JP2007024088A - Shaft fitting structure for constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure of fitting an inward joint member of a constant velocity universal joint to a shaft for establishing both specifications that disassembly is impossible after once assembly and that disassembly is possible after assembly without increasing the types of the inward joint member or the shaft and a retaining ring. <P>SOLUTION: The structure of fitting the inward joint member of the constant velocity universal joint to the shaft comprises the shaft 6 having a ring-shaped retaining ring groove 13, the inward joint member 3 of the constant velocity universal joint having a through-hole 9 through which it is fitted to the shaft 6, and the diameter-enlargeable/shrinkable retaining ring 14 arranged in the retaining ring groove 13. When pull-off force is applied to the shaft 6, the retaining ring 14 is laid between an abutting portion 10a formed in the through-hole 9 of the inward joint member 3 and the retaining ring groove 13. The retaining ring 14 has a side face where sufficient force component is not generated for shrinking the diameter of the retaining ring 14 in contact with the abutting portion 10a and a side face where sufficient force component is generated for shrinking the diameter of the retaining ring 14 in linear contact with the abutting portion 10a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fitting structure between a constant velocity universal joint and a shaft coupled thereto.

  For constant velocity universal joints used in automobile drive shafts, propulsion shafts, etc., for the purpose of simplifying maintenance man-hours when replacing boots, etc., the constant velocity universal joint inner joint member and the inner joint member are combined. A separable fitting structure with the shaft to be used has been conventionally employed.

  In the devices described in Patent Documents 1 and 2, a retaining ring is attached to a groove formed at the end of the shaft, and is engaged with a contact surface formed on the inner joint member by elastic expansion of the retaining ring. Then, an angle is provided on the contact surface that interferes with the retaining ring when the shaft is pulled out, and the retaining ring is reduced in diameter by the component force of the interference force with the retaining ring to disengage the engagement.

Patent Document 3 discloses a structure in which a retaining ring having a substantially rectangular cross section is attached to a groove formed at an end portion of a shaft, and an inclined surface formed at a terminal end portion of a spline of an inner joint member is brought into contact with the retaining ring. The retaining ring and the groove and the retaining ring and the inclined surface are in surface contact with each other.
Japanese Patent Laid-Open No. 08-068426 Japanese Utility Model Publication No. 64-005124 Japanese Patent Laid-Open No. 08-145065

  In the fitting structure between the shaft and the inner joint member, both a specification that cannot be disassembled once assembled and a specification that can be disassembled are required. However, the one of Patent Document 1 can be assembled and disassembled by setting the retaining ring mounting position to the non-end face side of the shaft and providing a tool engagement groove for reducing the diameter of the retaining ring on the end face of the inner joint member. However, in this case, time and cost must be spent on machining the tool engagement groove of the inner joint member.

  Patent Document 2 discloses that the retaining ring is reduced in diameter so that the shaft can be pulled out. However, in order to establish a specification that cannot be disassembled and a specification that can be disassembled, the angle of the inclined portion is determined. It is not clear what to manage.

  In Patent Document 3, since the retaining ring abuts against the inclined surface of the inner joint member, when a force in the pulling direction is applied to the shaft, only a structure in which the retaining ring is reduced in diameter and pulled out is disclosed. It is not clear how the shaft and the inner joint member can be distinguished from those that cannot be disassembled and those that can be disassembled.

  The object of the present invention is to satisfy both specifications such as a specification that cannot be disassembled once assembled and a specification that can be disassembled after assembly without increasing the types of inner joint members, shafts and retaining rings. An object is to provide a fitting structure between an inner joint member of a quick universal joint and a shaft.

  The shaft fitting structure of the constant velocity universal joint of the present invention includes a shaft having a ring-shaped retaining ring groove, an inner joint member of the constant velocity universal joint having a through hole for fitting with the shaft, and a retaining ring groove. A retaining ring that can be elastically expanded and contracted in diameter, and when a force in the drawing direction is applied to the shaft, a contact portion formed in the through hole of the inner joint member and a retaining ring groove A retaining ring is interposed between the side surface and the abutment portion, which does not generate a force sufficient to reduce the diameter of the retaining ring when the retaining ring comes into contact with the abutment portion; And a side surface that generates a component force sufficient to reduce the diameter of the retaining ring by contact with the wire. And by selecting the shape of the retaining ring and its assembly direction, both specifications are established: the specification that the shaft and inner joint member cannot be disassembled once, and the specification that can be disassembled even after assembly. be able to. In addition, depending on the direction of the retaining ring, it is possible to easily visually determine whether the specification is an unresolvable specification or a resolvable specification.

