JP2017137965A - Constant velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constant velocity joint capable of achieving long life of a retainer.SOLUTION: A constant velocity joint 100 includes: an outside joint member 10 having a plurality of raceway grooves 11; an inside joint member 20 having a plurality of leg shafts 22; a roller 30 capable of rolling in the raceway groove 11; a plurality of needle bearings 40 for supporting an inner peripheral surface of the roller 30 rotatably with respect to an outer peripheral surface of the leg shaft 22 of the inside joint member 20; a retainer 50 formed in a cylindrical shape and arranged at a further tip side of the leg shaft 22 than the plurality of needle bearings 40; and a cover ring 60 for preventing the retainer 50 from coming off the tip side of the leg shaft 22. The retainer 50 includes: a second restriction part 53 as a restriction part which comes into contact with the cover ting 60 and which is prevented from coming off the tip side of the leg shaft 22; and a buffer part 54 connected to an end part on an inner diameter side of the restriction part, and capable of relatively displacing in the shaft direction of the leg shaft 22 with respect to the restriction part by elastic deformation.SELECTED DRAWING: Figure 3B

Description

  The present invention relates to a constant velocity joint.

  Patent Document 1 discloses an outer joint member in which a plurality of raceway grooves are formed, an inner joint member having a plurality of leg shafts, a roller capable of rolling the raceway grooves, and an inner peripheral surface of the roller as an outer periphery of the leg shaft. There is known a constant velocity joint including a plurality of needle bearings that are rotatably supported with respect to a surface. Some of these constant velocity joints include a retainer and a retaining ring that are inserted into the leg shaft. The retainer is disposed closer to the tip end side of the leg shaft than the plurality of needle bearings, and prevents the plurality of needle bearings from coming off from the tip end side of the leg shaft. The retaining ring is disposed in a state in which the displacement of the leg shaft in the axial direction is restricted on the distal end side of the leg shaft relative to the retainer, and prevents the retainer from coming off from the distal end side of the leg shaft.

  By the way, in the constant velocity joint having the above-described configuration, when the outer joint member and the inner joint member transmit torque in a state where the joint operation angle is taken, the plurality of needle bearings are displaced toward the distal end side of the leg shaft, The retainer is pressed against the distal end side of the leg shaft. Since the retainer pressed against the distal end side of the leg shaft is restricted from being displaced toward the distal end side of the leg shaft by the retaining ring, the retainer disposed between the plurality of needle bearings and the retaining ring includes a plurality of needles. A pressing force toward the tip end side of the leg shaft is repeatedly applied at a portion in contact with the bearing.

  In this regard, Patent Document 1 discloses a technique for improving the load resistance of the retainer by forming a bent portion in the retainer and bringing a plurality of shaft-like rolling elements (needle bearings) into contact with the bent portion. ing.

JP 2011-163410 A

  However, in the technique described in Patent Document 1 described above, there is a possibility that the retainer may be worn out at an early stage in a portion that comes into contact with the plurality of shaft-like rolling elements.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a constant velocity joint capable of extending the life of a retainer.

  The constant velocity joint of the present invention includes an outer joint member having a plurality of raceway grooves that are open on one side in the rotation axis direction and extending in the rotation axis direction, and an inner joint having a plurality of leg shafts extending in the radial direction with respect to the rotation axis. A member, a roller that can roll into the raceway groove of the outer joint member, a plurality of needle bearings that rotatably support the inner peripheral surface of the roller with respect to the outer peripheral surface of the leg shaft of the inner joint member, and a cylinder And a retainer disposed on the distal end side of the leg shaft with respect to the plurality of needle bearings, and disposed on a distal end side of the leg shaft with respect to the retainer, and the retainer comes off from the distal end side of the leg shaft. A retaining ring for restricting this, and an annular groove on which the retaining ring is mounted is formed on the outer peripheral surface of the leg shaft, and the retainer has an inner diameter on the tip side of the leg shaft of the retaining ring. From outside diameter A restricting portion that is formed large, has an inner diameter on the base end side of the leg shaft that is smaller than an outer diameter of the retaining ring, and is restricted from coming out of the distal end side of the leg shaft in contact with the retaining ring And a buffer portion connected to an end portion on the small inner diameter side of the restricting portion and capable of relative displacement in the axial direction of the leg shaft with respect to the restricting portion by elastic deformation.

  According to the constant velocity joint of the present invention, when the plurality of needle bearings are displaced toward the distal end side of the leg shaft and the plurality of needle bearings are pressed against the retainer, the buffer portion is elastically deformed. Since the shock applied to the retainer from the plurality of needle bearings is buffered by the elastic deformation of the buffer portion, it is possible to prevent the displacement portion from being worn out at an early stage in a portion where the plurality of needle bearings are pressed. Therefore, the life of the retainer can be extended.

  Further, since the buffer portion is connected to the small inner diameter end of the restricting portion, and the buffer portion can be displaced relative to the restricting portion in the axial direction of the leg shaft, the pressing force received from the plurality of needle bearings is applied to the restricting portion. It is possible to suppress transmission. Therefore, it is possible to prevent the occurrence of a problem that the restricting portion is displaced to the distal end side of the leg shaft due to the pressing force received from the plurality of needle bearings.

