JP2008039036A - Tripod type constant velocity joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high precision tripod type constant velocity joint capable of reducing cost by decreasing the number of parts while reducing induction thrust force. <P>SOLUTION: An inner circumference surface of a roller 30 pivoted by a tripod shaft part 22 is formed as a shape of a part of spherical surface of a sphere 100. A plurality of balls 40, 50, 60 are provided between the inner circumference surface of the roller 30 and an outer circumference surface of the tripod shaft part 22 as three rows in a direction of the tripod shaft direction. A spherical diameter of the ball 40 at the center in the shaft direction is formed larger than those of balls 50, 60 at both ends in the shaft direction. These balls 40, 50, 60 roll while contacting with the inner circumference surface of the roller 30 and the outer circumference surface of the tripod shaft part 22. Hence the roller 30 is rockable for the tripod shaft part 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  In the tripod type constant velocity joint, when the rotational force is transmitted when the joint angle is not 0 degree, the roller rotates around the axis of the tripod shaft part and reciprocates in the axial direction along the guide groove of the outer race. Move back and forth. By the way, conventionally, the tripod shaft portion has a columnar shape, and the roller has a cylindrical shape that can slide only in the tripod shaft direction. In this case, slip occurs between the roller and the guide groove, and as a result, an induced thrust force is generated in the joint axial direction. This induced thrust force causes vibration and noise of the vehicle body and adversely affects the NVH performance of the vehicle.

  Accordingly, in order to reduce the induced thrust force, for example, JP-A-3-172619 (Patent Document 1), JP-A 2000-320563 (Patent Document 2), and JP-A-62-146019 (Patent Document 1). There is one disclosed in Reference 3). In the tripod constant velocity joint disclosed in Patent Document 1, the outer peripheral surface shape of the tripod shaft portion is spherical. Accordingly, the roller can swing with respect to the tripod shaft portion, and no slip occurs between the roller and the guide groove.

  In the tripod constant velocity joint disclosed in Patent Document 2, the tripod shaft portion is always an elliptic cylinder having the same axial orthogonal cross-sectional shape. The elliptic cylinder has a shape in which a gap is formed between the tripod shaft and the roller in the intermediate shaft axial direction, and the tripod shaft and the roller are in contact with each other in the torque transmission direction. Therefore, when viewed from the direction of torque transmission, the roller can operate so as to be inclined with respect to the tripod shaft portion. As a result, no slip occurs between the roller and the guide groove.

Further, the tripod constant velocity joint disclosed in Patent Document 3 is provided with a guide ring for bearing the roller member, and a spherical surface is formed on the inner peripheral surface of the guide ring, and the spherical surface and the tripod shaft portion are interposed between the spherical surface and the tripod shaft portion. The balls are arranged in double rows. Accordingly, the guide ring can swing with respect to the tripod shaft portion, and no slip occurs between the roller and the guide groove.
Japanese Patent Laid-Open No. 3-172619 JP 2000-320563 A JP-A-62-146019

  By the way, the parts arranged between the tripod shaft part and the guide groove in the tripod type constant velocity joint of Patent Documents 1 and 2 are composed of at least an inner roller, an outer roller, and a needle bearing. Further, the parts disposed between the tripod shaft portion and the guide groove in the tripod type constant velocity joint of Patent Document 3 are composed of a ball, a guide ring, an outer roller, and a needle bearing.

  Here, it is a problem that is always required to improve the accuracy of the tripod type constant velocity joint. As a solution to this, for example, it is conceivable to reduce the backlash due to component tolerance by reducing the number of components. That is, for example, the accuracy can be improved by reducing the number of parts arranged between the tripod shaft and the guide groove. Further, the cost can be reduced by reducing the number of parts.

  The present invention has been made in view of such circumstances, and provides a tripod constant velocity joint capable of reducing the number of parts while reducing the induced thrust force and achieving high accuracy and low cost. With the goal.