  According to a second aspect of the present invention, in the shaft fitting structure of the constant velocity universal joint according to the first aspect, the side surface which does not generate a component force sufficient to reduce the diameter of the retaining ring is assembled toward the contact portion side. It is what. In this case, a component force sufficient to reduce the diameter of the retaining ring is not generated, and a specification that cannot be disassembled is established.

  According to a third aspect of the present invention, in the shaft fitting structure of the constant velocity universal joint according to the first aspect, the side surface generating the component force sufficient to reduce the diameter of the retaining ring is assembled toward the contact portion side. It is what. In this case, a component force sufficient to reduce the diameter of the retaining ring is generated, and a disassembling specification is established.

  According to a fourth aspect of the present invention, in the shaft fitting structure of the constant velocity universal joint according to any one of the first to third aspects, the side surface that does not generate a component force sufficient to reduce the diameter of the retaining ring when contacting the contact portion. Is a plane abutting from the vertical direction of the abutting portion.

  According to a fifth aspect of the present invention, in the shaft fitting structure of the constant velocity universal joint according to any one of the first to fourth aspects, a surface that generates a component force sufficient to reduce the diameter of the retaining ring when contacting the contact portion. Is an inclined surface.

  According to a sixth aspect of the present invention, in the shaft fitting structure of the constant velocity universal joint according to any one of the first to fourth aspects, a surface that generates a component force sufficient to reduce the diameter of the retaining ring when contacting the contact portion. Is a circular arc surface.

  According to the present invention, by selecting the shape and direction of the retaining ring, the contact portion with the retaining ring formed in the through hole of the inner joint member and the contact state are changed, so that the shaft can be pulled in the pulling direction. By controlling the component force in the direction of diameter reduction applied to the retaining ring when it receives, it can be divided into specifications that cannot be disassembled and specifications that can be disassembled. Therefore, it is not necessary to create a dedicated inner joint member, shaft, and retaining ring for each specification, and specifications that cannot be disassembled and disassembled without increasing load such as parts management man-hours and costs. Can be established.

  By selecting the retaining ring assembly direction, it is possible to identify whether the inner joint member and the shaft cannot be disassembled or disassembled, so that there is no special shape processing in the retaining ring groove or through hole, and With only one type of retaining ring, two required specifications can be satisfied. Therefore, parts management is simplified. In addition, the present invention can be more easily and reliably implemented because the assembly direction of the retaining ring can be visually discriminated.

  Embodiments of the present invention will be described below with reference to the drawings. First, the overall structure of the inner joint member and the shaft will be described with reference to FIGS. 1 to 3, then the specifications that cannot be disassembled with reference to FIG. 2, and the specifications that can be disassembled with reference to FIG. 4. explain. For convenience of explanation, the tip side means the left side in the figure, and the anti-tip side means the right side in the figure.

  Constant velocity universal joints can transmit torque at an equal angular speed between rotating shafts that form an angle, and are used for power transmission devices such as drive shafts and propulsion shafts of automobiles and power transmission devices of various industrial machines, for example. . Constant velocity universal joints are roughly classified into fixed types and sliding types. The fixed types include the Zepper type and the undercut free type, and the sliding types include the double offset type, the cross groove type, and the tripod type. The present invention can be applied regardless of the type of constant velocity universal joint, but here, a fixed type constant velocity universal joint will be described as an example. In addition to the tripod type, the inner ring is an inner joint member, but in the tripod type, a spider or tripod member having a portion called a trunnion or a leg shaft is an inner joint member.

  As shown in FIG. 1, the fixed type constant velocity universal joint 1 mainly includes an outer ring 2 as an outer joint member, an inner ring 3 as an inner joint member, a ball 4 as a torque transmission element, and a cage 5. As a component. When one of the outer ring 2 and the inner ring 3 is set as the driving side and the other is set as the driven side, the ball 4 is interposed between the two and plays a role of transmitting torque.

