JP2007120615A - Fixed type constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixed type constant velocity universal joint having an inner ring, a cage and a torque transmitting ball formed in a temporarily assembled unit, the cage having a joint-corner-side end which is thin and liable to strength poverty but becomes thicker for more strength. <P>SOLUTION: In the fixed type constant velocity universal joint, the inner peripheral face of the cage 40 contacting the inner ring 20 consists of a spherical portion 46a located on the opening side of an outer ring 10 and a cylindrical porion 46b located on the corner side of the outer ring 10. The cylindrical portion 10b permits the axial movement of the inner ring 20 in a predetermined range, and when the inner ring 20 is at an axial-movement stroke end, the torque transmitting ball 30 is stored in a pocket 42 of the cage 40. An inner diameter B<SB>6</SB>of the cage 40, located on the outer ring corner side of the pocket 42, is set to be smaller than an cage inner diameter B<SB>5</SB>which restricts the axial-movement stroke end of the inner ring 20 and to be larger than a maximum diameter A<SB>2</SB>of a non-spherical portion of the inner ring 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fixed type constant velocity universal joint, and in particular, improves the cage strength of a fixed type constant velocity universal joint in which an inner ring, a cage and a torque transmitting ball are made into a temporary assembly unit capable of unit handling and are inserted into an outer ring from the same direction. About what

  Fixed type constant velocity universal joints allow only angular displacement between the connected drive side and driven side shafts, and are used in axle connection parts of automobile drive shafts and power transmission systems of various industrial machines. . As a type of the fixed type constant velocity universal joint, conventionally, a Zepper type constant velocity universal joint and an undercut free type (hereinafter referred to as UJ type) constant velocity universal joint are known.

  A zeppa type constant velocity universal joint which is a fixed type constant velocity universal joint includes an outer ring, an inner ring, a ball and a cage. A plurality of curved ball grooves are formed at equal intervals on the inner spherical surface of the outer ring and the outer spherical surface of the inner ring. The ball is assembled between the outer ring ball groove and the inner ring ball groove, and the cage is assembled between the outer ring and the inner ring. The UJ type constant velocity universal joint was developed for the purpose of higher operating angle than the Zepper type constant velocity universal joint. The ball center locus of the guide groove of the outer ring is the center of the joint among the arcs of the Zepper type meridian. The section on the opening side of the outer ring is a straight line parallel to the joint axis from the cross section perpendicular to the axis passing through (see Patent Document 1).

When the cage is assembled to the outer ring of such a fixed type constant velocity universal joint, in the fixed type constant velocity universal joint described in Patent Document 1, the cage is first placed in the outer ring, and then the inner ring is placed inside the cage. Passing through the outer ring, place it on the back side of the normal position, and in that state, insert the torque transmission ball (hereinafter simply referred to as “ball”) into the cage pocket from the inside, and then place the inner ring in the normal position. Finally, a member that supports the inner ring in the axial direction is inserted and fixed to the outer ring.
JP-A-6-193645 (FIGS. 6 to 9)

  The fixed type constant velocity universal joint described in Patent Document 1 has a shallow track groove in the inner ring due to its assembling method, and the torque load capacity becomes small. In other words, after inserting the cage into the outer ring, the inner ring is inserted inside the cage, the inner ring is pushed down to the bottom of the outer ring, and the ball is inserted into the pocket from the inside of the cage. In order to push down to the bottom of the inner ring, it is necessary to set the outer diameter of the inner ring smaller than the inner diameter of the cage. Here, since the outer diameter of the intermediate shaft fitted to the inner ring is a specified value, the track groove of the inner ring becomes shallower when the outer diameter of the inner ring is reduced. As a result, there arises a problem that the torque load capacity is reduced.

  Further, the fixed type constant velocity universal joint described in Patent Document 1 has a structure in which the outer spherical surface of the inner ring is supported in the axial direction by the concave spherical surface of the bottom member arranged on the bottom of the outer ring. Since the concave spherical surface of the bottom member supporting the inner ring in the axial direction is located in a relatively narrow range including the joint central axis, it is difficult to maintain constant velocity at a large operating angle, and vibration There is a problem that the amount of heat generation and wear increases due to a large relative displacement between the concave spherical surface of the bottom member and the outer spherical surface of the inner ring. In addition, the work of putting the ball from the inside of the outer ring and the cage is complicated, and the work efficiency in the assembly process is poor.

  Therefore, in order to solve the above problems, the present applicant has proposed a fixed type constant velocity universal joint in which an inner ring, a cage and a torque transmission ball are made into a temporarily assembled unit capable of unit handling (Japanese Patent Application No. 2005-57857, Japanese Patent Application No. 2005-57864). In this fixed type constant velocity universal joint, after inserting the inner ring into the cage, the ball is inserted into the pocket from the outside of the cage to obtain a temporary assembly unit. In this temporarily assembled unit state, the top of the ball is inserted into the outer ring from the coaxial direction so as not to protrude from the cage pocket to the outer diameter side.

