the posture of the guide block 6 is always maintained. Can be held constant.

  As shown in FIGS. 2 and 3, a stopper ring 20 that prevents the retainer 10 from coming out of the opening end of the outer ring 1 is provided at the opening end of the outer ring 1. The stopper ring 20 has an annular plate portion 21 that is brought into contact with the open end of the outer ring 1. A cylindrical portion 22 is provided on the outer periphery of the annular plate portion 21, and the cylindrical portion 22 is press-fitted into the outer periphery of the opening end portion of the outer ring 1. The opening end of the cylindrical portion 22 is crimped inward, and an annular bent portion 22a formed by the crimping engages with an engagement groove 23 provided on the outer periphery of the opening end of the outer ring 1, The stopper ring 20 is prevented from moving in the axial direction by the engagement.

  A cutout 24 is formed in the annular plate portion 21 at a position facing the opening end of the track groove 2 of the outer ring 1, and projecting pieces 25 provided on both sides of each cutout 24 are formed on the side surface of the track groove 2. It is inserted into the raceway groove 3.

  When the tripod member 4 moves toward the opening end of the outer ring 1 by attaching the stopper ring 20 having the above structure to the opening end of the outer ring 1, the ball 9 hits the protruding piece 25 provided on the stopper ring 20. The retainer 10 is prevented from coming off by the contact.

  As shown in FIGS. 2 and 3, a movement amount regulating mechanism that regulates the movement amount of the cage 10 to ½ of the movement amount of the guide block 6 between the inner surface of the outer wall of the track groove 2 and the outer surface of the guide block 6. 30 is provided.

The movement amount regulating mechanism 30 is provided with a flat lever 31 on the outer surface side of the plate body portion 10a in the cage 10, and a head such as a rivet penetrating both the central portion in the length direction of the lever 31 and the plate body portion 10a. By clamping the end of the fulcrum pin 32 with a portion, the lever 31 is supported in a swingable manner, the lever 31 is connected to the cage 10, and the pin 33 provided on the pin support piece 26 of the stopper ring 20 and The pins 34 attached to the guide block 6 are inserted into the guide grooves 35 formed at both ends of the lever 31, and the distances l ₁ and l ₂ from the pins 33 and 34 to the rotation center of the lever 31 are equal. . At this time, a notch portion 36 into which the pin 34 on the guide block 6 side is inserted is formed in the plate body portion 10a of the cage 10 so that the guide block 6 and the cage 10 can move relative to each other. .

  In the movement amount regulating mechanism 30 configured as described above, when the guide block 6 moves, the pin 34 provided on the guide block 6 presses one side edge of the guide groove 35, so that the lever 31 is centered on the pin 34. It swings and the cage 10 also moves in the same direction as the guide block 6. At this time, since the ratio of the distance from the pin 33 provided on the stopper ring 20 to the rotation center of the lever 31 and the distance from the pin 33 to the guide block side pin 34 is 1: 2, the cage 10 is The movement amount is ½ of the movement amount of the guide block 6 and can be made the same as the movement amount of the ball 9 that moves by contact with the raceway grooves 3 and 8. For this reason, the ball 9 does not interfere with the pocket 10c of the cage 10, and the ball 9 can be prevented from slipping.

  In FIG. 2, the pin 33 is provided on the pin support piece 26 of the stopper ring 20, but the pin 33 may be fixed to the outer ring 1.

  As shown in FIG. 1, a boot 40 is provided on the opening end side of the outer ring 1. The boot 40 has a bellows shape, and is formed of an elastic body such as rubber and is extendable in the axial direction.

  A large-diameter cylindrical portion 41 provided at one end of the boot 40 is fitted to the outer periphery of the open end portion of the outer ring 1 and is fixed to the outer ring 1 by tightening a boot band 42 wound around the outer periphery.

  The small diameter cylindrical portion 43 provided at the other end of the boot 40 is fitted to the outer periphery of the torque transmission shaft 44 connected to the tripod member 4, and the torque transmission shaft is tightened by the boot band 45 wound around the outer periphery. 44 is fixed.

