JP4115043B2 - Tripod type constant velocity universal joint - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sliding tripod type constant velocity universal joint used when transmitting rotation of a drive shaft of an automobile to a drive wheel.
[0002]
[Prior art]
Generally, a fixed type constant velocity universal joint and a sliding type constant velocity universal joint are incorporated in a power transmission system that transmits the rotation of the engine to driving wheels.
[0003]
As a sliding type constant velocity universal joint, the one shown in FIG. 8 is conventionally known. This constant velocity universal joint is a tripod type constant velocity universal joint, and three track grooves 21 are formed on the inner periphery of the outer joint member 20 at intervals of 120 °, and the inner side of the outer joint member 20 is formed. Three leg shafts 23 extending in the radial direction are provided on the outer periphery of the tripod member 22 inserted in the roller, and a roller 24 supported rotatably around each leg shaft 23 is slidably inserted into the track groove 21. Thus, rotational torque is transmitted between the outer joint member 20 and the tripod member 22.
[0004]
Here, the roller guide surfaces 21 a provided on both sides of the track groove 21 are cylindrical surfaces having an arcuate cross section when cut along a plane orthogonal to the axis of the outer joint member 20. The outer periphery of each is a spherical surface 24a.
[0005]
The roller 24 is supported by needle rollers 25 incorporated therein so as to be rotatable and movable in the axial direction of the leg shaft 23, and a retaining ring 26 and a thrust attached to the distal end portion of the leg shaft 23. It is retained by a washer 27.
[0006]
[Problems to be solved by the invention]
By the way, in the conventional constant velocity universal joint, when the outer joint member 20 and the tripod member 22 take the operating angle and transmit the rotational torque, the roller guide surface 21a and the roller 24 are in an oblique relationship. . At this time, the roller 24 tries to rotate in the direction indicated by the arrow in the figure, whereas the roller guide surfaces 21a on both sides of the track groove 21 for guiding the rolling movement of the roller 24 are cylindrical surfaces and are outer joint members. Since the roller 24 is parallel to the axis 20, the roller 24 moves while being restrained by the track groove 21, and a relatively large longitudinal tilting moment acts on the roller 24. For this reason, the needle roller 25 that supports the roller 24 is rotated by contact with the roller 24 while receiving a load at the end. Accordingly, the needle roller 25 is easily skewed, and the roller 24 cannot be smoothly rotated due to the skew of the needle roller 25, and slip occurs between the roller 24 and the roller guide surface 21a to generate heat. This slip induces a thrust force in the axial direction, which gives rise to a problem of generating vibrations and generating noise.
[0007]
Here, as schematically shown in FIG. 9, if the roller guide surfaces 21 a on both sides of the track groove 21 are flat surfaces and a cylindrical roller is used as the roller 24, the roller 24 can be correctly rolled and rotated. However, in this case, the operating angle cannot be taken between the outer joint member 20 and the tripod member 22 due to the interference between the outer peripheral surface of the roller 24 and the roller guide surface 21a.
[0008]
That is, considering the case where the outer joint member 20 and the tripod member 22 have an operating angle, the intersection O ′ of the axis of the three leg shafts 23 of the tripod member 22 is the axis O of the outer joint member 20. When the rotational torque is transmitted, an intersection point O ′ of the axis of the leg shaft 23 tries to swing around the axis O with the deviation r as a radius. Considering 23 as a basis, the other two leg shafts 23 are inclined by an angle γ as compared with the case where the operating angle is 0 degree. Therefore, interference occurs between the outer peripheral surface of the roller 24 supported by the leg shaft 23 and the roller guide surface 21a as shown by a chain line A, and the outer joint member 20 and the tripod member 22 take an operating angle. Therefore, a mechanism for preventing interference between the outer peripheral surface of the roller 24 and the roller guide surface 21a is required.
[0009]
An object of the present invention is to provide a tripod type constant velocity universal joint capable of smoothly rotating a roller that transmits rotational torque between an outer joint member and a tripod member and suppressing generation of vibration and noise. Is to provide.