(First invention)
The tripod type constant velocity joint of the first invention includes an outer race, a tripod, a roller, and a plurality of balls. The outer race has a cup shape, and three guide grooves extending in the outer race rotation axis direction are formed on the inner peripheral surface. The tripod includes a boss portion and three columnar tripod shaft portions that extend from the boss portion radially outward of the intermediate shaft shaft and are inserted into the guide grooves. The roller has a ring shape with an inner peripheral surface formed in a partial spherical shape, and is rotatably supported around each tripod shaft portion so as to be rotatable around the tripod shaft, and is engaged with the guide groove so as to be able to roll. The plurality of balls are formed of a plurality of spheres and have at least three rows in the tripod axis direction between the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the roller. .

  According to the tripod type constant velocity joint of the first aspect of the invention, the roller has a partially spherical inner peripheral surface and is disposed between the tripod shaft and a plurality of balls. As a result, the roller can swing (is swingable) with respect to the tripod shaft. Therefore, no slip occurs between the roller and the guide groove, and the induced thrust force can be reduced.

  Furthermore, according to the first invention, the parts disposed between the tripod shaft and the guide groove are only the ball and the roller. Thus, according to the first aspect of the present invention, the number of parts of the part is reduced as compared with the prior art. Therefore, with the reduction in the number of parts, it is possible to reduce the play due to the tolerance of parts, and as a result, it is possible to improve, for example, the rotational position accuracy of the tripod type constant velocity joint. Furthermore, the cost can be reduced with the reduction in the number of parts.

  Further, the plurality of balls are arranged in at least three rows in the tripod axis direction. Thereby, the surface pressure produced between each ball | bowl and a tripod shaft part or a roller is reduced. In particular, as in Patent Document 3, the surface pressure is clearly reduced as compared with the case where two rows of balls are arranged. Thus, by reducing the surface pressure, the ball can reliably roll with respect to the tripod shaft and the roller. Accordingly, it is possible to extend the life of the balls, tripod shafts and rollers. The plurality of balls may be arranged in at least three rows in the tripod axis direction, and may be arranged in four rows, five rows, or more rows.

  Here, in the first invention, at least three rows of balls are arranged. The inner peripheral surface of the roller has a partial spherical shape, and the tripod shaft portion has a cylindrical shape. Therefore, when all the balls have the same diameter, the ball may be disposed between the inner peripheral surface of the roller and the outer peripheral surface of the tripod shaft portion in a state where the ball is in contact with the inner peripheral surface of the roller. Can not. Therefore, by using a plurality of ball diameters, it is possible to reliably form a state where the ball is in contact with the inner peripheral surface of the roller.

  The tripod type constant velocity joint of the first invention may further include a cage that is disposed between the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the roller and holds a plurality of balls. By providing the cage, relative positioning between the balls can be achieved. Therefore, the ball can roll with respect to the tripod shaft and the roller reliably and stably. In particular, since the balls in the first invention are arranged in three or more rows in the tripod axis direction and have different sphere diameters, positioning to a stable position is not easy. In such a case as in the first invention, by providing the cage, the effect of the relative positioning between the balls is increased.

  Further, the cage may hold the balls positioned in two predetermined rows adjacent in the tripod axial direction so as to be alternately positioned in the circumferential direction. Thereby, the distance between the ball centers in the tripod axis direction of the predetermined two rows of balls can be reduced. Thereby, size reduction of a tripod type | mold constant velocity joint can be achieved. Furthermore, since the distance between the ball centers can be reduced, a large number of balls can be arranged between the tripod shaft and the roller. Thereby, the surface pressure which arises between each ball | bowl and a tripod shaft part or a roller can be reduced more.

  The cage may hold the balls located in two predetermined rows adjacent in the tripod axis direction so as to be located at the same position in the circumferential direction. That is, in this case, the ball centers of the balls located in the two rows are aligned in the circumferential direction. Of course, the ball centers of all rows of balls may be arranged so as to coincide with the circumferential direction. Moreover, although the said effect is exhibited by providing a cage, it can also comprise so that a cage may not be provided. In this case, cost reduction can be achieved by reducing the number of parts.