  The length L from the opening end of the outer ring 1 of the large-diameter cylindrical portion 41 to the inwardly bent portion 46 that follows the large-diameter cylindrical portion 41 is such that the inwardly bent portion 46 is disposed outside the slide region of the guide block 6. It is supposed to be the length.

  Here, the guide block 6 can be moved to the opening side of the outer ring 1 to a position where the ball 9 abuts against the protruding piece 25 of the stopper ring 20, and the chain line (A) in FIG. A length L of the large-diameter cylindrical portion 41 is set so that one limit position of the slide region of the guide block 6 when abutting is shown, and the bent portion 46 is disposed outside the limit position. .

  A support ring 47 is fitted inside the large diameter cylindrical portion 41. The support ring 47 is formed of a hard material such as metal or synthetic resin, and one end portion on the outer ring 1 side is press-fitted into the outer periphery of the cylindrical portion 22 of the stopper ring 20.

  In the case of a tripod type constant velocity universal joint without the stopper ring 20, one end portion of the support ring 47 is press-fitted into the outer periphery of the opening end portion of the outer ring 1.

  As described above, the large-diameter cylindrical portion 41 of the boot 40 has a length in which the inwardly bent portion 46 following the large-diameter cylindrical portion 41 is disposed outside the slide region of the guide block 6, and the large-diameter cylindrical portion. When the outer ring 1 and the tripod member 4 transmit the torque by taking the operating angle by press-fitting the hard support ring 47 provided inside 41 to the outer periphery of the opening end of the outer ring 1, the guide block 6 It will reciprocate without interfering with the inwardly bent portion 46 of the boot 40, and the boot 40 can be prevented from being damaged by the guide block 6.

  In FIG. 1, the support ring 47 is fitted inside the large-diameter cylindrical portion 41, but the support ring 47 may be fixed to the large-diameter cylindrical portion 41.

  5 to 7 show examples of fixing the support ring 47. In FIG. 5, a band 48 is wound around the outer periphery of the large-diameter cylindrical portion 41, and the support ring 47 is fixed to the large-diameter cylindrical portion 41 by tightening the band 48.

  In FIG. 6, the support ring 47 is fixed to the large-diameter cylindrical portion 41 by bonding. Reference numeral 49 denotes an adhesive layer.

  In FIG. 7, the support ring 47 is fixed to the large-diameter cylindrical portion 41 by tightening and bonding a band 48 wound around the outer periphery of the large-diameter cylindrical portion 41.

  As described above, by fixing the support ring 47 to the large-diameter cylindrical portion 41, the fitting portion between the large-diameter cylindrical portion 41 and the support ring 47 is relatively displaced when the boot 40 is expanded or folded. Since it can prevent, it can prevent that the large diameter cylinder part 41 is damaged by the contact with the support ring 47. FIG.

  Here, in fixing the support ring 47 by tightening the band 48, as shown in FIGS. 8 and 10, if an engagement groove 50 extending in the circumferential direction is provided in the band tightening portion on the outer periphery of the support ring 47, the band Since the large-diameter cylindrical portion 41 is elastically deformed inward and engages with the engaging groove 50 when the 48 is tightened, the support ring 47 can be more firmly fixed.

  Further, as shown in FIGS. 9 and 10, if the circular arc surface 51 is formed on the outer periphery of the front end portion of the support ring 47, the large diameter cylindrical portion 41 smoothly contacts the front end of the support ring 47. Damage to the large-diameter cylindrical portion 41 can be prevented more effectively.

  FIG. 11 shows another embodiment of the tripod type constant velocity universal joint according to the present invention. In this embodiment, the length L of the large-diameter cylindrical portion 41 formed at one end of the boot 40 is the same as that shown in FIG. 1, the large-diameter cylindrical portion 41 is thick, and the outer ring 1 and the tripod member. No. 4 has a waist so that the straight cylinder shape can be maintained in a torque transmission state in which the operating angle takes the maximum.

  Since the other structure is the same as the tripod type constant velocity universal joint shown in FIG. 1, the same code | symbol is attached | subjected to the same components and description is abbreviate | omitted.

  Also in the tripod type constant velocity universal joint shown in FIG. 11, it is possible to prevent the guide block 6 from interfering with the inwardly bent portion 46 following the large-diameter cylindrical portion 41. It can be prevented from being damaged.