[0010]
[Means for Solving the Problems]
In order to solve the above-described problems, in the present invention, an outer joint member in which three track grooves in the axial direction are formed on the inner periphery and both sides of each track groove serve as roller guide surfaces, and a radial direction A tripod member having three leg shafts extending, a roller provided on each leg shaft, and a rolling element incorporated in each roller and rotatably supporting the roller around the leg shaft, by inserting each of the rollers to the outer joint member track groove of contact with the roller guide surface, contact between the roller guide surface roller when the transmission of torque outer joint member and the tripod member takes an operating angle ball in tripod constant velocity universal joint so as to transmit the rotational torque is reciprocated in an arc shape along the roller guide surfaces while rolling in mutual outer joint member and the tripod member, the rolling elements by The roller is provided with an arc-shaped raceway surface on which the ball rolls, and a race ring having a cross-sectional arc-like raceway surface on which the ball rolls is fitted on the leg shaft. The configuration was adopted.
[0011]
As described above, by supporting the roller rotatably by the ball, the problem of skew when the roller is supported by the needle roller is eliminated, and the roller can be rotated smoothly.
[0012]
For this reason, at the time of torque transmission in which the outer joint member and the tripod member take the operating angle and transmit the rotational torque, the sliding resistance of the roller moving along the roller guide surface is small, and the generation of vibration and noise is suppressed. Can do.
[0013]
Here, when the contact between the roller and the roller guide surface is a point contact that contacts at the approximate center in the roller width direction, or an angular contact that contacts at two points at both ends in the width direction of the roller, the roller guide surface and the roller Compared with the case where the outer joint member and the tripod member take a working angle, the resistance at the contact portion between the roller guide surface and the roller is small and the longitudinal direction applied to the roller is smaller than the case where the outer joint member and the tripod member are in contact with each other. The tilt moment of the can be reduced.
[0014]
For this reason, the roller can smoothly change its posture in the track groove, and can move the roller smoothly along the track groove.
[0015]
As a method of making point contact between the roller and the roller guide surface, the outer periphery of the roller is a spherical surface and the roller guide surface is a cylindrical surface having a radius of curvature larger than the radius of the spherical surface, or the roller guide surface is a flat surface and the roller A method of making the outer periphery of the spherical surface spherical can be adopted.
[0016]
Further, as a method of bringing the roller and the roller guide surface into contact with each other at two points, a method is adopted in which the roller guide surface is a Gothic arch formed by two inclined surfaces inclined in opposite directions, and the outer periphery of the roller is a spherical surface. be able to.
[0017]
If the roller guide surface is a flat surface and the outer periphery of the roller is a spherical surface, the roller will interfere with the roller guide surface during torque transmission in which the outer race member and tripod member take an operating angle and transmit rotational torque. Can be prevented.
[0018]
Here, the roller guide surface may be a flat surface, and the outer peripheral surface of the roller may be a cylindrical surface. In this case, on the inside of the raceway, the cross-sectional shape cut by a plane including the axis of the raceway is a curved surface with a convex arc shape, enabling the relative inclination of the leg shaft and the raceway, and the outer raceway. This prevents the roller guide surface and the roller from interfering with each other during torque transmission in which the member and the tripod member take an operating angle and transmit rotational torque.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the outer joint member 1 has a shaft portion 2 at the closed end, and three track grooves 3 are formed on the inner periphery at intervals of 120 °. Both sides of 3 are roller guide surfaces 4.
[0020]
A tripod member 10 is inserted inside the outer joint member 1. A torque transmission shaft 11 is connected to the tripod member 10 by fitting a serration 10a.
[0021]
The tripod member 10 has three leg shafts 12 projecting in the radial direction on the outer periphery, and a race ring 13 is slidably fitted to each leg shaft 12. A roller 14 is provided outside the raceway 13, and a ball 15 is assembled between a raceway groove 14 a having a circular arc cross section formed on the inner peripheral surface of the roller 14 and a raceway surface 13 a provided on the outer periphery of the raceway 13. The roller 14 is rotatably supported by the ball 15.
[0022]
The roller 14 is slidably inserted into the track groove 3 of the outer joint member 1. As shown in FIG. 3, the outer periphery of the roller 14 is a spherical surface 14 b, while the roller guide surfaces 4 on both sides of the track groove 3 have a cross-sectional shape cut by a plane perpendicular to the axis of the outer joint member 1. It is a circular cylindrical surface. The radius of curvature of the roller guide surface 4 made of this cylindrical surface is larger than the radius of the spherical surface 14b of the roller 14, and when the rotational torque is transmitted between the outer joint member 1 and the tripod member 10, the spherical surface 14b of the roller 14 is cylindrical. The roller guide surface 4 is made in point contact.
