JP2013234718A - Slide type tripod constant velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide type tripod constant velocity joint in which an induced thrust force accompanying changes in an attitude of a roller can be reliably reduced.SOLUTION: A slide type tripod constant velocity joint includes a biasing member 40, which is provided on a roller 31 in such a manner that the biasing member can rotate together with each roller 31 with respect to an outer ring 10 and can move in an extending direction of a raceway groove 11. The biasing member 40 comes in contact with a groove bottom face 11a of each raceway groove 11 and biases the roller 31 to the radially inside of the outer ring 10.

Description

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

  The sliding tripod type constant velocity joint is required to reduce the induced thrust force. Japanese Patent Laid-Open No. 3-277824 (Patent Document 1) describes that a roller, a needle roller, and a cage keep the posture of the outer ring with respect to the axis line unchanged. That is, by moving a cage (also referred to as an inner roller) fitted to the convex spherical surface of the tripod shaft portion along the rail of the raceway groove of the outer ring, the postures of the roller, needle roller, and cage are maintained.

JP-A-3-277824

  Here, a force that rotates between the tripod shaft and the needle roller acts on the cage (inner roller). That is, the cage slides along the rail of the raceway groove of the outer ring while the rail regulates the rotation of the cage. As a result, the sliding resistance increases, which may cause an induced thrust force.

  This invention is made in view of such a situation, and it aims at providing the sliding tripod type | mold constant velocity joint which can reduce the induced thrust force accompanying the attitude | position of a roller reliably. .

  (Claim 1) A sliding tripod type constant velocity joint according to the present means is formed in a cylindrical shape, an outer ring having three raceway grooves formed on an inner peripheral surface, and three pieces extending radially outward respectively. A tripod having a tripod shaft portion, three rollers supported by the tripod shaft portions so as to be rotatable and swingable, and arranged so as to be able to roll in the groove extending direction in the raceway grooves, and the outer ring The roller is provided so as to be rotatable together with each roller and to be movable in the groove extending direction, and is in contact with the groove bottom surface of each track groove to urge the roller inward in the radial direction of the outer ring. Three urging members.

(Claim 2) Further, the contact portion between each urging member and the groove bottom surface of each raceway groove is rotated by the roller from the contact portion when the end surface of the roller and the groove bottom surface of the track groove contact each other. You may make it set to an axial center side.
(Claim 3) Particularly, the contact portion between each of the biasing members and the groove bottom surface of each of the raceway grooves is a one-point contact, and the contact portion is between the rotation axis of the roller and the raceway groove. You may make it set so that an intersection may be included.

(Claim 4) Further, the urging member includes a seat portion that contacts a groove bottom surface of the raceway groove, and extends radially outward from the seat portion, and in an axial direction of the roller with respect to the roller. And a leg portion that is locked and elastically deformable in the axial direction of the roller.
(Claim 5) The urging member may include a plurality of the leg portions.

  (Claim 6) The sliding tripod type constant velocity joint is rotatable relative to the outer roller and the outer roller capable of rolling the raceway groove, and is rotated relative to the tripod shaft portion. A roller unit having an inner roller capable of swinging and a rolling element that rolls between an inner peripheral surface of the outer roller and an outer peripheral surface of the inner roller, the roller also serving as the outer roller Good.

  (Claim 1) The urging member contacts the groove bottom surface of the raceway groove and urges the outer ring radially inward. Thereby, the attitude | position of the roller with respect to a track groove can be hold | maintained, and it can reduce that an induced thrust force generate | occur | produces, when a roller rolls a track groove. Here, the urging member is provided on the roller so as to be rotatable together with the roller with respect to the outer ring and to be movable in the groove extending direction. In this state, the urging member is in contact with the groove bottom surface of the raceway groove. That is, the urging member is not restricted in rotation with respect to the raceway groove but moves in the groove extending direction while rotating. Therefore, according to this means, there is no generation of induced thrust force due to the rotation restriction of the cage (inner roller) as in the prior art. Therefore, the induced thrust force can be reliably reduced.

