JPH03277824A - Slide type constant velocity joint - Google Patents

Abstract

PURPOSE:To reduce slide components by providing at least three channels in an outside member, and providing an inside member extending for rush therein, a cage, a roller and a control means for keeping their positions invariable. CONSTITUTION:An outside member 22 has at least three channels 34 which extend in the axial direction of a shaft 20, with equal spaces in the circumferential direction. An inside member 25 has a roller shaft 28 which extends to the outside in the radial direction of an axial line of a shaft 24 so as to enter each channel 24, and the periphery thereof is formed into a projecting spherical surface 29. A recessed spherical surface 31 is formed on the inner periphery of a cage 20 to be engaged with the projecting spherical surface 29. A roller 32 is supported by the cage 30 freely to rotate through a needle roller 42 as a rotating member to touch the outside member 22. A guide 25 for supporting the needle roller 42 is provided in the inner periphery of the roller 32, and an annular retainer 44 is provided outside thereof. A control means 50 for keeping positions of the cage 30 and the roller 32 against the axial line of the first shaft 20 is provided, and the former can be moved relatively in the radial direction transverse to the described axial line.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sliding constant velocity joint, and particularly to a sliding tripod type constant velocity joint suitable for use by being incorporated into a drive shaft of a vehicle.

(Prior Art) A sliding tripod type constant velocity joint is an outer member connected to a first shaft and has three grooves extending in the axial direction of the shaft at equal intervals in the circumferential direction. an outer member and an inner member coupled to a second shaft, the inner member having a tripod shaft extending radially outwardly of the axis of the second shaft so as to project into each of the grooves; The device includes a roller support member or cage attached to each of the tripod shafts, and a roller rotatably supported by each cage and in contact with the outer member. The outer peripheral surface of the roller is formed as a convex spherical surface centered on the axis of the tripod shaft, and each groove has a roller groove having a concave surface that matches the convex spherical surface of the roller in the axial direction of the first shaft. It is set in.

When the constant velocity joint rotates in a state where the axis of the first shaft and the axis of the second shaft intersect, that is, with a joint angle, a forcing force with a period three times the number of rotations, so-called rotation 3 The following force is generated in the axial direction of the shaft, causing vibrations in the vehicle. As shown in FIG. 8, this forcing force is composed of a rolling component A due to rolling friction between the roller 10 and the roller groove 11, a spin component B due to spin, a component between the tripod shaft or cage and the inner circumferential surface of the roller, and an outer circumferential surface of the roller. This is caused by a slip component C due to sliding friction between the surface and the roller groove.

The above three components do not contribute equally to the generation of forcing force, and according to calculations, as shown in FIG. 10, the slip component C has the greatest influence.

As shown in FIG. 9, this slip component is caused by the fact that the contact portion between the roller 10 and the roller groove 11 is always on the normal plane of the axis of the outer member 12, so that the direction of the frictional force f is different from the driving force. This is mainly based on the fact that the reaction force component F1 of F, the angle θ, and the residual component 1 of the frictional force f occur.

There are many proposals for reducing the above-mentioned forcing force, and those related to the present invention include JP-A-1-288626, JP-U-54-6425, and JP-A-63-158.
There are those described in Japanese Patent Application Laid-open No. 327 and Japanese Patent Application Laid-open No. 132046/1983.

In the constant velocity joint described in JP-A-1-288626, the roller is composed of a roller inner ring, a roller middle ring, and a roller outer ring, and the roller inner ring is attached to a tripod shaft via a needle bearing so that it can only rotate. There is. A spherical surface centered on the axis of the tripod shaft is formed on the outer periphery of the roller inner ring, and the inner periphery of the roller middle ring is brought into spherical contact with this spherical surface. A cylindrical surface is formed, and the inner periphery of the roller outer ring is fitted into this cylindrical surface.

In the constant velocity joint described in Japanese Utility Model Application Publication No. 64-6425, an inner roller is slidably fitted to a tripod shaft. The outer periphery of the inner roller is formed as a convex spherical surface centered on the axis of the tripod shaft, and a holder having a concave spherical surface that matches the convex spherical surface is fitted to the inner roller so as to be able to swing, and the outer roller is rotated by the holder. possible to install,
The holder is provided with a flange that suppresses inclination of the holder.

