JP2007120667A - Tripod-type constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a vibration-proof material that is less likely to be peeled off, and to improve durability of a tripod-type constant velocity universal joint. <P>SOLUTION: The tripod-type constant velocity universal joint comprises an outer joint member 10, having three track grooves 12 formed in the inner periphery, an inner joint member 20, having three leg shafts 24 protruding in the radial direction, and a torque transmission element 30 rotatably, movably in the axial direction, and freely swivelably supported by each of the leg shafts 24 and stored in the track groove 12 of the outer joint member 10. The vibration-proof material 38 is assembled in the torque transmission element 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a tripod type constant velocity universal joint and can be used for power transmission of automobiles and various industrial machines.

  In Patent Document 1, an outer ring of a tripod type constant velocity universal joint is configured by a combination of an inner outer cylinder, an outer outer cylinder, and a vibration isolating material interposed therebetween, and either one of the inner outer cylinder or the outer outer cylinder is used. It is described that the surface is provided with an interference portion protruding in the direction of narrowing the gap between them.

  In Patent Document 2, the outer ring of the tripod type constant velocity universal joint is configured by a combination of an inner outer cylinder, an outer outer cylinder, and a vibration isolating material interposed between both, and at both ends of the inner outer cylinder and the outer outer cylinder, It is described that an interference portion protruding in the direction of narrowing the gap between the two is provided.

In Patent Document 3, interference protrusions are provided along the axial direction in the circumferential direction of the inner diameter surface of the tripod type constant velocity universal joint, and each interference protrusion is provided at a circumferentially equal position on the outer diameter surface of the inner outer cylinder. An interference fitting groove is provided, in which the strip is provided with a required clearance in the rotation direction, and the inner diameter surface of the outer outer cylinder between the interference projections and the outer diameter surface of the inner outer cylinder between the interference projections. It describes that an anti-vibration material is interposed between them.
JP-A-2-16825 Japanese Patent Laid-Open No. 5-100343 JP-A-3-272322

  In the case of a conventional tripod type constant velocity universal joint in which the outer ring is composed of a combination of an inner outer cylinder and an outer outer cylinder, and a vibration isolating material is interposed between the two, Become. This shearing force becomes a factor that peels off the vulcanized adhesion of the vibration isolator. If the vulcanization adhesion of the vibration isolator is peeled off, the tripod type constant velocity universal joint as the torque transmission device cannot perform the intended function.

  The main object of the present invention is to improve the durability of the tripod type constant velocity universal joint by making it difficult to peel off the vibration isolator.

  This invention incorporates a vibration isolator into the torque transmission element between the outer ring of the tripod type constant velocity universal joint and the leg shaft, and gives a torque with a compressive force displaced in the torque load direction of the vibration isolator, in other words, The problem is solved by applying a torque in the direction of compressing the vibration isolator.

  That is, the tripod type constant velocity universal joint of the present invention includes an outer joint member having three track grooves on the inner periphery, an inner joint member having three leg shafts protruding in the radial direction, and each leg shaft. And a torque transmission element that is supported so as to be rotatable, axially movable, and swingable, and is accommodated in a track groove of an outer joint member, and a vibration isolating material is incorporated in the torque transmission element. It is.

  According to a second aspect of the present invention, in the tripod type constant velocity universal joint according to the first aspect, the torque transmission element includes an outer roller and an inner roller that are relatively rotatable via a needle roller, and the outer roller or the inner roller is Further, it is characterized by being composed of two or more concentric cylinders with a vibration isolating material interposed between them.

  The vibration isolator may be press-fitted between the cylinders (Claim 3), or may be vulcanized and bonded to the cylinders (Claim 4).

  According to a fifth aspect of the present invention, in the tripod type constant velocity universal joint according to any one of the first to fourth aspects, an interference protrusion that handles an excessive load is provided.

  The invention according to claim 6 is the tripod type constant velocity universal joint according to claim 5, wherein the interference protrusion is provided integrally with the outer roller or the inner roller.

  A seventh aspect of the invention is the tripod type constant velocity universal joint according to the fifth aspect, wherein the interference protrusion is interposed between the outer roller and the inner roller.

  The invention according to claim 8 is the tripod type constant velocity universal joint according to claim 1, wherein the torque transmitting element is composed of an outer roller and an inner roller that are relatively rotatable via a needle roller, and the outer roller or the inner roller Or the material which comprises both is made into the vibration isolator, It is characterized by the above-mentioned.

  According to the present invention, by incorporating the vibration isolator into the torque transmission element between the outer ring and the leg shaft of the tripod type constant velocity universal joint, torque acts in the direction of compressing the vibration isolator, Since the transmission torque can be handled by the compressive force, the vibration isolator is difficult to peel off. Therefore, according to the present invention, the durability of the tripod constant velocity universal joint is improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, the basic configuration of the tripod constant velocity universal joint will be described with reference to FIGS. 9 and 10.