  Further, the plurality of needle bearings displaced toward the distal end side of the leg shaft are urged by the buffer portion and pushed back toward the proximal end side of the leg shaft. Therefore, the state in which the plurality of needle bearings are displaced toward the distal end side of the leg shaft can be eliminated at an early stage.

It is a partial expanded sectional view of the constant velocity joint in 1st embodiment of this invention, and shows a cross section perpendicular | vertical to the rotating shaft direction of an outer joint member and an inner joint member. It is a partial expanded sectional view of a retainer, and shows the central axis direction section of a retainer. It is the elements on larger scale of a constant velocity joint, and is the figure which expanded a part of constant velocity joint shown by FIG. It is a partial expanded sectional view of a constant velocity joint, and shows the state where the needle bearing was displaced from the state shown in FIG. 3A toward the tip side of the leg shaft. It is a partial expanded sectional view of the retainer in a second embodiment, and shows the central axis direction section of a retainer. It is a partial expanded sectional view of a constant velocity joint, and respond | corresponds to FIG. 3A. It is a partial expanded sectional view of a constant velocity joint, and shows the state where the needle bearing was displaced from the state shown in FIG. 5A to the tip end side of the leg shaft.

  Hereinafter, an embodiment to which a constant velocity joint according to the present invention is applied will be described with reference to the drawings. First, the constant velocity joint 100 in the first embodiment of the present invention will be described with reference to FIGS. 1 to 3B.

<First embodiment>
(1. Overview of constant velocity joint 100)
As shown in FIG. 1, the constant velocity joint 100 is a single roller type tripod type constant velocity joint, and is used, for example, at a connection portion between a vehicle differential and an intermediate shaft of a drive shaft. The constant velocity joint 100 mainly includes an outer joint member 10, an inner joint member 20, three rollers 30, a plurality of needle bearings 40, three retainers 50, and three retaining rings 60.

  The outer joint member 10 is formed in a bottomed cylindrical shape, and a stem portion (not shown) connected to a differential (not shown) is formed outside the bottom surface of the outer joint member 10. Three track grooves 11 extending in the axial direction of the outer joint member 10 are formed on the inner peripheral surface of the outer joint member 10 at equal intervals in the circumferential direction. FIG. 1 shows only one track groove 11 among the three track grooves 11 formed in the outer joint member 10.

  The inner joint member 20 is disposed inside the outer joint member 10. The inner joint member 20 includes a boss portion 21 and three leg shafts 22. The boss portion 21 is formed in a cylindrical shape. The outer peripheral surface of the boss portion 21 is formed in a spherical convex shape, and a female spline 21 a is formed on the inner peripheral surface of the boss portion 21. The female spline 21a is fitted to a male spline (not shown) formed on the outer peripheral surface of an intermediate shaft (not shown). In FIG. 1, only the leg shaft 22 of the inner joint member 20 is seen in a cross-sectional view, and the external shape of those other than the leg shaft 22 is schematically illustrated.

  The leg shaft 22 is a columnar portion extending radially outward from the outer peripheral surface of the boss portion 21. The three leg shafts 22 are arranged around the rotation axis of the inner joint member 20 at equal intervals in the circumferential direction, and are inserted into the three raceway grooves 11 respectively.

  The leg shaft 22 mainly includes a proximal end portion 23, a distal end portion 24, and an annular groove 25. The proximal end portion 23 is a cylindrical portion located on the proximal end side of the leg shaft 22, and the distal end portion 24 is a portion located on the distal end side of the leg shaft 22 relative to the proximal end portion 23. The annular groove 25 is a groove-shaped portion formed over the entire circumference of the leg shaft 22 between the base end portion 23 and the distal end portion 24.

  The roller 30 is an annular member that can roll on the raceway groove 11, and the three rollers 30 are accommodated in each of the three raceway grooves 11. The needle bearing 40 is a rolling element that rotatably supports the inner peripheral surface of the roller 30 with respect to the outer peripheral surface of the base end portion 23, and the plurality of needle bearings 40 includes the outer peripheral surface of the base end portion 23 and the roller 30. It arrange | positions between the inner peripheral surfaces of.

  The inner joint member 20 is formed with a flange portion 28 that protrudes outward in the radial direction of the leg shaft 22 from the end portion on the base end side (lower side in FIG. 1) of the leg shaft 22. The flange portion 28 includes a first seat surface 28a and a second seat surface 28b. The first seating surface 28a and the second seating surface 28b are annular surfaces facing the distal end side (upper side in FIG. 1) of the leg shaft 22, and the first seating surface 28a is on the inner peripheral side with respect to the second seating surface 28b. And in the axial direction of the leg axis | shaft 22, it is located in the front end side of the leg axis | shaft 22 rather than the 2nd seat surface 28b. The first seating surface 28a supports the end surfaces of the plurality of needle bearings 40 facing the base end side of the leg shaft 22, and restricts displacement of the plurality of needle bearings 40 toward the boss portion 21 side (the lower side in FIG. 1). On the other hand, the second seating surface 28 b supports the end surfaces of the plurality of rollers 30 facing the base end side of the leg shaft 22, and restricts displacement of the rollers 30 toward the boss portion 21.