[0023]
The constant velocity universal joint shown in the embodiment has the above-described structure. When the operating angle between the outer joint member 1 and the tripod member 10 is 0 degree, the transmission of rotational torque between the members 1 and 10 is a roller guide surface. 4 and the engaging portion of the roller 14 engaged therewith. In this case, when plunging due to relative movement between the outer joint member 1 and the tripod member 10 occurs, the roller 14 rolls along the roller guide surface 4 of the track groove 3.
[0024]
As shown in FIG. 2, when the outer joint member 1 and the tripod member 10 transmit the rotational torque that takes the operating angle θ, the leg shaft 12 rotates around the axis of the torque transmission shaft 11, and the track groove 3 As a result, an angular deflection twice as large as the operating angle θ occurs.
[0025]
At this time, since the roller 14 is supported so as to be rotatable about the axis of the leg shaft 12, the roller 14 has an arc shape along the roller guide surface 4 while changing an inclination angle with respect to the roller guide surface 4. Reciprocates.
[0026]
In this case, since the contact between the roller 14 and the roller guide surface 4 is a point contact, the resistance at the contact portion is small, and the inclination moment in the front-rear direction applied to the roller 14 is also small. For this reason, the roller 14 smoothly changes its posture in the track groove 3 and also has a small resistance at the contact portion between the ball 15 and the raceway surface 14a, so that the roller 14 rotates smoothly and slides when the roller 14 moves. Resistance is small, and generation of vibration and noise can be suppressed.
[0027]
Further, when the leg shaft 12 rotates around the axis of the torque transmission shaft 11, the intersection of the axis of the leg shaft 12 swings around the axis of the outer joint member 1 as in the case shown in FIG. Therefore, the leg shaft 12 moves in the axial direction with respect to the raceway 13.
[0028]
In the embodiment shown in FIG. 3, the roller guide surface 4 is a cylindrical surface, and the radius of curvature thereof is larger than the radius of the spherical surface 14b of the roller 14, so that the roller 14 and the roller guide surface 4 are brought into point contact. As shown in FIG. 4, the roller guide surface 4 is formed by two inclined surfaces 4 a and 4 b inclined in opposite directions, and each inclined surface 4 a and 4 b is brought into point contact with the spherical surface 14 b of the roller 14. Good. In this case as well as in the case shown in FIG. 3, the roller 14 can be smoothly rotated and the posture of the roller 14 can be smoothly changed.
[0029]
As shown in FIG. 5, when a retaining ring 16 is attached to the tip of each leg shaft 12 and the race ring 13 is prevented from coming off by the retaining ring 16, the leg shaft 12 is composed of the race ring 13, balls 15, and rollers 14. Since the roller assembly can be retained and retained, the assembly of the constant velocity universal joint in which the tripod member 10 is inserted into the outer joint member 1 can be facilitated.
[0030]
FIG. 6 shows another example of the constant velocity universal joint according to the present invention. In the example shown in FIGS. 6 (I) and (II), the roller guide surface 4 is a flat surface, and the outer periphery of the roller 14 is a curved surface having an arc-shaped cross section cut by a plane including the axis of the roller 14. The curved surface 14c and the roller guide surface 4 are in point contact as 14c.
[0031]
Further, a retaining ring 17 is attached to the tip end portion of the leg shaft 12, and the retaining ring 17 and the shoulder 18 formed on the outer periphery of the tripod member 10 prevent the race ring 13 from moving in the axial direction of the leg shaft 12. ing.
[0032]
Also in the constant velocity universal joint in the above embodiment, the roller guide surface 4 is a flat surface, and the contact between the roller guide surface 4 and the roller 14 is a point contact. During torque transmission in which the member 1 and the tripod member 10 take a working angle to transmit rotational torque, the roller 14 can be smoothly rolled and moved along the roller guide surface 4, and slide resistance can be reduced. it can.
[0033]
7 (I) and 7 (II), the roller guide surface 4 is a flat surface, and the outer periphery of the roller 14 is a cylindrical surface 14d so that the roller guide surface 4 and the roller 14 are in line contact with each other. . In addition, the inner periphery of the bearing ring 13 is a curved surface 13b having a convex arc shape in a cross-sectional shape cut by a plane including the axis of the bearing ring 13.
[0034]
Further, a retaining ring 16 is attached to the tip end portion of the leg shaft 12, and a distance between the retaining ring 16 and the shoulder portion 8 of the tripod member 10 that allows the relative movement of the leg shaft 12 and the race ring 13 in the axial direction is possible. Is also provided.