  As shown in the figure, the tripod type constant velocity universal joint includes an outer ring 10 as an outer joint member, a tripod 20 as an inner joint member, and a roller assembly 30 as a torque transmission element as main components. . One of the two shafts to be connected is connected to the outer ring 10 and the other is connected to the tripod 20.

  In the illustrated embodiment, the outer ring 10 includes a cylindrical portion and a shaft portion, and the cylindrical portion has a cup shape opened at one end. Three track grooves 12 are formed on the inner circumference of the cylindrical portion at the circumference equally divided position. The track grooves 12 extend in the axial direction, and both side walls of each track groove 12 are roller guide surfaces 14.

  The tripod 20 includes a boss 22 in which a serration (or spline, the same applies hereinafter) hole 26 is formed, and a leg shaft 24 that protrudes in a radial direction from the circumferential bisector of the boss 22. Each leg shaft 24 carries a roller assembly 30.

  The roller assembly 30 includes an outer roller 32 and an inner roller 34. That is, the outer roller 32 and the inner roller 34 are unitized via a plurality of needle rollers 36 to constitute a roller assembly capable of relative rotation. The roller assembly 30 is accommodated in the track groove 12 of the outer ring 10, and the outer roller 34 can roll along the roller guide surface 14. The roller guide surface 14 is a concave curved surface that matches the outer peripheral surface of the outer roller 32. For example, the roller guide surface 14 is configured by a part of a cylindrical surface whose axis is parallel to the axis of the outer ring 10, and the cross-sectional shape thereof is an arc corresponding to the generatrix of the outer peripheral surface of the outer roller 32.

  Alternatively, the outer peripheral surface of the outer roller 32 is a convex curved surface (torus surface) having an arc having a center of curvature at a position radially away from the axis of the leg shaft 24, and the cross-sectional shape of the roller guide surface 14 is a Gothic arch. Shape. Thereby, the outer peripheral surface of the outer roller 32 and the roller guide surface 14 form an angular contact. Even if the cross-sectional shape of the roller guide surface 14 is tapered with respect to the outer peripheral surface of the spherical outer roller, the angular contact between them is realized. As described above, by adopting a configuration in which the outer peripheral surface of the outer roller 32 and the roller guide surface 14 form an angular contact, the roller is less likely to shake, so that the posture is stabilized.

  The inner roller 34 is fitted on the outer peripheral surface of the leg shaft 24. With the cylindrical outer peripheral surface of the inner roller 34 as an inner raceway surface and the cylindrical inner peripheral surface of the outer roller 32 as an outer raceway surface, a needle roller 36 is interposed between these inner and outer raceway surfaces so as to be able to roll. As shown in FIG. 10B, the needle roller 36 is incorporated in a so-called all-roller state in which as many rollers as possible are inserted and there is no cage. Reference numeral 38 denotes a washer for preventing the needle roller 36 from coming off, and is attached to an annular groove formed on the inner peripheral surface of the end of the outer roller 32.

  The outer peripheral surface of the leg shaft 24 has a straight shape parallel to the axis of the leg shaft 24 when viewed in the longitudinal section (FIG. 9), and the long axis is the axis of the joint when viewed in the transverse section (FIG. 10A). It is a substantially elliptical shape that is orthogonal. The cross-sectional shape of the leg shaft is a substantially elliptical shape with a reduced thickness as viewed in the axial direction of the tripod 20. In other words, the cross-sectional shape of the leg shaft is such that the surfaces facing each other in the axial direction of the tripod are retracted in the mutual direction, that is, on the smaller diameter side than the virtual cylindrical surface. A specific example of such a shape is a substantially elliptical shape. The term “substantially oval” includes not only an elliptical shape as defined but also a shape generally called an oval shape or an oval shape. As a result, the leg shaft 24 comes into contact with the inner peripheral surface of the inner roller 34 in a direction perpendicular to the joint axis, and forms a gap between the leg shaft 24 and the inner peripheral surface of the inner roller 34 in the joint axial direction.

  The inner peripheral surface of the inner roller 34 has an arcuate convex cross section. That is, the generatrix of the inner peripheral surface is a convex arc with a radius r (FIG. 10C). Since the cross-sectional shape of the leg shaft 24 is substantially elliptical as described above, and a predetermined clearance is provided between the leg shaft 24 and the inner roller 34, the inner roller 34 has a leg shaft. In addition to being able to move 24 in the axial direction, it can swing with respect to the leg shaft 24. As described above, since the inner roller 34 and the outer roller 32 are unitized so as to be relatively rotatable via the needle roller 36, the inner roller 34 and the outer roller 32 can swing as a unit with respect to the leg shaft 24. There is a relationship. Here, swinging means that the axis of the roller assembly (32, 34) is inclined with respect to the axis of the leg shaft 24 in a plane including the axis of the leg shaft 24 (see FIG. 9).