  The retainer 50 is a cylindrical member that is disposed closer to the distal end side of the leg shaft 22 than the roller 30 and the plurality of needle bearings 40, so that the roller 30 and the plurality of needle bearings 40 are removed from the distal end side of the leg shaft 22. To prevent. The detailed configuration of the retainer 50 will be described later.

  The retaining ring 60 is a ring-shaped member that is attached to the annular groove 25, and is disposed closer to the distal end side of the leg shaft 22 than the retainer 50. A slit (not shown) is formed in the retaining ring 60, and the retaining ring 60 can be expanded in diameter by being elastically deformed so that the width of the slit is widened. The inner diameter of the retaining ring 60 in a state where it is not elastically deformed is set to be smaller than the outer diameter of the portion of the annular groove 25 where the outer diameter is the smallest. As a result, the retaining ring 60 is attached to the annular groove 25 with a radially inward biasing force, so that rattling of the retaining ring 60 can be suppressed and the retaining ring attached to the annular groove 25 can be suppressed. It is possible to prevent 60 from being displaced relative to the leg shaft 22.

(2. Detailed configuration of retainer 50)
As shown in FIGS. 2 and 3A, the retainer 50 includes a first restricting portion 51, a guide portion 52, a second restricting portion 53, and a buffer portion 54. In FIG. 2, the boundaries of the parts constituting the retainer 50 are indicated by broken lines.
The first restricting portion 51 is a portion that is disposed on the most distal side (the upper side in FIG. 2, the upper side in FIG. 3A) of the leg shaft 22 in the state of being inserted into the leg shaft 22. It forms in the taper shape which diameter-reduces by a fixed ratio as it goes to (FIG. 2 lower side, FIG. 3A lower side). The guide portion 52 is a cylindrical portion extending from the end portion of the first restricting portion 51 disposed on the base end side of the leg shaft 22 to the base end side of the leg shaft 22.

  Here, the outer diameter of the portion having the largest outer diameter in the first restricting portion 51 (the outer diameter of the end portion in the axial direction of the first restricting portion 51 and located on the distal end side of the leg shaft 22) is The outer diameter of the guide portion 52 is set to be smaller than the inner diameter of the roller 30. Accordingly, the roller 30 is allowed to displace to the tip end side of the leg shaft 22 beyond the needle bearing 40, while being restricted from being displaced to the tip end side of the leg shaft 22 beyond the first restricting portion 51. . That is, the roller 30 is supported so as to be relatively displaceable with respect to the needle bearing 40 and the retainer 50, and is prevented from slipping out from the retainer 50 to the distal end side of the leg shaft 22.

  The second restricting portion 53 is an end portion in the axial direction of the guide portion 52 and is a portion extending from an end portion disposed on the proximal end side of the leg shaft 22, and is directed from the distal end side of the leg shaft 22 to the proximal end side. As the inner diameter decreases, the taper is reduced at a constant rate. The second restricting portion 53 has an inner diameter at the base end side of the leg shaft 22 having the smallest inner diameter larger than the outer diameter of the portion of the leg shaft 22 with the largest outer diameter, The dimension is set to be smaller than the outer diameter of the retaining ring 60 in the state where it is mounted in the groove 25. Accordingly, the second restricting portion 53 is restricted from moving beyond the retaining ring 60 toward the distal end side of the leg shaft 22.

  The buffer portion 54 is a portion that is disposed closest to the base end side of the leg shaft 22 in a state of being inserted into the leg shaft 22, and a surface directed toward the base end side of the leg shaft 22 is a plurality of needle bearings 40. It faces the end face of the leg shaft 22 facing the tip side. In addition, the thickness dimension of the buffer part 54 is set to a dimension smaller than the thickness dimension of the second restricting part 53.

  The buffer portion 54 includes a connection portion 55 and a displacement portion 56. The connecting portion 55 is a U-shaped portion that opens radially outward (right side in FIG. 2) in the axial section of the retainer 50, and is an end portion in the axial direction of the connecting portion 55 and the leg shaft 22. The end located on the distal end side is connected to the end on the proximal end side of the leg shaft 22 which is the portion of the second restricting portion 53 having the smallest inner diameter.

  The displacement portion 56 is an annular portion that extends outward in the radial direction from an end portion in the axial direction of the connection portion 55 that is located on the proximal end side of the leg shaft 22. The displacement portion 56 is disposed opposite to the end surfaces of the plurality of needle bearings 40 facing the distal end side of the leg shaft 22 in the axial direction of the leg shaft 22, and the surface facing the end surfaces of the needle bearings 40 is the center of the leg shaft 22. It is formed in a planar shape perpendicular to the axis A (see FIG. 1). Further, the thickness dimension of the displacement portion 56 is set to be larger than the thickness dimension of the connection portion 55. Further, when the displacement portion 56 is connected to the end portion of the second restriction portion 53 on the proximal end side of the leg shaft 22 via the connection portion 55, the second restriction portion 53 and the displacement portion 56 are connected to each other. An opening interval S having a predetermined axial length is formed.