In the constant velocity joint described in JP-A-63-158327, the rollers are arranged between an outer ring having a cylindrical surface on the outer periphery, an inner ring fitted to the tripod shaft, and the outer ring and the inner ring. Consists of multiple rolling elements. The tripod shaft is formed as a convex spherical surface having a center on its axis, and the inner ring has a concave spherical surface that matches the convex spherical surface. In this constant velocity joint, two full surfaces of the groove provided in the outer member into which the tripod shaft is inserted are formed as parallel planes, and the outer ring moves on these parallel planes. The outer ring is swingable in a plane parallel to a plane including the axes of the three tripod shafts.

In the constant velocity joint described in Japanese Unexamined Patent Publication No. 54-132046, a convex spherical surface centered on the axis of the tripod shaft is provided on the tripod shaft or a guide ring attached to the tripod shaft, and the concave spherical surface of the cage is aligned with the convex spherical surface centered on the axis of the tripod shaft. The roller fits into the spherical surface and can swing about the tripod shaft.

(Problems to be Solved by the Invention) The most effective way to reduce the rotational third-order forcing force mentioned above is to reduce the slip component. To this end, when the two shafts rotate at a joint angle, all parts between the tripod shaft and the outer member, i.e. rollers, needle rollers, cages, etc., must maintain the same attitude with respect to the axis of the outer member. By doing so, the sliding friction force between the parts may be generated on a plane normal to the axis of the outer member, so that the residual component of the friction force described above may be eliminated.

In the constant velocity joint described in Japanese Unexamined Patent Publication No. 1-288626, when the two shafts rotate at a joint angle, the roller inner ring and the roller middle ring, which are integrated with the tripod shaft by a snap link, are rotated through the spherical surface. As a result, the roller inner ring slides with respect to the roller outer ring in the axial direction of the roller middle ring, so that the postures of the roller outer ring and the roller middle ring with respect to the roller groove remain unchanged. Further, since the relative movement between the roller inner ring and the roller outer ring occurs in the radial direction perpendicular to the axis of the shaft of the outer member, the above-mentioned slip component can be reduced.

On the other hand, since the posture of the roller inner ring does not change with respect to the axis of the outer member, the inclination of the tripod axis causes the needle roller, which is a rolling element placed between the tripod axis and the roller inner ring, to incline, causing the roller outer ring to rotate. On the other hand, this rolling element no longer performs its original function. As a result, the sliding surface when the roller outer ring rotates is not fixed, and the sliding parts come into surface contact.In the end, with this constant velocity joint, the sliding component either decreases or sliding friction is included in the rolling component. It becomes like this.

In the constant velocity joint described in Japanese Utility Model Application Publication No. 64-6425, when the two shafts rotate at a joint angle, either the tripod shaft swings together with the inner roller, or the holder is prevented from tilting by the flange. As a result, the attitude of the outer roller relative to the roller groove remains unchanged. On the other hand, relative movement in the axial direction of the tripod shaft occurs between the tripod shaft and the inner roller, and the residual component of the sliding frictional force becomes a forcing force.

The constant velocity joint described in JP-A-63-158327 is intended to be substantially integrated from the tripod shaft to the outer ring, so that no sliding frictional force is generated. However, in a tripod-type constant velocity joint, when rotating at the joint angle, the output shaft always whirls three times per rotation, and this whirling is caused by the spherical contact between the spherical bushing and the inner ring. , and the slippage between the outer ring and the outer member. The slip between the outer ring and the outer member that occurs at this time does not change with respect to the attitude of the outer ring or the axis of the outer member, so its residual component becomes a forcing force.

In the constant velocity joint described in JP-A-54-132046, when the two axes rotate at a joint angle, there is nothing to restrict the inclination of the roller, so in reality the roller or cage inclines. As a result, if the slipping component occurs, or if the inclination of the roller is to be restricted, a forcing force is generated by the sliding friction force, similar to the constant velocity joint described in the above-mentioned Japanese Utility Model Publication No. 64-6425. or occur.