  In such a fixed type constant velocity universal joint, since the ball is already assembled in the temporary assembly unit, it is not necessary to push the inner ring down to the bottom of the outer ring.

  However, in the proposed temporary assembly unit of the fixed type constant velocity universal joint, in order to prevent the top of the ball from protruding from the cage pocket to the outer diameter side, the inner ring is axially moved relative to the cage. Must be close to the stroke end. If the outer diameter of the inner joint end of the cage is constant, if the inner ring stroke is set deeper toward the inner joint side, the thickness of the inner joint end of the cage will be reduced by that amount. That is, as the stroke of the inner ring is deepened toward the joint back side, the ball can be accommodated in the pocket with a margin, while the inner diameter of the joint back side end portion of the cage increases.

  In addition, in the proposed fixed constant velocity universal joint, the temporary assembly unit is inserted into the outer ring, and then the inner ring is moved in a direction that is relatively pulled out of the cage to give the ball a normal position. However, there is no contact on the joint back side, and contact is only on the joint opening side. Since the axial force of the joint is supported by the contact between the inner and outer rings and the cage only on the outer ring opening side, the contact situation between the outer ring opening side inner spherical surface and the cage outer spherical surface becomes severe, and the strength and durability of the joint are reduced. descend.

  An object of the present invention is to increase the thickness of the inner end of the joint of the cage, which tends to be thin and insufficient in strength, in a fixed constant velocity universal joint in which the inner ring, the cage and the torque transmission ball are a temporary assembly unit capable of unit handling. The purpose is to increase the strength. Another object of the present invention is to support a portion of the joint axial force acting on the cage by the inner ring outer spherical surface abutting the cage inner diameter surface on the inner side of the joint with the joint having a high operating angle. Therefore, the contact state between the outer ring and the cage on the outer ring opening side is relaxed to improve the strength and durability of the joint.

  The present invention provides an outer ring having a plurality of ball grooves that are open at one end and extend axially on an inner spherical surface, an inner ring that has a plurality of ball grooves extending axially on the outer spherical surface, and a ball groove of a pair of outer rings. A torque transmission ball incorporated between the inner ring and a ball groove of the inner ring, and a cage that is interposed between the inner spherical surface of the outer ring and the outer spherical surface of the inner ring and holds the torque transmission ball in the pocket in the axial direction. The inner peripheral surface of the cage in contact with the inner ring is composed of a spherical portion located on the opening side of the outer ring and a cylindrical portion located on the inner side of the outer ring, the cylindrical portion allows axial movement of the inner ring over a predetermined range, In the fixed type constant velocity universal joint in which the torque transmission ball is accommodated in the cage pocket when the inner ring is at the stroke end of the axial movement, the inner diameter located on the inner side of the outer ring of the pocket is the inner diameter of the cage. The inner ring Smaller than the cage inner diameter for regulating the stroke end of the movement, and characterized by being larger than the sagittal section the maximum diameter of the inner ring.

  The inner diameter of the cage and the back side of the outer ring of the pocket is a part facing the inner ring ball groove. This part allows the inner ring to pass through the maximum diameter of the ball notch when the inner ring is inserted into the cage. On the other hand, when the inner ring, the cage and the torque transmitting ball are used as a temporary assembly unit capable of unit handling, the inner ring is On the other hand, it is a portion that faces the inner ring ball groove while being moved to the stroke end but does not interfere with the outer ring spherical surface. The inner ring stroke end with respect to the cage is restricted by a protrusion formed on the inner diameter of the inner end of the joint on the extension of the column portion between the pockets. In this type of fixed type constant velocity universal joint, as described above, the inner diameter of the pocket located on the inner side of the outer ring is larger than the inner diameter of the cage that restricts the stroke end of the inner ring in the axial movement (the inner diameter of the protrusion). By setting it to be smaller and larger than the maximum diameter of the inner ring sphere, the inner end of the cage joint, which tends to be thin and insufficient in strength, is shaped like a stepping stone but thickened to increase its strength. Can do.

  The present invention also provides an outer ring having a plurality of ball grooves that are open at one end and extend axially on the inner spherical surface, an inner ring that has a plurality of ball grooves extending axially on the outer spherical surface, and a pair of outer ring balls. A torque transmission ball incorporated between the groove and the ball groove of the inner ring, and a cage that is interposed between the inner spherical surface of the outer ring and the outer spherical surface of the inner ring and holds the torque transmission ball in the pocket in the axial direction. The inner peripheral surface of the cage in contact with the inner ring is composed of a spherical portion located on the opening side of the outer ring and a cylindrical portion located on the inner side of the outer ring, and the cylindrical portion allows axial movement of the inner ring over a predetermined range. In a fixed type constant velocity universal joint in which the torque transmission ball is accommodated in the cage pocket when the inner ring is at the stroke end of the axial movement, the inner diameter of the cage that is located on the back side of the outer ring of the pocket The above When the inner diameter of the inner ring is perpendicular to the axis of the cage and the inner ring is inserted into the cage. The inner ring ball groove side surface is applied to the radial surface of the diameter-enlarging step, the inner ring spherical center is shifted from the cage axis, and the inner ring can be inserted into the cage while the inner ring axis is tilted about the inner ring radial axis. It is characterized by that.

