JP2010007701A - Sliding type tripod constant velocity joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliding type tripod constant velocity joint, in which the rear surface side of a roller unit can be prevented from applying large force to a raceway track groove. <P>SOLUTION: The sliding type tripod constant velocity joint comprises: a pair of intermediate members 40a, 40b disposed so as to sandwich each tripod shaft section 22 from both sides of side surfaces of the raceway track groove 11 in an outer ring 10 and mounted so as to be rockable relative to the tripod shaft section 22; a plurality of rolling elements 50 mounted between the side surface of the raceway track groove 11 and a power transmission surface 42 facing the side surfaces of the raceway track groove 11 of the pair of the intermediate members 40a, 40b so as to be slidable along the side surface of the raceway track groove 11; and a cage 60 for supporting the rolling elements 50 so that the rolling elements 50 can circulate on the outer peripheries of the pair of the intermediate members 40a, 40b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sliding tripod type constant velocity joint.

  As a conventional sliding tripod type constant velocity joint, for example, there is one described in Japanese Unexamined Patent Publication No. 2000-256694 (Patent Document 1). In the sliding tripod type constant velocity joint described in Patent Document 1, the tripod shaft portion has a columnar shape, and the inner peripheral surface of the roller has a cylindrical shape. In this case, the roller is always positioned coaxially with the tripod shaft. Therefore, when the joint angle is added, the direction in which the roller rolls on the raceway groove (roller groove) does not coincide with the direction in which the raceway groove extends. As a result, slip occurs between the roller and the raceway groove, and as a result, an induced thrust force is generated in the joint axial direction. This induced thrust force causes generation of vibration and noise of the vehicle body.

  Therefore, in order to reduce the induced thrust force, for example, there is one described in Japanese Patent Laid-Open No. 2006-162056 (Patent Document 2). In the sliding tripod type constant velocity joint described in Patent Document 2, the outer peripheral surface of the tripod shaft portion has a spherical convex shape, and the inner peripheral surface of the inner roller that constitutes the roller unit that contacts the outer peripheral surface has a cylindrical shape. . As a result, the tripod shaft portion can swing with respect to the roller unit, and the direction in which the outer roller constituting the roller unit tries to roll on the raceway groove can always coincide with the direction in which the raceway groove extends. It is possible to prevent slippage between the rail and the raceway groove. As a result, the induced thrust force can be reduced.

Other configurations are described in Japanese Patent Application Laid-Open No. 63-163031 (Patent Document 3) and Japanese Patent No. 2763624 (Patent Document 4). The sliding tripod type constant velocity joint described in Patent Document 3 has a configuration in which a pair of intermediate members are provided outside the tripod shaft portion, and a needle is disposed between each intermediate member and the side surface of the raceway groove. Further, the sliding tripod constant velocity joint described in Patent Document 4 is provided with a cylindrical integral intermediate member on the outer periphery of the tripod shaft portion, and the needle can circulate on the outer peripheral surface of the integral intermediate member. The needle rolls along the intermediate member and the side surface of the raceway groove.
JP 2000-256694 A JP 2006-162056 A JP 63-163031 A Japanese Patent No. 2763624

  Here, in the constant velocity joint described in Patent Document 2, when the joint angle is added, the tripod shaft portion slides in the axial direction of the tripod shaft portion with respect to the roller unit. Therefore, in the conventional sliding tripod type constant velocity joint, the position of the inner peripheral surface of the inner roller that contacts the tripod shaft portion changes. As a result, the roller unit operates so as to swing around the direction in which the raceway groove of the outer ring extends. For this reason, the back side of the portion of the roller unit that is transmitting power to the outer raceway groove contacts the raceway groove, and a frictional force is generated between the roller unit and the raceway groove. There is a risk of increased strength. In addition, it is conceivable to prevent the contact on the rear side by increasing the clearance between the raceway groove and the roller unit. However, in such a configuration, there is a possibility that the rotation play of the roller unit is increased.

  Moreover, in the constant velocity joint described in Patent Document 3, when the joint angle is small, the needle rolls in the raceway groove. However, since the number of needles is limited to a finite number in the direction in which the raceway grooves extend, if the joint angle is increased, the needles slip relative to the raceway grooves and the intermediate member. This slip induces a thrust force.

  On the other hand, in the constant velocity joint described in Patent Document 4, since the needle is configured to circulate, the needle rolls with respect to the raceway groove and the intermediate member, and slippage can be prevented. However, since the intermediate member has an integral structure, a problem similar to the problem in the constant velocity joint described in Patent Document 2 occurs. That is, a state in which the intermediate member applies a force to the outer ring via the needle can occur on the back side of the portion where the power is transmitted. Thus, the generation of force on the back side induces a thrust force.

  The present invention has been made in view of such circumstances, and the member that contacts the raceway groove of the outer ring is configured to roll reliably with respect to the raceway groove, and the tripod shaft portion is relative to the roller unit. An object of the present invention is to provide a sliding tripod type constant velocity joint capable of preventing the back side of the roller unit from applying a large force to the raceway groove even when sliding in the axial direction of the tripod shaft portion.

(Means 1) The sliding tripod type constant velocity joint according to means 1 is
An outer ring having a cylindrical shape and formed with three raceway grooves extending in the outer ring rotation axis direction on the inner peripheral surface;
A boss portion coupled to the shaft, and three tripod shaft portions that are erected so as to extend radially outward of the boss portion from the outer peripheral surface of the boss portion and are inserted into the raceway grooves, respectively. Tripod,
A pair of intermediate members disposed so as to sandwich the tripod shaft from both sides of the side surface of the raceway groove, and provided so as to be swingable with respect to the tripod shaft;
A plurality of rolling elements provided between the side surface of the raceway groove and a power transmission surface facing the side surface of the raceway groove of the pair of intermediate members so as to roll along the side surface of the raceway groove;
A cage that supports the rolling elements such that the rolling elements can circulate around the outer periphery of the pair of intermediate members;
It is characterized by providing.

  According to the present invention, since the rolling element is configured to circulate around the outer periphery of the pair of intermediate members so that the rolling element can roll on the raceway groove, the member that contacts the raceway groove of the outer ring is reliably attached to the raceway groove. It is configured to roll. Therefore, since the member that contacts the raceway groove of the outer ring can be prevented from slipping with respect to the raceway groove, the generation of the induced thrust force due to this can be prevented.

  Further, the roller unit of the constant velocity joint of Patent Documents 2 and 4 changes the position where the tripod shaft portion slides during power transmission and contacts the tripod shaft portion on the inner peripheral surface of the inner roller, so that the outer ring raceway is changed. The above-mentioned problem has occurred because the rocker integrally swings around the direction in which the groove extends and contacts the raceway groove on the back side of the portion where power is transmitted.

  On the other hand, the present invention includes a pair of intermediate members that are disposed so as to sandwich the tripod shaft portion and are swingably provided on the tripod shaft portion. That is, the pair of intermediate members are independent of each other. By doing in this way, even if the load position by the tripod shaft part generated on the power transmission side changes, the operation of the intermediate member on the power transmission side does not affect the operation of the intermediate member on the back surface side. . Accordingly, since it is possible to prevent the back side of the roller unit from applying a large force to the raceway groove, the generation of the induced thrust force can be greatly reduced.