(Second invention)
The tripod type constant velocity joint of the second invention includes an outer race, a tripod, a roller, a plurality of balls, and a cage. The outer race has a cup shape, and three guide grooves extending in the outer race rotation axis direction are formed on the inner peripheral surface. The tripod includes a boss portion and three columnar tripod shaft portions that extend from the boss portion radially outward of the intermediate shaft shaft and are inserted into the guide grooves. The roller has a ring shape with an inner peripheral surface formed in a partial spherical shape, and is rotatably supported around each tripod shaft portion so as to be rotatable around the tripod shaft, and is engaged with the guide groove so as to be able to roll. The plurality of balls are spherical and contact at least the inner peripheral surface of the roller, and are arranged in at least two rows in the tripod axial direction between the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the roller. The cage is disposed between the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the roller, and holds the balls located in two predetermined rows adjacent in the tripod shaft direction so as to be alternately positioned in the circumferential direction. .

  According to the tripod constant velocity joint of the second invention, the induced thrust force can be reduced as in the first invention. Furthermore, the number of parts can be reduced. As a result, for example, the rotational position accuracy of the tripod type constant velocity joint can be improved, and the cost can be reduced. Furthermore, in the second invention, the cage holds balls positioned in two predetermined rows adjacent in the tripod axis direction so as to be alternately positioned in the circumferential direction. Thereby, the distance between the ball centers in the tripod axis direction of the predetermined two rows of balls can be reduced. Thereby, size reduction of a tripod type | mold constant velocity joint can be achieved. Furthermore, since the distance between the ball centers can be reduced, a large number of balls can be arranged between the tripod shaft and the roller. Thereby, the surface pressure which arises between each ball | bowl and a tripod shaft part or a roller can be reduced more.

  In the second invention, the plurality of balls may be arranged in at least two rows in the tripod axis direction, and may be arranged in three rows, four rows, five rows, or more rows.

(Matters common to the first and second inventions)
Below, the more preferable aspect common to the 1st invention mentioned above and the 2nd invention is described.

  The cage may be formed with a plurality of windows in the circumferential direction, and one ball may be held in each window. Further, the cage may be formed with a plurality of windows in the circumferential direction, and each window may hold at least one ball in each row. That is, when two rows of balls are arranged, two balls are held in each window, and when three rows of balls are arranged, three balls are held in each window. As described above, when a plurality of balls are held in each window, a partition between the plurality of balls held in one window is not formed as compared with a case where one ball is held in each window. It will be. Therefore, the distance between the balls in the tripod axis direction can be shortened, and as a result, the tripod constant velocity joint can be reduced in size.

  The inner diameter of the inner peripheral surface of the roller may be formed so that the center of the roller in the roller rotation axis direction is maximized. Here, the inner peripheral surface of the roller has a partial spherical shape. Therefore, both sides of the roller have a target shape with the center in the roller rotation axis direction as the center. That is, one end of the roller may be disposed on either the tip side or the root side of the tripod shaft portion. Thereby, the moldability and assembly property of a roller become favorable. The inner diameter of the inner peripheral surface of the roller may be formed such that the end of the roller in the roller rotation axis direction is maximized, or may be formed such that the distance between the center and the end is maximized. Good. However, in this case, it is not possible to obtain the effects of good moldability and assemblability as described above.

  Further, when at least three rows of balls are arranged in the tripod axis direction, the following is preferable. That is, the ball diameters of the balls arranged in both end rows in the tripod axis direction are formed to be smaller than the ball diameters of the balls arranged in the center side row in the tripod axis direction. In this case, the inner diameter of the inner peripheral surface of the roller is formed such that the vicinity of the center in the roller rotation axis direction of the roller is maximized. Therefore, the moldability and assembly property of the roller are good. The ball diameter of the balls arranged in the end side row may be formed larger than the ball diameter of the balls arranged in the center side row.

  Moreover, you may make it a some ball contact | abut on the outer peripheral surface of a tripod shaft part. In this case, the ball rolls while being in contact with the outer peripheral surface of the tripod shaft and the inner peripheral surface of the roller. By bringing the ball directly into contact with the tripod shaft, the number of parts can be minimized.

