JP2012197803A - Sliding type tripod constant velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sliding type tripod constant velocity joint that reduces a contact load between a raceway groove on the non-load side and a roller unit, and reduces induced thrust force as a result.SOLUTION: The sliding type tripod constant velocity joint 1 includes: an outer ring 10 on which three raceway grooves 11 are formed; a tripod 20 including three tripod shaft parts 22 which are erected to be extended to the outside of a boss part 21 in the radial direction from the outer peripheral surface of the boss part 21 and which are inserted into the three raceway grooves 11 respectively; and the roller unit 30. When torque is transmitted between an inner roller 32 and the tripod shaft part 22, locking parts 22a, 22b are locked to locking grooves 32a, 32b respectively, so that the swing movement of the inner roller with respect to the tripod shaft part 22 is regulated in the plane perpendicular to the rotary shaft Ao of the outer ring.

Description

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

  Examples of the sliding tripod type constant velocity joint include those described in Patent Documents 1 to 3. This sliding tripod type constant velocity joint is pivotally supported by a cylindrical outer ring in which three raceway grooves are formed, a tripod having three tripod shaft portions extending in the radial direction, and each tripod shaft portion. Equipped with a double roller type roller unit. The double roller type roller unit has an outer roller that can roll on the raceway groove of the outer ring, an inner roller that is pivotally supported on the outer peripheral surface of the tripod shaft, and an outer roller and an inner roller. And a snap ring that is fixed to the outer roller and restricts axial movement of the inner roller and the needle. The tripod shaft portion is configured to be capable of swinging with respect to the roller unit. As a result, when torque is transmitted with the joint angle added, the direction in which the roller unit tries to roll the raceway groove coincides with the direction in which the raceway groove extends. Therefore, the slip generated between the roller unit and the raceway groove can be suppressed, and the generation of the induced thrust force can be reduced.

JP-A-10-246241 JP 2004-125175 A JP 2006-162056 A

  Here, in the sliding tripod type constant velocity joints described in Patent Documents 1 to 3, when the torque is transmitted with the joint angle added, the tripod shaft portion is in contact with the roller unit. It slides in the axial direction. Therefore, the position where the roller unit receives force from the tripod shaft changes in the axial direction of the roller unit. As a result, as described in Patent Document 3, a moment is generated to rotate the roller unit around an axis parallel to the outer ring rotation axis. Then, when the roller unit is viewed from the axial direction of the outer ring rotating shaft (that is, the direction in which the raceway groove of the outer ring extends), the roller unit swings with respect to the tripod shaft in a plane perpendicular to the outer ring rotating shaft. become. Therefore, the non-load side (back side), which is the opposite side of the outer ring raceway groove and the load side that is transmitting torque, contacts the raceway groove and friction between the roller unit and the raceway groove. Force may be generated. This may affect the generation of induced thrust force.

  The present invention has been made in view of such circumstances, and by reducing the contact load between the track groove on the non-load side and the roller unit, a sliding type that can reduce the induced thrust force as a result. An object is to provide a tripod type constant velocity joint.

In order to solve the above-described problem, according to the invention according to claim 1, the outer ring formed in a cylindrical shape and formed with three raceway grooves extending in the direction of the outer ring rotating shaft on the inner peripheral surface is coupled to the shaft. A tripod comprising three tripod shafts that are erected so as to extend radially outward of the boss part from the outer peripheral surface of the boss part and inserted into the raceway grooves, An outer roller that is rotatably arranged in the raceway groove, and a swing motion with respect to the tripod shaft in a plane that is pivotally supported on the outer peripheral side of the tripod shaft and includes the axis of the shaft and the axis of the tripod shaft And an inner roller that is allowed to slide in the axial direction of the tripod shaft portion, a needle that is rollably interposed between an inner peripheral surface of the outer roller and an outer peripheral surface of the inner roller, and the outer roller Fixed to Is, a sliding tripod type constant velocity joint and a snap ring for restricting axial movement of said inner roller and said needle relative to the outer roller,
A locking groove extending in the axial direction of the tripod shaft portion is formed in one of the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the inner roller facing the outer peripheral surface, and the other is related to the locking groove. A locking portion that stops is formed, and when the inner roller performs torque transmission with the tripod shaft portion, the locking portion locks in the locking groove, thereby Oscillating motion with respect to the tripod shaft portion is restricted in a plane perpendicular to the plane.

  According to a second aspect of the present invention, in the first aspect, the locking groove and the locking portion are configured such that when the torque is transmitted between the tripod shaft portion and the inner roller, the outer periphery of the tripod shaft portion. It is formed outside the contact range between the surface and the inner peripheral surface of the inner roller.