  Here, the outer ring 2 is bell-shaped, and ball grooves 7 extending in the axial direction are formed on the spherical inner peripheral surface at equal intervals in the circumferential direction. In the inner ring 3, ball grooves 8 extending in the axial direction are formed on a spherical outer peripheral surface at equal intervals in the circumferential direction. The ball groove 7 of the outer ring 2 and the ball groove 8 of the inner ring 3 form a pair, and one ball 4 is incorporated between each pair of ball grooves 7 and 8. The cage 5 is interposed between the outer ring 2 and the inner ring 3, and all balls are held on the same plane by the cage 5.

  A through hole 9 is formed at the center of the inner ring 3, and a spline (or serration, the same applies hereinafter) 10 is formed on the inner peripheral surface thereof. By fitting the spline 10 with a spline 11 formed at the end of the shaft 6, the inner ring 3 and the shaft 6 are coupled so that torque can be transmitted. As shown in FIG. 2, a hole 12 having a diameter larger than that of the through hole 9 is provided on the front end side of the through hole 9, thereby forming a surface 12 a continuous with the surface 10 a perpendicular to the terminal axis of the spline 10. It is. The hole 12 may be larger in diameter than the small diameter of the spline 10 (the diameter of the circle formed by the tooth tip) and smaller than the large diameter (the diameter of the circle formed by the tooth bottom). In this case, the surface 12a is not formed, Only the surface 10a is present.

  A ring-shaped retaining ring groove 13 for mounting a retaining ring 14 is formed on the distal end side of the shaft 6. The retaining ring groove 13 has a depth that allows the retaining ring 14 to be reduced in diameter until the outer diameter becomes smaller than the small diameter of the spline 10 of the inner ring 3. The position of the retaining ring groove 13 on the shaft 6 only needs to be within the range of the length of the through hole 9 in a state where the inner ring 3 and the shaft 6 are assembled, and the shaft end at the end of the shaft 6 is more than the end of the spline 11. It may be on the side.

  Both side walls of the retaining ring groove 13, that is, the tip side wall 13 a and the opposite tip side wall 13 b extend perpendicular to the axis. The dimension between the walls 13a and 13b is given a slight gap with respect to the width of the retaining ring. The wall 13b on the opposite end side serves as a contact portion that pushes the retaining ring 14 in the insertion direction when the shaft 6 is inserted into the through hole 9. Further, the distal wall 13a serves as a contact portion that pushes the retaining ring 14 in the pulling direction when a pulling force is applied to the shaft 6.

  As shown in FIG. 3, the retaining ring 14 is a ring shape with a part cut away, and can be elastically expanded and contracted. The retaining ring 14 partially protrudes outward from the outer diameter of the shaft 6 (the large diameter of the spline 11) in a state where a force for reducing the diameter is not applied.

  When the shaft 6 and the inner ring 3 are assembled, the retaining ring 14 is disposed in the retaining ring groove 13, and the shaft 6 is inserted into the through hole 9 with the retaining ring 14 having a reduced diameter. At this time, the retaining ring 14 moves while sliding in contact with the small diameter of the spline 10 of the through hole 9. When the tip of the shaft 6 passes through the through hole 9 and the end 9a on the opposite end side of the through hole 9 contacts the shoulder 6a of the shaft 6, insertion is blocked. In order to restrict the insertion allowance of the shaft 6, a retaining ring may be attached separately so that the retaining ring hits the opposite end side of the through hole 9 to prevent further insertion.

  When the insertion of the shaft 6 into the through-hole 9 is stopped, the retaining ring 14 is removed from the spline 10 and positioned in the hole 12, so that the diameter is expanded by elasticity. When the retaining ring 14 is enlarged in diameter, the outer peripheral surface of the retaining ring 14 comes into contact with the peripheral wall of the hole 12 and the assembly of the shaft 6 and the inner ring 3 is completed. If the outer diameter of the retaining ring 14 is larger than the small diameter of the spline 10, the outer peripheral surface of the retaining ring 14 does not necessarily need to contact the peripheral wall of the hole 12.

  Although various cross-sectional shapes of the retaining ring 14 can be employed, in order to establish a specification that the inner ring 3 and the shaft 6 cannot be disassembled and a dismountable specification by using a retaining ring having the same cross-sectional shape and selecting its orientation. Must be as described below.