  Further, when the tripod constant velocity joint of the present invention has a ring shape, is fitted to the outer peripheral surface of the tripod shaft portion, and further includes a collar that can slide in the tripod shaft direction with respect to the tripod shaft portion, The plurality of balls may be arranged between the outer peripheral surface of the collar and the inner peripheral surface of the roller so as to roll in contact with the outer peripheral surface of the collar. In other words, in this case, the ball rolls in a state of being in contact with the outer peripheral surface of the collar and the inner peripheral surface of the roller. By providing the collar, it is possible to prevent the ball from directly contacting the tripod shaft.

  In particular, when a color is provided, the following is recommended. For example, a groove may be formed on the outer peripheral surface of the collar over the circumferential direction. This groove may be shaped to follow the surface of the ball. Thereby, the ball and the collar are not a single point contact but a multiple point contact or a line contact.

  According to the tripod type constant velocity joint of the present invention, it is possible to achieve high accuracy and low cost by reducing the number of parts while reducing the induced thrust force.

  Next, the present invention will be described in more detail with reference to embodiments.

(1) 1st Embodiment Next, an embodiment is given and this invention is demonstrated in detail. Here, the tripod type constant velocity joint of the first embodiment will be described by taking as an example a case where it is used for coupling a power transmission shaft of a vehicle. Specifically, this is a case where the shaft portion connected to the differential gear is used as a connecting portion between the intermediate shaft.

  The tripod type constant velocity joint will be described with reference to FIGS. FIG. 1 is a sectional view in the axial direction of the intermediate shaft of the tripod type constant velocity joint of the first embodiment. FIG. 2 is a view showing only the balls 40, 50, 60 and the cage 70 of the first embodiment.

  The tripod type constant velocity joint includes an outer race 10 connected to one side shaft (not shown), a tripod 20 connected to the other side shaft (not shown) (intermediate shaft), the outer race 10 and the tripod. 20 and a roller 30 and balls 40 to 60 interposed between them and a cage 70 that holds the balls 40 to 60.

  The outer race 10 is formed in a cup shape (bottomed cylindrical shape), and the outer side of the cup bottom is connected to a shaft on one side. Three guide grooves 11 extending in the outer race rotation axis direction (front-rear direction in FIG. 1) are formed at equal intervals on the inner peripheral surface of the cup-shaped portion of the outer race 10. In FIG. 1, only one guide groove 11 is shown.

  The tripod 20 is disposed inside the cup-shaped portion of the outer race 10. The tripod 20 includes a boss portion 21 and three tripod shaft portions 22. The boss portion 21 has a cylindrical shape, and the inner peripheral side of the boss portion 21 is connected to the end portion of the other side shaft (intermediate shaft). Each tripod shaft portion 22 extends outwardly in the radial direction of the intermediate shaft shaft (axial center of the tripod 20) on the outer peripheral side of the boss portion 21 and is equally spaced in the circumferential direction of the boss portion 21. Is formed. The tripod shaft portion 22 has a cylindrical shape.

  The roller 30 has a ring shape. The roller 30 is pivotally supported on the outer peripheral side of the tripod shaft portion 22 so as to be rotatable around the tripod shaft. The inner peripheral surface of the roller 30 forms a part of the sphere 100 shown by a broken line in FIG. That is, the inner peripheral surface of the roller 30 is formed in a partial spherical shape of the sphere 100. The inner diameter of the inner peripheral surface of the roller 30 is formed such that the center in the direction of the roller rotation axis (coaxial with the tripod axis in FIG. 1) is maximized. That is, the distance between the inner peripheral surface of the roller 30 and the roller rotation shaft becomes smaller as the center in the roller rotation shaft direction coincides with the radius of the sphere 100 and goes toward the end in the roller rotation shaft direction.

  Further, the outer peripheral surface of the roller 30 has an arc shape that is convex outward in the roller shaft cross section, and has a shape that follows the guide groove 11. Then, the roller 30 is fitted into the guide groove 11 and the outer peripheral surface of the roller 30 is engaged with the guide groove 11 so as to be able to roll around the vertical axis in FIG. 1 (around the roller rotation axis).