  According to a third aspect of the present invention, in the first or second aspect, the locking groove and the locking portion are formed to have a square cross-sectional shape in a plane perpendicular to the axis of the tripod shaft.

  According to the first aspect of the present invention, when the inner roller transmits torque with the tripod shaft, the locking portion is locked in the locking groove. As a result, the inner roller is configured to be restricted from swinging with respect to the tripod shaft in a plane orthogonal to the outer ring rotation axis. That is, the inner roller is restricted from rotating about an axis parallel to the outer ring rotation axis. Here, the inner roller and the needle are restricted in axial movement with respect to the outer roller by a snap ring fixed to the outer roller, and constitute a double roller type roller unit integrated with the outer roller. In other words, when the torque is transmitted, the inner roller is restricted from swinging partly as described above, so that the roller unit including the inner roller similarly has a tripod shaft in a plane perpendicular to the outer ring rotation axis. Swinging movement against the club will be restricted.

  As a result, when torque is transmitted with the joint angle added, the posture of the roller unit can be maintained even if a moment is generated to rotate the roller unit around an axis parallel to the outer ring rotation axis. Can do. Therefore, the non-load side (rear side) which is the opposite side of the outer ring raceway groove and the load side which is transmitting torque is prevented from coming into contact with the raceway groove. The contact load between the track groove on the side and the roller unit can be reduced. As a result, the induced thrust force can be reduced, and power loss and vibration generation due to contact on the back side can be suppressed.

  According to the second aspect of the present invention, the locking groove and the locking portion are formed outside the contact range between the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the inner roller. When performing torque transmission, the locking groove and the locking portion regulate the swinging motion of the inner roller with respect to the tripod shaft in a plane orthogonal to the outer ring rotation shaft, while other swinging motions and tripod shafts Allow sliding in the axial direction. Therefore, for example, a configuration in which the locking groove is formed in the inner roller and the locking portion is formed in the tripod shaft portion, or a configuration in which the locking groove is formed in the tripod shaft portion and the locking portion is formed in the inner roller may be adopted. . Furthermore, it is good also as a structure provided in any phase around the axis line of a tripod shaft part.

  Here, when torque transmission is performed between the tripod shaft portion and the inner roller, the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the inner roller are in contact with each other within an elliptical contact range. This contact range varies depending on the magnitude of the transmitted torque. However, when the area of the contact range decreases, the surface pressure (load per unit area) increases accordingly. In addition, the engagement groove and the engagement portion provided in the tripod shaft portion and the inner roller do not directly contribute to torque transmission. Therefore, when the tripod shaft portion and the engagement portion are formed inside the contact range, the area of the contact range is reduced. become. Therefore, as in the present invention, by forming the locking groove and the locking portion outside the contact range, the area of the contact range is secured, and the surface pressure in the contact range is prevented from increasing when torque is transmitted. it can. Therefore, torque can be reliably transmitted and the posture of the roller unit can be efficiently maintained.

  According to the invention which concerns on Claim 3, the cross-sectional shape of the latching groove and the latching | locking part is formed in the square. Here, when torque is transmitted with the joint angle added, a moment is generated in the roller unit about the axis parallel to the outer ring rotation axis. At this time, the posture of the roller unit is maintained by the locking portion being locked in the locking groove. In addition, a part of the swinging motion of the inner roller with respect to the tripod shaft part and a function that allows sliding, or in the manufacture of assembling the inner roller to the tripod shaft part, a predetermined gap is provided between the locking groove and the locking part. A gap may be provided. In such a case, when the moment as described above is generated, the locking portion tends to rotate relative to the locking groove from the relationship with the center of the moment. Therefore, when the cross-sectional shapes of the locking groove and the locking portion are formed in a square shape, when the locking portion rotates with respect to the locking groove, both corners of the locking portion come into contact with the side surface of the locking groove. The gap provided between them is filled. As a result, the locking portion can be reliably locked in the locking groove, so that the posture of the roller unit can be suitably maintained even when a moment occurs.