  (Claim 2) Here, the closer the contact position between the rotating body and the non-rotating body is to the center axis of the rotating body, the narrower the contact range between them, and the lower the relative speed due to rotation. The frictional force becomes smaller. Thereby, the sliding resistance between both in contact decreases. Then, the contact portion between the biasing member and the groove bottom surface of the raceway groove is on the rotation axis side of the roller from the contact portion when the end surface of the roller and the groove bottom surface of the raceway groove are in contact with each other. Thereby, the sliding resistance by the said contact site can be made small. Thereby, the induced thrust force can be reduced.

  (Claim 3) In particular, the contact portion between the biasing member and the groove bottom surface of the raceway groove includes the intersection of the rotation axis of the roller and the raceway groove, so that the sliding resistance due to the contact portion is further increased. Can be small. Therefore, the induced thrust force can be reduced more reliably.

  (Claim 4) Since the seat portion of the urging member is located on the rotation axis side of the roller, the sliding resistance between the seat portion and the groove bottom surface can be reduced. Furthermore, the posture of the roller with respect to the track groove can always be maintained in a desired posture by the leg portion biasing the roller against the track groove by the elastic force of the leg portion. Thereby, the induced thrust force can be reliably reduced.

  (Claim 5) When the urging member is assembled to the outer roller by using a plurality of leg portions of the urging member, the leg portion is attached to the side where the tip side of the leg portion is separated from the seat portion in the rotation axis direction. It becomes elastically deformable so as to move inward in the radial direction of the biasing member. Therefore, the assembling property of the urging member to the outer roller is good.

  (Claim 6) The urging member is provided on the outer roller which is the member closest to the raceway groove among the members constituting the roller unit. Therefore, the structure becomes easy, the assembling property becomes good, and the cost can be reduced.

1st embodiment of this invention: 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 the figure which looked at the urging member from the axial direction (figure which looked at the urging member of Drawing 1 from the upper part). FIG. 3 is a sectional view taken along line III-III in FIG. 2. 2nd embodiment of this invention: It is the figure which looked at the biasing member from the axial direction. It is VV sectional drawing of FIG.

  The sliding tripod type constant velocity joint of this embodiment will be described with reference to FIGS. Here, the case where the sliding tripod constant velocity joint of the present 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. In this case, the constant velocity joint is used at a connection portion between the differential gear and the intermediate shaft of the drive shaft.

  The sliding tripod type constant velocity joint includes an outer ring 10 connected to a hole (not shown) of a differential gear, a tripod 20 connected to an intermediate shaft (not shown) on the other side, and an outer ring 10, The three roller units 30 interposed between the tripod shaft portions 22 of the tripod 20 and the three urging members 40 are provided.

  The outer ring 10 is formed in a cylindrical shape (for example, a bottomed cylindrical shape), and one end side is connected to the differential gear. Then, three track grooves 11 extending in the outer ring axial direction (the front-rear direction in the drawing of 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 groove bottom surface 11a of each raceway groove 11 is formed in a planar shape. Further, the groove side surfaces 11b and 11c of each raceway groove 11 are formed in a cross-sectional shape that approximates an arcuate concave shape. For example, the cross-sectional shapes of the groove side surfaces 11b and 11c are formed in a Gothic arch shape.

  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 inner spline 21 a is formed on the inner peripheral side of the boss portion 21. The inner spline 21a is connected to an outer spline (not shown) on the outer peripheral surface of the end portion of the intermediate shaft.

  Each tripod shaft portion 22 is provided 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 ° 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 is formed in a partially spherical convex shape. That is, the axial cross-sectional shape of the outer peripheral surface of the tripod shaft portion 22 is formed in an arcuate convex shape.

