JP2005344737A - Tripod constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tripod constant velocity universal joint having less durability degradation. <P>SOLUTION: Raceway grooves 3, 8 are provided in both sides of a guide block 6 supported by a leg shaft 5 of a tripod member 4 and in the side face of an outer ring track groove 2, and a plurality of balls 9 incorporated between the raceway grooves 3, 8 are held by a cage 10. In the outer face of the guide block 6, a guide groove 13 is formed extending to the moving direction of the guide block 6. A protruded strip 14 provided on the cage 10 is slidably inserted into the guide groove 13 to allow smooth rolling of the balls at all times while preventing the inclination of the guide block 6 to the cage 10, thus lessening durability degradation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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 type of tripod type constant velocity universal joint, those described in Patent Document 1 and Patent Document 2 are conventionally known. In the tripod type constant velocity universal joint described in Patent Literature 1, three track grooves are formed on the inner periphery of the outer ring, and a track extending in the outer ring axial direction on a pair of side surfaces facing each other in the outer ring circumferential direction of each track groove. A tripod member provided inside the outer ring is provided with a groove, and three leg shafts are formed. A guide block supported relatively swingably by each leg shaft is accommodated in the track groove, A plurality of balls are assembled between the raceway grooves provided on both sides of the guide block and the outer ring side raceway groove, and each ball is held by a cage built between the inner periphery of the track groove and the guide block. Torque is transmitted between the outer ring and the tripod member.

  On the other hand, in the tripod type constant velocity universal joint described in Patent Document 2, the cage in the tripod type constant velocity universal joint described in Patent Document 1 is disposed between the outer wall inner surface of the outer ring track groove and the outer surface of the guide block. A pair of guide grooves extending in the length direction are formed at both ends of the swingable lever supported by the center portion in the length direction by the plate body portion, and inserted into each guide groove. One of the pair of pins is provided on the outer ring side and the other pin is provided on the guide block side, and the dimensions from the swing center of the lever to the outer ring side pin are the same as the dimensions from the swing center of the lever to the guide block side pin. As a dimension, when the guide block is moved, the cage is moved by a half of the moving amount of the guide block.

  In any of the above tripod type constant velocity universal joints, 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, Since it rolls by contact with the raceway groove, it has the characteristics that it has very good vibration and noise and has good NVH characteristics.

Further, in the tripod type constant velocity universal joint described in Patent Document 2, the amount of movement of the ball that rolls due to contact with the raceway groove and the amount of movement of the cage are the same, so the interference between the cage and the ball The NVH characteristics can be further improved.
Japanese Patent Publication No. 64-5164 JP 2002-235769 A

  By the way, in any of the tripod type constant velocity universal joints described in Patent Document 1 and Patent Document 2, when the outer ring and the tripod member take the operating angle and transmit torque, the leg shaft formed in the guide block is inserted. The guide block rotates and tilts about a straight line connecting the center of the load side ball and the non-load side ball due to the frictional force of the contact portion between the cylindrical hole and the leg shaft, or passes through the center of the cylindrical hole. Rotation occurs around a straight line parallel to the track groove, causing an inclination.

  On the other hand, in the tripod type constant velocity universal joint described in Patent Document 2, the guide block is centered on the axis of the leg shaft by the frictional force at the contact surface between the lever and the guide block side pin due to the swing of the lever. Rotates and tilts.

  Each of these inclinations may hinder the rolling of the ball and reduce the durability.

  The subject of this invention is preventing the inclination of a guide block and suppressing the fall of durability in the above tripod type constant velocity universal joints.

  In order to solve the above-described problems, in the present invention, three track grooves extending in the axial direction are formed on the inner periphery of the outer ring, and straight lines extending in the outer ring axial direction on the side surfaces of the respective track grooves facing each other in the outer ring circumferential direction. Guide block provided with a ring-shaped raceway groove, and provided with three leg shafts at positions corresponding to the track grooves on the tripod member built inside the outer ring, and supported by each leg shaft in a relatively swingable manner. Is provided in the track groove, a track groove facing the outer ring raceway groove is provided on both sides of the guide block, a plurality of balls are assembled between the facing track grooves, and the balls are held by a cage. The constant velocity universal joint employs a configuration in which an inclination preventing means for preventing the guide block from being inclined with respect to the cage is provided between the guide block and the cage.