1st embodiment: It is a radial direction fragmentary sectional view of a sliding tripod type | mold constant velocity joint, Comprising: The part of one track groove is shown among three track grooves. It is a figure which shows the tripod seen from the axial direction of the tripod shaft part. It is a figure which shows an inner roller, (a) is a perspective view of an inner roller, (b) is the figure seen from the axial direction of the inner roller. In the tripod of FIG. 2, it is a figure which shows the state which assembled | attached only the inner roller to the tripod shaft part. It is a figure which shows the contact range at the time of torque transmission, (a) shows the contact range in the outer peripheral surface of the front-end | tip part of a tripod shaft part, (b) shows the contact range in the inner peripheral surface of an inner roller. FIG. 5 is a cross-sectional view taken along the line AA of FIG. 4 showing the tripod shaft and the roller, where (a) shows a state in which the axes of both members are coincident, and (b) shows the swinging motion of the roller with respect to the tripod shaft Indicates the state of 2nd embodiment: It is sectional drawing which shows a tripod shaft part and a roller, (a) shows the state in which the axis line of both members corresponds, (b) shows the roller swinging with respect to the tripod shaft part. It shows the state.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the sliding tripod type constant velocity joint of the present invention will be described below with reference to the drawings. Here, the case where the sliding tripod constant velocity joint of the embodiment is used for connecting a power transmission shaft of a vehicle will be described as an example. For example, it is preferably used as an inboard joint of an automobile drive shaft. That is, in this case, the constant velocity joint is used for a connecting portion between the shaft portion connected to the differential gear and the intermediate shaft of the drive shaft.

<First embodiment>
(Configuration of sliding tripod type constant velocity joint 1)
The sliding tripod type constant velocity joint 1 of the first embodiment will be described with reference to FIGS. The sliding tripod type constant velocity joint 1 in this embodiment includes an outer ring 10 connected to a shaft portion (not shown) on the differential gear side, a tripod 20 connected to the intermediate shaft 2 on the other side, and an outer ring 10. And a tripod 20 and a roller unit 30 interposed therebetween.

  The outer ring 10 is formed in a cylindrical shape (for example, a bottomed cylindrical shape), and a connecting shaft portion integrally formed on one end side is connected to a differential gear. Three track grooves 11 extending in the direction of the outer ring rotation axis Ao (the front-rear direction in FIG. 1) are formed at equal intervals in the circumferential direction of the outer ring shaft on the inner peripheral surface of the cylindrical portion of the outer ring 10. In FIG. 1, only one track groove 11 is shown. The cross-sectional shape orthogonal to the groove extending direction of each raceway groove 11 is a U-shape that opens toward the outer ring rotation axis Ao that is the rotation center of the outer ring 10. That is, each raceway groove 11 is formed from a groove bottom surface formed on a substantially flat surface, and groove side surfaces on both sides formed in a circular arc shape so as to be opposed to each other and have a maximum facing distance in the central portion in the depth direction. The

  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 is formed in an annular shape, and an internal spline 21 a is formed on the inner peripheral side of the boss portion 21. The internal spline 21a is connected to an external spline (not shown) formed at the end of the intermediate shaft 2. Each tripod shaft portion 22 is erected so as to extend from the outer peripheral surface of the boss portion 21 toward the radially outer side of each boss portion 21. These tripod shaft portions 22 are formed at equal intervals (120 ° 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. Each tripod shaft portion 22 is formed in a shape that approximates a cylindrical shape as a whole. Specifically, the outer peripheral surface of the tripod shaft portion 22 has a partial spherical shape.

  Moreover, the tripod shaft part 22 has two protrusions 22a and 22b extending on the outer peripheral surface in the axis At direction of the tripod shaft part 22 (vertical direction in FIG. 1). In the present embodiment, as shown in FIG. 2, the protrusions 22 a and 22 b are shafts that are the rotation center of the intermediate shaft 2 in the outer peripheral surface of the tripod shaft 22 as viewed from the axis At direction of the tripod shaft 22. They are arranged in a phase that coincides with the rotation axis As. That is, when the tripod 20 is disposed inside the outer ring 10, the protrusion 22 a is positioned on the opening side of the outer ring 10, and the protrusion 22 b is positioned on the cylinder bottom side of the outer ring 10.

  The protrusions 22a and 22b have a convex arc shape along the outer peripheral surface of the tip portion of the tripod shaft portion 22 formed in a partially spherical shape as an overall shape. And it forms from the upper part where the partial spherical surface was formed in the front-end | tip part of the tripod shaft part 22 to the lower part. Further, the protrusions 22a and 22b are formed in a square cross-sectional shape on a plane perpendicular to the axis At of the tripod shaft 22. Furthermore, the width direction center part of the protrusions 22a and 22b is formed so as to exist in a plane including the shaft rotation axis As and the axis line At of the tripod shaft part 22 when viewed from the axis At direction of the tripod shaft part 22. Yes. The protruding portions 22a and 22b are portions that are engaged with concave grooves 32a and 32b formed on the inner peripheral surface of the inner roller 32 described later, and correspond to the “engaging portion” of the present invention.