  In this fixed type constant velocity universal joint, the joint inner end of the cage is made thicker than that described above. That is, the inner diameter of the cage, which is located on the back side of the outer ring of the pocket, is set to the minimum inner diameter part that is smaller than the maximum diameter of the spherical part of the inner ring. If the diameter is reduced so far, the inner ring cannot be inserted into the cage by the conventional method. Therefore, an enlarged diameter step is formed on the inner diameter part of the outer ring on the inner diameter side, and the inner ring is placed at a right angle on the enlarged diameter step, and the spherical center and the cage axis are shifted. Then, the position where the small diameter side of the inner ring, that is, the joint back side can get over the minimum inner diameter part is searched, and the inner ring is inserted into the cage while the inner ring is inclined around the radial axis at that position. This fixed type constant velocity universal joint can further increase the strength of the cage's inner joint, so that the strength of the cage can be further increased, and when the minimum inner diameter is a concave spherical surface with the same curvature as the inner ring outer spherical surface, the joint takes an operating angle. In this state, the minimum inner diameter portion can be supported by the inner ring outer spherical surface. As a result, a part of the axial force acting on the cage can be supported by the inner ring, the contact state between the outer ring and the cage on the outer ring opening side can be relaxed, and the strength and durability of the joint can be improved. .

As described above, according to the present invention, the inner diameter of the pocket located on the inner side of the outer ring is set to be smaller than the inner diameter of the cage that regulates the stroke end of the inner ring in the axial direction movement and larger than the maximum diameter of the inner ring. By doing so, it is possible to increase the strength of the cage by increasing the thickness of the end portion on the back side of the joint, which tends to be thin and insufficient in strength.
In addition, the inner diameter of the cage, which is located on the back side of the outer ring of the pocket, is set to the minimum inner diameter part that is smaller than the maximum diameter of the inner ring. Strength can be increased.
Also, when the minimum inner diameter portion is a concave spherical surface having the same curvature as the inner ring outer spherical surface, the joint inner axial outer force is applied to the cage by supporting the minimum inner diameter portion with the inner ring outer spherical surface with the joint at an operating angle. The part can be supported by the inner ring, the contact state between the outer ring and the cage on the outer ring opening side can be relaxed, and the strength and durability of the joint can be improved.

  In addition, according to the present invention, the following effects peculiar to the fixed type constant velocity universal joint in which the inner ring, the cage, and the torque transmission ball are made into a temporarily assembled unit capable of unit handling can be obtained. That is, it becomes easy to manufacture a fixed type constant velocity universal joint, that is, to assemble components. One is that the inner ring, cage and ball temporary assembly unit can be unit-handled, and the other is that when making the temporary assembly unit, the ball can be inserted into the cage from the outside, so workability is good. .

  A temporary assembly unit that can handle the inner ring, cage, and ball as a unit, and the combination of the temporary assembly unit and the outer ring constitutes a fixed constant velocity universal joint, so that the outer ring has various shapes according to the application. On the other hand, a common temporary assembly unit can be used. For example, even when the outer ring outer shape or the shape of the connecting shaft with the wheel differs depending on the vehicle type or the like, only the temporary assembly unit can be used, which greatly contributes to cost reduction.

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

  FIG. 1 shows a longitudinal section of a UJ (undercut free) type fixed constant velocity universal joint. As shown in the figure, the fixed type constant velocity universal joint includes an outer ring 10, an inner ring 20, a ball 30, a cage 40 and a shaft 50 as main components. The outer ring 10 includes a mouse portion 10a and a stem portion 10b. In this embodiment, the stem portion 10b has a serration portion 10b1 and a screw portion 10b2. As shown in FIGS. 2 and 3, the mouse portion 10 a has a bowl shape opened at one end. An inner peripheral surface (hereinafter referred to as “inner spherical surface”) 12 of the mouse portion 10 a is a partial spherical surface centered at a point O where the stem portion 10 b which is a coupling two axis of the joint and the central axis of the shaft 50 intersect. A plurality, here, eight ball grooves 14 extending in the axial direction are formed on the inner spherical surface 12 at equal intervals in the circumferential direction. A raised portion that is raised in a short columnar shape is formed at the bottom of the mouse portion 10a. A concave spherical surface seat 18 is formed on the top surface of the raised portion. The center of curvature of the spherical seat 18 is the joint center O. An annular space 19 is formed around the spherical seat 18. In this embodiment, the stem portion 10b has a serration portion 10b1 and a screw portion 10b2.