  Here, the “roller unit” is composed of a member that transmits the power from the tripod shaft to the raceway groove of the outer ring. For example, the roller unit in the tripod type constant velocity joint of Patent Document 2 includes an inner roller and an outer roller. And a roller support and a snap ring. The roller unit in the tripod type constant velocity joint of the present invention includes an intermediate member, a rolling element, and a cage.

(Means 2) In the sliding tripod type constant velocity joint of means 1,
The outer peripheral surface of the tripod shaft portion is a spherical convex shape,
In a posture in which the outer ring rotation axis and the shaft rotation axis coincide with each other,
A distance between a point on the tripod axis in a plane passing through the center of the tripod axis direction of the rolling element and orthogonal to the tripod axis and the outer ring rotation axis is defined as an outer ring PCR;
The distance between the center of curvature of the outer peripheral surface of the tripod shaft and the shaft rotation axis is defined as tripod PCR,
The tripod PCR may be set larger than the outer ring PCR.

  Here, if the outer ring PCR (pitch circle radius) and the tripod PCR (pitch circle radius) are set to match in a posture where the outer ring rotation axis and the shaft rotation axis match, a joint angle is added. When power is transmitted, the contact area between the tripod shaft and the roller unit slides in the width direction of the roller unit, and the center of the sliding width is located on the inner side in the outer ring radial direction with respect to the roller unit. Therefore, for example, when a sphere is applied to the rolling element, the backlash may increase as the load position of the tripod shaft portion with respect to the roller unit increases from the width center of the roller unit. Moreover, when a needle is applied to a rolling element, there is a possibility that the needle will wear unevenly.

  Therefore, by setting the tripod PCR larger than the outer ring PCR, when the power is transmitted with a predetermined joint angle, the center of the sliding width of the contact area between the tripod shaft and the roller unit is relative to the roller unit. It can be located near the center in the radial direction. As a result, rotation backlash can be reduced, and uneven rolling of rolling elements such as needles can be prevented. However, when the tripod PCR is larger than the outer ring PCR as compared with the case where the tripod PCR and the outer ring PCR match, the load position on the roller unit by the tripod shaft portion is located on the outer side in the outer ring radial direction. Therefore, the possibility that the roller unit contacts the raceway groove of the outer ring on the back side of the power transmission is increased. However, since the pair of intermediate members are independent, it is possible to avoid contact between the raceway groove and the roller unit on the rear side of the power transmission without taking a large gap.

(Means 3) In the sliding tripod type constant velocity joint of means 1 or 2,
The pair of intermediate members may be formed with a smooth intermediate member introduction surface with respect to the power transmission surface so as to smoothly contact and guide the circulating rolling elements to the power transmission surface.

  Here, of the pair of intermediate members, the member performing power transmission is positioned with respect to the tripod shaft portion and the outer ring. On the other hand, since the cage is a member that does not contribute to power transmission, the position of the cage is not stable. Therefore, it is not easy to allow the rolling elements to enter the power transmission surface of the intermediate member from a cage whose position is not stable in a predetermined posture. Accordingly, the power transmission surface of the intermediate member and the intermediate member introduction surface that allows the rolling element to enter the power transmission surface are formed on the same member, so that the posture of the rolling element that enters the power transmission surface can be stably adjusted. Can do.

(Means 4) In the sliding tripod type constant velocity joint of means 3,
The circulation path which is the locus of the rolling elements circulated by the cage is
A first circulation path that is a circulation path of the rolling element that moves on the power transmission surface and follows the power transmission surface;
A second circulation path that is a circulation path of the rolling element that moves on the intermediate member introduction surface and that follows the intermediate member introduction surface and is smoothly connected to the first circulation path;
It is good to have a 3rd circulation path smoothly connected to an end part on the opposite side to said 1st circulation path among said 2nd circulation paths.

  Here, since the intermediate member introduction surface is not a part that transmits power to or from the raceway groove, a very large load is not applied to the rolling elements that move on the intermediate member introduction surface. Therefore, it is possible to stably cause the rolling elements to enter the second circulation path following the intermediate member introduction surface from the third circulation path. As a result, the rolling elements can be smoothly moved from the third circulation path to the second circulation path, and further from the second circulation path to the first circulation path following the power transmission surface.

(Means 5) In the sliding tripod type constant velocity joint of any one of means 1 to 4,
It is preferable that the cage is not restricted in the power transmission direction with respect to the pair of intermediate members.

  For example, a clearance is provided between all the surfaces (including the power transmission surface and the intermediate member introduction surface) facing the side surface of the raceway groove in the pair of intermediate members and the cage. Thereby, it can prevent that a rolling element acts so that a rolling element may provide force to the raceway groove of an outer ring in the back side of power transmission. Therefore, the above-described effect can be surely achieved.

(Means 6) In the sliding tripod constant velocity joint of any one of means 1 to 5,
The outer peripheral surface of the tripod shaft portion is a spherical convex shape,
The inner surfaces of the pair of intermediate members may be spherical concave shapes fitted to the outer peripheral surface of the tripod shaft portion.

  By configuring the tripod shaft portion and the pair of intermediate members to be swingable so as to be spherically fitted, the load (surface pressure) per unit area of the intermediate member can be reduced, and the durability of the intermediate member can be improved. it can. Further, since the intermediate member is driven by the sliding tripod shaft portion, the position is determined with respect to the tripod shaft portion, and power can be stably transmitted. Furthermore, in the present invention, since the pair of intermediate members are arranged so as to sandwich the tripod shaft portion, all the inner surfaces thereof can be easily formed into a spherical concave shape. Therefore, the power transmission area between the tripod shaft part and the pair of intermediate members can be increased, and when the tripod shaft part and the intermediate member make an angular contact, the two points where the angular contact comes into contact are further separated and stabilized. Can be achieved.

(Means 7) In the sliding tripod type constant velocity joint of means 1 to 5,
The rolling element is a cylindrical needle,
In a posture in which the outer ring rotation axis and the shaft rotation axis coincide with each other,
The retainer supports the needle such that the cylindrical axis direction of the needle is parallel to the tripod axis direction,
The pair of intermediate members may form the power transmission surface slidable in the outer ring radial direction with respect to the needle.

  Thereby, the needle abuts against the raceway side surface of the outer ring in the cylindrical axis direction to transmit power, so that the roller unit as a whole has a small rotational backlash and can stably transmit power.

(Means 8) In the sliding tripod type constant velocity joint of the means 1 to 5,
Further, the rolling element is a spherical or barrel-shaped roller,
In a posture where the outer ring rotation axis and the shaft rotation axis match,
The pair of intermediate members may be formed with a power transmission surface capable of swinging in the outer ring radial direction with respect to the rolling elements.

  When the rolling element is spherical, it has a simple shape and has the highest rigidity and can be circulated most smoothly, so that even a large amount of power can be transmitted stably. Further, when the rolling element is a barrel-shaped roller, the width in the direction orthogonal to the tripod axis can be made smaller than that of the spherical shape, so that the entire width of the roller unit can be reduced. Further, the intermediate member can swing in the outer ring radial direction with respect to the rolling element, so that power can be transmitted to the rolling element according to the position of the sliding tripod shaft portion. Here, the barrel-shaped roller has a columnar shape, and a cross section cut in the direction perpendicular to the column stretching is circular, and a portion corresponding to the outer peripheral surface in the cross section cut in the column stretching direction is a circular arc.