  The roller unit 30 is configured to be annular as a whole. The roller unit 30 is pivotally supported on the outer peripheral side of the tripod shaft portion 22. The roller unit 30 is allowed to swing with respect to the tripod shaft portion 22 and to slide in the axis At direction of the tripod shaft portion 22 in a plane including the shaft rotation axis As and the axis line At of the tripod shaft portion 22 and rotate the outer ring. Oscillating motion with respect to the tripod shaft is restricted in a plane perpendicular to the axis Ao. Further, the roller unit 30 is arranged to roll along the groove side surface of the raceway groove 11. The roller unit 30 is a double roller type roller composed of an outer roller 31, an inner roller 32, a needle roller 33, and snap rings 34 and 35.

  The outer roller 31 is formed in an annular shape. The axial cross-sectional shape of the outer peripheral surface of the outer roller 31 is generally formed in a shape corresponding to the groove side surface of the raceway groove 11, that is, a shape obtained by inverting the groove side surface of the raceway groove 11. Specifically, the axial sectional shape of the outer peripheral surface of the outer roller 31 is formed in a convex arc shape represented by a single radius of curvature. The outer roller 31 is inserted into the raceway groove 11 so that its central axis is orthogonal to the outer ring rotation axis. Further, the inner peripheral surface of the outer roller 31 is formed in a cylindrical inner peripheral surface shape, that is, substantially the same diameter along the axial direction of the outer roller 31. However, ring grooves 31a and 31b are formed on both opening sides of the inner circumferential surface of the outer roller 31 over the entire circumference.

  As shown in FIGS. 3A and 3B, the inner roller 32 is formed in a cylindrical shape. The inner roller 32 is disposed on the outer peripheral side of the tripod shaft 22 and is pivotally supported by the tip of the tripod shaft 22. Here, when the posture in which the roller rotation axis Ar, which is the central axis of the inner roller 32, coincides with the axis At of the tripod shaft portion 22 is set as a reference posture, the inner peripheral surface of the inner roller 32 has the tripod shaft portion 22. Two concave grooves 32a and 32b extending in the axis At direction are formed. The concave grooves 32a and 32b are formed in a linear shape along the roller rotation axis Ar on the cylindrical inner surface of the inner roller 32 as an overall shape.

  In addition, the concave grooves 32a and 32b have a square cross-sectional shape in a plane orthogonal to the axis At of the tripod shaft portion 22 in the above-described reference posture. That is, as shown in FIG. 4, the inner roller 32 is fitted with a predetermined gap between the protruding portion 22a of the tripod shaft portion 22 and the recessed portion 32b of the protruding portion 22b of the tripod shaft portion 22 with a predetermined gap. Is done. Therefore, the inner roller 32 is located on the outer peripheral side of the tripod shaft portion 22 so that the concave grooves 32a and 32b are positioned in a phase that coincides with the shaft rotation axis As of the intermediate shaft 2 when viewed from the axis At direction of the tripod shaft portion 22. Placed in.

  With such a configuration, as shown in FIG. 4, the concave grooves 32 a and 32 b are formed to extend in the axis At direction of the tripod shaft portion 22 in a state where the inner roller is assembled on the outer peripheral side of the tripod shaft portion 22. Therefore, the protrusions 22a and 22b fitted with a predetermined gap can slide in the extending direction of the concave grooves 32a and 32b. Therefore, the inner roller 32 is allowed to swing with respect to the tripod shaft part 22 in a plane including the shaft rotation axis As of the intermediate shaft 2 and the axis line At of the tripod shaft part 22. Similarly, the inner roller 32 is allowed to slide with respect to the tripod shaft portion 22 in the axis At direction of the tripod shaft portion 22.

  On the other hand, when the inner roller 32 attempts to move with respect to the tripod shaft portion 22 in a direction different from the direction of the axis At of the tripod shaft portion 22, the protrusions 22a and 22b are grooves of the concave grooves 32a and 32b. It will come into contact with the side. That is, the inner roller 32 is restricted from swinging with respect to the tripod shaft 22 in a plane orthogonal to the outer ring rotation axis Ao by the protrusions 22a and 22b being engaged with the concave grooves 32a and 32b. Thus, the concave grooves 32a and 32b of the inner roller 32 are portions that are locked to the protrusions 22a and 22b of the tripod shaft portion 22, and correspond to the “locking grooves” of the present invention.

  Further, the axial length of the inner roller 32 (width in the roller rotation axis Ar direction) corresponds to a separation distance between the ring grooves 31a and 31b on both sides formed in the outer roller 31, as shown in FIG. The outer diameter of the inner roller 32 is smaller than the inner diameter of the outer roller 31. The inner roller 32 is spaced radially inward of the outer roller 31 and is coaxial with the outer roller 31. In the radial gap between the inner roller 32 and the outer roller 31, a plurality of needle rollers 33 are disposed over the entire circumference. The outer roller 31 can rotate relative to the inner roller 32 through the needle roller 33.