(3. Operation of retainer 50)
Here, in the constant velocity joint 100, when torque transmission is performed between the outer joint member 10 (see FIG. 1) and the inner joint member 20, the outer joint member 10 and the inner joint member 20 have a predetermined joint operating angle. As a result, a force is applied to displace the roller 30 in the axial direction of the leg shaft 22. At this time, the plurality of needle bearings 40 in contact with the inner peripheral surface of the roller 30 tends to be displaced in the axial direction of the leg shaft 22 so as to follow the roller 30. The plurality of needle bearings 40 are supported by the first seating surface 28a at the end facing the base end side of the leg shaft 22, and the displacement of the leg shaft 22 toward the base end side is restricted. When 40 is about to be displaced toward the distal end side of the leg shaft 22, a pressing force toward the distal end side of the leg shaft 22 is applied to the retainer 50.

  As shown in FIG. 3B, when a pressing force toward the distal end side of the leg shaft 22 is applied to the retainer 50, the displacement portion 56 is accompanied by elastic deformation of the connection portion 55 so as to reduce the opening distance S in the radially outward direction. Is displaced in the direction approaching the second restricting portion 53. At this time, the pressing force applied from the plurality of needle bearings 40 to the buffer portion 54 is buffered by the connection portion 55 that is elastically deformed, so that the impact received by the displacement portion 56 can be reduced. Thereby, in the site | part where the some needle bearing 40 is pressed, it can suppress that the displacement part 56 wears out early, Therefore The lifetime improvement of the retainer 50 can be achieved.

  Further, the buffer portion 54 is connected to the small inner diameter side end portion of the second restricting portion 53, that is, the proximal end portion in the axial direction of the leg shaft 22, and the displacement portion 56 is connected to the second restricting portion 53. Therefore, the impact applied to the buffer portion 54 from the plurality of needle bearings 40 can be prevented from being transmitted to the second restricting portion 53. Accordingly, it is possible to prevent the occurrence of a problem that the second restricting portion 53 is displaced to the distal end side of the leg shaft 22 due to the pressing force received from the plurality of needle bearings 40 over the retaining ring 60.

  In addition, since the thickness dimension of the second restricting portion 53 is set to be larger than the thickness dimension of the buffer portion 54 (the connecting portion 55 and the displacement portion 56), along with the elastic deformation of the connecting portion 55. It can suppress that the 2nd control part 53 elastically deforms. Accordingly, it is possible to prevent the second restricting portion 53 from moving beyond the retaining ring 60 toward the distal end side of the leg shaft 22.

  Furthermore, since the thickness dimension of the connection part 55 is set to a dimension smaller than the thickness dimension of the displacement part 56, when the pressing force which goes to the front end side of the leg shaft 22 from the needle bearing 40 is added to the displacement part 56 In addition, it is possible to improve the durability of the displacement portion 56 against the pressing force received from the needle bearing 40 while facilitating elastic deformation of the connection portion 55.

  Moreover, since the displacement part 56 is connected to the 2nd control part 53 via the connection part 55, and the connection part 55 is formed in the U shape opened to radial direction outward, the displacement part 56 and the 2nd control part 53 are formed. A wide opening interval S can be ensured. As a result, a sufficient amount of displacement of the displacement portion 56 in the axial direction of the leg shaft 22 can be secured, so that the displacement portion 56 displaced toward the distal end side of the leg shaft 22 is prevented from contacting the second restricting portion 53. it can. As a result, the elasticity of the connecting portion 55 can be set high, so that the impact received by the displacement portion 56 when the plurality of needle bearings 40 are pressed can be effectively buffered.

  Furthermore, a biasing force is generated in the connecting portion 55 that is elastically deformed so that the displacement portion 56 is displaced toward the distal end side of the leg shaft 22 and the opening interval S becomes small. The urging force of the connecting portion 55 that attempts to widen the opening interval becomes a force that displaces the displacement portion 56 toward the proximal end side of the leg shaft 22, and the plurality of needle bearings 40 displaced toward the distal end side of the leg shaft 22 This is the force to push back to the base end side of 22. Thus, the plurality of needle bearings 40 displaced toward the distal end side of the leg shaft 22 are urged by the buffer portion 54 and pushed back to the proximal end side of the leg shaft 22, so that the plurality of needle bearings 40 The state displaced to the tip side can be eliminated at an early stage.

  Here, when the plurality of needle bearings 40 and the displacement portion 56 come into contact with each other, when the peripheral portion of the end surface of the plurality of needle bearings 40 facing the distal end side of the leg shaft 22 is pressed against the displacement portion 56, The displacement portion 56 is locally worn at the pressed portion. Since this local wear of the displacement portion 56 may cause damage to the displacement portion 56, it is possible to prevent the displacement portion 56 from coming into contact with the peripheral portions of the end faces of the plurality of needle bearings 40. This is desirable in terms of extending the life.