  Hereinafter, an embodiment in which a sliding tripod type constant velocity joint of the present invention (hereinafter simply referred to as “constant velocity joint”) is embodied will be described with reference to the drawings. Here, the case where the constant velocity joint of this embodiment is used for connection of a power transmission shaft of a vehicle will be described as an example. For example, it is a case where it uses for the connection part of the axial part connected with the differential gear, and the intermediate shaft of a drive shaft.

<First embodiment>
The constant velocity joint 1 of 1st embodiment is demonstrated with reference to FIGS. FIG. 1 is a view seen from the opening side of the outer ring 10 in a partly assembled state of the constant velocity joint 1 of the first embodiment. FIG. 2 is a radial sectional view of a part of the constant velocity joint 1. FIG. 3 is a perspective view of the roller unit 30. 4 (a) is a plan view of the roller unit 30, FIG. 4 (b) is an AA cross-sectional view (cross-sectional view on the short diameter side) of the roller unit 30, and FIG. 4 is a partial cross-sectional view of the roller unit 30 taken along the line B-B (including a partial cross section on the long diameter side). FIG. 5 is a perspective view of one of the pair of intermediate members 40. 6 (a) is a front view of the intermediate member 40, FIG. 6 (b) is a partial cross-sectional view taken along line EE of the intermediate member 40, and FIG. 6 (c) is an F direction arrow of the intermediate member 40. FIG. 6D is a GG cross-sectional view of the intermediate member 40, and FIG. 6E is a HH cross-sectional view of the intermediate member 40. FIG. 7 is a perspective view of the cage 60. FIG. 8A is a plan view of the cage 60, FIG. 8B is a CC cross-sectional view (cross-sectional view on the short diameter side) of the cage 60, and FIG. It is DD sectional drawing (the figure containing the partial cross section by the side of a long diameter) of the holder | retainer 60.

  As shown in FIGS. 1 and 2, the constant velocity joint 1 includes an outer ring 10, a tripod 20, and a roller unit 30.

  The outer ring 10 is formed in a cylindrical shape (for example, a bottomed cylindrical shape), and one end side is connected to a differential gear (not shown). Three track grooves 11 extending in the outer ring axial direction (front-rear direction in FIG. 1) are formed on the inner peripheral surface of the cylindrical portion of the outer ring 10 at equal intervals in the circumferential direction of the outer ring shaft. The cross-sectional shape orthogonal to the groove extending direction in each raceway groove 11 forms a U-shape. That is, each track groove 11 includes a groove bottom surface formed in a substantially planar shape and side surfaces formed in a planar shape orthogonal to the groove bottom surface and facing each other in parallel.

  Further, locking projections 12 for narrowing the opening width of the track groove 11 are formed on both opening edges of the track groove 11. The locking protrusion 12 is for restricting the position of a retainer 60 constituting a roller unit 30 described later. That is, the retainer 60 is always positioned inside the raceway groove 11 by the locking projection 12.

  The tripod 20 is disposed inside the cylindrical portion of the outer ring 10. The tripod 20 includes a boss portion 21 and three tripod shaft portions 22. The boss portion 21 has a cylindrical shape, and an inner peripheral spline 21a is formed on the inner peripheral side. The inner peripheral spline 21a is fitted and connected to the outer peripheral spline at the end of the intermediate shaft (not shown). Moreover, the outer peripheral surface of the boss | hub part 21 is formed in the substantially spherical convex shape.

  Each tripod shaft portion 22 is erected so as to extend from the outer peripheral surface of the boss portion 21 outward in the radial direction of the boss portion 21. These tripod shaft portions 22 are formed at equal intervals (120 deg intervals) in the circumferential direction of the boss portion 21. At least the tip of each tripod shaft portion 22 is inserted into each raceway groove 11 of the outer ring 10. The outer peripheral surface of each tripod shaft part 22 is formed in a spherical convex shape.

  As shown in FIGS. 3 and 4, the roller unit 30 has an annular shape as a whole, and is disposed on the outer peripheral side of the tripod shaft portion 22. Further, the roller unit 30 is fitted in the raceway groove 11 so as to be movable in the direction in which the raceway groove 11 extends. The roller unit 30 includes an intermediate member 40, a plurality of rolling elements 50, and a cage 60.

  The outer shape of the intermediate member 40 as a whole is formed in a substantially rectangular shape. Furthermore, when the intermediate member 40 is viewed as a whole, a portion corresponding to a circular hole is formed at the center of the intermediate member 40. The intermediate member 40 includes a pair of members 40a and 40b. The pair of intermediate members 40a and 40b are separately configured so as to be symmetrical with respect to a plane passing through the central axis of the tripod shaft portion 22 (also referred to as “tripod shaft”) and the rotation axis of the intermediate shaft, being independent. Then, as shown in FIG. 2, the pair of intermediate members 40 a and 40 b are arranged so as to sandwich the tripod shaft portion 22 from both sides of the side surface of the raceway groove 11. That is, both the intermediate members 40a and 40b are arranged so as to sandwich the tripod shaft portion 22 from both sides in the power transmission direction (the direction around the outer ring rotation axis or the intermediate shaft rotation axis). The pair of intermediate members 40 a and 40 b are provided so as to be capable of swinging in the rotational axis direction of the outer ring 10 with respect to the tripod shaft portion 22 and swingable in the circumferential direction of the outer ring 10.

  The detailed shape of each intermediate member 40a, 40b will be described with reference to FIG. 5 and FIGS. 6 (a) to 6 (d). The surface of each intermediate member 40a, 40b has a tripod contact surface 41, a power transmission surface 42, an intermediate member introduction surface 43, and axial end surfaces 44, 45. Here, when the pair of intermediate members 40a and 40b are viewed as one body, the tripod contact surface 41 forms the inner surface, and the power transmission surface 42, the intermediate member introduction surface 43, and the axial end surfaces 44 and 45 form the outer surface. .

  The tripod contact surface 41 is formed in a partially spherical concave shape so as to oscillately contact with the tripod shaft portion 22 in the axial direction of the outer ring 10 and the circumferential direction of the outer ring 10. The center of the spherical surface of the tripod contact surface 41 is the center of the lateral width (the thickness of the intermediate member 40) in FIG. 6A of the tripod contact surface 41 and the vertical width (intermediate member) of the tripod contact surface 41 in FIG. 40 is located on a straight line passing through the center of the outer ring 10 in the axial direction).

  The power transmission surface 42 and the intermediate member introduction surface 43 are provided on the back surface side of the tripod contact surface 41, that is, on the right side in FIG. The power transmission surface 42 is flat and rectangular. The intermediate members 40 a and 40 b are arranged so that the power transmission surface 42 is parallel to the side surface of the raceway groove 11. In other words, in a posture in which the rotation axis of the outer ring 10 and the rotation axis of the intermediate shaft coincide (joint angle 0 deg), the power transmission surface 42 is parallel to a plane passing through the central axis of the tripod shaft portion 22 and the rotation axis of the intermediate shaft. It becomes. Further, the power transmission surface 42 is positioned at the center portion in the vertical direction of FIG. 6B and has a width of about two-thirds of the vertical width of FIG. 6B. That is, the power transmission surface 42 is located on the back surface side of the deepest portion of the tripod contact surface 41. The power transmission surface 42 has a range that can contact the plurality of rolling elements 50.

