JP2006266330A - Slide type constant velocity ball joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slide type constant velocity ball joint allowing grease to flow easily without increasing size of an inside clearance of the ball joint and capable of compressing the joint sufficiently when sliding in. <P>SOLUTION: A communicating channel 10 for letting lubricant flow is formed in the axial direction in at least one section on an inside diameter face 1a between mutual guide channels 1b of an outer side joint member 1 of the slide type constant velocity ball joint or on an outside diameter face 4b between mutual pockets 4c of a retainer 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sliding type constant velocity ball joint used for automobiles, industrial machines, and the like, and more particularly to a sliding type constant velocity ball joint having improved assemblability to automobiles, industrial machines and the like.

  Constant velocity universal joints can be broadly divided into fixed types that allow only angular displacement between two axes, and sliding types that allow angular displacement and axial displacement, depending on the use conditions and applications. Selected. Representative examples of the fixed type include a Zepper type constant velocity universal joint, and examples of the sliding type include a double offset type constant velocity universal joint, a tripod type constant velocity universal joint, and the like. Among sliding types, tripod type constant velocity universal joints use rollers as torque transmission members, and others use balls as torque transmission members (see Patent Document 1 and Non-Patent Document 1).

  For example, a double offset type constant velocity ball joint is shown in FIG. FIG. 6 shows an inboard joint of a drive shaft of an automobile, and an outer joint member 31 is connected to a differential output shaft through a flange portion 31 c thereof, and an inner joint member 32 is connected to a drive shaft 35.

  The outer joint member 31 has six (or eight) linear guide grooves 31b formed in the axial direction on a cylindrical inner diameter surface 31a. The inner joint member 32 is formed with six (or eight) linear guide grooves 32b in the axial direction on a spherical outer diameter surface 32a. Six (or eight) torque transmitting balls 33 are arranged on a ball track formed by cooperation of the guide groove 31b of the outer joint member 31 and the guide groove 32b of the inner joint member 32. The torque transmission ball 33 is held by a cage 34. In order to lubricate the torque transmission ball 33, the outer joint member 31 is filled with a lubricant G such as grease or gear oil as indicated by broken line hatching. The open end of the outer joint member 31 opposite to the boot 36 is closed with an end plate 37.

In this sliding type constant velocity ball joint, the spherical center of the outer diameter surface 34b of the cage 34 and the spherical center of the inner diameter surface 34a are offset from the pocket center to the opposite side in the axial direction. It is called an offset type. When this type of joint transmits rotational torque while taking an operating angle, the cage 34 rotates to the position of the torque transmission ball 33 that moves on the ball track in accordance with the inclination of the inner joint member 32, and torque The transmission ball 33 is held within the angle bisector of the operating angle. Further, when the outer joint member 31 and the inner joint member 32 move relative to each other in the axial direction, slip occurs between the outer diameter surface of the cage 34 and the inner diameter surface of the outer joint member 31, and smooth axial movement (plan Zing) is possible.
JP-A-10-73129 (sliding type constant velocity ball joint) "Universal Joint and Driveshaft DESIGN MANUAL" (double offset joint on pages 167-170)

  When a drive shaft or propeller shaft having a sliding type constant velocity ball joint at one end is assembled to an automobile, the sliding type constant velocity ball joint may be compressed (slid in) and attached. However, the sliding type constant velocity ball joint has a situation in which the gap between the internal parts is small and the grease as the lubricant G does not flow easily. Specifically, as shown in FIGS. 8 and 9, since the gap between the inner diameter surface 31a of the outer joint member 31 and the outer diameter surface 34b of the cage 34 is small, the inner joint member as shown in FIGS. The grease G at the back of 32 or the retainer 34 hardly flows to the opposite side (left side in FIG. 9) when the inner joint member 32 slides in. For this reason, when the sliding type constant velocity ball joint is assembled by slide-in, the resistance of the slide-in is large, and it may take time to assemble. In particular, when the sliding amount of the joint is increased, the amount of grease to be enclosed inside increases inevitably because the outer joint member 31 becomes longer, and a large amount of grease stays on the bottom side of the outer joint member 31 when assembly is started. Since the grease G must be slid in while being compressed, it takes a long time to finish the slide-in, or the slide-in becomes insufficient.

