JP2007120663A - Fixed constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a constant velocity universal joint capable of displaying a damping function regardless of slide resistance. <P>SOLUTION: The fixed constant velocity universal joint is equipped with an outer ring 10, having a plurality of ball grooves 14 formed on an inner ball face 12 extending in the axial direction, an inner ring 20, having a plurality of ball grooves 24 formed on the outer ball face 22 extending in the axial direction, a plurality of balls 30 assembled between the pairs of the ball grooves 14 and of the outer ring 10 and the ball grooves 24 of the inner ring 20, and a cage 40 interposed in between the outer ring 10 and the inner ring 20 for holding all the balls 30 within the same plane. The outer ring 10 is constituted of an outside member 10A and an inside member 10B, having a vibration-proof material 50 interposed therebetween. Projections 52, extending in the axial direction, are provided on the inner peripheral face of the outside member 10A or on the outer peripheral face of the inside member 10B; a groove 54, fitting with the projections 52 in the rotational direction with a clearance therebetween, is provided on the outer peripheral face of the inside member 10B or on the inner peripheral face of the outside member 10A; and the vibration-proof material 50 is interposed between the projections 52 and between the inner peripheral face of the outside member 10A and the outer peripheral face of the inside member 10B. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fixed type constant velocity universal joint and can be used for power transmission of automobiles and various industrial machines.

  As one means for solving the sound vibration problem of automobiles involving a drive system, an outer ring is constituted by a combination of an outer member and an inner member, and a vibration isolating material formed of an elastic material such as rubber in a cylindrical gap therebetween. There is known a so-called vibration-proof type slide type constant velocity universal joint with a gap interposed therebetween. This vibration isolator has an action of absorbing vibration transmitted through the constant velocity universal joint in the middle of transmission (damping).

  In Patent Document 1, an outer ring of a slide type constant velocity universal joint is configured by a combination of an outer member, an inner member, and a vibration isolating material interposed therebetween, and either the outer member or the inner member is interposed between the two. It is described that an interference portion protruding in the direction of narrowing the clearance is provided.

  In Patent Document 2, an outer ring of a slide type constant velocity universal joint is configured by a combination of an outer member, an inner member, and a vibration damping material interposed between the outer member and the inner member. It is described that an interference portion protruding in the direction of narrowing is provided.

In Patent Document 3, interference protrusions are provided along the axial direction in the circumferential direction of the inner peripheral surface of the outer member, and the interference protrusions are rotated in the circumferential direction on the outer peripheral surface of the inner member in the rotational direction. An interference fitting groove that fits the required gap is provided, and an anti-vibration material is interposed between the inner peripheral surface of the outer member between the interference protrusions and the outer peripheral surface of the inner member between the interference protrusions. Is described.
JP-A-2-16825 Japanese Patent Laid-Open No. 5-100343 JP-A-3-272322

  When the outer ring is composed of a combination of an outer member and an inner member, and a slide type constant velocity universal joint with an anti-vibration material interposed between the two is used for the drive shaft of an automobile, As the pressure rises, the internal pressure increases and the slide resistance increases. If the slide resistance increases, it will adversely affect the vehicle's NVH (noise, vibration, harshness), so it is desirable to keep it as small as possible.

  A main object of the present invention is to provide a constant velocity universal joint capable of exhibiting a damping function regardless of slide resistance.

  The fixed type constant velocity universal joint according to the present invention includes an outer ring in which a plurality of ball grooves extending in the axial direction on the inner spherical surface are formed at equal intervals in the circumferential direction, and a plurality of ball grooves extending in the axial direction on the outer spherical surface. An inner ring formed at equal intervals in the direction, a plurality of balls assembled between the ball groove of the outer ring and the ball groove of the inner ring that form a pair, and all the balls in the same plane interposed between the outer ring and the inner ring A holding cage, and the outer ring is configured by an outer member and an inner member with a vibration isolating material interposed therebetween, and on the inner peripheral surface of the outer member or the outer peripheral surface of the inner member in the axial direction. Protruding ridges are provided, and grooves are provided on the outer peripheral surface of the inner member or the inner peripheral surface of the outer member so as to fit with the ridges in a rotational direction, and the vibration isolator is interposed between the ridges. It is interposed between the inner peripheral surface of the outer member and the outer peripheral surface of the inner member. Is shall.