  The intermediate member introduction surfaces 43 are formed on both sides adjacent to the power transmission surface 42. The intermediate member introduction surface 43 is a curved surface that is slightly curved, and is formed smoothly (continuously without a step) with respect to the power transmission surface 42. The intermediate member introduction surface 43 is convex outward and curved to the side not protruding from the plane of the power transmission surface 42. That is, the intermediate member introduction surface 43 is curved toward the side away from the side surface of the raceway groove 11 as it goes from the power transmission surface 42 side to the axial end surfaces 44 and 45 side. Furthermore, the intermediate member introduction surface 43 is formed in a substantially trapezoidal shape so that the width in the left-right direction in FIG. 6A becomes narrower from the power transmission surface 42 side toward the axial end surfaces 44 and 45 side. The intermediate member introduction surface 43 provides contact guidance so that the rolling elements 50 circulating around the outer periphery of the intermediate member 40 smoothly enter the power transmission surface 42, and the rolling elements 50 are smoothly discharged from the power transmission surface 42. Guide the contact so that

  The axial end faces 44 and 45 are parts located at both upper and lower ends in FIG. Both axial end surfaces 44 and 45 are flat surfaces orthogonal to the power transmission surface 42. That is, the axial end surfaces 44 and 45 are formed of a plane orthogonal to the side surface of the raceway groove 11. Here, the horizontal cross-sectional shape of each intermediate member 40 in FIGS. 6A and 6B is an equilateral triangle as shown in FIGS. 6C and 6E. And the axial direction end surfaces 44 and 45 are also forming the equilateral triangle shape, as shown in FIG.6 (d).

  As shown in FIGS. 2 and 4, the rolling element 50 is a needle. The rolling element 50 includes a columnar portion 51 and small-diameter shaft portions 52 that are circular in cross section cut in the column stretching orthogonal direction (left-right direction in FIG. 2) and are provided at both ends in the column stretching direction. As shown in FIG. 4B, the small-diameter shaft portion 52 may have a shape or a stepped shape (not shown) that becomes smaller in diameter as it approaches the end portion. And the some rolling element 50 is provided so that it may circulate in the outer periphery at the time of seeing a pair of intermediate member 40a, 40b as integral. Some of the plurality of rolling elements 50 can roll along the side surface of the raceway groove 11 and the power transmission surface 42 between the side surface of the raceway groove 11 and the power transmission surface 42 of the pair of intermediate members 40a and 40b. Is provided. That is, power is transmitted between the power transmission surface 42 and the side surface of the raceway groove 11 via the rolling elements 50.

  As shown in FIGS. 7 and 8A, the cage 60 has an annular shape as a whole. The cage 60 includes a pair of circulation path forming members 61 and 62 that form a circulation path of the rolling element 50, and a pair of connecting portions 63 and 64. The pair of circulation path forming members 61 and 62 is located on the periphery of the cage 60 and has an oval shape. The pair of circulation path forming members 61 and 62 has a shape surrounding the pair of intermediate members 40a and 40b.

  Specifically, the circulation path forming member 61 includes linear portions 61a and 61b facing each other and semicircular arc-shaped curved portions 61c and 61d connecting the linear portions 61a and 61b. The other circulation path forming member 62 is composed of a straight portion and a curved portion, like the circulation path forming member 61.

  Furthermore, each of the pair of circulation path forming members 61 and 62 is formed in a U-shaped cross-sectional shape in which the small diameter shaft portion 52 of the rolling element 50 can be inserted and engages with the cylindrical portion 51. . That is, the width (the distance between the inner peripheral edge and the outer peripheral edge) of the pair of circulation path forming members 61 and 62 is formed smaller than the maximum diameter of the columnar portion 51 of the rolling element 50. The U-shaped opening sides of the circulation path forming members 61 and 62 are provided so as to face each other in a state of being separated by a distance longer than the axial length of the columnar portion 51 of the rolling element 50. The maximum width in the facing direction of the pair of circulation path forming members 61 and 62 is set slightly smaller than the width of the side surface of the raceway groove 11. That is, the cage 60 is configured such that its inclination with respect to the track groove 11 is regulated by the groove bottom surface and the locking projection 12 of the track groove 11 and can be inserted into the track groove 11.

  A pair of connection parts 63 and 64 connect the circumferential direction center part (upper and lower end part of Fig.8 (a)) among the curved parts 61c and 61d of a pair of circulation path formation members 61 and 62, respectively. That is, the space between the pair of circulation path forming members 61 and 62 is open at a portion other than the connecting portions 63 and 64 as shown in FIG.

  The connecting portions 63 and 64 are formed in a U-shape that opens to the outside of the cage 60. The U-shaped bottom opening opposite side of the connecting portions 63 and 64 (inside the retainer 60) is formed in a planar shape. And the U-shaped bottom opening opposite side of a pair of connection parts 63 and 64 is provided so that it may oppose in parallel. Further, the distance between the pair of connecting portions 63 and 64 on the opposite side of the bottom surface of the U-shape is substantially the same as the distance between the axial end surfaces 44 and 45 of the intermediate members 40a and 40b. In addition, the U-shaped bottom surface opening side (outside of the cage 60) of the connecting portions 63 and 64 is formed in a plane parallel to the bottom surface opposite opening side.

  In addition, one of the end portions of the connection portions 63 and 64 on the opening side of the U-shape is connected to the respective circumferential center portions of the curved portions 61c and 61d of the circulation path forming member 61, and the other end portion is circulated. Each of the curved portions of the path forming member 62 is connected to a central portion in the circumferential direction.

  Then, the small-diameter shaft portion 52 of the rolling element 50 is inserted into the U-shape inside the pair of circulation path forming members 61 and 62. In this way, the rolling element 50 is supported by the pair of circulation path forming members 61 and 62. That is, the pair of circulation path forming members 61 and 62 supports the rolling elements 50 such that the plurality of rolling elements 50 can circulate around the outer circumferences of the pair of intermediate members 40a and 40b. Here, the U-shaped shape of the pair of circulation path forming members 61 and 62 is a shape having a slight gap with respect to the outer peripheral surface of the small-diameter shaft portion 52 of the rolling element 50. Further, in a state where the small diameter shaft portion 52 of the rolling element 50 is inserted into the circulation path forming members 61 and 62, the columnar portion 51 of the rolling element 50 protrudes inward from the inner peripheral edge of the circulation path forming members 61 and 62, And it protrudes outside from the outer periphery of the circulation path formation members 61 and 62.

  Here, in a state where the pair of intermediate members 40a and 40b are arranged on the outer peripheral side of the tripod shaft portion 22 and the pair of intermediate members 40a and 40b are arranged inside the cage 60, the respective circulation path forming members 61, 62 straight portions 61a and 61b (the left and right straight portions in FIG. 8A) (corresponding to the “first circulation path” of the present invention) are formed between the power transmission surface 42 of the intermediate members 40a and 40b and the raceway grooves 11. It arrange | positions between the side surfaces so that it may be in a state (copied state) substantially parallel to both. That is, the circulation path formed by the straight portions 61 a and 61 b is a circulation path when the rolling element 50 moves on the power transmission surface 42. Further, a gap is formed in at least one of the straight portions 61 a and 61 b and the side surfaces of the power transmission surface 42 and the raceway groove 11.