  In addition, the diameter of the spherical seat 18 is made larger than the diameter of the shaft 50, and the stem portion 10b including the expanded spherical seat 18 is manufactured separately from the outer ring 10 with the surface indicated by the broken line P in FIG. At the final stage of assembly of the fixed type constant velocity universal joint, it may be integrated with the outer ring 10 by a coupling means such as a screw. If such a separate stem portion or the expanded spherical seat 18 is used, when the shaft 50 is inserted into the inner ring 20 inserted into the outer ring 10, the inner ring 20 is not inclined as shown in FIG. That's it.

  In order to avoid interference with the shaft when the joint takes the maximum operating angle, a tapered chamfer 16a that opens to the outside is formed on the end surface of the outer ring 10 on the opening side. A cylindrical portion 16 b is formed between the chamfer 16 a and the outer ring inner spherical surface 12 and between the ball grooves 14. The cylindrical portion 16b forms the minimum inner diameter of the outer ring 10 opening. When the temporary assembly unit composed of the inner ring 20, the cage 40 and the torque transmission ball 30 is inserted into the outer ring 10 in the coaxial direction, the outer edge of the pocket 42 of the temporary assembly unit cage 40 passes through the inside of the cylindrical portion 16b. .

The inner ring 20 has a spherical shape as shown in FIGS. 1 and 4, and a plurality of, here, eight ball grooves 24 extending in the axial direction are formed on the partial spherical outer peripheral surface (hereinafter referred to as “outer spherical surface”) 22. It is formed at equal intervals in the direction. The inner ring 20 is coupled to the shaft 50 by a spline hole 26 so that torque can be transmitted. In FIG. 4, reference signs A ₁ and A ₂ indicate the outer diameter of the outer spherical surface 22 of the inner ring 20 and the minimum projected diameter (the maximum diameter of the spherical notch portion) in the central cross section of the outer spherical surface 22, respectively.

  In the state where the fixed type constant velocity universal joint shown in FIG. 1 is assembled, the end portion of the spline hole 26 of the inner ring 20 located on the spherical seat 18 side is made larger than the outer diameter of the spherical seat 18. The spherical seat 18 of the outer ring 10 and the outer spherical surface 22 of the inner ring 20 are provided with a hardened surface layer by heat treatment. As can be seen from FIG. 1, the end surface of the shaft 50 is a spherical surface having substantially the same radius of curvature as the outer spherical surface 22 of the inner ring 20, and both form one spherical surface when the shaft 50 is assembled to the inner ring 20.

As shown in FIG. 1, the center of curvature O ₁ of the ball groove 14 of the outer ring 10 and the center of curvature O ₂ of the ball groove 24 of the inner ring 20 are offset from the joint center O by an equal distance f in the axial direction. Therefore, the ball grooves 14 and 24 of the inner and outer rings 10 and 20 forming a pair have a wedge shape that expands toward the large end face side opening of the outer ring 10.

The fixed type constant velocity universal joint of this embodiment has no undercut in the ball grooves 14 and 24 (undercut free). That is, the ball groove 14 of the outer ring 10 is composed of a circular arc bottom 14a parallel straight bottom 14b to the axis positioned on the large end face positioned on the small end face side to the center of curvature O ₁ as a boundary. Similarly, the ball groove 24 of the inner ring 20 has an arc bottom 24a located on the large end face side of the outer ring 10 and a straight bottom 24b parallel to the axis located on the small end face side of the outer ring 10 with the center of curvature O ₂ as a boundary. Composed.

The cage 40 is interposed between the inner spherical surface 12 of the outer ring 10 and the outer spherical surface 22 of the inner ring 20. A plurality of, here, eight pockets 42 are arranged in the circumferential direction of the cage 40. The outer spherical surface 44 of the cage 40 is in contact with the inner spherical surface 12 of the outer ring 10. As shown in FIGS. 5A and 5B and FIG. 6, the diameter B ₂ of the corner portions 41 and 43 formed by the outer spherical surface 44 of the cage 40 and the side wall facing the axial direction of the pocket 42 is the outside of the cage 40. It is smaller than the outer diameter B _{1 of the} spherical surface 44. Diameter B ₂ is are smaller than the inner diameter C ₁ of the cylindrical portion 16b of the outer ring 10 (B ₂ <C _1). This is a dimensional relationship required when the cage 40 is inserted in the coaxial direction.

Here, although the diameter B ₂ of the portion indicated by reference numeral 41 is a little larger, it can be entered if it is slightly inclined from the same axis, but the above-described dimensional relationship (B ₂ <C ₁ ) is required for the diameter B ₂ of the portion indicated by reference numeral 43. is there. It is also possible to provide a portion to be cut to reduce the diameter B ₂ such as chamfering the corners 41 and 43 of the cage 40. If the diameter B ₂ can be reduced, the inner diameter C ₁ of the cylindrical portion 16b of the outer ring 10 can also be reduced, and thereby the range of the inner ring spherical surface that guides the outer spherical surface of the cage can be expanded in the direction of the large end face. The speed, durability, etc. are improved.

