JP2007016811A - Shaft fitting structure of constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fitting structure of an internal joint member and a shaft of a constant velocity universal joint capable of achieving both of a specification for precluding disassembling after once assembling and a specification for allowing disassembling even after assembling, without increasing the kinds of internal joint member and shaft. <P>SOLUTION: The separation of the shaft is prevented when the power in the drawing-out direction is added to the shaft 6, by mounting retaining rings 14 respectively between a contact portion 10, 12 formed on a through hole 9 of the internal joint member 3 and a retaining ring groove, and the contact portions 10, 12 are composed of planes vertical to the drawing-out direction of the shaft 6. The specification for precluding disassembling after once assembling, and the specification for allowing disassembling even after assembling, can be distinguished by the shape of the retaining ring 14. <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 provide a constant velocity universal joint capable of satisfying both specifications: 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 and shafts. It is providing the fitting structure of the inner joint member of this, 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 shafts to prevent the shaft from coming off, and the contact portion is formed of a plane perpendicular to the shaft drawing direction. And, by selecting the shape of the retaining ring to be used, it is possible to establish both the specifications that the shaft and the inner joint member cannot be disassembled once assembled and the specifications that can be disassembled even after being assembled. . In addition, since the shape of the retaining ring is different, it is possible to easily visually determine whether the specification is a non-decomposable specification or a demountable specification.

  According to the present invention, by selecting the shape of the retaining ring, the contact state between the retaining ring and the retaining ring formed in the through hole of the inner joint member is changed, and the shaft is 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 produce a dedicated inner joint member or shaft for each specification, and assembling a specification that cannot be disassembled and a specification that can be disassembled without increasing load such as parts management man-hours and costs. be able to.

  Embodiments of the present invention will be described below with reference to the drawings. First, the fitting structure of the inner joint member and the shaft will be described with reference to FIGS. 1 to 3, and then the specification that cannot be disassembled by the shape of the retaining ring with reference to FIGS. 2, 4, and 5. Next, the disassembled specification will be described with reference to FIGS. 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. If one of the outer ring 2 and the inner ring 3 is on the driving side and the other is on the driven side, the ball 4 is interposed between them to transmit 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 the balls 4 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 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, the front end side of the through hole 9 is a surface continuous with a surface 10 a perpendicular to the axis formed at the end of the spline 10 by providing a hole 12 having a larger diameter than the through hole 9. 12a is formed. 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, There is only a surface 10a at the end of the spline 10 perpendicular to the axis.

  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.

  The shaft 6 and the inner ring 3 are assembled by inserting the shaft 6 into the through hole 9 with the retaining ring 14 disposed in the retaining ring groove 13 and the retaining ring 14 having a reduced diameter. At this time, the retaining ring 14 slides and moves while elastically contacting 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 reaches a position where the contact with the spline 10 is substantially eliminated, the end 9a on the side opposite to the tip of the through hole 9 is connected to the shoulder 6a of the shaft 6. Insertion is prevented by hitting. 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 counter bore 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 counterbore 12 to complete the assembly of the shaft 6 and the inner ring 3. 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.

  Various types of cross-sectional shapes of the retaining ring 14 can be adopted, but the inner ring 3 and the shaft 6 are roughly classified into two types, one having specifications that cannot be disassembled and one having specifications that can be disassembled.

  The retaining ring 14 for establishing a specification that cannot be disassembled may have a shape that does not generate a force for reducing the diameter of the retaining ring 14. For example, as shown in FIG. 2, when the retaining ring 14 has a square shape with parallel surfaces 14 a and 14 b, the surface 14 b on the opposite end side is a surface 10 a perpendicular to the axis of the through hole 9 and What is necessary is just to contact 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 front surface 14 a 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, since the surface 14b on the opposite end side of the retaining ring 14 hits the surfaces 10a and 12a of the inner joint member and the reaction force F of the withdrawal force is in the opposite direction to the withdrawal force, the diameter of the retaining ring 14 is reduced. No power is generated. Therefore, the shaft 6 cannot be pulled out from the inner ring 3.

  FIGS. 8A to 8H illustrate the cross-sectional shape of the retaining ring 14 having such a specification that cannot be disassembled. 8 (a) to 8 (f) basically have surfaces corresponding to the surfaces 14a and 14b of the retaining ring 14 of FIG. 2, but are inclined at other corners. A circular arc surface and a convex portion are provided. 8 (g) and 8 (h) show point contact with the surfaces 10a and 12a by inclining the surfaces in contact with the surfaces 10a and 12a of the inner joint member so that the overall cross-sectional shape is triangular or trapezoidal. It is a thing. Since no force for reducing the diameter of the retaining ring 14 is generated, it is not always necessary to make contact with the surfaces 10a and 12a.