  The snap rings 34 and 35 are retaining rings formed in a C shape having a cut portion so that the diameter can be reduced. These snap rings 34 and 35 are fitted in the ring grooves 31a and 31b of the outer roller 31, respectively. The snap rings 34 and 35 are hooked in the axial direction of the roller unit 30 with respect to the inner roller 32 and the needle roller 33. That is, the snap rings 34 and 35 restrict the inner roller 32 and the needle roller 33 from moving relative to the outer roller 31 in the axial direction.

  In such a roller unit 30, the inner roller 32 and the needle roller 33 constitute a double roller type roller unit 30 integrated with the outer roller 31 together with snap rings 34 and 35 fixed to the outer roller 31. Yes. Therefore, when the inner roller 32 is restricted from swinging partly due to the engagement with the protrusions 22a and 22b of the tripod shaft portion 22, the roller unit 30 including the inner roller 32 is also the outer ring rotating shaft. The swing motion with respect to the tripod shaft portion 22 is restricted in a plane orthogonal to Ao.

  In the above-described sliding tripod type constant velocity joint 1, when torque is transmitted, the outer peripheral surface of the tripod shaft portion 22 and the inner peripheral surface of the inner roller come into contact with each other within an elliptical contact range. FIG. 5A shows the contact range Tr1 on the outer peripheral surface of the tripod shaft portion 22, and FIG. 5B shows the contact range Tr2 on the inner peripheral surface of the inner roller 32 facing this range. The contact ranges Tr1 and Tr2 vary depending on the magnitude of torque transmitted. Further, when the size of the torque to be transmitted is equal, if the areas of the contact ranges Tr1 and Tr2 are reduced, the surface pressure (load per unit area) is increased accordingly. Further, the protrusions 22a and 22b of the tripod shaft 22 and the concave grooves 32a and 32b of the inner roller 32 do not directly contribute to torque transmission. Therefore, in this embodiment, the protrusions 22a and 22b and the concave grooves 32a and 32b are formed outside the contact ranges Tr1 and Tr2 shown in FIGS. 5A and 5B.

(Operation and effect of sliding tripod type constant velocity joint 1)
Next, the operation of the above-described sliding tripod type constant velocity joint 1 will be described with reference to FIGS. Here, in FIG. 1, when the tripod 20 rotates clockwise around the shaft rotation axis As, the right groove side surface in FIG. 1 of the raceway groove 11 of the outer ring 10 becomes the torque load side, and the raceway groove 11. The left side surface of the groove in FIG. 1 is the non-load side of the torque. For example, the groove side surface of the raceway groove 11 is formed in a Gothic arch shape, and the outer peripheral surface of the outer roller 31 is formed in a convex arc shape having a single radius of curvature. In this case, the outer roller 31 is in angular contact with the groove side surface of the raceway groove 11 at two contact points.

  Here, when the joint angle is not added, the outer ring rotation axis Ao and the shaft rotation axis As coincide with each other, and as shown in FIG. 6A, the tip of the tripod shaft portion 22 is the inner roller. It is located in the central part of 32 axial widths. On the other hand, when torque is transmitted by adding a joint angle, the tripod 20 rotates eccentrically relative to the outer ring rotation axis Ao while rotating about the shaft rotation axis As. In this eccentric rotation, when viewed from the direction of the outer ring rotation axis Ao, the angle formed by the adjacent tripod shaft portions 22 varies depending on the phase of the intermediate shaft 2, so that each tripod shaft portion 22 has a raceway groove 11 of the outer ring 10. Are generated in order to fit in each.

  Therefore, as shown in FIG. 6 (b), the tripod shaft portion 22 is connected to the roller unit 30 to be pivotally supported in the axis At direction of the tripod shaft portion 22 when torque is transmitted with a joint angle added. Will slide into. Further, the tripod shaft portion 22 performs a swing motion relative to the tripod shaft portion 22 with respect to the roller unit 30 in the plane including the shaft rotation axis As and the axis line At of the tripod shaft portion 22 with respect to the added joint angle. To do. At this time, the protruding portions 22a and 22b of the tripod shaft portion 22 slide with respect to the concave grooves 32a and 32b of the inner roller 32, thereby allowing these sliding and swinging motions.