  The roller unit 30 is configured to be annular as a whole. The three roller units 30 are rotatable on the outer peripheral side of each tripod shaft portion 22, are slidable, and are supported so as to be able to swing. Furthermore, each roller unit 30 is arranged so as to be able to roll along the groove extending direction of each track groove 11, that is, along the groove side surfaces 11b and 11c. The roller unit 30 includes an outer roller 31, an inner roller 32, a needle roller 33 (rolling element), and retaining 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 surfaces 11b and 11c of the raceway groove 11, that is, an arc convex shape in which the groove side surfaces 11b and 11c of the raceway groove 11 are reversed. Yes. The outer roller 31 is fitted into the raceway groove 11 so that its center axis is orthogonal to the outer ring rotation axis. However, gaps are formed between the outer roller 31 and the groove side surfaces 11b and 11c to such an extent that the outer roller 31 can roll on the groove side surfaces 11b and 11c. Further, the inner peripheral surface of the outer roller 31 is formed in a cylindrical inner peripheral shape, that is, substantially the same diameter over the axial direction of the outer roller 31. Retaining 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.

  The inner roller 32 is formed in a cylindrical shape. The axial length of the inner roller 32 corresponds to the distance between the retaining ring grooves 31 a and 31 b formed on the both sides of the outer roller 31. The outer diameter of the inner roller 32 is smaller than the inner diameter of the outer roller 31. The inner roller 32 is coaxially disposed so as to be spaced radially inward of 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 arranged to roll over the entire circumference. Through the needle roller 33, the inner roller 32 can rotate relative to the outer roller 31. The inner roller 32 having a cylindrical inner peripheral surface is inserted into the tripod shaft portion 22 having a partially spherical convex shape, so that the inner roller 32 can rotate with respect to the tripod shaft portion 22 and can slide and swing. Supported as possible.

  The retaining rings 34 and 35 are formed in a C-shape having a cut portion so that the diameter can be reduced. These retaining rings 34 and 35 are fitted into retaining ring grooves 31a and 31b of the outer roller 31, respectively. The retaining 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 retaining 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.

  Here, the thickness of the retaining ring 34 fitted in the retaining ring groove 31a (the retaining ring groove on the center axis side (downward in FIG. 1) of the outer ring 10) corresponds to the groove width of the retaining ring groove 31a. The retaining ring 35 fitted in the retaining ring groove 31b (the retaining ring groove on the groove bottom surface 11a side (upper side in FIG. 1) of the raceway groove 11) is thinner than the groove width of the retaining ring groove 31b. A gap is formed between the groove 31b and the axial direction.

  Each urging member 40 is formed in a shape substantially like a disc spring. The urging member 40 is formed by, for example, pressing a steel plate. Specifically, as shown in FIGS. 2 and 3, the urging member 40 includes a seat portion 41 and a plurality of (for example, three) leg portions 42. The seat portion 41 is formed in a partially spherical convex shape, and the outer diameter of the outer peripheral edge of the seat portion 41 is smaller than the inner diameter of the inner roller 32.

  Each leg portion 42 is formed so as to extend from the outer peripheral edge of the seat portion 41 radially outward and in the axial direction (the side opposite to the convex shape of the seat portion 41). Therefore, the leg portion 42 can be elastically deformed so that the distal end side of the leg portion 42 moves away from the seat portion 41 in the rotation axis L direction and radially inward of the urging member 40. Further, the outer peripheral end of each leg portion 42 is bent toward the seat portion 41 side.

  As shown in FIG. 1, the urging member 40 formed in this way is disposed between the groove bottom surface 11 a of each track groove 11 and the outer roller 31. That is, the convex surface side of the seat portion 41 is substantially in contact with the groove bottom surface 11a, and the leg portion 42 is separated from the groove bottom surface 11a. Therefore, the seat 41 of the biasing member 40 contacts the groove bottom surface 11a. That is, the contact portion between the seat portion 41 and the groove bottom surface 11a is located closer to the rotation axis L side of the outer roller 31 than the contact portion when the end surface of the outer roller 31 and the groove bottom surface 11a of the raceway groove 11 contact each other. Yes. In particular, the contact portion between the seat portion 41 and the groove bottom surface 11 a is located closer to the rotational axis L side of the outer roller 31 than the inner peripheral surface of the inner roller 32.