  Moreover, in order to make it a specification which cannot be disassembled, the component force which expands a retaining ring may be generated. For example, the retaining ring 14 shown in FIG. 4 has a polygonal cross-sectional shape, and the tip side surface is an inclined surface 14c whose width gradually increases from the inner diameter side to the outer diameter side. 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 inclined surface 14 c of the retaining ring 14 comes into contact with the end portion 13 c of the wall 13 a on the tip side of the retaining ring groove 13 of the shaft. Depending on the inclination angle of the inclined surface 14 c of the retaining ring 14, a component force in the direction of expanding the retaining ring 14 is generated. However, when the outer peripheral surface of the retaining ring 4 is in contact with the peripheral wall of the hole 12, the retaining ring 14 cannot be further expanded in diameter. Therefore, after all, the inner joint member 3 and the shaft 6 cannot be disassembled.

  FIGS. 8 (i) to 8 (o) exemplify the cross-sectional shape of the retaining ring 14 having such specifications that cannot be disassembled. Both have a polygonal cross section having an inclined surface corresponding to the inclined surface 14c in contact with the end portion 13c of the wall 13a on the distal end side of the retaining ring groove 13. In the case of the retaining ring having the sectional shape shown in FIGS. 8 (i) to 8 (m), the retaining ring having the sectional shape shown in FIGS. 8 (n) and (o) operates in the same principle as in FIG. The surface of the joint member 3 that contacts the surfaces 10a and 12a is inclined so that the overall cross-sectional shape is a triangle (n) or a trapezoid (o), thereby making point contact with the surfaces 10a and 12a. Since the outer peripheral surface of the retaining ring 14 is in contact with the hole 12 and further diameter expansion is prevented, it is not always necessary to make contact with the surfaces 10a and 12a.

  Furthermore, the cross-sectional shape of the retaining ring 14 for making the specification that cannot be disassembled is not limited to the square shape as described above, but may be a circular shape as shown in FIG. In that case, as shown in FIG. 5, the retaining ring 14 is in point contact with either the surface 10a perpendicular to the axis of the through hole 9 or the surface 12a continuous therewith. Further, a specification that cannot be disassembled is established even if the radius r of the retaining ring 14 is larger than the radial dimension obtained by adding the surface 10a perpendicular to the axis of the through hole 9 and the surface 12a continuous therewith. In this case, the end portion 10b of the surface 10a perpendicular to the axis of the through-hole 9 (the tooth tip portion of the spline 10) and the retaining ring 14 are in contact with each other, and the component force in the direction of reducing the diameter of the retaining ring 14 is somewhat However, since the force required to reduce the diameter of the retaining ring 14 is sufficiently small, the inner joint member 3 and the shaft 6 cannot be disassembled after all.

  Incidentally, when the inclination of the line segment connecting the contact point between the end portion 10b of the surface 10a perpendicular to the axis of the through hole 9 and the retaining ring 14 and the center of the retaining ring 14 exceeds 20 degrees, the retaining ring 14 is removed. Since the component force in the direction to reduce the diameter becomes larger than the sum of the force that the retaining ring 14 itself wants to expand and the force necessary to reduce the diameter of the retaining ring 14, it changes to a resolvable specification. However, in order to mount the retaining ring 14 having such a large diameter, the width of the retaining ring groove 13 becomes unnecessarily large. FIGS. 8 (q) to 8 (u) exemplify modified examples of the retaining ring 14 having a circular cross section and a specification that cannot be disassembled as shown in FIG. 8 (p). These are shapes in which a flat portion and a notch are provided in a part of a circular cross section, but the specifications which cannot be disassembled are established when operating under the conditions described above with reference to FIG.

  Next, the shape of the retaining ring 14 when selecting a decomposable specification will be described. In this case, it is only necessary to generate a force for reducing the diameter of the retaining ring 14 larger than the sum of the force of the retaining ring 14 itself to increase the diameter and the force necessary to reduce the diameter of the retaining ring 14. For example, as shown in FIG. 6, the retaining ring 14 has a polygonal cross-sectional shape, and 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 inner joint member 3. You may make it contact | connect the edge part 10b (tooth front-end | tip part of the spline 10) of the surface 10a perpendicular | vertical to the axis line.