  In this regard, the surface of the displacement portion 56 that faces the end surfaces of the plurality of needle bearings 40 facing the distal end side of the leg shaft 22 is formed in a planar shape perpendicular to the central axis A of the leg shaft 22. The displacement portion 56 is configured to be in surface contact with the central portion excluding the peripheral edge portion of the end face. Thereby, since the displacement part 56 can avoid being locally worn in the site | part where the some needle bearing 40 is pressed, the lifetime improvement of the retainer 50 can be achieved.

  In the state where the retaining ring 60 is mounted in the annular groove 25, the retainer 50 always contacts the retaining ring 60, and the retainer 50 always contacts the end surfaces of the plurality of needle bearings 40 facing the distal end side of the leg shaft 22. Since the retaining ring 60 mounted in the annular groove 25 is restricted from being displaced in the axial direction with respect to the leg shaft 22, the retainer 50 and the plurality of needles sandwiched between the retaining ring 60 and the first seat surface 28a. The play of the bearing 40 can be suppressed.

  Further, the plurality of needle bearings 40 are not displaced toward the distal end side of the leg shaft 22 (the end surfaces of the plurality of needle bearings 40 facing the proximal end side of the leg shaft 22 are in contact with the first seat surface 28a). The retaining portion 60 of the retainer 50 is slightly elastically deformed, the retaining ring 60 is assembled, and the urging force generated at the connecting portion 55 is reduced, whereby the displacement portion 56 exerts a force to press the needle bearing 40. Can be small. Thereby, while suppressing the backlash of the retainer 50 and the plurality of needle bearings 40, it is possible to suppress the smooth rotation of the needle bearing 40, and the displacement portion 56 is quickly worn out by friction with the needle bearing 40. Can be prevented.

  Further, even if there is an error in the dimension of the needle bearing 40 in the axial direction, the dimensional error of the needle bearing 40 is reduced by adjusting the axial position of the leg shaft 22 while the connecting portion 55 is elastically deformed. Can be absorbed.

<Second embodiment>
Next, a second embodiment will be described with reference to FIGS. 4 to 5B. In the first embodiment, the case where the connecting portion 55 is formed in a U-shape that opens radially outward with respect to the central axis of the retainer 50 has been described. However, in the second embodiment, the connecting portion 255 has the retainer 250. A U-shape that is formed in a U-shape that opens radially outward with respect to the central axis of the tube, and that opens inward in the radial direction (left side in FIG. 4) continuously to the U-shape that opens outward in the radial direction. It is formed into a shape. Note that. The same code | symbol is attached | subjected to the structure same as above-described 1st embodiment, and the description is abbreviate | omitted.

(4. Configuration of retainer 250)
As shown in FIGS. 4 and 5A, the retainer 250 in the second embodiment includes a first restricting portion 51, a guide portion 52, a second restricting portion 53, and a buffer portion 254. The buffer unit 254 includes a connection unit 255 and a displacement unit 256. In FIG. 4, the boundaries between the parts constituting the retainer 250 are indicated by broken lines.

  The connecting portion 255 is formed in a U shape that opens radially outward (right side in FIG. 4) in the axial section, and further formed in a U shape that opens continuously inward in the radial direction (left side in FIG. 4). The end portion of the leg shaft 22 that is the end portion in the axial direction of the connecting portion 255 and located on the distal end side of the leg shaft 22 is the portion of the second restricting portion 53 that has the smallest outer diameter. It is connected to the end portion (lower side in FIG. 4) located on the base end side.

  The displacement portion 256 is an annular portion that extends inward in the radial direction from an end portion in the axial direction of the connection portion 255 that is located on the proximal end side of the leg shaft 22. When the retainer 250 is mounted on the leg shaft 22, the displacement portion 256 is a plane in which the surface facing the end surfaces of the plurality of needle bearings 40 facing the distal end side of the leg shaft 22 is orthogonal to the central axis A of the leg shaft 22. It is formed in a shape. Thereby, since the displacement part 256 can be surface-contacted with respect to the center part except the peripheral part of the end surface of the needle bearing 40, in the site | part which contacts the needle bearing 40, the displacement part 256 wears out locally. Can be prevented.

  Further, when the displacement portion 256 is connected to the end portion of the second restriction portion 53 on the proximal end side of the leg shaft 22 via the connection portion 255, between the second restriction portion 53 and the displacement portion 256, An opening interval S having a predetermined axial length is formed.

(5. Operation of retainer 250)
As shown in FIG. 5B, when a pressing force toward the distal end side of the leg shaft 22 is applied to the retainer 250, the displacement portion 256 becomes the second restricting portion while being accompanied by elastic deformation of the connecting portion 255 that reduces the opening interval S. It is displaced in a direction approaching 53. At this time, since the pressing force applied from the plurality of needle bearings 40 to the buffer portion 254 is buffered by the connection portion 255 that is elastically deformed, the impact received by the displacement portion 256 can be reduced. Accordingly, it is possible to prevent the displacement portion 256 from being worn out at an early stage at a portion where the plurality of needle bearings 40 are pressed, and thus the life of the retainer 250 can be extended.