  In this embodiment, since the cross-sectional shape of the leg shaft 24 is as described above, the leg shaft 24 can be connected to the outer ring 10 without changing the posture of the roller assembly when the joint takes an operating angle (FIG. 9). Can be tilted against. Further, since the inner peripheral surface of the inner roller 34 has an arcuate convex cross section, as shown by a broken line in FIG. 10C, the contact ellipse of both is close to a point, and the area is also reduced at the same time. Therefore, the frictional moment for tilting the roller assembly (32, 34, 36) is greatly reduced. Further, the posture of the roller assembly is always stable, and the roller is held parallel to the roller guide surface, so that it can roll smoothly. As a result, the induced thrust and slide resistance are reduced, and variations in their values are also reduced.

  The tripod type constant velocity universal joint shown in FIG. 11 is also a double roller type, but the leg shaft 24 is made spherical, and the swing of the roller assembly 30 (32, 34, 36) The movement in the axial direction is performed between the outer roller 32 and the inner roller 34.

  Next, referring to FIG. 1, the outer roller 32 of the roller assembly 30 is divided into a concentric outer cylindrical body 32a and an inner cylindrical body 32b, and a vibration isolating material 38 is provided between the two (32a, 32b). Intervened. The vibration isolator 38 is made of rubber or other elastic material and is press-fitted between the cylinders 32a and 32b or vulcanized and bonded.

  As shown in FIG. 2, the inner roller 34 may be divided into concentric cylindrical bodies 34a and 34b, and a vibration isolator 38 may be interposed between the both (34a and 34b). As illustrated in the drawing, it can be divided into two or more cylinders in addition to the inner and outer cylinders. Further, the vibration isolator 38 can be incorporated in both the outer roller 32 and the inner roller 34, but the power between the outer ring 10 and the leg shaft 24 can be obtained by incorporating the vibration isolator 38 in at least one of the rollers. A damping function can be exhibited in the transmission path.

  In the embodiment shown in FIG. 3, the needle roller 36 is formed of a vibration isolating material. Also in this case, the damping function can be exhibited in the power transmission path between the outer ring 10 and the leg shaft 24.

  4 to 8 correspond to modifications of the embodiment of FIG. 1, and are provided with an interference protrusion 40 that bears excessive torque in place of the vibration isolator 38. 4 to 8, the right side (b) of each figure shows the time of excessive torque load.

  In the modified examples shown in FIGS. 4 to 6, the interference protrusion 40 is provided on the outer peripheral surface of the inner roller 34. That is, by forming the annular groove on the outer peripheral surface of the inner roller 34, the portions remaining on both sides of the annular groove are used as the interference protrusion 40. In this case, the vibration isolator 38 is in the annular groove. For example, a rubber vibration isolator is vulcanized and bonded to the bottom surface of the annular groove.

  In the modification of FIG. 4, the inner peripheral surface of the outer cylinder 32a and the outer peripheral surface of the inner cylinder 32b of the outer roller 32 are cylindrical surfaces. Therefore, at the time of excessive torque load, as shown in FIG. 4B, the inner peripheral surface of the outer cylindrical body 32a and the outer peripheral surface of the inner cylindrical body 32b interfere with each other and the abnormal deformation of the vibration isolator 38 is caused. To prevent.

  In the modification of FIG. 5, the inner peripheral surface of the outer cylindrical body 32a and the outer peripheral surface of the inner cylindrical body 32b of the outer roller 32 are partial spherical surfaces. In other words, the bus on the inner peripheral surface of the outer cylinder 32a and the bus on the outer peripheral surface of the inner cylinder 32b are arcs having a center of curvature on the central axis. Therefore, at the time of excessive torque load, as shown in FIG. 5B, the inner peripheral surface of the outer cylindrical body 32a and the outer peripheral surface of the inner cylindrical body 32b interfere with each other between the spherical surfaces.

  In the modification of FIG. 6, the inner peripheral surface of the outer cylinder 32a and the outer peripheral surface of the inner cylinder 32b are annular curved surfaces (torus surfaces). In this case, the bus on the inner peripheral surface of the outer cylinder 32a and the bus on the outer peripheral surface of the inner cylinder 32b are arcs, but the center of curvature is located at a point away from the central axis. Therefore, at the time of excessive torque load, as shown in FIG. 6B, the inner peripheral surface of the outer cylindrical body 32a and the outer peripheral surface of the inner cylindrical body 32b interfere with each other between the annular curved surfaces, and the vibration isolator 38 is abnormal. Prevent deformation.