  Further, when the tripod shaft portion 22 slides with respect to the roller unit 30, the load center in the contact range of both members also moves. Then, as shown in FIG. 1, a counterclockwise moment in FIG. 1 is generated around the turning center Oa of the angular contact on the groove side surface of the raceway groove 11 and the outer peripheral surface of the outer roller 31. The rotation center Oa of the angular contact is an extending direction of the raceway groove 11, that is, an axis parallel to the outer ring rotation axis Ao. That is, the roller unit 30 is applied with a force for swinging the tripod shaft portion 22 in a plane perpendicular to the outer ring rotation axis Ao by the generated moment. Therefore, when the posture of the roller unit 30 is not maintained, the roller unit 30 is in contact with the non-load side of the torque of the raceway groove 11 and a frictional force may be generated between the roller unit 30 and the raceway groove 11. There is.

  On the other hand, in the sliding tripod type constant velocity joint 1 of the present embodiment, as shown in FIG. 6B, when a moment is generated to rotate the roller unit 30 around the turning center Oa. In addition, the protrusions 22 a and 22 b of the tripod shaft 22 are engaged with the concave grooves 32 a and 32 b of the inner roller 32. As a result, the inner roller 32 is restricted from swinging with respect to the tripod shaft 22 in a plane perpendicular to the outer ring rotation axis Ao, so that the roller unit 30 is restricted from rotating around the turning center Oa and maintains its posture. Is done.

  Therefore, the non-load side (back side), which is the opposite side of the load side performing torque transmission with the raceway groove 11 of the outer ring 10 among the outer rollers 31 constituting the roller unit 30, is in contact with the raceway groove 11. Can be prevented. Therefore, the contact load between the track groove 11 on the non-load side and the roller unit 30 can be reduced. As a result, the induced thrust force can be reduced, and power loss and vibration generation due to contact on the back side can be suppressed.

  Further, the concave grooves 32 a and 32 b and the protrusions 22 a and 22 b are formed outside the contact ranges Tr 1 and Tr 2 between the outer peripheral surface of the tripod shaft portion 22 and the inner peripheral surface of the inner roller 32. Since the concave grooves 32a and 32b and the ridges 22a and 22b do not directly contribute to torque transmission, when they are formed inside the contact ranges Tr1 and Tr2, the areas of the contact ranges Tr1 and Tr2 are reduced. . If it does so, surface pressure (load per unit area) will increase according to the part for which the area of contact range Tr1 and Tr2 became small. Therefore, by adopting the configuration as described above, it is possible to secure the areas of the contact ranges Tr1 and Tr2 and suppress the increase in the surface pressure in the contact ranges Tr1 and Tr2 when torque is transmitted.

  Here, the concave grooves 32a and 32b and the protrusions 22a and 22b may be provided with a predetermined gap between them for the function of allowing a predetermined operation or for assembling manufacture. However, depending on the positional relationship between the position at which the protrusions 22a and 22b are engaged with the concave grooves 32a and 32b and the turning center Oa of the moment, the rotation around the turning center Oa of the roller unit 30 by an amount corresponding to the provided gap. May be allowed to rotate. Therefore, in this embodiment, the concave grooves 32a and 32b and the protrusions 22a and 22b are configured to have a square cross-sectional shape. Thereby, the clearance gap provided between both was filled so that the corner | angular part of protrusion 22a, 22b may contact | abut to the side surface of concave groove 32a, 32b. As a result, the protrusions 22a and 22b can be reliably locked in the concave grooves 32a and 32b, so that the posture of the roller unit 30 can be suitably maintained even when a moment is generated.

<Second embodiment>
(Overall configuration of sliding tripod type constant velocity joint 101)
The sliding tripod type constant velocity joint 101 of the second embodiment will be described with reference to FIG. The sliding tripod type constant velocity joint 101 in this embodiment is mainly different from the first embodiment in the configuration of the locking portion. Since other configurations are substantially the same as those of the first embodiment, detailed description thereof is omitted. Only the differences will be described below. The sliding tripod constant velocity joint 101 includes an outer ring 10, a tripod 120 connected to the intermediate shaft 2, and a roller unit 30 interposed between the outer ring 10 and the tripod 20.

  The tripod 120 includes a boss portion 21 and three tripod shaft portions 122. As shown in FIG. 7A, a total of four tripod shaft portions 122 are arranged on the outer peripheral surface along the axis At direction of the tripod shaft portion 122 (vertical direction in FIG. 7A). Projections 122a and 122b. In the present embodiment, the protrusions 122a and 122b are in a phase that coincides with the shaft rotation axis As on the outer peripheral surface of the tripod shaft 122 as viewed from the direction of the axis At of the tripod shaft 122, as in the first embodiment. Is arranged. That is, when the tripod 120 is disposed inside the outer ring 10, the protrusion 122 a is positioned on the opening side of the outer ring 10, and the protrusion 122 b is positioned on the cylinder bottom side of the outer ring 10.

