JP2009156402A - Sliding constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constant velocity universal joint that allows axial displacement and in which there is no rattling in the rotating direction. <P>SOLUTION: This sliding constant velocity universal joint is equipped with an outer ring 10 having a ball groove 16 formed therein extending axially on a cylindrical inner peripheral face 14, an inner ring 20 having a ball groove 26 formed therein extending axially on a spherical outer peripheral face 24, a ball 30 interposed between the pair of the ball groove 16 of the outer ring 10 and the ball groove 26 of the inner ring 20, and a cage 32 interposed between the inner peripheral face 14 of the outer ring 10 and the outer peripheral face 24 of the inner ring 20 for holding the ball 30 at a prescribed position. A separate plate 40 is disposed in the ball groove 26 of the inner ring 20, and an elastic member 46 is interposed between the inner ring 20 and the plate 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sliding constant velocity universal joint used in a steering system and a power transmission system of an automobile.

  As shown in FIG. 5, the steering device converts the rotational motion of the steering wheel 50 into the reciprocating motion of the tie rod portion by transmitting the rotational motion of the steering wheel 50 to the steering gear via one or a plurality of steering shafts 52. When the steering shaft 52 cannot be arranged in a straight line in consideration of the vehicle-mounted space or the like, the one or more universal joints 54 are used to accurately rotate the steering gear with the steering shaft 52 bent as shown in the figure. I am trying to communicate. A constant velocity universal joint can be used for the universal joint 54.

  The constant velocity universal joint connects the drive shaft and the driven shaft so that torque can be transmitted at a constant speed even when the two shafts are angled. The fixed type allows only angular displacement, and the angular displacement. In addition to the above, it can be roughly classified into a sliding type that allows axial displacement.

  As an example used in a steering device, Patent Document 1 describes a fixed type constant velocity universal joint with reduced rotational direction play. This constant velocity universal joint is a so-called ball type using a ball as a torque transmission element. As shown in FIG. 6, an outer ring 110 as an outer joint member, an inner ring 120 as an inner joint member, and a ball as a torque transmission element. 130 and a cage 132 for holding the ball 130 are main components.

  The outer ring 110 includes a mouse portion 112 and a stem portion 118, and is connected to a drive shaft or a driven shaft so as to be able to transmit torque at a spline (or serration, the same applies hereinafter) shaft portion of the stem portion 118 that does not appear in the drawing. It has become. The mouse portion 112 has a spherical inner peripheral surface 114, and ball grooves 116 extending in the axial direction are formed at equal intervals in the circumferential direction of the spherical inner peripheral surface.

  The inner ring 120 is connected to a shaft (driven shaft or drive shaft) 128 through a spline hole 122 so that torque can be transmitted. The inner ring 120 has a spherical outer peripheral surface 124, and ball grooves 126 extending in the axial direction are formed at equal intervals in the circumferential direction of the spherical outer peripheral surface 124.

  The ball groove 116 of the outer ring 110 and the ball groove 126 of the inner ring 120 make a pair, and one ball 130 is interposed between each pair of ball grooves 116, 126. The center O1 of the ball groove 116 of the outer ring 110 and the center O2 of the ball groove 126 of the inner ring 120 are offset from each other across the joint center O by an equal distance in the axial direction. For this reason, the ball track formed by the ball groove 116 of the outer ring 110 and the ball groove 126 of the inner ring 120 that form a pair has a wedge shape that is gradually reduced from one to the other in the axial direction, from right to left in FIG. Presents.

  The cage 132 has pockets 134 penetrating in the radial direction, and by accommodating one ball 130 in each pocket 134, all the balls 130 are held in the same plane. The cage 132 is interposed between the outer ring 110 and the inner ring 120, and the spherical outer peripheral surface 136 has a spherical inner peripheral surface 114 and the spherical inner peripheral surface 138 has a spherical outer peripheral surface. 124 is spherically fitted. Accordingly, the outer ring 110 and the inner ring 120 can only be angularly displaced.