  In the modification shown in FIG. 7, the interference protrusion 40 is provided on the inner peripheral surface of the outer cylinder 32 a of the outer roller 32. That is, by providing an annular groove on the inner peripheral surface of the outer cylindrical body 32a, the inner peripheral surface remaining on both sides of the annular groove is used as the interference protrusion 40. And the vibration isolator 38 is attached to the annular groove. The inner peripheral surface of the outer cylindrical body 32a and the outer peripheral surface of the inner cylindrical body 32b are cylindrical surfaces. Therefore, at the time of excessive torque load, as shown in FIG. 7B, the inner peripheral surface (= interference protrusion 40) of the outer cylindrical body 32a and the outer peripheral surface of the inner cylindrical body 32b interfere with each other between the cylindrical surfaces. The abnormal deformation of the vibration isolator 38 is prevented.

  In the case of the modification shown in FIG. 8, the inner peripheral surface of the outer cylindrical body 32a and the outer peripheral surface of the inner cylindrical body 32b of the outer roller 32 are both cylindrical surfaces, and are separated from each other (32a, 32b). The interference protrusion 40 is interposed. Here, the case where the interference protrusion 40 is mounted on the inner cylinder 32b side is illustrated, and an annular groove is formed on the outer peripheral surface of the inner cylinder 32b, and a retaining ring 33 for retaining is mounted. Here too, when an excessive torque load is applied, as shown in FIG. 8B, the inner peripheral surface of the outer cylindrical body 32a and the interference protrusion 40 interfere with each other between the cylindrical surfaces, thereby causing abnormal deformation of the vibration isolator 38. To prevent.

  Except for the embodiment of FIG. 3, the vibration isolator 38 may be inserted over the entire circumference, or may be divided and inserted.

Cross-sectional view of tripod type constant velocity universal joint showing an embodiment of the present invention Cross-sectional view similar to FIG. 1 showing another embodiment Cross-sectional view similar to FIG. 1 showing still another embodiment (A) is sectional drawing of the roller which shows the modification of embodiment of FIG. 1, (b) is sectional drawing of the roller at the time of excessive load (A) is sectional drawing of the roller which shows the modification of embodiment of FIG. 1, (b) is sectional drawing of the roller at the time of excessive load (A) is sectional drawing of the roller which shows the modification of embodiment of FIG. 1, (b) is sectional drawing of the roller at the time of excessive load (A) is sectional drawing of the roller which shows the modification of embodiment of FIG. 1, (b) is sectional drawing of the roller at the time of excessive load (A) is sectional drawing of the roller which shows the modification of embodiment of FIG. 1, (b) is sectional drawing of the roller at the time of excessive load Vertical section of tripod type constant velocity universal joint (A) is a cross-sectional view of the tripod type constant velocity universal joint of FIG. 9, (B) is a cross-sectional view of the roller assembly, and (C) is a vertical cross-sectional view of the inner roller. Cross section of tripod type constant velocity universal joint

Explanation of symbols

10 Outer ring (outer joint member)
12 Track groove 14 Roller guide surface 20 Tripod (inner joint member)
22 Boss 24 Leg shaft 26 Serration hole 30 Roller assembly (torque transmission element)
32 Outer roller 32a Outer cylinder 32b Inner cylinder 34 Inner roller 34a Outer cylinder 34b Inner cylinder 36 Needle roller 33 Washer 38 Anti-vibration material 40 Interference protrusion

Claims (8)

  An outer joint member having three track grooves on the inner periphery, an inner joint member having three leg shafts projecting in the radial direction, and supported by each leg shaft so as to be rotatable, axially movable, and swingable. A tripod type constant velocity universal joint comprising a torque transmission element housed in a track groove of an outer joint member and incorporating a vibration isolating material into the torque transmission element.   The torque transmission element includes an outer roller and an inner roller that are rotatable relative to each other via a needle roller, and the outer roller or the inner roller has two or more concentric cylindrical bodies with a vibration isolating material interposed therebetween. The tripod type constant velocity universal joint of Claim 1 comprised by these.   The tripod constant velocity universal joint according to claim 2, wherein the vibration isolator is press-fitted between the cylindrical bodies.   The tripod constant velocity universal joint according to claim 2, wherein the vibration isolator is vulcanized and bonded to the cylindrical body.   The tripod type constant velocity universal joint according to any one of claims 1 to 4, further comprising an interference protrusion that handles an excessive load.   The tripod type constant velocity universal joint according to claim 5, wherein the interference protrusion is provided integrally with the outer roller or the inner roller.   6. The tripod constant velocity universal joint according to claim 5, wherein the interference protrusion is interposed between an outer roller and an inner roller.   The tripod type according to claim 1, wherein the torque transmitting element is composed of an outer roller and an inner roller which are rotatable relative to each other via a needle roller, and the material constituting the outer roller or the inner roller or both is a vibration isolator. Fast universal joint.

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