  If the internal clearance of the sliding type constant velocity ball joint is increased, the grease G will flow more easily and the resistance of the slide-in will be reduced. However, the vibration and noise of the joint will be reduced, and the life will be shortened. With major disadvantages. Accordingly, there is a demand for measures to reduce the slide-in resistance without increasing the internal clearance of the joint.

  An object of the present invention is to facilitate the flow of grease without enlarging the internal gap of the sliding type constant velocity ball joint, and to enable the joint to be sufficiently compressed during sliding-in.

  In order to solve the above-mentioned problems, an invention according to claim 1 is directed to an outer joint member in which a plurality of linear guide grooves are formed in an axial direction on a cylindrical inner surface and filled with a lubricant, and the outer joint member The inner joint member, which is inserted in a swingable manner and has a plurality of linear guide grooves formed on the spherical outer diameter surface in the axial direction, and the guide groove of the outer joint member and the guide groove of the inner joint member cooperate. Torque transmission balls respectively disposed on a plurality of ball tracks formed by operation, a pocket for holding the torque transmission balls, a spherical outer diameter surface guided in contact with an inner diameter surface of the outer joint member, and an inner joint member A spherical inner surface that is in contact with and guided by the outer diameter surface, and the spherical center of the outer diameter surface and the spherical center of the inner diameter surface are offset to the opposite side in the axial direction with respect to the pocket center, respectively. Sliding type constant velocity ball join with cage In, the inner surface between the guide grooves cross the outer joint member, characterized in that formed at least one location, the communicating groove for lubricant flow in the axial direction.

  The communication groove may be formed on the outer diameter surface of the cage, instead of being formed on the inner diameter surface of the outer joint member as described above, or on the inner diameter surface of the outer joint member (claim 2). . Further, the communication groove may be formed at a plurality of locations in the circumferential direction (claim 3).

  By forming the communication groove in this way, the lubricant accumulated on the bottom side of the outer joint member at the time of slide-in easily flows to the opposite side of the inner joint member through the communication groove.

  In the present invention, since the communication groove for lubricant flow is formed on the inner diameter surface of the outer joint member or the outer diameter surface of the cage, a drive shaft or propeller shaft having a sliding type constant velocity ball joint at one end can be slid in. When assembled in an automobile, the lubricant accumulated on the bottom side of the outer joint member tends to flow to the opposite side of the inner joint member through the communication groove, and it becomes easy to compress the joint sufficiently and install it. improves.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 show a double offset type constant velocity ball joint as a sliding type constant velocity ball joint according to an embodiment of the present invention. This embodiment shows a case where the present invention is applied to an inboard joint of a drive shaft for a rear suspension of an automobile, and an outer joint member 1 is connected to a differential output shaft via an integral flange portion 1c, and an inner joint member 2 is shown. Is coupled to the drive shaft 5. The drive shaft 5 protruding from the outer joint member 1 is covered with a boot 6 to prevent entry of dust and the like into the outer joint member 1 and leakage of the internal lubricant. Reference numerals 8 and 9 are boot mounting bands, and 11 is a circlip for retaining the torque transmitting ball 3.

  The outer joint member 1 has six (or eight) linear guide grooves 1b formed in the axial direction on a cylindrical inner diameter surface. The inner joint member 2 has six (or eight) linear guide grooves 2b formed in the axial direction on a spherical outer diameter surface. Six (or eight) torque transmitting balls 3 are arranged on a ball track formed by cooperation of the guide groove 1b of the outer joint member 1 and the guide groove 2b of the inner joint member 2. The torque transmission ball 3 is held by a cage 4. In order to lubricate the torque transmission ball 3, the outer joint member 1 is filled with a lubricant G such as grease as indicated by broken line hatching. The open end of the outer joint member 1 opposite to the boot 6 is closed with an end plate 7.