When the inner ring 120 receives the spring force of the compression coil spring 156 by the receiving member 160 attached to the cage 132 via the pressing member 150, the inner ring 120 is axially displaced toward the opening side of the outer ring 110 cup. Due to the displacement, there is provided a mechanism in which the ball 130 is always in contact with the ball 130 interposed in the ball track shaped like a wedge. As shown in FIG. 7, this mechanism includes a pressing member 150 provided on the inner ring 120 side, a receiving member 160 provided on the cage 132 side, and a compression coil spring 156 interposed therebetween. The pressing member 150 includes a cylindrical body 152 and a head 154 having a larger diameter than the body 152, and the body 152 is inserted into a shaft hole formed in the shaft 128. A compression coil spring 156 interposed between the head 154 and the end face of the shaft 128 presses the pressing member 150 in a direction protruding from the end face of the shaft 128. A convex spherical receiving surface 158 formed on the head 154 of the pressing member 150 is in elastic contact with the receiving surface 162 of the receiving member 160. The receiving surface 162 has a concave spherical shape having a center of curvature on the axis of the inner ring 120. The receiving member 160 is fixed by fitting its outer peripheral edge into an annular groove formed on the inner periphery of the end of the retainer 132.
Japanese Patent Laid-Open No. 2003-130082

  Since the constant velocity universal joint of Patent Document 1 is a fixed type, it cannot be displaced in the axial direction. However, the steering shaft may be subjected to an axial load due to twisting or bending of the vehicle body during traveling. In order to allow the axial displacement to absorb this axial load, we would like to adopt a sliding type. In the sliding type, however, the constant velocity universal joint of Patent Document 1 proposes a structure in which the rotary play is packed. Cannot be adopted. That is, in Patent Document 1, the inner ring 120 and the cage 132 are relatively moved in the axial direction using the compression coil spring 156, and the ball 130 is pushed toward the narrow side of the wedge-shaped ball track via the cage 132. As a result, the clearance between the ball grooves 116 and 126 and the ball 130 is eliminated and the play in the rotational direction is reduced. However, this is possible because it is a fixed type, and cannot be employed in a sliding type in which the outer ring and the inner ring can be displaced in the axial direction.

  An object of the present invention is to provide a constant velocity universal joint that can be displaced in the axial direction and has no backlash.

  According to the present invention, a separate plate is disposed in a ball groove of an inner joint member of a double offset type constant velocity universal joint which is one of sliding type constant velocity universal joints, and an elastically deformable intermediate member is interposed therebetween. As a result, a structure of a sliding type constant velocity universal joint that can slide (displace in the axial direction) and has no backlash in the rotational direction has been realized.

  That is, the present invention provides an outer joint member that forms a pair of an outer joint member in which a ball groove extending in the axial direction is formed on the cylindrical inner peripheral surface, and an inner joint member in which a ball groove extending in the axial direction is formed on the spherical outer peripheral surface. A ball interposed between the ball groove of the member and the ball groove of the inner joint member and an inner surface of the outer joint member and an outer peripheral surface of the inner joint member to hold the ball in place. In the sliding type constant velocity universal joint provided with the cage, the wall surface of the ball groove of the inner joint member is constituted by a separate plate, and an elastic member is interposed between the inner joint member and the plate. It is characterized by.

  According to a second aspect of the present invention, in the sliding type constant velocity universal joint according to the first aspect, the wall surface of the ball groove and the inner side surface of the plate are each arcuate when viewed in cross section of the ball groove of the inner joint member, and the elastic member Is a polygon or a waveform.

  According to a third aspect of the present invention, in the sliding type constant velocity universal joint according to the first aspect, the wall surface of the ball groove and the inner surface of the plate are polygonal or corrugated when viewed in a cross section of the ball groove of the inner joint member. Thus, the elastic member has a flat plate shape.

  According to a fourth aspect of the present invention, in the sliding type constant velocity universal joint according to the first, second, or third aspect, a ball is provided with a tightening allowance by an elastic member. In other words, the dimension between the ball groove of the outer joint member and the ball groove of the inner joint member is smaller than the outer diameter of the ball with the ball removed.

  A fifth aspect of the present invention is the sliding constant velocity universal joint according to any one of the first to fourth aspects, wherein the elastic member is made of plastic.

  A sixth aspect of the present invention is the sliding constant velocity universal joint according to any one of the first to fourth aspects, wherein the elastic member is made of rubber.

  The invention according to claim 7 is the sliding constant velocity universal joint according to any one of claims 1 to 4, wherein the elastic member is made of a steel plate having a carbon content of 1% or less subjected to thermosetting treatment. It is characterized by.