  Furthermore, since the seat portion 41 formed in a partially spherical convex shape contacts the groove bottom surface 11a, the contact portion is a one-point contact (contact of only the portion of the seat portion 41). In particular, the contact portion between the seat 41 and the groove bottom surface 11a includes an intersection point P between the rotation axis L of the outer roller 31 and the groove bottom surface 11a. More specifically, the center of the seat portion 41 coincides with the rotational axis L of the outer roller 31.

  The outer peripheral ends of the leg portions 42 are fitted into the retaining ring grooves 31 b of the outer roller 31. Here, each leg portion 42 can be elastically deformed so that the tip side thereof moves away from the seat portion 41 in the rotation axis direction and radially inward of the urging member 40. Therefore, when the urging member 40 is assembled to the retaining ring groove 31b, the leg portion 42 is elastically moved so that the tip of each leg portion 42 moves away from the seat portion 41 and radially inward of the urging member 40. Deform. And the front-end | tip of the leg part 42 is inserted in the radial direction inner side of the outer roller 31, and the elastic force of the leg part 42 is open | released so that the front-end | tip of the leg part 42 may be fitted in the retaining ring groove 31b. If it does so, each leg part 42 will reset and it will be fitted in the retaining ring groove 31b. A plurality of leg portions 42 are provided, and the elastic deformation of each leg portion 42 makes the assembly of the urging member 40 to the outer roller 31 very good. In this way, the leg portion 42 is locked in the axial direction of the outer roller 31.

  Here, since the retaining ring 35 is fitted in the retaining ring groove 31 b on the groove bottom surface 11 a side, the leg portion 42 is fitted closer to the groove bottom surface 11 a side than the retaining ring 35. Thus, the retaining ring 35 and the urging member 40 are positioned with respect to the outer roller 31 by fitting the retaining ring 35 and the leg portion 42 of the urging member 40 into the retaining ring groove 31b. Therefore, the urging member 40 is provided on the outer roller 31 so as to be rotatable with the outer roller 31 with respect to the outer ring 10 and to be movable in the groove extending direction. The urging member 40 is formed so as not to contact the tripod shaft portion 22, the inner roller 32, and the needle roller 33.

  Next, the operation of the sliding tripod type constant velocity joint will be described. When the outer ring 10 or the tripod 20 rotates in a state where the joint angle is taken, torque is transmitted between the outer ring 10 and the tripod 20 via the roller unit 30. At this time, the tripod shaft portion 22 moves along the track groove 11 and swings the track groove 11. Further, since the outer roller 31 is fitted into the groove side surfaces 11 b and 11 c of the raceway groove 11, the roller unit 30 tries to maintain the posture with respect to the raceway groove 11. That is, the roller unit 30 swings while rotating relative to the tripod shaft part 22 and sliding in the roller axis direction.

  At this time, a force that inclines the roller axis direction acts on the roller unit 30 by the swinging operation of the tripod shaft portion 22 and sliding in the roller axis direction. Therefore, a force that changes the posture of the track groove 11 acts on the roller unit 30. This force generates a force that causes an induced thrust force between the outer roller 31 and the raceway groove 11. This phenomenon becomes prominent when the joint angle is increased.

  However, since the sliding tripod type constant velocity joint includes the urging member 40, the occurrence of the induced thrust force can be reduced. The principle will be described below. The urging member 40 is disposed between the outer roller 31 and the groove bottom surface 11 a of the raceway groove 11. Specifically, the seat portion 41 of the urging member 40 contacts the groove bottom surface 11 a and the leg portion 42 is fitted in the retaining ring groove 31 b of the outer roller 31.