  The protrusions 122a and 122b are formed so as to protrude radially outward from the center of the spherical surface from the outer peripheral surface of the tip portion of the tripod shaft portion 122 formed in a partially spherical shape as an overall shape. Further, the protrusions 122a and 122b have a semicircular cross-sectional shape on a plane orthogonal to the axis At of the tripod shaft 122. Further, the central portion in the width direction of the protrusions 122a and 122b is formed so as to exist in a plane including the shaft rotation axis As and the axis At of the tripod shaft 122 when viewed from the axis At direction of the tripod shaft 122. . The protrusions 122a and 122b are portions that are engaged with the concave grooves 32a and 32b formed on the inner peripheral surface of the inner roller 32, and correspond to the “engaging portion” of the present invention.

(Operation and effect of sliding tripod type constant velocity joint 101)
As described above, the locking portion in the sliding tripod type constant velocity joint 101 of the present embodiment is a protrusion formed so that the locking portion in the first embodiment extends in the axis At direction of the tripod shaft portion 22. It differs from the portions 22a and 22b in that it has a plurality of protrusions 122a and 122b.

  Here, when torque transmission is performed with a joint angle added, the tripod shaft 122 is moved in the direction of the axis At of the tripod shaft 122 with respect to the roller unit 30 to be supported as shown in FIG. Slide. Further, the tripod shaft part 122 performs the swing motion with respect to the tripod shaft part 22 in the plane including the shaft rotation axis As and the axis line At of the tripod shaft part 122 with respect to the roller unit 30 by the added joint angle. To do. At this time, the protrusions 122a and 122b of the tripod shaft 122 slide with respect to the concave grooves 32a and 32b of the roller unit 30 to allow these sliding and swinging motions.

  When a moment is generated to rotate the roller unit 30 about the turning center Oa, the lower protrusion 122a of the two protrusions 122a is concave as shown in FIG. 7B. The upper protrusion 122b of the two protrusions 122b is engaged with the concave groove 32b. As a result, the inner roller 32 is restricted from swinging with respect to the tripod shaft 22 in a plane perpendicular to the outer ring rotation axis Ao, so that the roller unit 30 is restricted from rotating around the turning center Oa and maintains its posture. Is done. Therefore, the non-load side (back side), which is the opposite side of the load side performing torque transmission with the raceway groove 11 of the outer ring 10 among the outer rollers 31 constituting the roller unit 30, is in contact with the raceway groove 11. Can be prevented. Accordingly, the same effects as those of the first embodiment can be obtained.

<Modification of the first and second embodiments>
In the first and second embodiments, concave grooves 32a and 32b are formed on the inner peripheral surface of the inner roller 32 as the locking grooves, and the ridges 22a and 22b are formed on the outer peripheral surfaces of the tripod shaft portions 22 and 122 as the locking portions. Alternatively, the protrusions 122a and 122b are formed. On the other hand, the arrangement relationship between the locking groove and the locking portion may be interchanged. Specifically, a concave groove may be formed on the outer peripheral surface of the tripod shaft portion 22 as the locking groove, and a ridge or protrusion may be formed on the inner peripheral surface of the inner roller 32 as the locking portion. Even in such a configuration, the same effect as that of the first and second embodiments is obtained.

  Further, in the first and second embodiments, the protrusion 22a has two phases that coincide with the shaft rotation axis As on the outer peripheral surfaces of the tripod shafts 22 and 122 when viewed from the axis At direction of the tripod shaft 22. 22b or protrusions 122a and 122b. Furthermore, two concave grooves 32 a and 32 b extending in the axis At direction of the tripod shaft portions 22 and 122 are formed on the inner peripheral surface of the inner roller 32. On the other hand, the protrusions 22a and 22b (projections 122a and 122b) and the concave grooves 32a and 32b may be only one pair. Even in such a configuration, the same effects as in the first embodiment can be obtained.

  Further, in the first embodiment, the locking portions are protrusions 22a and 22b formed from the upper part to the lower part where the partial spherical surface is formed at the tip of the tripod shaft part 22, and in the second embodiment the tripod shaft. A total of four protrusions 122a and 122b are arranged on the outer peripheral surface of the portion 122 at two locations on the top and bottom. On the other hand, the locking portion may be disposed only on the upper side or the lower side of the outer peripheral surfaces of the tripod shaft portions 22 and 122. Specifically, in the first embodiment, the protrusions 22a and 22b may be formed only at the upper or lower part where the partial spherical surface is formed at the tip of the tripod shaft part 22. In the second embodiment, a total of two protrusions only on the upper side or the lower side may be formed at the tip of the tripod shaft part 122. Even in such a configuration, the same effects as those of the first and second embodiments can be obtained.