As can be seen from FIG. 5 (A), the inner circumferential surface 46 of the cage 40 has a spherical portion 46a of radius B ₃ was smoothly continuous with each other at the axial center (in FIG. 1 coincide with the joint center O) as indicated by the dashed line consists of the combination of the cylindrical portion 46b of the diameter _{B 4 (2 × B 3 =} B 4). That is, the large end surface side of the outer ring 10 from the center in the axial direction is a spherical surface portion 46a that contacts the outer spherical surface 22 of the inner ring 20 and supports the inner ring 20 in the radial direction and the axial direction, and the small end surface of the outer ring 10 from the axial center. The side is a cylindrical portion 46b that is in contact with the outer ring of the inner ring and supports the inner ring 20 in the radial direction. The cylindrical portion 46b is necessary to retract the inner ring 20 in the axial direction from the normal position during the assembly process (see FIGS. 8 and 9).

A protrusion 48 protruding toward the inner diameter side is provided at the end of the cylindrical portion 46b. As shown in FIG. 5A, at least the protrusions 48 need only be on the extended lines of the pillars between the pockets. As shown in FIG. 8, the protrusion 48 defines the stroke end of the axial movement of the inner ring 20 in order to prevent the inner ring 20 from falling off when the inner ring 20, the ball 30 and the cage 40 are used as a temporary assembly unit. It functions as a stopper (see FIGS. 8 and 9A). Therefore, the inner diameter B _{5 of the} projection 48 is set smaller than the outer diameter A ₁ of the outer spherical surface 22 of the inner ring 20 (B ₅ <A ₁ ).

A minimum inner diameter portion 49 is formed on the inner surface of the cage 40 between the protrusions 48, that is, on the inner surface of the back side of the joint of the pocket 42. The inner diameter _{B 6} of the minimum inner diameter portion 49 is smaller than the inner diameter of the projection 48, and is set to be larger than the inner ring of the spherical segment portion maximum diameter _{A 2 (A 2 <B 6} <B 5). The minimum inner diameter portion is formed in the same number as the pocket, and forms a rectangular region in plan view.

  The ball groove 14 of the outer ring 10 and the ball groove 24 of the inner ring 20 make a pair, and a ball 30 is incorporated between each pair of ball grooves 14 and 24. One ball 30 is accommodated in each pocket 42 of the cage 40. The cage 40 acts so that all the balls 30 are positioned on the bisector of the angle formed by the outer ring 10 and the inner ring 20, that is, the operating angle of the joint, whereby the constant velocity of the joint is maintained. .

  Next, a manufacturing method of the fixed type constant velocity universal joint having the above-described configuration, that is, an assembly procedure of components including the outer ring 10, the inner ring 20, the ball 30, and the cage 40 will be described.

First, as shown in FIG. 7, the inner ring 20 is inserted into the cage 40 with the axes orthogonal to each other. At this time, the magnitude relationship (A ₂ <B ₅ ) between the minimum projected diameter A ₂ (FIG. 4) in the central cross section of the outer spherical surface 22 of the inner ring 20 and the inner diameter B ₅ (FIG. 8) of the projection 48 of the cage 40 is expressed. Use. Then, the inner ring 20 is turned so that the two axes coincide with each other to be coaxial. If the diameter difference (B ₅ -A ₂ ) is small, it may be pushed in the same direction from the beginning.

  The inner ring 20 is moved in the axial direction within the cylindrical portion 46b of the cage 40, and the outer spherical surface 22 of the inner ring 20 is brought into contact with the projection 48 of the cage 40, so that both are in the positional relationship shown in FIG. At this time, the inner ring 20 stops at the position where the outer spherical surface 22 hits the protrusion 48 of the cage 40, that is, the position retracted by the distance indicated by the symbol X from the normal position by the stopper function of the protrusion 48 described above. At this time, since the smallest inner diameter portion 49 located on the joint back side of the pocket 42 faces the ball groove 24 of the inner ring 20, interference with the outer spherical surface 22 of the inner ring 20 does not occur.

As shown in FIG. 10, the ball 30 is inserted into the pocket 42 from the outside in a state where the phase of the ball groove 24 of the inner ring 20 and the phase of the pocket 42 of the cage 40 are matched. The ball 30 is pushed in until it hits the ball groove 24 of the inner ring 20. The top or the circumscribed circle diameter D ₁ of the ball 30 in this state, the diameter B ₂ corners 41, 43 of the pocket 42 of the cage 40 (FIG. 5 (B), the Fig. 6) or less.