  A vibration isolator absorbs vibration transmitted through the fixed constant velocity universal joint during the transmission (damping). When the torque load is applied and the relative displacement in the rotational direction between the outer member and the inner member reaches a certain level or more, the protrusions and the grooves collide and interfere with each other. For this reason, further relative displacement is limited, and abnormal deformation of the vibration isolator is avoided.

  A plurality of the protrusions may be provided, a thin plate member may be interposed on the inner peripheral surface of the outer member between the protrusions, and the vibration isolating material may be bonded to the inner surface of the thin plate member. By doing in this way, while the thin plate member performs the effect | action which determines the relative position of the rotation direction of the inner side member with respect to an outer side member, the slip between an outer side member and a vibration isolator is prevented.

  When the central angle of the clearance C formed between the ridge and the inner surface of the groove is α and the central angle of the distance L from the ridge to the rising portion of the vibration isolator is β, α ≦ By satisfying the relationship of β, the vibration isolator is not exposed from the outer peripheral surface of the inner member even when the relative displacement between the outer member and the inner member reaches the maximum. Therefore, it is possible to prevent the vibration isolating material from projecting in the radial direction, and to further improve the durability of the vibration isolating material that avoids stress concentration occurring in the projecting portion.

  The present invention can be applied to a fixed constant velocity universal joint (UJ) of an undercut free type in addition to a fixed type constant velocity universal joint (BJ) of a Rzeppa type. In BJ, the ball groove is arcuate, whereas in UJ, the ball groove of the outer joint member and the ball groove of the inner joint member are provided with straight portions where the groove bottoms are linear, and the undercut is eliminated. Higher angle specification than BJ.

  Since the fixed type constant velocity universal joint does not slide, there is no problem of an increase in slide resistance due to an increase in internal pressure. In other words, by providing a vibration isolating material in the outer ring of the fixed type constant velocity universal joint, it will not slide even if the joint internal pressure rises. Can do. By this damping effect, vibration due to resonance (for example, lock-up booming noise) is suppressed.

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

  First, the basic configuration of the fixed type constant velocity universal joint will be described with reference to FIGS. Here, FIG. 4 shows a Rzeppa type (BJ) as an example of a fixed type constant velocity universal joint, and FIG. 6 shows an undercut free type (UJ). FIG. 5 which shows a cross section is common to both.

  The fixed type constant velocity universal joint illustrated in the drawings 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 40 that holds the ball 30. It is a major component. If the two axes to be connected by the fixed type constant velocity universal joint are called a first rotation axis X and a second rotation axis Y, the first rotation axis X is coupled to the outer ring 10 and the second rotation axis. Y is coupled to the inner ring 20 so that torque is transmitted at an equiangular speed even when they are angled.

  The outer ring 10 includes a mouse portion 16 and a stem portion 18, and is coupled to a hub wheel and other first rotation shafts (not shown) by the stem portion 18 so that torque can be transmitted. The mouse portion 16 has a bell shape opened at one end, and a plurality of ball grooves 14 extending in the axial direction are formed on the concave spherical inner peripheral surface (hereinafter referred to as inner spherical surface) 12 at equal intervals in the circumferential direction. is there. The ball groove 14 extends to the open end of the mouse portion 16.

  The inner ring 20 has a convex spherical outer peripheral surface (hereinafter referred to as an outer spherical surface) 22, and a plurality of ball grooves 24 extending in the axial direction are formed on the outer spherical surface 22 at equal intervals in the circumferential direction. The ball groove 24 is cut in the axial direction of the inner ring 20. The inner ring 20 is formed with a spline (or serration, the same applies hereinafter) hole 26 for coupling with the shaft 28 so as to transmit torque. The shaft 28 corresponds to the second rotation axis Y described above.

  In the case of UJ, as shown in FIG. 6, the ball groove 14 of the outer ring 10 is composed of an arc portion 14a and a straight portion 14b, and the arc portion 14a is located on the back side of the mouse portion 16, that is, on the non-opening end side. 14b is located on the opening end 15 side. Furthermore, the linear portion 14b can be formed in a tapered shape whose diameter is increased from the back side of the mouse portion 16 toward the opening end 15 side.