  In the first and second embodiments, the locking groove (concave groove 32a, 32b) and the locking portion (projected portion 22a, 22b, protruding portion 122a, 122b) to be locked to the tripod shaft portion 22, The phase is assumed to be arranged in a phase that coincides with the shaft rotation axis As when viewed from the direction of the axis At of 122. As described above, the locking groove and the locking portion regulate the swinging motion of the inner roller 32 relative to the tripod shaft portions 22 and 122 in a plane orthogonal to the outer ring rotation axis Ao when torque is transmitted. Any other configuration that allows the swing motion and the sliding of the tripod shaft portion 22 in the axial direction may be used. Therefore, the phase at which the locking groove and the locking portion are arranged is not limited to the above-described phase, and may be configured to be provided at any phase around the axis At of the tripod shaft portions 22 and 122.

  However, the locking groove and the locking portion need to allow a swinging motion with respect to the tripod shaft portions 22 and 122 in a plane in which the roller unit 30 includes the shaft rotation axis As and the axis line At of the tripod shaft portion 22. For this reason, the center portion in the width direction of the locking portion is the axis of the shaft rotation axis As and the tripod shaft portions 22 and 122 when viewed from the axis At direction of the tripod shaft portions 22 and 122 regardless of the phase. It needs to be formed so as to exist in a plane parallel to the plane including At.

  Furthermore, from the viewpoint of preventing an increase in the surface pressure in the contact ranges Tr1 and Tr2 between the tripod shafts 22 and 122 and the inner roller 32, it is preferable to arrange them in a phase outside the contact ranges Tr1 and Tr2. The moment generated in the roller unit 30 is centered on the turning center Oa that is an axis parallel to the outer ring rotation axis Ao. Therefore, the position where the concave groove 32a serving as the locking groove and the protrusion 22a serving as the locking portion are locked can be suitably maintained in the posture of the roller unit 30 as the moment is away from the turning center Oa of the moment. it can. Therefore, by providing the concave groove 32a and the ridge 22a in a phase around the axis At of the tripod shaft 22 positioned on the shaft rotation axis As, the distance between the locking position and the turning center Oa is secured. Even if the load side and the non-load side are interchanged, the posture of the roller unit 30 can be suitably maintained.

DESCRIPTION OF SYMBOLS 1,101: Sliding tripod type constant velocity joint, 2: Intermediate shaft 10: Outer ring, 11: Track groove 20: Tripod, 21: Boss part, 21a: Internal spline 22,122: Tripod shaft part, 22a, 22b : Projection (locking part)
122a, 122b: Protrusions (locking portions)
30: roller unit, 31: outer roller, 31a, 31b: ring groove 32: inner roller, 32a, 32b: concave groove (locking groove)
33: Needle roller (needle), 34, 35: Snap ring Ao: Outer ring rotating shaft, As: Shaft rotating shaft At: Tripod shaft axis, Ar: Roller rotating shaft Tr1, Tr2: Contact range, Oa: Center of rotation

Claims (3)

An outer ring formed in 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,
An outer roller arranged to roll in the raceway groove;
The pivot is supported on the outer peripheral side of the tripod shaft, and allows swinging movement with respect to the tripod shaft and sliding in the axial direction of the tripod shaft in a plane including the axis of the shaft and the axis of the tripod shaft. The inner roller
A needle interposed so as to roll between an inner peripheral surface of the outer roller and an outer peripheral surface of the inner roller;
A snap ring fixed to the outer roller and restricting axial movement of the inner roller and the needle with respect to the outer roller;
A sliding tripod type constant velocity joint comprising:
A locking groove extending in the axial direction of the tripod shaft portion is formed in one of the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the inner roller facing the outer peripheral surface, and the other is related to the locking groove. A locking part to stop is formed,
When the torque is transmitted between the inner roller and the tripod shaft portion, the tripod shaft portion is engaged with the engagement groove in the plane perpendicular to the outer ring rotation axis. Sliding tripod type constant velocity joint with controlled swing motion against In claim 1,
The locking groove and the locking portion are provided in a contact range between the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the inner roller when torque is transmitted between the tripod shaft portion and the inner roller. Sliding tripod type constant velocity joint formed outside. In claim 1 or 2,
The locking groove and the locking portion are slidable tripod type constant velocity joints in which a cross-sectional shape in a plane orthogonal to the axis of the tripod shaft portion is formed in a square shape.

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