  The cross-sectional shape of the retaining ring 14 for establishing a specification that cannot be disassembled may be such that a component force in a direction to reduce the diameter of the retaining ring 14 is not generated or is not sufficient to reduce the diameter of the retaining ring. For example, as shown in FIG. 2, when the cross-sectional shape of the retaining ring 14 is a square having side surfaces 14 a and 14 b parallel to each other, the side surface 14 a on the opposite end side is a surface perpendicular to the axis of the through hole 9. What is necessary is just to contact 10a and the surface 12a continuous with it. When a pulling force, that is, a force in the direction of arrow B in FIG. 2 is applied to the shaft 6, the side surface 14 b on the tip side of the retaining ring 14 is pushed by the wall 13 a of the retaining ring groove 13. As a result, the shaft 6 moves slightly to the right in the drawing, that is, moves within the range (gap) between the width of the retaining ring groove 13 and the width of the retaining ring 14. However, the side surface 14a on the opposite end side of the retaining ring 14 hits the surfaces 10a and 12a of the inner ring 3, and the reaction force F of the withdrawal force is in the opposite direction to the withdrawal force, so that a component force is generated to reduce the diameter of the retaining ring 14. do not do. Therefore, the shaft 6 cannot be pulled out from the inner ring 3. In this case, the side surface 14a is a flat surface that comes into contact with the contact portions 10a and 12a from the vertical direction.

  The cross-sectional shape of the retaining ring 14 for establishing the decomposable specifications is necessary to reduce the diameter of the retaining ring 14, that is, a force sufficient to reduce the retaining ring 14, that is, a force for expanding the retaining ring 14 itself. A force in a direction to reduce the diameter of the retaining ring 14 larger than the sum of forces may be generated. For example, as shown in FIG. 4, the retaining ring 14 has a polygonal cross-sectional shape, an inclined surface 14 d with an inclination angle α with respect to the axis of 70 degrees or less is provided on the opposite end side, and the inclined surface 14 d is the axis of the inner ring 3. On the other hand, it may be in contact with the end portion 10b (the tooth tip portion of the spline 10) of the vertical surface 10a. This corresponds to the case where the retaining ring 14 described as the specification that cannot be disassembled with reference to FIG.

  When the pulling force B is applied to the shaft 6, the shaft 6 moves in parallel to the right side in the figure, and the right inclined surface 14d of the retaining ring 14 and the end portion 10b of the surface 10a of the inner ring 3 come into contact with each other. And the inclination angle (alpha) of the inclined surface 14d of the retaining ring 14 acts, and the component force of the direction which reduces the diameter of the retaining ring 14 generate | occur | produces. Therefore, as shown in FIG. 5, the retaining ring 14 can be reduced in diameter and the shaft 6 can be pulled out from the inner ring 3. If the inclination angle α of the inclined surface 14d exceeds 70 degrees, the component force in the direction to reduce the diameter of the retaining ring 14 becomes smaller, so that the diameter of the retaining ring 14 cannot be reduced and cannot be disassembled. End up. In addition, when the inclination angle α is less than 45 degrees, the component force in the direction of reducing the diameter becomes too large, and there is a possibility that it will come out even with a small pulling force. Therefore, it is desirable to set the inclination angle α to 45 degrees to 70 degrees, preferably 60 degrees to 70 degrees.

  As described above, the cross-sectional shape of the retaining ring 14 that can establish a specification that cannot be disassembled and a specification that can be disassembled by selecting the mounting direction with the same shape is illustrated in FIGS. 6 and 7 as an example. To do. FIGS. 6A to 6H and FIGS. 7A to 7H have a relationship in which the same shape is horizontally reversed.

  6 (a) to 6 (h) show the cross-sectional shape and direction of the retaining ring that establishes the decomposable specification, and the same action as described in relation to FIGS. 4 and 5 works. The cross-sectional shapes shown in FIGS. 6A to 6D are polygonal (trapezoidal) and triangular, and the portion in contact with the end 10b of the inner ring 3 is an inclined surface. The inclination angle of the inclined surface is 70 degrees or less. Further, in the cross-sectional shapes shown in FIGS. 6E to 6H, the portion in contact with the end 10b of the inner ring 3 is a curved line such as an arc or an ellipse. The inclination angle of the tangent line of the arc or ellipse is 70 degrees or less. When the retaining rings having the cross-sectional shapes shown in FIGS. 6A to 6H are mounted in opposite directions, the cross-sectional shapes shown in FIGS. 7A to 7H are obtained, and the specifications that cannot be disassembled are established. The same action as described in connection with FIG.