  Here, the tilt prevention means forms two guide grooves extending in the moving direction of the guide block in parallel with the both side surfaces of the guide block on both sides of the outer surface of the guide block. A ridge extending to the front and rear ends in the moving direction of the cage may be provided at a corresponding position, and the ridge may be slidably inserted into the guide groove to prevent the guide block from tilting. Alternatively, a guide surface parallel to the side surface of the guide block is formed on both sides of the outer surface of the guide block, and a protrusion that is guided by the guide surface is provided on the cage to prevent the guide block from tilting. It may be a thing.

  In the tripod type constant velocity universal joint according to the present invention, the guide block manufacturing cost can be reduced by cutting the guide block into a predetermined length after the drawing process and performing carburizing, quenching and tempering.

  As described above, by providing the tilt prevention means between the guide block and the cage, when the outer ring and the tripod member take the operating angle and transmit torque, the guide block is mounted on the cage that is guided by the ball. On the other hand, since the tilting of the ball is prevented, the rolling of the ball can be prevented from being hindered, and the durability can be prevented from being lowered.

  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 circumference 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 leg shaft 5 is inserted into a cylindrical hole 7 provided in the guide block 6. Is relatively swingable.

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

  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 holding members 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 of the guide block 6. A plate portion 10b is provided, and a pocket 10c for accommodating the ball 9 is formed in each holding plate portion 10b.

  As shown in FIGS. 3 and 4, an inclination preventing means 12 is provided between the guide block 6 and the cage 10 to prevent the cage 10 from tilting in the circumferential direction of the outer ring.

  The tilt prevention means 12 includes two guide grooves 13 formed on both sides of the outer surface of the guide block 6 and ridges 14 formed on the plate body portion 10a of the retainer 10, and the guide groove 13 is a guide. Parallel to both side surfaces of the block 6, the guide block 6 extends in the moving direction. On the other hand, the protrusion 14 has a length that reaches the front and rear ends of the cage 10 in the moving direction. The protrusion 14 is slidably inserted into the guide groove 13 formed in the guide block 6.

  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 attached to the opening end of the outer ring 1.

  As shown in FIGS. 3 and 5, the stopper ring 20 has an annular plate portion 21 that abuts 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.

  In the tripod type constant velocity universal joint configured as described above, when the outer ring 1 and the tripod member 4 take torque and transmit torque, the guide block 6 moves along the track groove 2 in the direction of the outer ring axis, The ball 9 rolls by contact with the ball rolling surfaces 3a and 8a of the raceway grooves 3 and 8.

  Here, when the guide block 6 moves, the movement amount of the ball 9 is ½ of the movement amount of the guide block 6 ignoring the slip of the contact portions of the raceway grooves 3 and 8 with the ball rolling surfaces 3a and 8a. If there is a difference in the amount of movement between the ball 9 and the cage 10, the ball 9 will slip and generate vibration.

  In order to prevent the occurrence of the vibration, the movement amount regulation mechanism 30 shown in FIGS. 2 and 3 regulates the movement amount of the cage 10 to ½ of the movement amount of the guide block 6.

The movement amount regulating mechanism 30 is provided with a plate-like 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 retainer 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 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 made 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 33. The cage 10 swings 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 the same as the movement amount of the ball 9 that moves by the contact of the raceway grooves 3 and 8 with the ball rolling surfaces 3a and 8a.

  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.

  In the tripod type constant velocity universal joint having the above-described configuration, when the outer ring 1 and the tripod member 4 take torque and transmit torque, the guide block 6 moves along the track groove 2 in the outer ring axial direction. In addition, even when the outer ring 1 and the tripod member 4 move relative to each other at an operating angle, the guide block 6 moves along the track groove 2 in the direction of the outer ring axis.

  When the guide block 6 moves, the ball 9 rolls due to contact with the ball rolling surfaces 3a and 8a of the raceway grooves 3 and 8, and the ball 9 ignores the sliding with the ball rolling surfaces 3a and 8a. Move by half of the movement amount of block 6.

  On the other hand, since the cage 10 holding the ball 9 is regulated to ½ of the amount of movement of the guide block 6 by the movement amount regulating mechanism 30, the amount of movement of the ball 9 and the cage 10 is equal and slips on the ball 9. Is prevented from occurring.