Incidentally, denoted by reference numeral D ₂ in FIG. 9 (A), the distance from the bottom of the ball groove 24 of the inner ring 20 to the corner portion formed between the spherical portion side wall of the spherical portion 46a and the pocket 42 of the cage 40, a ball diameter If the dimensional relationship is set to be small, the ball 30 does not fall off to the inner diameter side, unit handling is possible, and handling becomes very easy. Such a dimensional relationship depends on the position (X) of the protrusion 48 of the cage 40 described above with reference to FIG. Normally, there is an interference between the ball 30 and the pocket 42, so that it is difficult for the ball 30 and the pocket 42 to drop off.

  Next, as shown in FIG. 11, the temporary assembly unit of the inner ring 20, the cage 40, and the ball 30 is inserted from the opening of the outer ring 10. As shown in FIG. 12, this insertion is performed with the phase of the ball groove 14 of the outer ring 10 and the ball groove 24 of the inner ring 20 being shifted by α / 2, where α is the angle between adjacent balls. As a result, the outer spherical surface 44 of the cage 40 abuts on the inner spherical surface 12 of the outer ring 10, and at that time, the outer spherical surface 22 of the inner ring 20 occupies the annular space 19 at the bottom of the outer ring 10, as shown in FIGS. 13 and 14. Become.

  The ball 30 of the temporarily assembled unit only needs to be able to pass the cylindrical portion 16b of the outer ring 10 at the top of the ball, and after passing through this, the ball 30 can move radially outward along the inner spherical surface 12 of the outer ring 10.

  Here, the axial position of the contact portion where the outer spherical surface 22 of the inner ring 20 is in contact with the bottom of the outer ring 10 is more advantageous in terms of reducing the axial size of the joint. Since there is little difference in level between 18 and the bottom of the annular space 19, it is advantageous in processing. Therefore, after the ball has passed through the outer ring cylindrical portion 16b, before the outer spherical surface 44 of the cage 40 hits the inner spherical surface 12 of the outer ring 10, the outer spherical surface 22 of the inner ring 20 hits the bottom of the outer ring 10 and the inner ring moves further. As a result, the contact portion can be positioned on the larger end face side if the ball jumps radially outward as the cage further advances to the inner side of the outer ring mouth portion.

  Next, as shown in FIG. 15, the phases of the temporarily assembled units (20, 30, 40) and the outer ring 10 are shifted by α / 2 angles to match the phases of the ball grooves 14, 24 of the inner / outer rings 10, 20. Then, as shown in FIG. 16, a jig 54 is hooked on the clip groove 27 formed in the spline hole 26 of the inner ring 20 to move the inner ring 20 in the axial direction toward the opening side of the outer ring 10. 22 is brought into contact with the spherical surface portion 46 a of the cage 40. At this time, the ball 30 moves radially outward as the inner ring 20 moves in the axial direction, and the inner ring 20 and the ball 30 occupy the normal position.

  Next, as shown in FIG. 17, the shaft 50 is inserted into the spline hole 26 of the inner ring 20 while the inner ring 20 is inclined with respect to the outer ring 10 and the outer spherical surface 22 of the inner ring 20 is in contact with the spherical seat 18 of the outer ring 10. Insert and prevent the clip 52 from coming off. The reason why the inner ring 20 is tilted at this time is that the inner ring 20 escapes into the annular space 19 in the coaxial state. Then, the fixed constant velocity universal joint is completed by returning the shaft 50 to the same axis as the outer ring 10 (FIG. 1).

  In the embodiment shown in FIGS. 18 and 19, a collar 28 is provided on the inner ring 20 '. The collar 28 is positioned on the opening side of the outer ring 10 and has a recess 29 for hooking the jig 56. Using the jig 56, the inner ring 20 is pulled in the axial direction toward the opening side of the outer ring 10, and the shaft 50 is pushed into the spline hole 26 of the inner ring 20 as it is and the clip 52 prevents the inner ring 20 from coming off.

  In any embodiment, the outer spherical surface 22 of the inner rings 20 and 20 ′ is supported in the axial direction by the spherical seat 18 provided on the outer ring 10, and the outer spherical surface 22 of the inner rings 20 and 20 ′ is supported by the cylindrical portion 46 b of the cage 40. Since the structure is supported in the radial direction, a sufficient torque load capacity can be ensured, vibration and noise can be prevented, and constant velocity can be maintained.

Next, a second embodiment of the present invention will be described with reference to FIGS. In this embodiment, the minimum inner diameter portion 49 of the cage 40 is further raised (thickened) to a new minimum inner diameter portion 49 ′, and the joint back side of the aforementioned minimum inner diameter portion 49 is arranged in the thickness direction. A diameter-expanded step 47 is formed by cutting. The minimum inner diameter portion 49 ′ is a concave spherical surface having the same curvature as the inner ring outer spherical surface 22, and the minimum inner diameter portion 49 ′ can be supported by the inner ring outer spherical surface 22 in a state where the joint takes an operating angle. Since the enlarged diameter step portion 47 does not constitute a functional surface of the joint, the processing accuracy may be low. The inner diameter _{B 7} of the new minimum inner diameter portion 49 'is an inner ring of the spherical segment portion maximum diameter _{A 2} is smaller than _(B 7 _<A 2). The inner diameter B ₈ of the expanded stepped portion is larger than the outer diameter A ₁ of the outer spherical surface 22 of the inner ring 20 (A ₁ <B ₈ ). Except for the minimum inner diameter portion 49 ′ and the enlarged diameter step portion 47, this embodiment is the same as the above embodiment.