  Since the outer roller 31 is fitted into the groove side surfaces 11b and 11c of the raceway groove 11, the position of the outer roller 31 is restricted to some extent. As described above, the leg portion 42 of the urging member 40 can be elastically deformed in the axial direction of the urging member 40. Therefore, when the seat portion 41 contacts the groove bottom surface 11 a, the leg portion 42 can urge the outer roller 31 inward in the radial direction of the outer ring 10. Further, in addition to the legs 42 of the biasing member 40 biasing the outer roller 31 radially inward, the outer roller 31 is fitted into the groove side surfaces 11b and 11c, so that the outer roller 31 is , Hold a certain posture. In this way, the generation of the induced thrust force can be reduced by holding the outer roller 31 in a constant posture.

  By the way, the urging member 40 is provided on the outer roller 31 so as to be rotatable with the outer roller 31 with respect to the outer ring 10 and to be movable in the groove extending direction. In this state, the urging member 40 is in contact with the groove bottom surface 11 a of the raceway groove 11. That is, the urging member 40 is not restricted in rotation with respect to the raceway groove 11 but moves in the groove extending direction while rotating. Accordingly, there is no generation of induced thrust force due to the rotation restriction of the cage (inner roller) as in the prior art. Therefore, the induced thrust force can be reliably reduced.

  In general, the closer the contact position between the rotating body and the non-rotating body is to the center axis of the rotating body, the narrower the contact range between the two and the lower the relative speed due to rotation. The power is reduced. Thereby, the sliding resistance between both in contact decreases. Here, in the present embodiment, the outer roller 31 among the members constituting the roller unit 30 is the member closest to the raceway groove 11. The contact portion between the biasing member 40 and the groove bottom surface 11a of the raceway groove 11 is closer to the rotation axis L side of the outer roller 31 than the contact portion when the end surface of the outer roller 31 and the groove bottom surface 11a contact each other. Is located. Accordingly, the sliding resistance due to the contact portion with the groove bottom surface 11a can be reduced.

  In particular, the contact portion between the urging member 40 and the groove bottom surface 11a of the raceway groove 11 includes the intersection point P between the rotation axis L of the outer roller 31 and the raceway groove. It can be surely made small. Furthermore, the outer diameter of the outer peripheral edge of the seat portion 41 is smaller than the inner diameter of the inner roller 32. Accordingly, the contact range between the seat portion 41 and the groove bottom surface 11a is very narrow. As a result, the induced thrust force can be reduced more effectively.

  Further, the urging member 40 is provided on the outer roller 31 which is a member closest to the raceway groove 11 among the members constituting the roller unit 30. Therefore, the structure becomes easy, the assembling property becomes good, and the cost can be reduced.

  In the above embodiment, the seat 41 of the urging member 40 is always in contact with the groove bottom surface 11a. However, the present invention is not limited to this. For example, the seat 41 of the biasing member 40 may come into contact with the groove bottom surface 11a when the outer roller 31 is about to change its posture. In this case, the generation of the induced thrust force can be reduced by suppressing a large change in the posture of the outer roller 31. Furthermore, in a range where the change in the posture of the outer roller 31 is small, the seat portion 41 of the urging member 40 is not in contact with the groove bottom surface 11a, so that it is possible to suppress the generation of induced thrust force due to the contact between the two. Further, the urging member 40 is formed separately from the other members, but may be formed integrally with the outer roller 31 or the retaining ring 35, for example.

<Other embodiments>
Next, another embodiment of the urging member 140 will be described with reference to FIGS. 4 and 5. Although the urging member 40 is formed by pressing a steel plate, the urging member 140 according to the present embodiment includes, as shown in FIGS. 4 and 5, for example, a main body 141 obtained by pressing a steel plate, You may make it form with the rivet-shaped pin 146 fixed to the main-body part.