  Moreover, since the thickness dimension of the 2nd control part 53 is set to a dimension larger than the thickness dimension of the buffer part 254 (connection part 255 and the displacement part 256), it is 2nd in connection with the elastic deformation of the connection part 255. It is possible to suppress elastic deformation of the restricting portion 53. Accordingly, it is possible to prevent the second restricting portion 53 from moving beyond the retaining ring 60 toward the distal end side of the leg shaft 22.

  Further, the displacement portion 256 is connected to the small inner diameter end of the second restricting portion 53 via the connection portion 255, and the connection portion 255 is formed in a U shape that opens radially outward, and is continuous therewith. It is formed in a U shape that opens radially inward. In this case, since the axial length of the connecting portion 255 can be increased, a wide opening interval S between the displacement portion 256 and the second restricting portion 53 can be ensured. As a result, a sufficient amount of displacement of the displacement portion 56 in the axial direction of the leg shaft 22 can be secured, so that the impact received by the displacement portion 256 when the plurality of needle bearings 40 are pressed can be effectively reduced. it can.

  Further, the connecting portion 255 that is elastically deformed so that the opening portion S is displaced by the displacement portion 256 being displaced toward the distal end side of the leg shaft 22 generates an urging force to widen the opening interval S. The plurality of needle bearings 40 displaced toward the distal end side of 22 are urged by the buffer portion 54 and pushed back to the proximal end side of the leg shaft 22. Therefore, the state in which the plurality of needle bearings 40 are displaced toward the distal end side of the leg shaft 22 can be eliminated at an early stage.

  Further, in the displacement portion 256, a surface facing the end surfaces of the plurality of needle bearings 40 facing the distal end side of the leg shaft 22 is formed in a planar shape orthogonal to the central axis A of the leg shaft 22, and the end surface of the needle bearing 40 is formed. The displacement portion 256 is configured to be in surface contact with the central portion excluding the peripheral portion. As a result, it is possible to avoid the displacement portion 256 from being locally worn at a portion where the plurality of needle bearings 40 are pressed, so that the life of the retainer 250 can be extended.

(6. Others)
Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications and improvements can be made without departing from the spirit of the present invention. It can be easily guessed.

  For example, in each of the embodiments described above, of the outer peripheral surfaces of the displacement portions 56, 256, the surface facing the end surfaces of the plurality of needle bearings 40 facing the distal end side of the leg shaft 22 is orthogonal to the central axis A of the leg shaft 22. The case where the displacement portions 56 and 256 are brought into surface contact with the central portion excluding the peripheral edge portion of the end surface of the needle bearing 40 by using a flat surface is described. However, the present invention is not limited to this. For example, the surface opposite to the end surfaces of the plurality of needle bearings 40 is formed in a hemispherical shape that swells toward the end surfaces of the plurality of needle bearings 40, so that the displacement portions 56, 256 are peripheral portions of the end surfaces of the needle bearings 40. A configuration may be adopted in which surface contact is made with respect to the central portion excluding.

(7. Effect)
As described above, the constant velocity joints 100 and 200 are open at one side in the axial direction and have the outer joint member 10 having the plurality of raceway grooves 11 extending in the axial direction and the inner joint having the plurality of leg shafts 22 extending in the radial direction. A member 20, a roller 30 that can roll in the raceway groove 11 of the outer joint member 10, and a plurality of needles that rotatably support the inner peripheral surface of the roller 30 with respect to the outer peripheral surface of the leg shaft 22 of the inner joint member 20. A retainer 50, 250 that is formed in a cylindrical shape and disposed closer to the distal end side of the leg shaft 22 than the plurality of needle bearings 40, and is disposed closer to the distal end side of the leg shaft 22 than the retainers 50, 250. And a retaining ring 60 for restricting 50 and 250 from coming off from the distal end side of the leg shaft 22.

  In addition, an annular groove 25 in which the retaining ring 60 is mounted is formed on the outer peripheral surface of the leg shaft 22, and the retainers 50 and 250 have an inner diameter on the distal end side of the leg shaft 22 that is larger than an outer diameter of the retaining ring 60. A restricting portion that is formed to be large, has an inner diameter on the base end side of the leg shaft 22 smaller than an outer diameter of the retaining ring 60, and is restricted from coming out of the distal end side of the leg shaft 22 in contact with the retaining ring 60. And a buffer portion 54, 254 that is connected to the small inner diameter side end of the restricting portion and is capable of relative displacement in the axial direction with respect to the restricting portion by elastic deformation.

  According to the constant velocity joints 100 and 200, when the plurality of needle bearings 40 are displaced toward the distal end side of the leg shaft 22 and the plurality of needle bearings 40 are pressed against the retainers 50 and 250, the buffer portions 54 and 254 are elastically deformed. . Due to the elastic deformation of the buffer portions 54 and 254, the impact applied to the retainers 50 and 250 from the plurality of needle bearings 40 is alleviated, so that the displacement portions 56 and 256 are quickly worn at the portions where the plurality of needle bearings 40 are pressed. This can be suppressed. Therefore, the life of the retainers 50 and 250 can be extended.