  The balls 40, 50, 60 are formed of two kinds of spheres having a small diameter and a large diameter. Specifically, the ball 40 has a spherical shape with a large spherical diameter, and the balls 50 and 60 have a spherical shape with a small spherical diameter. These balls 40 to 60 are disposed between the outer peripheral surface of the tripod shaft portion 22 and the inner peripheral surface of the roller 30 so as to come into contact with the outer peripheral surface of the tripod shaft portion 22 and the inner peripheral surface of the roller 30. ). Further, three rows of small diameter balls 60, large diameter balls 40, and small diameter balls 50 are arranged in this order from the base side of the tripod shaft portion 22 in the tripod shaft direction. A plurality of large-diameter balls 40 and small-diameter balls 50 and 60 are arranged in the circumferential direction of the outer peripheral surface of the tripod shaft portion 22 in each row.

  Here, the large-diameter ball 40 has a value obtained by subtracting the cylindrical diameter of the tripod shaft portion 22 from the diameter of the sphere 100 and dividing it into two. The large-diameter ball 40 is disposed at a position in contact with the center in the roller rotation axis direction on the inner peripheral surface of the roller 30. Further, the small-diameter balls 50 and 60 are disposed so as to contact both end sides of the inner peripheral surface of the roller 30. The small-diameter ball 50 is disposed closer to the tip side of the tripod shaft portion 22 than the large-diameter ball 40. The small-diameter ball 60 is disposed closer to the root of the tripod shaft portion 22 than the large-diameter ball 40. The circumscribed circle of these balls 40, 50, 60 matches the sphere 100.

  Further, the large-diameter ball 40 and the small-diameter balls 50 and 60 roll on the outer peripheral surface of the tripod shaft portion 22 and roll on the inner peripheral surface of the roller 30. Therefore, since the rollers 30 are interposed between the balls 40, 50 and 60 as described above between the roller 30 and the tripod shaft 22, the roller 30 can swing with respect to the tripod shaft 22 (can swing). Become.

  The cage 70 has a ring shape. The inner peripheral surface of the cage 70 is formed in an outer concave arc shape in cross section. Further, the outer peripheral surface of the cage 70 is formed in an outer convex arc shape in the cross section. The cage 70 is disposed between the outer peripheral surface of the tripod shaft portion 22 and the inner peripheral surface of the roller 30 in a state of being separated from both. The cage 70 holds the balls 40, 50, 60.

  The position where the cage 70 holds the balls 40, 50, 60 will be described in detail with reference to FIG. As shown in FIG. 2, a plurality of large-diameter windows 71 and a plurality of small-diameter windows 72 and 73 are formed in the cage 70. Specifically, a plurality of large-diameter windows 71 are formed in the circumferential direction at the center in the axial direction. The large-diameter window 71 has substantially the same diameter as the large-diameter ball 40 and is large enough to accommodate the large-diameter ball 40. A plurality of small-diameter windows 72 are formed in the circumferential direction on one end side in the axial direction. A plurality of small-diameter windows 73 are formed in the circumferential direction on the other end side in the axial direction. These small-diameter windows 72 and 73 have substantially the same diameter as the small-diameter balls 50 and 60, and have a size that can accommodate the small-diameter balls 50 and 60.

  Further, the large-diameter window 71 and the small-diameter windows 72 and 73 are formed so as to be alternately positioned in the circumferential direction. That is, the center of the large-diameter window 71 and the centers of the small-diameter windows 72 and 73 are shifted in the circumferential direction. Specifically, the centers of the small-diameter windows 72 and 73 are located at a circumferential intermediate position between the centers of the adjacent large-diameter windows 71. That is, the cage 70 alternately holds the large-diameter balls 40 disposed at the center in the tripod axial direction and the small-diameter balls 50 and 60 disposed at both ends thereof in the circumferential direction.