  When the pulling force B is applied to the shaft 6, the shaft 6 moves in parallel to the right side in the drawing, and the inclined surface 14 d of the retaining ring 14 and the end portion 10 b of the surface 10 a of the inner joint member 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. 7, the retaining ring 14 can be reduced in diameter and the shaft 6 can be pulled out from the inner ring 3. When 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 small, so that the retaining ring 14 cannot be reduced in diameter and cannot be disassembled.

  FIGS. 9A to 9H illustrate the cross-sectional shape of the retaining ring 14 for establishing the decomposable specification. The cross-sectional shapes shown in FIGS. 9A to 9D are polygonal, trapezoidal, and triangular, and have a shape in which an inclined surface is provided in a portion in contact with the end 10b (FIG. 6) in the retaining ring cross-section. . Further, in the cross-sectional shapes shown in FIGS. 9E to 9H, the portion in contact with the end portion 10b (FIG. 6) is an arc or an ellipse.

  In some cases, the retaining ring of the specification that cannot be disassembled and the retaining ring of the specification that can be disassembled may have similar shapes, but in the specification that cannot be disassembled, the surface 14b of the retaining ring 14 perpendicular to the axis (FIGS. 2 and 2) 4) is in contact with a surface 10a perpendicular to the axis of the through-hole 9 and a surface 12a continuous therewith, and in a decomposable specification, the inclined surface 14d (FIG. 6) with the inclination angle α of the retaining ring 14 is Each contact mechanism is completely different because it is in contact with the end 10b of the surface 10a perpendicular to the axis (the tooth tip of the spline 10). However, if there is a slight difference in the shape of the retaining ring, it may not be possible to easily distinguish between the specifications that cannot be disassembled and the specifications that can be disassembled. It is desirable to give a clear shape difference, for example, by adopting a retaining ring with a polygonal cross section having a sloped surface 14d (FIG. 6) with an inclination angle α as a dismountable specification.

  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. The angle described above may be taken so that the effects described so far are not hindered. However, when the retaining ring 14 has the shape shown in FIG. 8A or the like, it comes into line contact with the surface 10a or the surface 12a.

  On the other hand, 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 a state where the inner ring 3 and the shaft 6 are assembled. For example, as shown in FIGS. It is also possible to provide the groove 15 with the retaining ring 14 so that the retaining ring 14 enters the groove 15. In that case, the same effect as described above 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 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 perpendicular to the axis 15 Groove 4 Ball (torque transmission element)
5 Cage 6 Shaft 6a Shoulder 11 Spline 13 Retaining Ring Groove 13a Tip Side Wall 13b Anti-tip Side Wall 13c End Side Wall End 14 Retaining Ring 14a Tip Side Surface (Vertical to Axis)
14b Anti-tip side surface (perpendicular to axis)
14c inclined surface 14d inclined surface

Claims (7)

  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 abutting portion formed in the through hole of the inner joint member and the retaining ring groove, so that the shaft can be removed. A shaft fitting structure for a constant velocity universal joint, wherein the contact portion is formed by a plane perpendicular to the shaft drawing direction.   The shaft fitting structure for a constant velocity universal joint according to claim 1, wherein a surface of a retaining ring that comes into contact with the abutting portion is in a shape that comes into contact with the abutting portion from a direction perpendicular thereto.   The shaft fitting structure for a constant velocity universal joint according to claim 2, wherein the retaining ring has a cross-sectional shape of a triangle or more.   The shaft fitting structure for a constant velocity universal joint according to claim 2, wherein the retaining ring has a circular or oval cross-sectional shape.   The abutting portion is the smallest diameter portion of the through hole and is in line contact with the surface of the retaining ring, and the surface of the retaining ring has a shape that generates a component force in a direction to reduce the diameter of the retaining ring; The shaft fitting structure of the constant velocity universal joint according to claim 1.   The shaft fitting structure for a constant velocity universal joint according to claim 5, wherein a surface of the retaining ring has an inclined surface that is in line contact with a contact portion of the through-hole, and a sectional shape of the retaining ring is a triangle or more polygon. .   The shaft fitting structure for a constant velocity universal joint according to claim 5, wherein a part of a cross-sectional shape of the retaining ring that is in line contact with the contact portion of the through hole is circular or elliptical.

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