An object of the present invention is to provide a sliding constant velocity joint that can reduce as much as possible the shear component that affects the rotational third-order force.

(Means for Solving Problem B) The sliding constant velocity joint according to the present invention has at least three grooves extending in the axial direction of the first shaft in the outer member coupled to the first shaft in the circumferential direction. an inner member coupled to a second shaft and extending radially outwardly of the axis of the second shaft so as to project into each of the grooves; and an inner member having a roller shaft having a convex spherical surface on the outer periphery; a cage having a concave spherical surface on the inner periphery, the concave spherical surface being fitted to the convex spherical surface and attached to each of the roller shafts; a roller that is rotatably supported via a rolling element and has on its inner peripheral surface a guide that is in contact with the outer member and supports the rolling element, and a retainer that prevents the rolling element from coming off; shaft and said second
and regulating means for keeping the postures of the cage and the rollers unchanged with respect to the axis of the first shaft when the cage and the roller rotate at a joint angle with respect to the axis of the first shaft. relative movement is possible in the radial direction orthogonal to the axis of.

(Operation and Effect) When the first shaft and the second shaft rotate at a joint angle, the roller shaft swings due to the action of its own convex spherical surface and the concave spherical surface of the cage, and this swing This causes the cage to move relative to the roller in a radial direction perpendicular to the axis of the first shaft, but the cage field and the attitude of the roller with respect to the axis of the first shaft are kept unchanged by the regulating means. the result,
While maintaining this posture, the roller rolls on the outer member, and the first
move in the axial direction of the axis.

When the two shafts rotate at a joint angle, by keeping the postures of all parts between the roller shaft and the outer member unchanged, the residual component of the frictional force mentioned above can be eliminated. The slip component that most affects the next forcing force can be extremely reduced. As a result, this force can be significantly reduced, reducing vibrations applied to the vehicle and improving ride comfort.

Since a guide to support the rolling elements and a retainer to prevent the rolling elements from coming off are located on the inner peripheral surface of the roller, if a guide is provided in the cage, the outer diameter of the cage will be increased as much as possible. It can be kept small. the result,
Interference between the cage and the roller shaft when the cage moves relative to each other as the roller shaft swings can be delayed, and the allowable joint angle can be increased. Further, while the cage is made compact, the pitch diameter of the torque transmission surface of the cage can be made large, which allows for a design that is advantageous in terms of strength.

(Example) As shown in FIGS. 1 and 2, the sliding constant velocity joint includes an outer member 22 coupled to a first shaft 20,
an inner member 26 coupled to a second shaft 24 and a roller shaft 2
8, a cage 30, and a roller 32.

The outer member 22 has three grooves 34 (only one is shown in the figure) extending in the axial direction of the shaft 20 at equal intervals in the circumferential direction. The number of grooves 34 can also be set to 4, 5, etc. The outer member 22 is integrated with the shaft 20 via a joint 23, and the end opposite to the joint 23 is open.

The inner member 26 has a roller shaft 28 that extends outward in the radial direction of the axis of the second shaft 24 so as to extend into each of the three grooves 34 of the outer member 22 . The outer periphery of the roller shaft 28 is formed as a convex spherical surface 29 having its center on the axis C.

In the illustrated embodiment, the inner member 26 has a cylindrical boss 27a.
The three roller shafts 28 (only one is shown in the figure) are arranged so that their axes C are orthogonal to the axis of the shaft 24 from bosses 27a spaced at equal intervals in the circumferential direction. It is integrally protruded.

A spline 27b is provided on the inner peripheral surface of the boss 27a, and a shaft 24 extending in the opposite direction to the shaft 20 is spline-coupled to the boss 27a. The boss 27a of the inner member 26, the roller shaft 28, and the shaft 24 are guided into the interior of the outer member 22 through the opening of the outer member 22.