  By configuring the tripod constant velocity joint as described above, the following effects are exhibited. First, since the roller 30 can swing with respect to the tripod shaft 22, the induced thrust force can be reduced. Furthermore, since the number of parts is reduced as compared with the prior art, it is possible to reduce the play due to the tolerance of the parts and improve the rotational position accuracy. Furthermore, cost reduction can be achieved. In addition, since the balls 40, 50, 60 are arranged in three rows in the tripod axis direction, the number of balls can be increased. As a result, the surface pressure generated between the balls 40, 50, 60 and the tripod shaft 22 or the roller 30 can be reduced. Furthermore, since the balls 40, 50, 60 are alternately arranged in the circumferential direction, the distance between the centers of the balls in the tripod axis direction of each row can be reduced, and as a result, the size can be reduced. Thus, a further effect of reducing the surface pressure generated between the balls 40, 50, 60 and the tripod shaft portion 22 or the roller 30 is exhibited.

(2) 2nd Embodiment Next, the tripod type | mold constant velocity joint of 2nd Embodiment is demonstrated with reference to FIG.3 and FIG.4. FIG. 3 is a sectional view in the axial direction of the intermediate shaft of the tripod constant velocity joint according to the second embodiment. FIG. 4 shows a collar 180 constituting the tripod type constant velocity joint of the second embodiment. In addition, in the tripod type | mold constant velocity joint of 2nd Embodiment, about the same structure as the tripod type | mold constant velocity joint of 1st Embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 3, the tripod constant velocity joint includes an outer race 10, a tripod 20, a roller 130, balls 40 to 60, a cage 170, and a collar 180.

  Here, the roller 130 and the cage 170 are substantially the same in configuration as the roller 30 and the cage 70 only by increasing the inner and outer diameters of the roller 30 and the cage 70 of the first embodiment.

  The collar 180 has a ring shape. The inner peripheral surface of the collar 180 is formed to have the same diameter as the outer diameter of the tripod shaft portion 22 in the axial direction. The collar 180 is fitted to the outer peripheral surface of the tripod shaft portion 22 so as to be slidable in the tripod shaft direction with respect to the outer peripheral surface of the tripod shaft portion 22. Further, as shown in FIGS. 3 and 4, three grooves 181, 182, and 183 are formed on the outer peripheral surface of the collar 180 in the circumferential direction.

  These grooves 181, 182, and 183 are formed at positions corresponding to the large-diameter ball 40, the small-diameter ball 50, and the small-diameter ball 60, respectively. Further, the cross-sectional shape of the groove 181 at the center in the axial direction is formed in an arc shape having the same diameter as the large-diameter ball 40. The grooves 182 and 183 at both ends in the axial direction are formed in an arc shape having the same diameter as the small diameter balls 50 and 60. These grooves 181, 182, and 183 are all formed at the same groove depth. Therefore, the groove width of the groove 181 at the center in the axial direction is wider than the groove widths of the grooves 182 and 183 at both ends in the axial direction.

  The large-diameter ball 40 rolls along the groove 181 at the center in the axial direction of the collar 180. Further, the small-diameter balls 50 and 60 roll along the grooves 182 and 183 at both ends in the axial direction of the collar 180, respectively.

  With the above configuration, the balls 40 to 60 are in contact with the collar 180 at a plurality of points or in line contact. Here, in the first embodiment, the balls 40 to 60 are in contact with the tripod shaft portion 22 at one point. Therefore, the surface pressure generated between the ball 40 and the collar 180 is reduced compared to the case of the first embodiment.

(3) Third Embodiment Next, a tripod constant velocity joint according to a third embodiment will be described with reference to FIGS. 5 and 6. FIG. 5 shows a sectional view in the axial direction of the intermediate shaft of the tripod type constant velocity joint of the third embodiment. FIG. 6 is a view showing only the balls 250 and 260 and the cage 270 of the third embodiment. In addition, in the tripod type | mold constant velocity joint of 3rd Embodiment, about the same structure as the tripod type | mold constant velocity joint of 1st Embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 5, the tripod type constant velocity joint includes an outer race 10, a tripod 20, a roller 30, balls 250 and 260, and a cage 270. The balls 250 and 260 are spherical with the same diameter. These balls 250 and 260 are disposed between the outer peripheral surface of the tripod shaft portion 22 and the inner peripheral surface of the roller 30 so as to contact the outer peripheral surface of the tripod shaft portion 22 and the inner peripheral surface of the roller 30. . Furthermore, two rows of balls 250 and balls 260 are arranged in this order from the base side of the tripod shaft portion 22 in the tripod shaft direction. A plurality of balls 250 and 250 are arranged in the circumferential direction of the outer peripheral surface of the tripod shaft portion 22 in each row.