[0035]
If formed as described above, the leg shaft 12 and the race 13 can be relatively tilted. Therefore, when the outer joint member 1 and the tripod member 10 take the operating angle and transmit the rotational torque, the leg shaft 12 It is possible to prevent the roller 14 from interfering with the roller guide surface 4 due to the tilt with respect to the raceway ring 13.
[0036]
For this reason, the roller 14 rolls and moves smoothly along the flat roller guide surface 4, and the slide resistance can be reduced.
[0037]
【The invention's effect】
As described above, according to the present invention, the raceway is fitted to the leg shaft, and the ball is assembled between the raceway surface formed on the outer periphery of the raceway and the raceway surface formed on the inner periphery of the roller. Since the outer joint member and the tripod member take an operating angle, the roller can be smoothly rotated even during torque transmission in which rotational torque is transmitted. Therefore, the slide resistance during the movement of the roller is small, and the generation of vibration and noise can be suppressed.
[Brief description of the drawings]
FIG. 1 is a partially cutaway front view showing an embodiment of a constant velocity universal joint according to the present invention. FIG. 2 is a longitudinal side view showing a state when the constant velocity universal joint shown in FIG. 3 is an enlarged cross-sectional view showing a roller support portion of the constant velocity universal joint shown in FIG. 1. FIG. 4 is a cross sectional view showing another example of the roller support portion of the constant velocity universal joint shown in FIG. A partially cutaway front view showing another example of the constant velocity universal joint according to the present invention. FIG. 6 (I) is a longitudinal side view showing still another example of the constant velocity universal joint according to the present invention. ) Is an enlarged cross-sectional view of the roller support portion. [FIG. 7] (I) is a longitudinal side view showing another example of the constant velocity universal joint according to the present invention. (II) is an enlarged cross-sectional view of the roller support portion. ] Vertical sectional side view showing a conventional constant velocity universal joint [Fig. 9] Schematic diagram schematically showing a constant velocity universal joint [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outer joint member 3 Track groove 4 Roller guide surface 4a, 4b Inclined surface 10 Tripod member 12 Leg shaft 13 Race ring 13a Track surface 13b Curved surface 14 Roller 14a Track surface 14b Spherical surface 14c Curved surface 14d Cylindrical surface 15 Ball

Claims (5)

Three track grooves in the axial direction are formed on the inner circumference, an outer joint member having both sides of each track groove as a roller guide surface, a tripod member having three leg shafts extending in the radial direction, and each leg A roller provided on the shaft and a rolling element incorporated in each roller and rotatably supporting the roller around the leg shaft, and each of the rollers is disposed in a track groove of the outer joint member. The roller is inserted into the roller guide surface and brought into contact with the roller guide surface, and the outer joint member and tripod member are rotated in an arc shape along the roller guide surface while rolling the roller by contact with the roller guide surface when torque is taken. In the tripod type constant velocity universal joint in which the outer joint member and the tripod member transmit the rotational torque to each other, the rolling element is a ball, and the ball rolls on the inner periphery of the roller. Refusal An arcuate raceway surface provided, tripod type constant velocity universal joint in which the ball is characterized in that the bearing ring with the outer periphery of the arcuate cross section of the raceway surfaces that roll was fitted to the trunnion. The outer periphery of the roller is a spherical surface, and the roller guide surface is cut by a plane perpendicular to the axis of the outer joint member, and the shape of the longitudinal section is an arc-shaped cylindrical surface. The tripod type constant velocity universal joint according to claim 1, wherein the tripod type constant velocity universal joint is set to be larger than the radius so as to make point contact between the roller and the roller guide surface. 2. The roller according to claim 1, wherein the outer periphery of the roller is a spherical surface, and the roller guide surface is formed of two inclined surfaces inclined relatively in opposite directions, and the roller and the roller guide surface are brought into contact at two points. Tripod type constant velocity universal joint. The tripod constant velocity universal joint according to claim 1, wherein the roller guide surface is a flat surface, and the outer periphery of the roller is a curved surface having an arcuate cross section when cut by a plane including the axis of the roller. The roller guide surface is a flat surface, the outer periphery of the roller is a cylindrical surface, and the inner periphery of the raceway is a curved surface having a convex arc shape cut along a plane including the axis of the raceway. Item 3. A tripod type constant velocity universal joint according to item 1.

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