In the second embodiment, the method for inserting the inner ring into the cage is different from that described above. Since the inner diameter B ₇ of the smallest inner diameter portion 49 ′ of the cage 40 is smaller than the maximum spherical diameter A _{2 of} the inner ring 20 (B ₇ <A ₂ ), the inner ring 20 cannot be inserted by the above-described method. Therefore, a unique charging method as shown in FIGS. First, as shown in FIG. 21, with the inner ring 20 being perpendicular to the axis of the cage 40, the inner ring 20 is slightly tilted in the left-right direction and four half of the eight corners are placed in the cage 40. Include. Here, the corner means the outer spherical surface 22 between the ball grooves 24. Next, the side surfaces of any pair of left and right ball grooves 24 on both sides of the inner ring 20 are applied to the radial surface of the diameter-enlarging step portion 47 (see FIGS. 22 and 23A). For this reason, the inner diameter B ₈ of the expanded step portion is larger than the outer diameter A ₁ of the outer spherical surface 22 of the inner ring 20. In this state, more than half of the inner ring 20 has entered the cage 40.

  Next, the spherical center of the inner ring 20 and the axis of the cage 40 are shifted. Since the inner ring 20 is surrounded by the enlarged diameter step portion 47, the maximum amount to be shifted is regulated by the enlarged diameter step portion 47. The direction in which the inner ring 20 is shifted is the left side in FIG. By shifting the inner ring 20 to the left, the left side of the outer spherical surface 22 of the inner ring 20 (becomes the joint opening side) comes into contact with the radial surface of the enlarged diameter step portion 47. The inner ring corner portion (tsubu) is provided with an appropriate taper surface 22a on the large end surface side, and this shift amount is secured. In this state, the circumferential position of the cage 40 where the side surface of the ball groove 24 on the opposite side (behind the joint back side) that is not in contact with the enlarged diameter step portion 47 of the inner ring 20 can get over the minimum inner diameter portion 49 ′. explore. In FIG. 23B, the side surface of the ball groove 24 on the opposite side that is not in contact with the radial surface of the enlarged diameter step portion 47 has come to a circumferential position where it can get over the minimum inner diameter portions 49′a and 49′d. Indicates the state. From this state, the inner ring 20 is inserted into the cage 40 while the axis of the inner ring 20 is tilted about the radial axis of the inner ring 20 indicated by a one-dot chain line (see FIG. 23C). FIG. 24 shows a state where the inner ring 20 is moved to the stroke end (X) with the inner ring 20 and the cage 40 aligned with each other. The outer spherical surface 22 of the inner ring 20 interferes with the projection 48 to determine the stroke end. Since the minimum inner diameter portion 49 ′ enters the ball groove 24 of the inner ring 20, it does not interfere with the outer spherical surface 22.

  The present invention is not limited to the embodiment described and illustrated above, and various modifications can be made without departing from the scope of the claims. For example, although the illustrated embodiment exemplifies one using eight torque transmitting balls, it is also possible to use six torque transmitting balls. However, if the number of torque transmission balls is eight, the ball PCD is larger than the ball diameter compared to the one using seven or less torque transmission balls, so the amount of ball jumping out from the cage outer spherical surface is small, the inner ring, In order to obtain a state in which the ball is pushed in a temporary assembly unit including a cage and a ball, the pushing amount of the ball in the radial direction is small. In addition, since the ball PCD is large with respect to the ball diameter, it is easy to ensure serration inside the inner ring, and it is easy to secure a spherical surface portion on the opposite side of the inner ring from the large end surface of the outer ring.