  Here, the ball 250 has a value slightly smaller than a value obtained by subtracting the cylindrical diameter of the tripod shaft portion 22 from the diameter of the sphere 100 and dividing it into two. Then, the ball 250 is disposed at a position in contact with the base side of the tripod shaft portion 22 slightly from the center in the roller rotation axis direction on the inner peripheral surface of the roller 30. Further, the ball 260 is disposed so as to abut on the tip side of the tripod shaft portion 22 slightly from the center in the roller rotation axis direction on the inner peripheral surface of the roller 30. The circumscribed circles of these balls 250 and 260 coincide with the sphere 100.

  The cage 270 has a ring shape. The inner peripheral surface of the cage 270 is formed in an outer concave arc shape in cross section. Further, the outer peripheral surface of the cage 270 is formed in an outer convex arc shape in cross section. The cage 270 is disposed between the outer peripheral surface of the tripod shaft portion 22 and the inner peripheral surface of the roller 30 in a state of being separated from both. The cage 270 holds the balls 250 and 260.

  The position where the cage 270 holds the balls 250 and 260 will be described in detail with reference to FIG. As shown in FIG. 6, a plurality of windows 271 and 272 are formed in the cage 270. Specifically, a plurality of windows 271 and 272 are formed in the circumferential direction at positions slightly shifted from the center in the axial direction toward both ends. These windows 271 and 272 have substantially the same diameter as the balls 250 and 260 and have a size that can accommodate the balls 250 and 260.

  Furthermore, the window 271 and the window 272 are formed so as to be alternately positioned in the circumferential direction. That is, the center of the window 271 and the center of the window 272 are shifted in the circumferential direction. Specifically, the center of the window 271 is located at a circumferential intermediate position between the centers of the adjacent windows 272. That is, the cage 270 holds the balls 250 and the balls 260 alternately in the circumferential direction.

  Even when it is set as the above structures, the same effect as the effect by the tripod type | mold constant velocity joint of 1st Embodiment is exhibited. However, by arranging the balls 250 and 260 in two rows in the tripod axis direction, the surface pressure generated between the balls and the tripod shaft portion 22 is larger than in the three-row arrangement of the first embodiment.

(4) Others The cages 70, 170, and 270 in the above embodiment can be configured as follows. The cage which consists of another form is demonstrated with reference to FIG. 7A and 7B show a cage applicable to the first embodiment or the second embodiment, and FIG. 7C shows a cage applicable to the third embodiment.

  A cage 370 shown in FIG. 7A has a ring shape, and a plurality of windows 371 are formed in the circumferential direction. The window 371 is formed so as to be inclined from one end side of the cage 370 toward the other end side. Furthermore, the circumferential width of the window 371 is formed so that the center in the axial direction is the widest and gradually decreases toward the end in the axial direction. That is, one window 371 accommodates and holds the balls 40, 50, 60 one by one.

  A cage 470 shown in FIG. 7B has a ring shape, and a plurality of windows 471 are formed in the circumferential direction. The window 471 is formed to extend in the axial direction of the cage 470. Further, the circumferential width of the window 471 is formed so that the center in the axial direction is the widest and gradually decreases toward the end in the axial direction. That is, one window 471 accommodates and holds the balls 40, 50, 60 one by one.

  A cage 570 shown in FIG. 7C has a ring shape, and a plurality of windows 571 are formed in the circumferential direction. The window 571 is formed so as to be inclined from one end side of the cage 570 toward the other end side. Further, the circumferential width of the window 571 is formed to be substantially constant. That is, the window 571 has a substantially parallelogram shape. The window 571 accommodates and holds the balls 250 and 260 one by one.

  As described above, a plurality of balls are accommodated and held in one window 371, 471, 571 formed in the cages 370, 470, 570, whereby the distance between the balls in the tripod axial direction can be shortened. . As a result, the tripod constant velocity joint can be reduced in size.