  Similarly, in UJ, the ball groove 24 of the inner ring 20 includes an arc portion 24a and a straight portion 24b, the arc portion 24a is located on the opening end 15 side of the mouse portion 16 of the outer ring 10, and the straight portion 24b is on the side opposite to the opening side. Located in. Also here, the straight portion 24b may be formed in a tapered shape whose diameter is increased from the opening end 15 side of the mouse portion 16 toward the back side.

  The ball groove 14 of the outer ring 10 and the ball groove 24 of the inner ring 20 make a pair, and one ball 30 is incorporated in a ball track constituted by each pair of ball grooves 14 and 24 so as to roll. The ball 30 is interposed between the ball groove 14 of the outer ring 10 and the ball groove 24 of the inner ring 20 to transmit torque. Each ball 30 is accommodated in a pocket 46 disposed in the circumferential direction of the cage 40. The number of balls 30 and thus also the ball grooves 14, 24 is arbitrary, but is 6 or 8 for example. FIG. 5 illustrates the case of eight.

  The cage 40 is slidably interposed between the outer ring 10 and the inner ring 20, is in contact with the inner spherical surface 12 of the outer ring 10 at the outer spherical surface 42, and is in contact with the outer spherical surface 22 of the inner ring 20 at the inner spherical surface 44. In FIG. 6, the clearance between the inner spherical surface 12 of the outer ring 10 and the outer spherical surface 42 of the cage 40 and between the outer spherical surface 22 of the inner ring 20 and the inner spherical surface 44 of the cage 40 are exaggerated.

  Further, there is a clearance due to the PCD clearance between the ball 30 and the ball track formed by the ball groove 14 of the outer ring 10 and the ball groove 24 of the inner ring 20 that make a pair. The PCD clearance is the difference between the pitch circle diameter of the ball groove 14 of the outer ring 10 and the pitch circle diameter of the ball groove 24 of the inner ring 20. In FIG. 6, the distance from the center O3 of the ball 30 to the center (outer ring track center) O1 of the ball groove 14 of the outer ring 10 is designated by PCR1, and the center of the ball groove 24 of the inner ring 20 from the center O3 of the ball 30 (inner ring track center). ) The distance to O2 is represented by the symbol PCR2.

  The outer ring track center O1 and the inner ring track center O2 are offset in the axial direction opposite to the joint center O. In FIG. 6, symbol F1 represents an outer ring offset, and symbol F2 represents an inner ring offset. As a result, the ball track composed of the ball groove 14 of the outer ring 10 and the ball groove 24 of the inner ring 20 that form a pair is a wedge that gradually expands from the back side of the mouth portion 16 of the outer ring 10 toward the opening end 15 side. It has a shape. When the torque is transmitted with the joint at the operating angle θ, a thrust (M) is applied to push the ball 30 from the narrow side to the wide side of the wedge-shaped ball track.

  As shown in FIG. 4, when the first rotation axis X and the second rotation axis Y have a certain operating angle θ other than 0 °, a bisector of the angle θ formed by both rotation axes X and Y is obtained. If all the balls 30 are in a vertical plane, that is, the joint center plane P, the rotational motion is transmitted at a constant angular velocity between the rotation axes X and Y from the center of the ball. The intersection of the joint center plane P and the rotation axes X and Y is referred to as a joint center O. In the fixed type constant velocity universal joint, the joint center O is fixed regardless of the operating angle θ.

  Next, referring to FIG. 1 and FIG. 2, the outer ring 10 is composed of an outer member 10A and an inner member 10B, and the inner member 10B is accommodated inside the outer member 10A. The outer member 10A is integral with the stem portion, and the ball groove 14 is formed in the inner member 10B.

  A protrusion 52 is formed on the inner peripheral surface of the outer member 10A. Similarly, a groove 54 is formed on the outer peripheral surface of the inner member 10B. Here, the protrusion 52 and the groove 54 are arranged at a circumferential tri-section position, and each extend in the axial direction. The width of the groove 54 is slightly wider than the width of the ridge 52, and the inner surfaces of both sides face the side surface of the ridge 52 with a slight clearance C (FIG. 2).