  Further, both end portions (corresponding to the “second circulation path” of the present invention) of the curved portions 61c and 61d of the pair of circulation path forming members 61 and 62 follow the intermediate member introduction surface 43 of the intermediate members 40a and 40b. Are arranged as follows. That is, the circulation path formed by both end portions of the curved portions 61 c and 61 d is a circulation path when the rolling element 50 moves on the intermediate member introduction surface 43. This circulation path is connected to be smoothly continuous with the circulation path formed by the straight portions 61a and 61b. Further, a gap is formed between both end portions of the curved portions 61 c and 61 d forming the circulation path and the intermediate member introduction surface 43. Of course, a gap is formed between both end portions of the curved portions 61 c and 61 d forming the circulation path and the side surface of the raceway groove 11.

  As described above, the power transmission surface 42 and the intermediate member introduction surface 43 that form one surface in the power transmission direction of the pair of intermediate members 40 a and 40 b have a gap between the circulation path forming members 61 and 62 of the cage 60. The shape can be formed. That is, the pair of intermediate members 40 a and 40 b are not restricted in the power transmission direction with respect to the pair of circulation path forming members 61 and 62.

  In addition, a circulation path (corresponding to a “third circulation path” in the present invention) connected to a portion following the intermediate member introduction surface 43 among the curved portions 61c and 61d of the pair of circulation path forming members 61 and 62 is: It is connected smoothly and continuously to a circulation path that follows the intermediate member introduction surface 43.

  And the connection part 63 is based on the relationship between the shape and the separation distance of the axial direction end surfaces 44 and 45 of each intermediate member 40a, 40b, and the shape and the separation distance of the U-shaped bottom side of the connection parts 63 and 64. , 64 are provided with intermediate members 40a, 40b between the connecting portions 63, 64 so as to restrict relative movement of the intermediate members 40a, 40b in the axial direction of the outer ring 10 (vertical direction in FIG. 8A). . However, since the intermediate members 40 a and 40 b are not restricted in the radial direction of the outer ring 10 (the vertical direction in FIG. 8B) with respect to the cage 60, the intermediate members 40 a and 40 b are separated from the cage 60. Can be moved in the radial direction (vertical direction in FIG. 8B). That is, the cage 60 does not contact the side surfaces of the pair of intermediate members 40 and the raceway grooves 11 in the power transmission direction.

  The operation of the constant velocity joint 1 described above will be described. When the outer ring 10 whose one end is connected to the differential gear receives power and rotates, each tripod shaft portion 22 transmits power through each roller unit 30 fitted in the raceway groove 11, and the tripod 20. The intermediate shaft connecting the two parts rotates at a constant speed. At this time, if the joint angle is not 0 deg, the tripod 20 rotates around the intermediate shaft while being inclined by the joint angle with respect to the rotation axis orthogonal cross section of the outer ring 10. Therefore, when viewed from the side surface of the raceway groove 11, the tripod shaft portion 22 reciprocates in the extending direction of the raceway groove 11 and swings with respect to the raceway groove 11 as the outer ring 10 and the tripod 20 rotate. To do.

  Further, as described above, the tripod 20 is inclined by the joint angle with respect to the rotation axis orthogonal cross section of the outer ring 10, so the angle formed by the tripod shaft parts 22 when viewed from the rotation axis direction of the outer ring 10 is Varies depending on the phase of the intermediate shaft. Therefore, since the three tripod shaft portions 22 are respectively accommodated in the raceway grooves 11, the rotation shaft of the shaft connecting the tripod 20 rotates eccentrically relative to the rotation shaft of the outer ring 10. Therefore, the end of the tripod shaft 22 reciprocates in the radial direction of the outer ring 10 as the outer ring 10 and the tripod 20 rotate.

  Here, the tripod contact surfaces 41 of the pair of intermediate members 40 a and 40 b constituting the roller unit 30 are fitted to the tripod shaft portion 22 so as to be swingable. Further, the pair of intermediate members 40 a and 40 b are regulated in the axial direction of the outer ring 10 by the cage 60 constituting the roller unit 30. Furthermore, the cage 60 is fitted in the raceway groove 11. Therefore, the cage 60 can move in the extending direction of the track groove 11 with respect to the track groove 11, but the inclination with respect to the track groove 11 is substantially constant. And the rolling element 50 has circulated through the outer periphery of a pair of intermediate member 40a, 40b.

  Accordingly, the rolling element 50 has the raceway groove 11 with respect to the raceway groove 11 and the power transmission surface 42 between the power transmission surface 42 of the member on the power transmission side of the intermediate members 40 a and 40 b and the side surface of the raceway groove 11. Rolls without sliding in the stretching direction. Thereby, generation | occurrence | production of an induced thrust force can be suppressed.

  In addition, a member that receives power through the plurality of rolling elements 50 among the pair of intermediate members 40 a and 40 b transmits power to the tripod shaft portion 22 that abuts on the tripod contact surface 41. At this time, if the joint angle is added as described above, the tripod shaft portion 22 reciprocates in the radial direction of the outer ring 10. Therefore, the intermediate member 40 a that is spherically fitted to the tripod shaft portion 22 follows the tripod shaft portion 22 and therefore slides in the radial direction of the outer ring 10 with respect to the rolling element 50. Thereby, the load point to which the most power is applied on the power transmission surface 42 reciprocates in the axial direction of the rolling element 50. By the movement of the load point, a swinging force is applied to the member on the power transmission side of the pair of intermediate members 40a and 40b with the point where the rolling element 50 and the side surface of the raceway groove 11 abut as a fulcrum.

  However, the pair of intermediate members 40a and 40b are independent on the power transmission side and the back side thereof. Thereby, even if the load position by the tripod shaft part generated on the power transmission side changes, the operation of the power transmission side member of the pair of intermediate members 40a and 40b affects the operation of the intermediate member on the back side. There is no effect. Therefore, since it is possible to prevent the back side of the roller unit 30 from applying a large force to the raceway groove 11, the generation of the induced thrust force can be greatly reduced. Further, it is not necessary to increase the gap between the intermediate member 40a (or 40b) on the back side and the raceway groove 11, and the occurrence of rotation play can be prevented.

  In particular, the cage 60 is not restricted in the power transmission direction with respect to the pair of intermediate members 40. Thereby, it can prevent that the holder | retainer 60 acts so that the rolling element 50 may provide force to the track groove 11 of the outer ring | wheel 10 in the back side of power transmission. Therefore, this can also reduce the generation of the induced thrust force on the back side of the power transmission.

  The pair of intermediate members 40a and 40b are formed with a smooth intermediate member introduction surface 43 with respect to the power transmission surface 42 so that the circulating rolling elements 50 are smoothly contacted and guided to the power transmission surface 42. . As described above, the power transmission surface 42 of the intermediate members 40a and 40b and the intermediate member introduction surface 43 that enters the rolling element 50 into the power transmission surface 42 are formed in the same member, thereby entering the power transmission surface 42. The posture of the rolling element 50 can be stably adjusted.

  Furthermore, the circulation path formed by both ends of the curved portions 61 c and 61 d of the pair of circulation path forming members 61 and 62 has a shape that follows the intermediate member introduction surface 43. Of the circulation path that follows the intermediate member introduction surface 43, the circulation path that is connected to the side opposite to the power transmission surface 42 (circulation path that is coupled to the coupling portions 63 and 64) follows the intermediate member introduction surface 43. Connected smoothly and continuously to the circuit.