The cage 30 has a concave spherical surface 31 on its inner periphery. The outer periphery of the cage 30 is a so-called cylindrical surface with a circular outline. The cage 30 is provided with two groove-shaped notches 38 in the diametrical direction for receiving the rails 36 provided on the outer member 22, as shown in FIG. When these notches 38 are lined up in the axial direction of the shaft 24, as shown in FIG. 1, the concave spherical surface 31 fits tightly into the convex spherical surface 29, and has a shape that makes sure contact with the convex spherical surface 29.

A width across flat portion 40 is cut on the convex spherical surface 29 of the roller shaft 28, and undercuts 39 are made on the cage 30 at two locations. The positions of the undercuts 39 correspond to the two cutouts 38 described above. The width across flats portion 40 is the shaft 24
The width L+ (Fig. 2) is the minimum clearance L2 of the part of the cage 30 without the undercut 39.
(Figure 3) Smaller. On the other hand, undercut 39 is
The diameter is set to be larger than the aperture d of the concave spherical surface 31 of the cage 30.

As a result of the above-mentioned configuration, if the portion of the cage 30 without the undercut 39 is arranged along the width across width portion 40 of the roller shaft 28, the convex spherical surface 29 of the roller shaft 28 faces the undercut 39. . In this state, if the cage 30 is fitted onto the roller shaft 28 and then the cage 30 is rotated 90 degrees, the cage 30 will be in the predetermined position shown in FIG. come into contact with.

Roller 32 is rotatably supported by cage 30 and contacts outer member 22 . In the illustrated embodiment, the roller 32 is formed in a cylindrical shape and is attached to the cage 30 via a needle roller 42 that is a rolling element. On the inner periphery of the roller 32, in a portion radially inward with respect to the axis of the shaft 24,
A kite 3 protrudes inward in the radial direction of the roller 32 and extends over the entire circumference in the circumferential direction for supporting the needle roller 42.
3 is provided. The protruding length of the guide 33 is slightly smaller than the diameter of the needle roller 42. An annular retainer 44 is disposed outside the needle roller 42, and a snap ring 46 is fitted to the inner periphery of the roller 32 to hold the retainer 44, thereby preventing the needle roller 42 from coming off.

The outer peripheral surface of the cage 30 is a cylindrical surface, the roller 32 is cylindrical, and the guide 33 of the roller 32 is a needle roller 4.
2, the cage 30, the roller 32, and the needle roller 42 can move relative to each other in the axial direction of the roller 32.

The constant velocity joint has a regulating means 50 that maintains the postures of the cage 30 and rollers 32 with respect to the axis of the first shaft 20 unchanged when the first shaft 20 and the second shaft 24 rotate at a joint angle. Be prepared. In the illustrated embodiment, the restricting means 50 includes a rail 36 extending in the axial direction of the shaft 20 at the center of the eight grooves 34 of the outer member 22, and a rail 36 extending in the axial direction of the shaft 20 at the center of the eight grooves 34 of the outer member 22; Extending roller groove 52
It is composed of.

The rail 36 fits into the two notches 38 of the cage 30,
The cage 30 is supported movably in the axial direction of the shaft 20.

The bottom surface of the notch 38 of the cage 30 is the inner surface 3 of the rail 36
7, the rail 36 causes the cage 30 to align with the shaft 20.
to prevent outward movement in the radial direction perpendicular to the axis of the On the other hand, the rail 36 has an inner surface 37 on a surface 54 of the roller 32 that is radially outward relative to the axis of the shaft 20.
Contact with. As a result, the roller 32 has two roller grooves 5
2 is regulated by each shoulder 53 and rail 36,
The attitude of the first shaft 20 with respect to the axis remains unchanged. That is, the roller 32 has its rotation axis aligned with the first shaft 2.
It moves along the roller groove 52 so as to be always perpendicular to the zero axis.

Since the roller 32 is regulated as described above by the regulating means 50 and the cage 30 and the roller 32 are movable relative to each other, the cage 30 and the roller 32 are perpendicular to the axis of the first shaft 20. It is possible to move relative to each other in the radial direction.