  According to an eighth aspect of the present invention, in the sliding type constant velocity universal joint according to any one of the first to fourth aspects, the elastic member is made of a spring steel plate.

  A ninth aspect of the present invention is the sliding constant velocity universal joint according to any one of the first to eighth aspects, wherein the number of balls is three or more.

  According to a tenth aspect of the present invention, in the sliding type constant velocity universal joint according to any one of the first to ninth aspects, the invention is used for a steering device of an automobile.

  According to the present invention, it is possible to provide a sliding type constant velocity universal joint that can be displaced in the axial direction to absorb a load and that does not have a rotation play.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, the basic configuration of a double offset type constant velocity universal joint will be described with reference to FIG. The double offset type constant velocity universal joint includes an outer ring 10 as an outer joint member, an inner ring 20 as an inner joint member, a ball 30 as a torque transmission element, and a cage 32 for holding the ball 30. As a component.

  The outer ring 10 includes a mouse portion 12 and a connection portion 18, and is connected to the drive shaft or the driven shaft through the connection portion 18 so that torque can be transmitted. The mouse portion 12 has a cylindrical inner peripheral surface 14, and ball grooves 16 extending in the axial direction are formed at equal intervals in the circumferential direction of the inner peripheral surface.

  The inner ring 20 is connected to a driven shaft or a drive shaft through a spline hole 26 so that torque can be transmitted. The inner ring 20 has a spherical outer peripheral surface 22, and ball grooves 24 extending in the axial direction are formed at equal intervals in the circumferential direction of the outer peripheral surface.

  The ball groove 16 of the outer ring 10 and the ball groove 24 of the inner ring 20 make a pair, and one ball 30 is interposed between each pair of ball grooves 16, 24. The cage 32 has pockets 38 penetrating in the radial direction. By housing one ball 30 in each pocket 38, all the balls 30 are held in the same plane.

  The cage 32 is interposed between the outer ring 10 and the inner ring 20, and is fitted to the cylindrical inner circumferential surface 14 of the outer ring 10 with a spherical outer circumferential surface 34, and the spherical surface of the inner ring 20 with a spherical inner circumferential surface 36. The outer peripheral surface 22 is spherically fitted. The center of the spherical outer peripheral surface 34 and the center of the spherical inner peripheral surface 36 of the cage 32 are offset by an equal distance in the axial direction on opposite sides of the joint center O.

  In the embodiment shown in FIG. 1, a plate 40 separate from the inner ring 20 is mounted in the ball groove 26 of the inner ring 20. An elastic member 46 is interposed between the inner ring 20 and the plate 40. Here, the cross section of the ball groove 26 of the inner ring 10 has a substantially arc shape, and the cross section of the inner side surface 42 of the plate 40 facing the same also has a substantially arc shape. The cross section of the outer surface 44 of the plate 40 is shaped into a shape that can provide a rolling surface for the ball 30 with the desired radius of curvature. As can be seen from FIG. 4, the longitudinal section of the plate 40 is linear.

  As the elastic member 46 interposed between the wall surface of the ball groove 26 of the inner ring 20 and the inner side surface 42 of the plate 40, for example, a flat plate or a sheet can be used. As a material of the elastic member 42, a spring steel plate or the like can be employed in addition to an elastic material such as rubber or plastic. And in the completion state (FIG. 1) of the constant velocity universal joint which consists of the outer ring | wheel 10, the inner ring | wheel 20, the ball | bowl 30, and the cage | basket 32, it sets to the dimension relationship which a fastening allowance is provided to the ball | bowl 30. In such a completed state, the plate 40 and the elastic member 46 are not likely to fall off, but the inner ring 20 and the elastic member 46 and the elastic member 46 and the plate 40 are not easily dispersed even when disassembled, for example. Are preferably connected using an adhesive or the like. When the material of the elastic material 46 is rubber, baking can also be used.

  In this embodiment, a ball track is formed by the ball groove 16 of the outer ring 10 and the plate 40 attached to the ball groove 26 of the inner ring 20 via an elastic member 46. Therefore, by appropriately setting the material and thickness of the elastic member 46, an appropriate tightening allowance can be given to the ball 30. As a result, a double offset type constant velocity universal joint with no rotation direction play is realized.