  Here, since the intermediate member introduction surface 43 is not a part that transmits power to and from the raceway groove 11, a very large load is not applied to the rolling elements 50 that move on the intermediate member introduction surface 43. Therefore, it is possible to stably cause the rolling element 50 to enter the circulation path that follows the circulation path intermediate member introduction surface 43 to which the coupling portions 63 and 64 are coupled. As a result, the circulation path from which the connecting portions 63 and 64 are connected to the circulation path that follows the intermediate member introduction surface 43, and further from the circulation path that follows the intermediate member introduction surface 43 to the circulation path that follows the power transmission surface 42. The moving body 50 can be moved smoothly.

  Further, by adopting a spherical fitting configuration in which the tripod shaft portion 22 and the pair of intermediate members 40a and 40b can swing, the load (surface pressure) per unit area of the intermediate members 40a and 40b is reduced, and the intermediate member The durability of 40a and 40b can be improved. Further, since the intermediate members 40a and 40b are driven by the sliding tripod shaft portion 22, the positions thereof are determined with respect to the tripod shaft portion 22 and power can be stably transmitted. Furthermore, since the pair of intermediate members 40a and 40b are disposed so as to sandwich the tripod shaft portion 22, all the tripod contact surfaces 41 of the intermediate members 40a and 40b can be easily formed into spherical concave shapes. Therefore, the power transmission area between the tripod shaft portion 22 and the pair of intermediate members 40a and 40b can be increased, and when the tripod shaft portion 22 and the intermediate members 40a and 40b are in angular contact, two locations where the contact is angular contact This point can be further separated and stabilized.

  Further, since the rolling element 50 is a cylindrical needle, the needle abuts the side surface of the raceway groove 11 of the outer ring 10 in the cylindrical axis direction to transmit power, so that the roller unit 30 has a small rotational play as a whole. Stable power transmission.

<Modification of First Embodiment>
In the first embodiment described above, the tripod contact surfaces 41 of the pair of intermediate members 40a and 40b are spherical concave. In addition, the tripod contact surface 41 of the pair of intermediate members 40a and 40b can be a cylindrical surface.

  In this case, other configurations are the same as those in the first embodiment. That is, the pair of intermediate members 40a and 40b are formed so that the tripod contact surface 41 becomes a cylindrical surface, and the tripod shaft portion 22 and the pair of intermediate members 40 are arranged so as to sandwich the tripod shaft portion 22. It becomes slidable.

  By adopting such a configuration, the tripod shaft portion 22 can increase the slidable range with respect to the roller unit 30, and the amount of sliding of the tripod shaft portion 22 by adding a joint angle is large. Even if it becomes, motive power can be transmitted, maintaining the effect mentioned above. Moreover, the structure which can suppress sliding between the rolling element 50 and intermediate member 40a, 40b by the said structure is employable.

<Second embodiment>
The constant velocity joint 101 of 2nd embodiment is demonstrated with reference to FIGS. FIG. 9 is a radial cross-sectional view of a part of the constant velocity joint 101 of the second embodiment. FIG. 10 is a perspective view of the roller unit 130. FIG. 11 is a perspective view of the cage 160. 12A is a plan view of the retainer 160, FIG. 12B is a view in the J direction of the retainer 160, and FIG. 12C is a KK cross section of the retainer 160. It is a figure (figure including the partial cross section of a major axis side). FIG. 13 is a perspective view of one of the pair of intermediate members 140. 14A is a front view of the intermediate member 140, FIG. 14B is an LL partial cross-sectional view of the intermediate member 140, and FIG. 14C is an M direction arrow of the intermediate member 140. FIG. 14D is a cross-sectional view of the intermediate member 140 taken along the line NN.

  As shown in FIGS. 9 and 10, the constant velocity joint 101 includes an outer ring 110, a tripod 20, and a roller unit 130. Here, the constant velocity joint 101 of the second embodiment is mainly different in that the rolling element 50 of the constant velocity joint 1 of the first embodiment is changed from a needle to a sphere. Accordingly, the side surface shape of the raceway groove 111 of the outer ring 110 and the shape of the outer surface of the pair of intermediate members 140 are different from those of the constant velocity joint 1 of the first embodiment. In addition, since the tripod 20 is the same as the tripod 20 of 1st embodiment, detailed description is abbreviate | omitted. Only the differences will be described below.

  The outer ring 110 differs from the outer ring 10 of the first embodiment only in the side surface shape of the raceway groove 111. As shown in FIG. 9, concave grooves that follow the spherical surface of the rolling element 150 are formed on the side surfaces on both sides of the raceway groove 111 so that the rolling element 150 made of a sphere is positioned with respect to the radial direction of the outer ring 110. ing. That is, in the concave groove on the side surface of the raceway groove 111, the radial sectional shape of the outer ring 110 is an arc.

  As shown in FIG. 10, the roller unit 130 has an annular shape as a whole, and is disposed on the outer peripheral side of the tripod shaft portion 22. The roller unit 130 includes an intermediate member 140, a plurality of rolling elements 150, and a cage 160.

  The intermediate member 140 includes a pair of members 140a and 140b. The surface of the pair of intermediate members 140a and 140b has a tripod contact surface 41, a power transmission surface 142, an intermediate member introduction surface 143, and axial end surfaces 44 and 45, as shown in FIGS. Yes. The tripod contact surface 41 and the axial end surfaces 44 and 45 are the same as in the first embodiment.

  A concave groove is formed in the power transmission surface 142 so as to follow the spherical surface of the rolling element 150 which is a sphere. The intermediate member introduction surfaces 43 formed on both sides adjacent to the power transmission surface 142 are also formed with concave grooves similar to the power transmission surface 142. Other configurations of the power transmission surface 142 and the intermediate member introduction surface 143 are the same as those in the first embodiment.

  As shown in FIG. 10, the rolling elements 150 are spheres, and a plurality of the rolling elements 150 are arranged so as to circulate around the outer periphery of the intermediate member 140 as in the case of the needle.

  The cage 160 has an annular shape as a whole as in the case where the rolling element is a needle. Whereas the circulation path forming members 61 and 62 constituting the cage 60 of the first embodiment have a U shape, the circulation path forming members 161 and 162 of the cage 160 of the second embodiment are Arc-shaped concave grooves are formed so as to be opposed to each other in the vertical direction in FIG. 9 and to support the spherical rolling element 150.

  The operation of the constant velocity joint 101 described above will be described. Unlike the case where the rolling element 150 is a needle, the arc-shaped concave grooves of the intermediate members 140a and 140b and the spherical surface of the rolling element 150 come into contact with each other, so that both can swing when viewed from the axial direction of the outer ring 110. Become. Therefore, when the joint angle is taken, when viewed from the axial direction of the outer ring 110, the intermediate members 140a and 140b swing with respect to the tripod shaft portion 22 that slides in the tripod shaft direction.

  The constant velocity joint 101 of 2nd embodiment comprised in this way has an effect similar to the effect by the constant velocity joint 1 of 1st embodiment. Furthermore, the rolling element 150 which is a sphere has high rigidity and excellent circulation. Furthermore, a sphere with few processing steps is relatively easy to produce, and can be simplified in assembling the constant velocity joint 101. Furthermore, by using the rolling element 150 as a sphere, it is possible to transmit power without biasing the load points applied to the respective members in accordance with the changing positional relationship between the tripod shaft portion 22 and the raceway groove 111.