  An anti-vibration material 50 formed of an elastic body such as rubber is interposed between the inner peripheral surface of the outer member 10A divided into three by the protrusion 52 and the outer peripheral surface of the inner member 10B divided into three by the groove 54. I'm allowed. The inner peripheral surface of the vibration isolator 50 and the outer member 10A and the outer peripheral surface of the vibration isolator 50 and the inner member 10B are bonded by, for example, vulcanization.

  In the fixed type constant velocity universal joint having the above-described configuration, the vibration isolator absorbs vibration transmitted through the joint during the transmission (damping). When the torque load is applied and the outer member 10A and the inner member 10B are relatively displaced in the rotational direction by a certain amount or more, the clearance C becomes 0, and the side surfaces of the protrusion 52 and the groove 54 collide with each other and interfere with each other. Further relative displacement is limited. Therefore, abnormal deformation of the vibration isolator 50 can be avoided.

  As shown in FIG. 3, the central angle corresponding to the clearance C between the protrusion 52 and the inner surface of the groove 54 is α, and corresponds to the distance L from the protrusion 52 to the rising portion of the vibration isolator 50. When the center angle is β, the relationship α ≦ β is established. By adopting such a configuration, even when the outer member 10A and the inner member 10B are relatively displaced relative to each other so that one clearance C becomes 0 and the other clearance becomes 2C, the vibration isolator 50 is It is maintained in a state covered with the inner member 10B. For this reason, it can prevent that the side part of the vibration isolator 50 protrudes inward from the part of the clearance gap 2C.

  In addition, the number of the protrusions 52 is not limited to 3 exemplified here, and one or more is sufficient. Further, a member other than the outer member 10A may be interposed between the outer member 10A and the vibration isolator 50. For example, as shown in FIG. 7, a thin plate member 53 is interposed on the inner diameter surface of the outer member 10 </ b> A between the protrusions 52, and the vibration isolator 50 is bonded to the inner surface of the thin plate member 53. The thin plate member 53 is restricted from moving in the circumferential direction by the protrusion 52.

The longitudinal cross-sectional view of the outer ring | wheel of the fixed type constant velocity universal joint which shows embodiment of this invention 1 is a cross-sectional view of the outer ring of FIG. Cross-sectional view similar to FIG. BJ longitudinal section 4 is a cross-sectional view of the joint of FIG. UJ longitudinal section Cross-sectional view similar to FIG. 2 showing another embodiment

Explanation of symbols

10 Outer ring (outer joint member)
16 Mouse part 10A Outer member 10B Inner member 12 Inner peripheral surface 14 Ball groove 18 Stem part 20 Inner ring (inner joint member)
22 outer peripheral surface 24 ball groove 26 spline hole 28 shaft 30 ball (torque transmission element)
40 Cage 42 Outer spherical surface 44 Inner spherical surface 46 Pocket 50 Anti-vibration material 52 Interference protrusion 53 Thin plate member 54 Interference groove

Claims (3)

An outer ring in which a plurality of ball grooves extending in the axial direction on the inner spherical surface are formed at equal intervals in the circumferential direction, and an inner ring in which a plurality of ball grooves extending in the axial direction on the outer spherical surface are formed at equal intervals in the circumferential direction are paired. A plurality of balls incorporated between the ball groove of the outer ring and the ball groove of the inner ring, and a cage that is interposed between the outer ring and the inner ring and holds all the balls in the same plane,
The outer ring is composed of an outer member and an inner member with a vibration isolating material interposed therebetween, and an axially extending protrusion is provided on the inner peripheral surface of the outer member or the outer peripheral surface of the inner member, An outer peripheral surface of the inner member or an inner peripheral surface of the outer member is provided with a groove that fits in the rotational direction with a gap in the rotation direction, and the vibration isolating material is disposed between the protrusions on the inner peripheral surface of the outer member. And a fixed type constant velocity universal joint interposed between the outer peripheral surface of the inner member and the inner member.   The fixed type constant velocity universal joint according to claim 1, wherein a plurality of the protrusions are provided, a thin plate member is interposed on an inner peripheral surface of the outer member between the protrusions, and the vibration isolating material is bonded to the inner surface of the thin plate member. When the central angle of the clearance X formed between the ridge and the inner surface of the groove is α and the central angle of the distance Y from the ridge to the rising portion of the vibration isolator is β, α ≦ The fixed type constant velocity universal joint according to claim 1 or 2, wherein a β relationship is established.

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