  In addition, since the buffer portions 54 and 254 are connected to the small inner diameter side end of the second restricting portion 53 as the restricting portion, and the buffer portions 54 and 254 can be relatively displaced in the axial direction with respect to the restricting portion, a plurality of needles It can suppress that the pressing force received from the bearing 40 is transmitted to a control part. Therefore, it is possible to prevent the occurrence of a problem that the restricting portion displaces beyond the retaining ring 60 toward the distal end side of the leg shaft 22 due to the pressing force received from the plurality of needle bearings 40.

  Further, the plurality of needle bearings 40 displaced toward the distal end side of the leg shaft 22 are urged by the buffer portions 54 and 254 and pushed back to the proximal end side of the leg shaft 22. Therefore, the state in which the plurality of needle bearings 40 are displaced toward the distal end side of the leg shaft 22 can be eliminated at an early stage.

  In the constant velocity joints 100 and 200 described above, the thickness of the buffer portions 54 and 254 is smaller than the thickness of the second restricting portion 53 as a restricting portion. According to this constant velocity joint 100,200, it can suppress that a control part elastically deforms with the elastic deformation of the buffer parts 54,254. Accordingly, it is possible to prevent the restricting portion from moving beyond the retaining ring 60 toward the distal end side of the leg shaft 22.

  In the constant velocity joints 100 and 200 described above, the buffer portions 54 and 254 are in surface contact with the central portion excluding the peripheral portion of the end surfaces in the axial direction of the plurality of needle bearings 40. According to the constant velocity joints 100 and 200, it is possible to prevent the displacement portions 56 and 256 from being locally worn at the portions that are in contact with the plurality of needle bearings 40, so that the displacement portions 56 and 256 are damaged early. Can be avoided.

  In the constant velocity joint 100 described above, the buffer portion 54 has an end portion on the distal end side of the leg shaft 22 connected to an end portion on the small inner diameter side of the second restricting portion 53 as a restricting portion, and is radially outside in the axial section. A connecting portion 55 that is formed in a U-shape that opens in the direction and can be elastically deformed so as to reduce the opening distance S in the radially outward direction, and an end portion of the connecting portion 55 that is located on the base end side of the leg shaft 22 A displacement portion 56 that is connected and can be displaced with respect to the restricting portion by elastic deformation of the connection portion 55, and in a state where the retainer 50 is mounted on the leg shaft 22, the displacement portion 56 is on the distal end side of the leg shaft 22. It faces the end surfaces of the plurality of needle bearings 40 facing the direction.

  According to this constant velocity joint 100, a wide radial spacing S can be ensured. Accordingly, a sufficient amount of displacement of the displacement portion 56 in the axial direction of the leg shaft 22 can be ensured, so that the displacement portion 56 displaced toward the distal end side of the leg shaft 22 contacts the second restriction portion 53 as a restriction portion. Can be prevented. As a result, the elasticity of the connecting portion 55 can be set high, and the impact received by the displacement portion 56 when the plurality of needle bearings 40 are pressed can be effectively mitigated.

  Further, the buffer portion 54 has an end portion on the distal end side of the leg shaft 22 connected to an end portion on the smaller inner diameter side of the restricting portion, and is formed closer to the distal end side of the leg shaft 22 than the second restricting portion 53 as the restricting portion. Therefore, before the impact applied to the buffer portion 54 from the plurality of needle bearings 40 is transmitted to the restricting portion, the shock is absorbed by the buffer portion 54, so that the impact can be prevented from being transmitted to the restricting portion. Therefore, it is possible to prevent the occurrence of a problem that the restricting portion is displaced beyond the retaining ring 60 toward the distal end side of the leg shaft 22 due to the pressing force received from the plurality of needle bearings 40.

  In the constant velocity joint 100 described above, the thickness dimension of the connection portion 55 is smaller than the thickness dimension of the displacement portion 56. According to the constant velocity joint 100, when a pressing force from the needle bearing 40 toward the distal end side of the leg shaft 22 is applied to the displacement portion 56, the pressing received from the needle bearing 40 while facilitating elastic deformation of the connecting portion 55. The durability of the displacement portion 56 with respect to force can be improved.

  In the constant velocity joint 200 described above, the buffer portion 254 has an end on the distal end side of the leg shaft 22 connected to an end on the small inner diameter side of the second restricting portion 53 as a restricting portion, and is radially inward in the axial cross section. A connecting portion 255 that is elastically deformable so as to reduce the radially inner opening interval S, and a base end side of the leg shaft 22 of the connecting portion 255. Connected to the end portion and displaceable with respect to the restricting portion by elastic deformation of the connecting portion 255, the surface facing the end surfaces of the plurality of needle bearings 40 is a plane orthogonal to the central axis A that is the axis of the leg shaft 22. A displacement portion 256 to be formed.