<Third embodiment>
The constant velocity joint 201 of the third embodiment will be described with reference to FIG. FIG. 15 is a radial cross-sectional view of a part of the constant velocity joint 201 of the third embodiment. As shown in FIG. 15, the constant velocity joint 201 includes an outer ring 110, a tripod 20, and a roller unit 230. Here, the constant velocity joint 201 of the third embodiment is different in that the rolling element 150 of the constant velocity joint 101 of the second embodiment is changed from a spherical body to a barrel-shaped roller. Only the differences will be described below.

  That is, the roller unit 230 includes the intermediate member 140, the plurality of rolling elements 250, and the cage 160. The rolling elements 250 are barrel-shaped rollers, and a plurality of rolling elements 250 are arranged so as to circulate around the outer periphery of the intermediate member 140 in the same manner as in the case of a sphere and a needle. The barrel-shaped roller is a rolling element having a columnar shape in which a cross section cut in the direction perpendicular to the column stretching is a circle, and a portion corresponding to the outer peripheral surface in the cross section cut in the column stretching direction is an arc.

  By adopting such a configuration, as in the spherical rolling element 150 in the second embodiment, the width in the direction perpendicular to the column extension is compared with that of the sphere while preventing the bias of load points applied to each member during power transmission. As a result, the entire constant velocity joint 201 can be reduced in size.

<Fourth embodiment>
The constant velocity joint 301 of 4th embodiment is demonstrated with reference to FIG. The constant velocity joint 301 of the fourth embodiment is configured such that the outer ring PCR (pitch circle radius) 302 and the tripod PCR 303 are set differently when the configuration of the constant velocity joint 1 of the first embodiment is used as a basis. . FIG. 16 is a radial cross-sectional view of a part of the constant velocity joint 301 of the fourth embodiment. In addition, since the constant velocity joint 301 of 4th embodiment consists substantially of the same structure as the constant velocity joint 1 of 1st embodiment, the same code | symbol is used for each component.

  As shown in FIG. 16, the outer peripheral surface of the tripod shaft portion 22 has a spherical convex shape, and the tripod PCR 303 is set larger than the outer ring PCR 302 in a posture in which the outer ring rotation shaft 13 and the intermediate shaft rotation shaft 23 coincide with each other. .

  The outer ring PCR302 is perpendicular to the tripod axis in the rolling element 50 located between the power transmission surface 42 and the side surface of the raceway groove 11 through the center of the width of the rolling element 50 in the tripod axis direction (vertical direction in FIG. 16). This is the shortest distance between the intersection 304 on the tripod axis in the plane and the outer ring rotating shaft 12. The tripod PCR 303 refers to the shortest distance between the center of curvature 305 on the outer peripheral surface of the tripod shaft portion 22 and the intermediate shaft rotation shaft 23.

  Here, it demonstrates with reference to FIG. 17 and FIG. FIG. 17 is a view of the constant velocity joint 301 with a predetermined joint angle as viewed from the opening side of the outer ring 10. FIG. 18 is a view of the constant velocity joint 301 with a predetermined joint angle as viewed from the opening side of the outer ring 10. FIG. 19 is a graph showing the maximum and minimum movement amount between the joint angle and the load point for each offset amount. In FIG. 19, (a) is an offset amount of 0 mm, (b) is an offset amount of 0.1 mm, (c) is an offset amount of 0.2 mm, and (d) is an offset amount of 0.3 mm. The load point is a position in the outer ring radial direction at a position where a load is applied during power transmission between the tripod shaft portion 22 and the intermediate members 40a and 40b.

  As shown in FIGS. 17 and 18, when a joint angle is added, the load point moves according to the rotational phase. Here, the load point when the joint angle is 0 deg is defined as a reference load point 306.

  For example, in FIG. 17, the intermediate shaft rotating shaft 23 is added as a joint angle in the right direction of FIG. 17, and in this state, the tripod 20 rotates together with the intermediate shaft, and one of the tripod shaft portions 22 is positioned upward in FIG. is doing. Then, as described above, the tripod 20 rotates eccentrically relative to the outer ring 10. Due to this eccentric rotation, the first load point 307 moves to the outer side in the radial direction of the outer ring 10 from the reference load point 306, and is at a position farthest from the outer ring rotating shaft 12.

  On the other hand, in FIG. 18, the intermediate shaft rotating shaft 23 is added as a joint angle in the upward direction of FIG. 18, and in this state, the tripod 20 rotates together with the intermediate shaft, and one of the tripod shaft portions 22 is positioned in the upward direction of FIG. is doing. Then, due to the eccentric rotation of the tripod 20, the second load point 308 moves inward in the radial direction of the outer ring 10 from the reference load point 306, and becomes the position closest to the outer ring rotating shaft 12.

  The amount of movement of the first load point 307 from the reference load point 306 is smaller than the amount of movement of the second load point 308 from the reference load point 306. Therefore, if the outer ring PCR 302 and the tripod PCR 303 are set so as to coincide with each other, the average moving amount of the load point applied to the roller unit 30 by the tripod shaft portion 22 is biased toward the direction closer to the outer ring rotating shaft 12. Therefore, it causes an increase in uneven wear of the rolling element 50.

  Therefore, by setting (offset) the tripod PCR 303 to be larger than the outer ring PCR 302 in advance, the average moving amount of the load point can be set at the center of the thickness of the roller unit 30 to prevent the load from being biased. However, since the amount of movement of each of the first load point 307 and the second load point 308 from the reference load point 306 depends on the joint angle to be added, the optimum offset amount differs depending on the predetermined joint angle. As shown in FIG. 19, the maximum and minimum values of the moved load points at the joint angles at the respective offset amounts are, for example, an offset amount of 0.1 mm is optimal when the joint angle is 7 deg. If the angle is 10 degrees, the offset amount is 0.2 mm, and if the joint angle is 13 degrees, the offset amount is 0.3 mm.

  Therefore, when the constant velocity joint is used, the offset amount is set according to the assumed common joint angle, thereby preventing the uneven wear of the rolling element 50 from increasing, and as a result, the durability of the constant velocity joint. In addition, vibration and noise can be reduced.

<Fifth embodiment>
A constant velocity joint 401 according to the fifth embodiment will be described with reference to FIGS. FIG. 20 is a radial cross-sectional view of a part of the constant velocity joint 401 of the fifth embodiment. FIG. 21 is a graph showing the joint angle and the rotational play amount for each offset amount. In FIG. 21, (a) is an offset amount of 0 mm, (b) is an offset amount of 0.2 mm, (c) is an offset amount of 0.3 mm, and (d) is an offset amount of 0.6 mm.

  The rolling element 50 is a sphere, and even in this case, when the outer ring PCR 302 and the tripod PCR 303 are set to coincide with each other due to the eccentric rotation of the tripod 20 as described in the fourth embodiment, the load is reduced. The average moving amount of the points is biased in the direction approaching the outer ring rotating shaft 13, and there is a problem that the rotational play is minimized when the joint angle at which this bias does not occur is 0 deg, and the rotational play increases as the joint angle is added. .

  Therefore, as shown in FIG. 20, the tripod PCR 303 is set (offset) larger than the outer ring PCR 302 in advance so that the rotation play is minimized when a predetermined joint angle is added, thereby preventing the rotation play from increasing. Can do. However, since the amount of rotation play depends on the joint angle to be added, the optimum offset amount differs depending on the predetermined joint angle. As shown in FIG. 21, when looking at the increment of the rotation play at the joint angle at each offset amount, for example, the offset amount of 0.2 mm is optimal if the joint angle is 6 deg, and similarly, the offset amount is 0 if the joint angle is 7 deg. .3 mm and a joint angle of 10 deg are required to have an optimum offset amount of 0.6 mm.