The longitudinal cross-sectional view of the fixed type constant velocity universal joint which shows embodiment of this invention. The principal part longitudinal cross-sectional view of an outer ring | wheel. The right view of the outer ring | wheel of FIG. It is an end view of an inner ring (A) is a longitudinal sectional view of the cage, (B) is a longitudinal sectional view around the pocket. FIG. 6 is a left side view of the cage of FIG. 5. Explanatory drawing which shows the process in which an inner ring | wheel is integrated in a cage. The principal part longitudinal cross-sectional view which shows the positional relationship of an inner ring | wheel and a cage. (A) is a longitudinal sectional view showing a process of incorporating a ball into a subassembly of an inner ring and a cage to form a temporarily assembled unit, and (B) is a side view of the temporarily assembled unit with the ball omitted. The left view of the temporary assembly unit of FIG. The principal part longitudinal cross-sectional view which shows the process in which the temporary assembly unit of an inner ring | wheel, a cage, and a ball | bowl is integrated in an outer ring | wheel. The end view of the state which installed the temporary assembly unit in the outer ring. XIII-XIII sectional drawing of FIG. XIV-XIV sectional drawing of FIG. FIG. 13 is an end view similar to FIG. 12 in a state where the phases of the ball grooves of the inner and outer rings are matched. The principal part longitudinal cross-sectional view of the coupling of FIG. The principal part longitudinal cross-sectional view of the coupling of FIG. 15 of the state which pushed in the shaft. Sectional drawing similar to FIG. 16 which shows another embodiment. Sectional drawing similar to FIG. 17 which shows another embodiment. (A) is an end view of the cage, (B) is a longitudinal sectional view of the cage, and (C) is a side view of the cage inner surface around the pocket. The longitudinal cross-sectional view of the cage which shows an inner ring | wheel insertion process. The longitudinal cross-sectional view of the cage which shows an inner ring | wheel insertion process. (A)-(C) is an end view of the cage showing the inner ring charging process. The longitudinal cross-sectional view of the cage of an inner ring | wheel insertion completion state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Outer ring 10a Mouse | mouth part 10b Stem part 10b1 Serration part 10b2 Screw part 12 Inner spherical surface 14,24 Ball groove 14a Arc bottom 14b Straight bottom 16a Chamfer 16b Cylindrical part 18 Spherical seat 19 Annular space 20 Inner ring 22 Outer spherical surface 24 Ball groove 24a Arc bottom 24b Straight bottom 26 Spline hole 27 Clip groove 29 Recess 30 Ball 40 Cage 41, 43 Corner portion 42 Pocket 44 Outer spherical surface 46 Inner circumferential surface 46a Spherical portion 46b Cylindrical portion 47 Expanded stepped portion 48 Protrusions 49, 49 'Minimum inner diameter portion 50 Shaft 52 Clip 54, 56 Jig

Claims (4)

An outer ring which is open at one end and has a plurality of ball grooves extending in the axial direction on the inner spherical surface, an inner ring having a plurality of ball grooves extending in the axial direction on the outer spherical surface, a pair of outer ring ball grooves and inner ring balls A cage that is provided between the groove and a cage that is interposed between the inner spherical surface of the outer ring and the outer spherical surface of the inner ring and that holds the torque transmitting ball in the pocket in the axial direction, and is in contact with the inner ring The inner peripheral surface of the outer ring is composed of a spherical part located on the opening side of the outer ring and a cylindrical part located on the inner side of the outer ring. The cylindrical part allows axial movement of the inner ring over a predetermined range, and the inner ring is axially In the fixed type constant velocity universal joint in which the torque transmission ball is placed in the cage pocket when it is at the end of the movement stroke,
The inner diameter of the cage, which is located on the back side of the outer ring of the pocket, is smaller than the inner diameter of the cage that regulates the stroke end of the inner ring in the axial direction movement, and larger than the maximum diameter of the ball notch of the inner ring. Fixed constant velocity universal joint characterized by setting. An outer ring which is open at one end and has a plurality of ball grooves extending in the axial direction on the inner spherical surface, an inner ring having a plurality of ball grooves extending in the axial direction on the outer spherical surface, a pair of outer ring ball grooves and inner ring balls A cage that is provided between the groove and a cage that is interposed between the inner spherical surface of the outer ring and the outer spherical surface of the inner ring and that holds the torque transmitting ball in the pocket in the axial direction, and is in contact with the inner ring The inner peripheral surface of the outer ring is composed of a spherical part located on the opening side of the outer ring and a cylindrical part located on the inner side of the outer ring. The cylindrical part allows axial movement of the inner ring over a predetermined range, and the inner ring is axially In the fixed type constant velocity universal joint in which the torque transmission ball is placed in the cage pocket when it is at the end of the movement stroke,
The inner diameter of the cage that is located on the back side of the outer ring of the pocket is set to a minimum inner diameter part that is smaller than the maximum diameter of the spherical part of the inner ring, and an enlarged stepped part on the back side of the outer ring of the minimum inner diameter part. When the inner ring is inserted into the cage perpendicularly to the cage axis, the side surface of the inner ring ball groove is applied to the radial surface of the enlarged stepped portion, and the spherical center of the inner ring and the cage axis are shifted. A fixed type constant velocity universal joint characterized in that the inner ring can be inserted into the cage while the inner ring axis is inclined about the inner ring radial axis.   3. A concave spherical surface having the same curvature as the outer spherical surface of the inner ring is formed on the minimum inner diameter portion, and the concave spherical surface is supported by the outer spherical surface of the inner ring in a state where the joint has an operating angle. Fixed constant velocity universal joint.   The fixed type constant velocity universal joint according to any one of claims 1 to 3, wherein the inner ring, the cage and the torque transmission ball are a temporarily assembled unit capable of unit handling.

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