  When torque is applied, the elastic member 46 is elastically deformed so that a slight gap is formed. Therefore, the ball 30 can be easily unrolled and rolled. Therefore, plunging of the joint is possible. By adjusting the elastic coefficient of the elastic member 46, the “rotational torque-torsion angle” diagram can be adjusted in accordance with the characteristics of the vehicle on which the constant velocity universal joint is mounted.

  The plate 40 shown in FIG. 1 has a substantially semi-cylindrical shape. However, as shown in FIG. 2, the elastic member 46 may be formed by dividing a cylindrical body having a polygonal cross section or a corrugated cross section into about half. . Examples of the material of the elastic member 46 include a spring steel plate and a steel plate having a carbon content of 1% or less that has been subjected to a thermosetting treatment. In this case, the thickness of the elastic member 46 itself does not change, and the polygonal cross-sectional shape is elastically deformed.

  Alternatively, as shown in FIG. 3, the wall surface of the ball groove 26 of the inner ring 20 and the inner side surface 42 of the plate 40 facing each other are formed into a polygonal cross section or a corrugated cross section, and a semi-cylindrical elastic member 46 is formed between them. You may make it interpose. Also in this case, the thickness of the elastic member 46 itself does not change, and the polygonal cross-sectional shape is elastically deformed. Therefore, examples of the material of the elastic member 46 include a spring steel plate or a steel plate having a carbon content of 1% or less that has been subjected to a thermosetting treatment.

  1 to 3 exemplify the case where the number of balls 30 is six, the number of balls 30 can be any number of three or more.

(A) is a cross-sectional view, and (B) is a partially enlarged view. (A) is a cross-sectional view, and (B) is a partially enlarged view. (A) is a cross-sectional view, and (B) is a partially enlarged view. It is a longitudinal cross-sectional view of a general double offset type constant velocity universal joint. It is a perspective view of a steering device. It is a longitudinal cross-sectional view of a fixed type constant velocity universal joint. It is the elements on larger scale of FIG.

Explanation of symbols

10 Outer ring (outer joint member)
12 Mouse part 14 Inner peripheral surface 16 Ball groove 18 Stem part 20 Inner ring (inner joint member)
22 spline hole 24 outer peripheral surface 26 ball groove 30 ball (torque transmission element)
32 cage 34 outer peripheral surface 36 inner peripheral surface 38 pocket 40 plate 42 inner side surface 44 outer side surface 46 elastic member

Claims (10)

An outer joint member in which a ball groove extending in the axial direction is formed on the cylindrical inner peripheral surface, an inner joint member in which a ball groove extending in the axial direction is formed in the spherical outer peripheral surface, and the ball groove and the inner side of the paired outer joint member A ball interposed between the ball grooves of the joint member, and a cage that is interposed between the inner peripheral surface of the outer joint member and the outer peripheral surface of the inner joint member and holds the ball in a predetermined position. In sliding constant velocity universal joints,
A sliding type constant velocity universal joint in which the wall surface of the ball groove of the inner joint member is constituted by a separate plate, and an elastic member is interposed between the inner joint member and the plate.   The sliding type constant velocity universal joint according to claim 1, wherein the ball groove and the inner side surface of the plate are each arcuate and the elastic member is polygonal or corrugated when viewed in cross section of the ball groove of the inner joint member.   The sliding type constant velocity universal joint according to claim 1, wherein the ball groove and the inner side surface of the plate are each polygonal or corrugated, and the elastic member is a flat plate shape when viewed from the cross section of the ball groove of the inner joint member.   The sliding type constant velocity universal joint according to claim 1, wherein a tightening allowance is given to the ball.   The sliding type constant velocity universal joint according to any one of claims 1 to 4, wherein the elastic member is made of plastic.   The sliding type constant velocity universal joint according to any one of claims 1 to 4, wherein the elastic member is made of rubber.   The sliding type constant velocity universal joint according to any one of claims 1 to 4, wherein the elastic member is made of a steel sheet having a carbon content of 1% or less subjected to a thermosetting treatment.   The sliding type constant velocity universal joint according to any one of claims 1 to 4, wherein the elastic member is made of a spring steel plate.   The sliding type constant velocity universal joint according to any one of claims 1 to 8, wherein the number of balls is three or more.   The sliding type constant velocity universal joint according to any one of claims 1 to 9, which is used for a steering device of an automobile.

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