  Therefore, when the constant velocity joint is used, an offset amount is set according to the assumed common joint angle, thereby preventing an increase in the rotational play of the rolling element 50 and, as a result, the durability of the constant velocity joint. In addition, vibration and noise can be reduced. Even when the rolling element 50 is a barrel-shaped roller, the same effect can be obtained by setting the tripod PCR 303 as described above.

1st embodiment: It is the figure seen from the opening side of the outer ring | wheel 10 in the one part assembly state of the constant velocity joint 1. FIG. FIG. 3 is a radial sectional view of a part of the constant velocity joint 1. 3 is a perspective view of a roller unit 30. FIG. (A) It is a top view of the roller unit 30, (b) It is AA sectional drawing (sectional view on the short diameter side) of the roller unit 30, (c) BB partial sectional view (long diameter) of the roller unit 30 FIG. 3 is a perspective view of one pair of intermediate members 40. FIG. (A) It is a front view of the intermediate member 40, (b) It is EE partial sectional drawing of the intermediate member 40, (c) It is a F direction arrow view of the intermediate member 40, (d) Of the intermediate member 40 It is GG sectional drawing, (e) It is HH sectional drawing of the intermediate member 40. 3 is a perspective view of a cage 60. FIG. (A) It is a top view of cage 60, (b) It is CC sectional view (sectional view on the short diameter side) of cage 60, (c) DD sectional view (longer diameter side) of cage 60 FIG. Second Embodiment: A radial cross-sectional view of a part of a constant velocity joint 101. FIG. 3 is a perspective view of a roller unit 130. FIG. It is a perspective view of the holder | retainer 160. FIG. (A) It is a top view of the holder | retainer 160, (b) It is a J direction arrow directional view of the holder | retainer 160, (c) KK sectional drawing (a figure including the partial cross section by the side of a major axis) of the holder | retainer 160 is there. 4 is a perspective view of one pair of intermediate members 140. FIG. (A) It is a front view of the intermediate member 140, (b) It is LL partial sectional drawing of the intermediate member 140, (c) It is a M direction arrow view of the intermediate member 140, (d) Of the intermediate member 140 It is NN sectional drawing. 3rd embodiment: It is a radial direction sectional drawing of a part of constant velocity joint 201. FIG. 4th embodiment: It is a radial direction sectional drawing of a part of constant velocity joint 301. FIG. It is the figure seen from the opening side of the outer ring | wheel 10 in the constant velocity joint 301 which added the predetermined joint angle | corner. It is the figure seen from the opening side of the outer ring | wheel 10 in the constant velocity joint 301 which added the predetermined joint angle | corner. Graph showing joint angle and maximum / minimum contact movement amount by offset amount 5th embodiment: It is a radial direction sectional drawing of a part of constant velocity joint 401. FIG. It is a graph which shows the joint angle according to offset amount, and the amount of rotation play.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 101, 201, 301, 401: Constant velocity joint 10, 110: Outer ring, 11, 111: Track groove, 12: Locking protrusion 13: Outer ring rotating shaft 20: Tripod, 21: Boss part, 21a: Inner circumference spline 22: Tripod shaft part, 23: Intermediate shaft rotating shaft 30, 130: Roller unit 40, 140: Intermediate member, 40a, 40b, 140a, 140b: Each intermediate member 41: Tripod contact surface, 42, 142: Power transmission surface 43 , 143: intermediate member introduction surface, 44, 45: axial end surface 50, 150, 250: rolling element, 51: cylindrical portion, 52: small diameter shaft portion 60, 160: cage 61, 62, 161, 162: circulation Road forming members 61a, 61b: straight portions, 61c, 61d: curved portions, 63, 64: connecting portions 302: outer ring PCR, 303: tripod P R, 304: intersection 305: center of curvature 306: reference load point 307: first load point 308: second load point

Claims (8)

An outer ring having a cylindrical shape and formed with three raceway grooves extending in the outer ring rotation axis direction on the inner peripheral surface;
A boss portion coupled to the shaft, and three tripod shaft portions that are erected so as to extend radially outward of the boss portion from the outer peripheral surface of the boss portion and are inserted into the raceway grooves, respectively. Tripod,
A pair of intermediate members disposed so as to sandwich the tripod shaft from both sides of the side surface of the raceway groove, and provided so as to be swingable with respect to the tripod shaft;
A plurality of rolling elements provided between the side surface of the raceway groove and a power transmission surface facing the side surface of the raceway groove of the pair of intermediate members so as to roll along the side surface of the raceway groove;
A cage that supports the rolling elements such that the rolling elements can circulate around the outer periphery of the pair of intermediate members;
A sliding tripod constant velocity joint characterized by comprising: The outer peripheral surface of the tripod shaft portion is a spherical convex shape,
In a posture in which the outer ring rotation axis and the shaft rotation axis coincide with each other,
A distance between a point on the tripod axis in a plane passing through the center of the tripod axis direction of the rolling element and orthogonal to the tripod axis and the outer ring rotation axis is defined as an outer ring PCR;
The distance between the center of curvature of the outer peripheral surface of the tripod shaft and the shaft rotation axis is defined as tripod PCR,
The sliding tripod constant velocity joint according to claim 1, wherein the tripod PCR is set to be larger than the outer ring PCR.   The pair of intermediate members is formed with a smooth intermediate member introduction surface with respect to the power transmission surface so as to smoothly contact and guide the circulating rolling elements to the power transmission surface. The sliding tripod type constant velocity joint according to 1 or 2. The circulation path which is the locus of the rolling elements circulated by the cage is
A first circulation path that is a circulation path of the rolling element that moves on the power transmission surface and follows the power transmission surface;
A second circulation path that is a circulation path of the rolling element that moves on the intermediate member introduction surface and that follows the intermediate member introduction surface and is smoothly connected to the first circulation path;
A third circulation path smoothly connected to the end opposite to the first circulation path of the second circulation path;
The sliding tripod type constant velocity joint according to claim 3, wherein:   The sliding tripod type constant velocity joint according to any one of claims 1 to 4, wherein the cage is not restricted in a power transmission direction with respect to the pair of intermediate members. The outer peripheral surface of the tripod shaft portion is a spherical convex shape,
6. The sliding tripod constant velocity according to claim 1, wherein inner surfaces of the pair of intermediate members have a spherical concave shape fitted to an outer peripheral surface of the tripod shaft portion. Joint. The rolling element is a cylindrical needle,
In a posture in which the outer ring rotation axis and the shaft rotation axis coincide with each other,
The retainer supports the needle such that the cylindrical axis direction of the needle is parallel to the tripod axis direction,
The sliding tripod type according to any one of claims 1 to 6, wherein the pair of intermediate members form the power transmission surface that is slidable in the outer ring radial direction with respect to the needle. Constant velocity joint. The rolling element is a spherical or barrel-shaped roller,
In a posture in which the outer ring rotation axis and the shaft rotation axis coincide with each other,
The sliding tripod according to any one of claims 1 to 6, wherein the pair of intermediate members form the power transmission surface that can swing in the outer ring radial direction with respect to the rolling elements. Type constant velocity joint.

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