Vertical front view showing an embodiment of a tripod constant velocity universal joint according to the present invention Sectional view along the line II-II in FIG. Sectional view along line III-III in FIG. Sectional view showing the tripod member retaining state Sectional drawing which shows an example of fixation of the support ring of FIG. Sectional drawing which shows the other example of fixation of a support ring Sectional drawing which shows the further another example of fixation of a support ring Sectional view showing another example of support ring Sectional view showing still another example of support ring Sectional view showing still another example of support ring Longitudinal front view showing another embodiment of the tripod type constant velocity universal joint according to the present invention Longitudinal front view showing a conventional tripod constant velocity joint

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Track groove 3 Track groove 4 Tripod member 5 Leg shaft 6 Guide block 8 Track groove 9 Ball 40 Boot 41 Large diameter cylindrical portion 43 Small diameter cylindrical portion 44 Torque transmission shaft 46 Inward bending portion 47 Support ring 48 Band 49 Adhesion Agent layer 50 Engaging groove 51 Arc surface

Claims (6)

  Three track grooves extending in the axial direction are formed on the inner periphery of the outer ring, and linear track grooves extending in the outer ring axial direction are provided on the opposite sides of each track groove in the outer ring circumferential direction, and are incorporated inside the outer ring. The tripod member is provided with three leg shafts at positions facing the respective track grooves, and a guide block supported relatively swingably by the respective leg shafts is accommodated in the track groove. A track groove facing the track groove is provided on both sides, a plurality of balls are assembled between the facing track grooves, and a large-diameter cylindrical portion at one end of an expandable bellows-like boot is fitted on the outer periphery of the opening end portion of the outer ring. In the tripod type constant velocity universal joint in which the small diameter cylindrical portion at the other end of the boot is fitted to the outer periphery of the torque transmission shaft connected to the tripod member so as to cover the opening of the outer ring, the large diameter cylinder of the boot The part that follows the large-diameter cylindrical part The hard part that extends to the position where the bent part of the mushroom is arranged axially outward from the sliding area of the guide block is fitted to the inner periphery of the large diameter cylindrical part to prevent the large diameter cylindrical part from bending. A tripod constant velocity universal joint, wherein the end of the support ring is press-fitted into the outer periphery of the opening end of the outer ring.   2. The tripod constant velocity universal joint according to claim 1, wherein the support ring is fixed to the large-diameter cylindrical portion by tightening a band wound around an outer periphery of the large-diameter cylindrical portion.   The tripod type constant velocity universal joint according to claim 2, wherein an engagement groove extending in a circumferential direction is formed in a band tightening portion of the support ring.   The tripod constant velocity universal joint according to any one of claims 1 to 3, wherein the support ring is fixed to the inner diameter surface of the large-diameter cylindrical portion by bonding.   5. The tripod type constant velocity universal joint according to claim 1, wherein a circular arc surface is formed on an outer periphery of a front end portion of the support ring.   Three track grooves extending in the axial direction are formed on the inner periphery of the outer ring, and linear track grooves extending in the outer ring axial direction are provided on the opposite sides of each track groove in the outer ring circumferential direction, and are incorporated inside the outer ring. The tripod member is provided with three leg shafts at positions facing the respective track grooves, and a guide block supported relatively swingably by the respective leg shafts is accommodated in the track groove. A track groove facing the track groove is provided on both sides, a plurality of balls are assembled between the facing track grooves, and a large-diameter cylindrical portion at one end of an expandable bellows-like boot is fitted on the outer periphery of the opening end portion of the outer ring. In the tripod type constant velocity universal joint in which the small diameter cylindrical portion at the other end of the boot is fitted to the outer periphery of the torque transmission shaft connected to the tripod member so as to cover the opening of the outer ring, the large diameter cylinder of the boot The part that follows the large-diameter cylindrical part The bent part of the mushroom extends to a position where it is arranged axially outward from the sliding area of the guide block, and the large-diameter cylindrical part can maintain a straight cylindrical shape in a torque transmission state where the outer ring and tripod member take an operating angle. Tripod type constant velocity universal joint characterized by having a thick wall.

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