It is an intermediate shaft axial direction sectional view of the tripod type constant velocity joint of a 1st embodiment. It is a figure which shows only ball | bowl 40, 50, 60 and the cage 70 of 1st Embodiment. It is an intermediate shaft axial direction sectional view of the tripod type constant velocity joint of a 2nd embodiment. It is a figure which shows the color | collar 180 which comprises the tripod type | mold constant velocity joint of 2nd Embodiment. It is a middle shaft axial direction sectional view of a tripod type constant velocity joint of a 3rd embodiment. It is a figure which shows only the balls 250 and 260 and the cage 270 of 3rd Embodiment. It is a figure which shows the cage of other embodiment.

Explanation of symbols

10: outer race, 11: guide groove,
20: Tripod, 21: Boss part, 22: Tripod shaft part,
30, 130: Roller,
40, 50, 60, 250, 260: ball,
70, 170, 270, 370, 470, 570: cage,
71-73, 271-272, 371, 471, 571: window,
180: Color

Claims (10)

An outer race having a cup shape and having three guide grooves formed in the inner race surface extending in the direction of the outer race rotation axis;
A tripod comprising: a boss portion; and three columnar tripod shaft portions each extending from the boss portion radially outward of the intermediate shaft shaft and inserted into each guide groove;
A roller having an inner peripheral surface formed in a ring shape formed in a partial spherical shape, rotatably supported around each tripod shaft portion around the tripod shaft, and rotatably engaged with the guide groove;
It consists of a sphere with a plurality of spherical diameters, contacts at least the inner peripheral surface of the roller, and is arranged in at least three rows in the tripod axial direction between the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the roller. A plurality of balls,
A tripod-type constant velocity joint.   The tripod constant velocity joint according to claim 1, further comprising a cage that is disposed between an outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the roller and holds the plurality of balls.   3. The tripod constant velocity joint according to claim 2, wherein the cage holds the balls positioned in two predetermined rows adjacent to each other in the tripod axial direction so as to be alternately positioned in the circumferential direction. An outer race having a cup shape and having three guide grooves formed in the inner race surface extending in the direction of the outer race rotation axis;
A tripod comprising: a boss portion; and three columnar tripod shaft portions each extending from the boss portion radially outward of the intermediate shaft shaft and inserted into each guide groove;
A roller having an inner peripheral surface formed in a ring shape formed in a partial spherical shape, rotatably supported around each tripod shaft portion around the tripod shaft, and rotatably engaged with the guide groove;
A plurality of balls made of a spherical shape, in contact with at least the inner peripheral surface of the roller, and arranged in at least two rows in the tripod axial direction between the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the roller; ,
The balls disposed between the outer peripheral surface of the tripod shaft portion and the inner peripheral surface of the roller and positioned in two predetermined rows adjacent in the tripod shaft direction are alternately positioned in the circumferential direction. A cage to hold,
A tripod-type constant velocity joint. The cage is formed with a plurality of windows in the circumferential direction,
The tripod constant velocity joint according to any one of claims 2 to 4, wherein at least one of the balls in each row is held in each of the windows.   The tripod type constant velocity joint according to any one of claims 1 to 5, wherein an inner diameter of the inner peripheral surface of the roller is formed such that a center of the roller in the roller rotation axis direction is maximized.   The sphere diameter of the balls arranged in both end rows in the tripod axis direction is smaller than the sphere diameter of the balls arranged in the center side row in the tripod axis direction. The tripod type constant velocity joint as described in one term.   The tripod type constant velocity joint according to any one of claims 1 to 7, wherein the plurality of balls are in contact with an outer peripheral surface of the tripod shaft portion. It has a ring shape, is further fitted with an outer peripheral surface of the tripod shaft portion, and further includes a collar that can slide in the tripod shaft direction with respect to the tripod shaft portion,
The plurality of balls are arranged between the outer peripheral surface of the collar and the inner peripheral surface of the roller so as to roll in contact with the outer peripheral surface of the collar. The tripod type constant velocity joint described in the item.   The tripod type constant velocity joint according to claim 9, wherein a groove is formed on an outer peripheral surface of the collar in a circumferential direction.

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