  The main body 141 has a shape in which the seat 41 is formed in a planar shape with respect to the biasing member 40 of the above embodiment, and a circular hole is formed in the seat 41. That is, the main body 141 includes a seat main body 142 and a plurality of (for example, three) leg portions 143. The seat body 142 is formed in a shape having a circular hole in the center of the disk. The leg part 143 is the same as the leg part 42 of the said embodiment. However, the axial height (the vertical width in FIG. 5) of the main body 141 is slightly lower than the axial height of the biasing member 40 of the above embodiment.

  The pin 146 has a head at one end of the shaft, and the end surface of the head is formed in a partially spherical convex shape. Then, the shaft portion of the pin 146 is inserted into the circular hole of the seat body 142 so that the head of the pin 146 protrudes on the side opposite to the side where the leg 143 is bent, and the pin 146 is inserted into the seat body 142. Fixed. For fixing the pin 146 and the seat body 142, various fixing methods such as press fitting and welding can be applied. Further, the pin 146 is formed of a material having a small friction coefficient with respect to the seat portion 41 of the biasing member 40 of the above embodiment.

  The urging member 140 formed in this way is disposed between the groove bottom surface 11a and the outer roller 31 as in the above embodiment. In other words, the convex head portion of the pin 146 contacts the groove bottom surface 11 a substantially in the form of a dot, and the outer peripheral end of the leg portion 143 is fitted in the retaining ring groove 31 b of the outer roller 31. That is, the seat main body 142 and the pin 146 in this embodiment correspond to the seat 41 in the above embodiment. Also in this embodiment, the same effects as described above are obtained. Furthermore, by forming the pin 146 with a material having a smaller coefficient of friction than the seat portion 41 of the above embodiment, the sliding resistance with the groove bottom surface 11a can be further reduced compared to the above embodiment, and the induced thrust force can be further increased. Can be reduced.

10: outer ring, 11: raceway groove, 11a: groove bottom surface, 20: tripod, 22: tripod shaft, 30: roller unit, 31: outer roller, 32: inner roller, 33: needle roller (rolling element), 40, 140: biasing member, 41: seat part, 42: leg part, 142: seat body (part of seat part), 143: leg part, 146: pin (part of seat part), P: outer roller Intersection of rotation axis and raceway groove bottom, L: Rotation axis of outer roller

Claims (6)

An outer ring formed in a cylindrical shape and having three raceway grooves formed on the inner peripheral surface;
A tripod comprising three tripod shafts each extending radially outward;
Three rollers rotatably and swingably supported on each tripod shaft, and arranged to roll in the groove extending direction in each track groove;
It is provided in the roller so as to be rotatable with each roller with respect to the outer ring and movable in the groove extending direction, and is in contact with the groove bottom surface of each raceway groove so that the roller is radially inward of the outer ring. Three biasing members for biasing,
Sliding tripod type constant velocity joint.   The contact portion between each urging member and the groove bottom surface of each track groove is set on the rotation axis side of the roller from the contact portion when the end surface of the roller and the groove bottom surface of the track groove contact each other. The sliding tripod type constant velocity joint according to claim 1. The contact portion between each of the urging members and the groove bottom surface of each of the raceway grooves is a one-point contact,
The sliding tripod constant velocity joint according to claim 2, wherein the contact portion is set to include an intersection of the rotation axis of the roller and the raceway groove. The biasing member is
A seat in contact with the groove bottom surface of the raceway groove;
A leg portion extending radially outward from the seat portion, locked to the roller in the axial direction of the roller, and elastically deformable in the axial direction of the roller;
A sliding tripod type constant velocity joint according to claim 2 or 3.   The sliding type tripod type constant velocity joint according to claim 4, wherein the biasing member includes a plurality of the leg portions. The sliding tripod type constant velocity joint includes an outer roller that can roll on the raceway groove, an inner roller that can rotate relative to the outer roller, can rotate relative to the tripod shaft, and can swing. A roller unit having a roller and a rolling element that rolls between an inner peripheral surface of the outer roller and an outer peripheral surface of the inner roller;
The sliding tripod constant velocity joint according to any one of claims 1 to 5, wherein the roller is the outer roller.

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