  According to this constant velocity joint 200, it is possible to ensure a wide opening interval S in the radial direction. As a result, a sufficient amount of displacement of the displacement portion 256 in the axial direction of the leg shaft 22 can be ensured, so that the displacement portion 256 displaced toward the distal end side of the leg shaft 22 contacts the second restriction portion 53 as the restriction portion. Can be prevented. As a result, the elasticity of the connecting portion 255 can be set high, so that the impact received by the displacement portion 256 when the plurality of needle bearings 40 are pressed can be effectively mitigated.

  Further, the buffer portion 254 has a distal end side end portion of the leg shaft 22 connected to a small inner diameter end portion of the restricting portion, and is formed closer to the base end side of the leg shaft 22 than the second restricting portion 53 as the restricting portion. Therefore, it can suppress that the impact added to the buffer part 254 from the some needle bearing 40 is transmitted to a control part. Therefore, it is possible to prevent the occurrence of a problem that the restricting portion displaces beyond the retaining ring 60 toward the distal end side of the leg shaft 22 due to the pressing force received from the plurality of needle bearings 40.

  In the constant velocity joints 100 and 200 described above, the buffer portions 54 and 254 always contact the end surface of the needle bearing 40 in a state where the retainers 50 and 250 are mounted on the leg shaft 22. According to the constant velocity joints 100 and 200, the displacement of the plurality of needle bearings 40 in the axial direction of the leg shaft 22 can be restricted, so that the backlash of the plurality of needle bearings 40 can be prevented.

  10: Outer joint member, 11: Track groove, 20: Inner joint member, 22: Leg shaft, 23: Base end part, 24: Tip part, 25 Annular groove, 30: Roller, 40: Needle bearing, 50, 250: Retainer, 53: Second restriction part (regulation part), 54,254: Buffer part, 55, 255: Connection part, 56, 256: Displacement part, 60: Retaining ring, 100, 200: Constant velocity joint

Claims (7)

An outer joint member having a plurality of raceway grooves that are open on one side of the rotation axis direction and extend in the rotation axis direction;
An inner joint member having a plurality of leg shafts extending radially with respect to the rotation axis;
A roller capable of rolling in the raceway groove of the outer joint member;
A plurality of needle bearings rotatably supporting the inner peripheral surface of the roller with respect to the outer peripheral surface of the leg shaft of the inner joint member;
A retainer that is formed in a cylindrical shape and is disposed closer to the distal end side of the leg shaft than the plurality of needle bearings;
A retaining ring that is disposed closer to the distal end side of the leg shaft than the retainer and restricts the retainer from coming off from the distal end side of the leg shaft;
With
An annular groove in which the retaining ring is mounted is formed on the outer peripheral surface of the leg shaft,
The retainer is
The inner diameter on the distal end side of the leg shaft is formed larger than the outer diameter of the retaining ring, the inner diameter on the proximal end side of the leg shaft is formed smaller than the outer diameter of the retaining ring, and is in contact with the retaining ring. And a restricting portion that is restricted from coming off from the distal end side of the leg shaft,
A buffer portion connected to the small inner diameter end of the restricting portion and capable of relative displacement in the axial direction of the leg shaft with respect to the restricting portion by elastic deformation;
A constant velocity joint.   The constant velocity joint according to claim 1, wherein a thickness dimension of the buffer portion is smaller than a thickness dimension of the restricting portion.   The constant velocity joint according to claim 1, wherein the buffer portion is in surface contact with a central portion excluding a peripheral edge portion of end surfaces in the axial direction of the plurality of needle bearings. The buffer portion is
The end of the leg shaft on the distal end side is connected to the small inner diameter end of the restricting portion, is formed in a U shape that opens radially outward in the axial section, and has a radially outward opening interval. A connecting portion that can be elastically deformed to be small
A displacement portion that is connected to an end portion of the connection portion located on a proximal end side of the leg shaft and is displaceable with respect to the restriction portion by elastic deformation of the connection portion;
With
4. The state according to claim 1, wherein in a state where the retainer is attached to the leg shaft, the displacement portion is opposed to end surfaces of the plurality of needle bearings facing the distal end side of the leg shaft. Constant velocity joint.   The constant velocity joint according to claim 4, wherein a thickness dimension of the connection portion is smaller than a thickness dimension of the displacement portion. The buffer portion is
The end of the leg shaft on the distal end side is connected to the small inner diameter end of the restricting portion, and is formed in a U-shape that opens radially inward in the axial cross section. A connecting portion that can be elastically deformed to reduce the opening interval of
The connecting portion is connected to an end portion on the proximal end side of the leg shaft, and is displaceable with respect to the restricting portion by elastic deformation of the connecting portion, and a surface facing the end surfaces of the plurality of needle bearings is the leg. The constant velocity joint of Claim 3 provided with the displacement part formed in the plane orthogonal to the axis line of an axis | shaft.   The constant velocity joint according to any one of claims 1 to 6, wherein the buffer portion is always in contact with an end surface of the needle bearing in a state where the retainer is mounted on the leg shaft.

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