  In addition, it is preferable that the shape of the retaining ring 14 is the same in both the non-decomposable specification and the demountable specification, and it is preferable to be able to cope with both specifications by changing the direction, but in order to make a clearer distinction, Retaining rings with different shapes may be used for specifications that cannot be disassembled and specifications that can be disassembled. In that case, the shape of the retaining ring of the specification that cannot be disassembled is not limited to that illustrated in FIGS. 6 and 7, and the side surface 14 a of the retaining ring 14 is perpendicular to the axis of the through hole 9, and What is necessary is just to be in contact with the continuous surface 12a.

  By the way, the surface 10a perpendicular to the axis of the through-hole 9 and the surface 12a continuous therewith are within 20 degrees from the surface perpendicular to the axis of the through-hole 9 to the opposite tip side, even if not literally perpendicular. May be tilted so that the effects described so far are not disturbed. However, in this case, in the specification that cannot be disassembled, the retaining ring 14 shown in FIG. 2 is in line contact with the surface 10a or the surface 12a.

  The position of the retaining ring groove 13 may be anywhere within the range of the through hole 9 of the inner ring 3 in the state where the inner ring 3 and the shaft 6 are assembled. For example, as shown in FIGS. A groove 15 may be provided, and the groove 15 and the retaining ring groove 13 may be opposed so that the retaining ring 14 enters the groove 15. In that case, the same effect as the contents described so far is obtained.

Vertical section of constant velocity universal joint Enlarged view of part A in FIG. 1 showing the embodiment Perspective view of retaining ring Enlarged view similar to FIG. 2 showing the embodiment Enlarged view similar to FIG. 2 showing the embodiment Cross section of retaining ring Cross section of retaining ring Enlarged view similar to FIG. 2 showing the embodiment Enlarged view similar to FIG. 2 showing the embodiment

Explanation of symbols

1 Constant velocity universal joint 2 Outer ring (outer joint member)
7 Ball groove 3 Inner ring (inner joint member)
8 Ball groove 9 Through-hole 9a End on the opposite end side 10 Spline 10a Surface perpendicular to the axis 12 Hole 12a Surface continuous with the surface 10a 4 Ball 5 Cage 6 Shaft 6a Shoulder 11 Spline 13 Retaining ring groove 13a Tip Side wall 13b Anti-tip side wall 14 Retaining ring

Claims (6)

A shaft having a ring-shaped retaining ring groove, an inner joint member of a constant velocity universal joint having a through-hole for fitting with the shaft, and elastically expanding / reducing diameter disposed in the retaining ring groove are possible. When a force in the pulling direction is applied to the shaft, the retaining ring is interposed between the contact portion formed in the through hole of the inner joint member and the retaining ring groove. And
When the retaining ring comes into contact with the abutting part, the side surface that does not generate a component force sufficient to reduce the diameter of the retaining ring, and when the retaining ring comes into contact with the abutting part, contact the line to reduce the diameter of the retaining ring. A shaft fitting structure of a constant velocity universal joint having a side surface that generates sufficient component force.   2. The shaft fitting structure for a constant velocity universal joint according to claim 1, wherein a side surface that does not generate a component force sufficient to reduce the diameter of the retaining ring is assembled toward the contact portion side.   The shaft fitting structure for a constant velocity universal joint according to claim 1, wherein a side surface that generates a component force sufficient to reduce the diameter of the retaining ring is assembled toward the contact portion side.   4. The constant velocity according to claim 1, wherein the side surface that does not generate a component force sufficient to reduce the diameter of the retaining ring when contacting the contact portion is a flat surface that contacts from the vertical direction of the contact portion. Universal joint shaft fitting structure.   The shaft fitting structure for a constant velocity universal joint according to any one of claims 1 to 4, wherein a surface that generates a component force sufficient to reduce the diameter of the retaining ring when it comes into contact with the contact portion is an inclined surface. The shaft fitting structure for a constant velocity universal joint according to any one of claims 1 to 4, wherein the surface that generates a component force sufficient to reduce the diameter of the retaining ring when it comes into contact with the contact portion is an arc surface.

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