  Here, when the outer ring 1 and the tripod member 4 take the operating angle and transmit torque, the guide shaft 6 is guided by the frictional force of the contact portion between the leg shaft 5 and the cylindrical shaft 7 for inserting the leg shaft formed in the guide block 6. The block 6 receives a rotational force centered on a straight line connecting the centers of the loaded ball 9 and the non-loaded ball 9, and receives a rotational force centered on a straight line parallel to the track groove 2 through the center of the cylindrical hole 7. .

  Furthermore, by the swing of the lever 31, the frictional force on the contact surface between the lever 31 and the guide block side pin 34 receives the rotational force around the axis of the leg shaft 5, When the guide block 6 is tilted with respect to the cage 10, the ball 9 is prevented from rolling.

  However, since two guide grooves 13 are formed on the outer surface of the guide block 6, and the protrusions 14 formed on the plate body portion 10a of the retainer 10 are slidably inserted into the guide grooves 13, Each of the rotational forces applied to the guide block 6 is received at the contact portion between the guide groove 13 and the protrusion 14.

  For this reason, the guide block 6 is prevented from being inclined relative to the cage 10, and the rolling of the ball 9 is not hindered, so that a decrease in durability can be suppressed.

  FIG. 6 shows another example of the tilt preventing means 12. The tilt prevention means 12 forms steps in the thickness direction of the guide block 6 on both sides of the outer surface of the guide block 6, and forms guide surfaces 15 parallel to the side surfaces of the guide block 6 on both sides of the guide block 6. The plate portion 10a of the cage 10 is provided with a protruding portion 16 formed of a bent piece, and the protruding portion 16 is slidably guided by the guide surface 15.

  In the tilt prevention means 12 as well, the guide block 6 can be prevented from tilting relative to the cage 10.

  In the manufacture of the guide block 6 shown in FIG. 2 and FIG. 6, if a manufacturing method in which the drawn product is cut to a predetermined length after the drawing process and carburized, quenched, and tempered is employed, the guide block 6 with low manufacturing cost can be obtained. it can.

  In the embodiment, between the guide block 6 of the tripod type constant velocity universal joint having the movement amount regulating mechanism 30 that regulates the movement amount of the cage 10 to ½ of the movement amount of the guide block 6 and the cage 10. Although the tilt prevention means 12 is provided, the tilt prevention means prevents the cage from tilting in the circumferential direction between the guide block and the cage of the tripod type constant velocity universal joint that does not have the movement amount regulating mechanism 30. May be provided.

A longitudinal front view showing an embodiment of a tripod constant velocity universal joint according to the present invention Partial cutaway side view of FIG. Sectional view along line III-III in FIG. Sectional view of the tilt prevention means shown in FIG. 1 is a perspective view of the stopper ring shown in FIG. Sectional drawing which shows the other example of an inclination prevention means

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 10 Cage 12 Tilt prevention means 13 Guide groove 14 Projection 15 Guide surface 16 Projection

Claims (4)

  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 side surfaces facing 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 corresponding to the track grooves, and a guide block supported relatively swingably by the leg shafts is accommodated in the track groove. In a tripod type constant velocity universal joint in which a plurality of balls are incorporated between the opposed raceway grooves and the balls are held by a cage, the guide block and the cage are connected to each other. A tripod type constant velocity universal joint provided with a tilt prevention means for preventing the guide block from tilting with respect to the cage.   The tilt preventing means forms two guide grooves extending in the moving direction of the guide block in parallel with both side surfaces of the guide block on both sides of the outer surface of the guide block, and the cage corresponds to each guide groove. The tripod type constant velocity universal joint according to claim 1, wherein a protrusion is provided at a position to reach the front and rear ends in the moving direction of the cage, and the protrusion is slidably inserted into the guide groove.   2. The structure according to claim 1, wherein the tilt preventing means has a configuration in which a guide surface parallel to the side surface of the guide block is formed on both sides of the outer surface of the guide block, and a protrusion that is guided by the guide surface is provided on the cage. The tripod type constant velocity universal joint described.   The tripod type constant velocity universal joint according to any one of claims 1 to 3, wherein the guide block is made of a heat-treated product that has been carburized, quenched, and tempered after drawing.

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