  FIG. 1 shows a double offset type constant velocity universal joint as a sliding type constant velocity universal joint according to this embodiment. This constant velocity universal joint includes an outer joint member 1 in which eight linear guide grooves 1b are formed in an axial direction on a cylindrical inner surface 1a, and eight linear guides on a spherical outer surface 2a. An inner joint member 2 in which a groove is formed in the axial direction and a serration (or spline) 2c for connecting the shaft portion to the inner diameter surface is formed, a guide groove 1b of the outer joint member 1, and a guide groove 2b of the inner joint member 2 Are composed of eight torque transmission balls 3 arranged on a ball track formed in cooperation with each other, and a holder 4 that holds the torque transmission balls 3.

  As shown in an enlarged view in FIG. 2, the cage 4 is contact-guided to a spherical outer diameter surface 4 b that is contact-guided to the inner-diameter surface 1 a of the outer joint member 1 and an outer-diameter surface 2 a of the inner joint member 2. A ring-shaped body having a spherical inner surface 4a and eight pockets 4c for accommodating the torque transmitting balls 3. The spherical center B of the outer diameter surface 4b and the spherical center A of the inner diameter surface 4a are offset to the opposite side in the axial direction by an equal distance from the center O of the pocket 4c (offset amount f = line segment OA). = Line segment OB). The radius of curvature Rc of the inner surface 4a of the cage 4 and the radius of curvature Ri of the outer surface 2a of the inner joint member 2 are substantially the same (apparently equal), and the axial dimension Lc of the pocket 4c of the cage 4 is the torque transmission ball. Slightly smaller than 3 diameter DBALL.

  When the outer joint member 1 and the inner joint member 2 are angularly displaced by an angle θ, the torque transmitting ball 3 guided by the cage 4 always has a bisection plane (θ / 2) of the angle θ at any operating angle θ. The constant velocity of the joint is ensured.

  As shown in FIGS. 1 and 3 to 5, communication grooves 10 are formed between all the guide grooves 1 b on the inner diameter surface of the outer joint member 1. These communication grooves 10 have a substantially V-shaped cross section in which the bottom portion forms an R surface and the left and right side walls open at an obtuse angle. The upper ends of the left and right side walls of the communication groove 10 follow the inner diameter surface 1a of the outer joint member 1 with a smooth curve.

  The width and depth of the communication groove 10 are appropriately set so that a required cross-sectional area of the communication groove 10 can be obtained. If the communication groove 10 is excessively wide and shallow, the region of the inner diameter surface 1a that comes into contact with the cage 4 becomes insufficient, and the guide action of the cage 4 becomes unstable. It is preferable that the width does not exceed half of the width of the surface 1a. The cross-sectional shape of the communication groove 10 may be an arbitrary shape such as a concave R shape other than the V shape. The communication groove 10 can be formed simultaneously with the forging when the outer joint member 1 is forged, but may be post-processed by machining or the like.

  If the required cross-sectional area is obtained, it may be sufficient to form the communication groove 10 at least at one place. However, if the communication groove 10 is formed between all the guide grooves 1b, the cross-sectional area of each communication groove 10 is sufficient. The strength of the outer joint member 1 due to the formation of the communication groove 10 can be minimized.

  The communication groove 10 is not formed on the inner diameter surface 1a of the outer joint member 1 as described above, or is formed on the inner diameter surface 1a of the outer joint member 1, and the outside of the cage 34 between the pockets 34c. One or a plurality of locations may be formed on the radial surface 4b. When the communication groove 10 is formed in both the outer joint member 1 and the cage 4, the two communication grooves 10 can be formed by being aligned with each other in the circumferential direction, or can be formed independently by shifting the positions. .

  The sliding type constant velocity ball joint of the present invention is configured as described above. When the drive shaft 5 with a joint shown in FIG. 1 is assembled to an automobile, the drive shaft 5 is compressed in the direction of the arrow and slide-in is performed. Part of the lubricant G that has accumulated on the bottom side of the joint member 1 flows to the opposite side of the inner joint member 2 through the communication groove 10 corresponding to the decrease in the internal space. Accordingly, the slide-in resistance is reduced and the drive shaft 5 can be sufficiently pushed.

  The present invention is not limited to a drive shaft that uses a sliding constant velocity ball joint, but can be similarly applied to a propeller shaft that uses a sliding constant velocity ball joint to improve the ease of assembly in an automobile. As a matter of course, the assemblability can be improved in the same manner when applied to a general industrial machine using a sliding constant velocity ball joint.

The longitudinal cross-sectional view of the sliding type constant velocity ball joint of this invention. FIG. 3 is an enlarged sectional view around the torque transmission ball of the ball joint. The lower half cross-sectional view of the ball joint. FIG. 4 is an enlarged cross-sectional view of a portion IV in FIG. 3. The V section expanded sectional view of FIG. The longitudinal cross-sectional view of the conventional sliding type constant velocity ball joint. The lower half cross-sectional view of the ball joint. The VIII section expanded sectional view of FIG. IX part expanded sectional view of FIG.

Explanation of symbols

1 outer joint member 1a inner diameter surface 1b guide groove 1c flange 2 inner joint member 2a outer diameter surface 2b guide groove 2c serration 3 torque transmitting ball 4 cage 4a inner diameter surface 4b outer diameter surface 5 drive shaft 6 boot 7 end plate 8, 9 Boot mounting band 10 Communication groove 11 Circlip 31 Outer joint member 31a Inner surface 31b Guide groove 32 Inner joint member 32a Outer surface 32b Guide groove 33 Torque transmission ball 34 Cage 36 Boot 37 End plate G Lubricant

Claims (3)

An outer joint member in which a plurality of linear guide grooves are formed in an axial direction on a cylindrical inner diameter surface and filled with a lubricant;
An inner joint member inserted in the outer joint member so as to be swingable, and having a plurality of linear guide grooves formed in the axial direction on a spherical outer diameter surface;
A torque transmission ball disposed on each of a plurality of ball tracks formed by cooperation of the guide groove of the outer joint member and the guide groove of the inner joint member;
A pocket for holding a torque transmission ball, a spherical outer diameter surface that is contact-guided to the inner diameter surface of the outer joint member, and a spherical inner diameter surface that is contact-guided to the outer diameter surface of the inner joint member; In the sliding type constant velocity ball joint provided with a cage in which the spherical center of the outer diameter surface and the spherical center of the inner diameter surface are offset to the opposite sides in the axial direction with respect to the pocket center,
A sliding type constant velocity ball joint, wherein at least one communicating groove for lubricant flow is formed in an axial direction on an inner diameter surface between guide grooves of the outer joint member. An outer joint member in which a plurality of linear guide grooves are formed in an axial direction on a cylindrical inner diameter surface and filled with a lubricant;
An inner joint member inserted in the outer joint member so as to be swingable, and having a plurality of linear guide grooves formed in the axial direction on a spherical outer diameter surface;
A torque transmission ball disposed on each of a plurality of ball tracks formed by cooperation of the guide groove of the outer joint member and the guide groove of the inner joint member;
A pocket for holding a torque transmitting ball, a spherical outer diameter surface that is contact-guided to the inner diameter surface of the outer joint member, and a spherical inner diameter surface that is contact-guided to the outer diameter surface of the inner joint member; In the sliding type constant velocity ball joint provided with a cage in which the spherical center of the outer diameter surface and the spherical center of the inner diameter surface are offset in the axial direction opposite to the pocket center,
A sliding type constant velocity ball joint characterized in that at least one communicating groove for lubricant flow is formed in an axial direction on an outer diameter surface between pockets of the cage.   The sliding type constant velocity ball joint according to claim 1 or 2, wherein the communication groove is formed at a plurality of locations in the circumferential direction.

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