With this configuration, the sliding distance between the cage 30 and the rollers 32 is the shortest, so the durability of the cage and rollers can be improved.

In order to prevent the roller 32 from changing its attitude with respect to the axis of the first shaft 20, it is sufficient to support the roller 32 at three or more points. FIG. 4 shows such support, and in the embodiment a, the roller 32 is supported by the inner surface 37 of the rail 36 and the shoulders 53 of each of the two roller grooves 52. In b, the outer circumferential surface of the roller 32 is formed to have a semicircular cross-sectional shape, and the roller groove 52 is formed to have a substantially semicircular cross-sectional shape.
The roller 32 is supported by the inner surface 37 of the roller 32 and the line of contact between the outer peripheral surface of the roller 32 and the roller groove 52. C, the outer circumferential surface of the roller 32 is formed to have a substantially triangular cross-sectional shape, and the roller groove 52 is formed to have a substantially triangular cross-sectional shape, so that the inner surface 37 of the rail 36 and the roller 32 The roller 32 is supported by a plurality of contact lines between the outer peripheral surface and the roller groove 52. Each roller has a guide 33 and an annular ring 47 for a snap ring on its inner circumferential surface.

It is preferable that the rail 36 is configured to fit into the notch 38 of the cage 30 as in the embodiment described above, since the positioning of the cage 30 can be ensured by the rail 36. Instead, if the inner surface of the outer member 22 is machined so that the inner surface of the outer member 22 becomes the same surface as the inner surface 37 of the rail 36, the inner surface of the outer member 22 itself can be adjusted to the position of the roller. can be regulated. In this case, the cage 30 is positioned separately.

When the first shaft 20 and the second shaft 24 rotate at a joint angle, as shown in FIG. oscillates by. Due to this rocking, the cage 30 slides on the needle roller 42, and the cage 30 is placed in the first position relative to the roller 32.
relative movement in the radial direction perpendicular to the axis of the shaft 20. Since the postures of the cage 30 and the rollers 32 are regulated by the regulating means, they move in the axial direction of the first shaft 20 without changing their postures with respect to the axial line of the first shaft 20.

When the cage 30 moves relatively as the roller shaft 28 swings, the cage 30 approaches the second shaft 24 . At this time, since the kite 33 that supports the needle roller 42 is provided on the inner periphery of the roller 32, as shown in FIG. You can take the corner. If a guide supporting the needle roller 42 is provided on the outer periphery of the cage 30, if the shoulder 29a butts against the guide of the cage 30, the joint angle cannot be increased more than that. Since it is located on the inner periphery, a large joint angle can be achieved.

The basic configuration of the sliding type constant velocity joint shown in Figures 5 and 6 is the same as the sliding type constant velocity joint shown in Figures 1 and 2, so the parts with the same configuration or function are the same. Detailed explanations of the reference numerals will be omitted.

The outer member 22 has three grooves 34 extending in the axial direction of a shaft (not shown) at equal intervals in the circumferential direction. On the other hand, the inner member 26 has a roller shaft 28 that projects into each of the three grooves 34 of the outer member 22. The outer periphery of the roller shaft 28 is formed as a convex spherical surface 29 having its center on the axis C.

The cage 30 has a concave spherical surface 31 on its inner periphery, and the outer periphery of the cage 30 is a cylindrical surface. As shown in FIG. 7, the cage 30 is provided with two groove-shaped notches 38 in the diametrical direction, into which the rails 36 provided on the outer member 22 are received. When these notches 38 are lined up in the axial direction of the shaft 24, the concave spherical surface 31 fits perfectly into the convex spherical surface 29 of the roller shaft.

A roller 62 is rotatably supported by the cage 30 and is different from the roller 32 of the previous embodiment in that it contacts the outer member 22. The roller 62 is formed in a cylindrical shape and is attached to the cage 30 via the needle roller 42.

The roller 62 has a guide rod 3 on its inner periphery at a portion radially inward with respect to the axis of the shaft 24, and a retainer 64 at a portion radially outward with respect to the axis of the shaft 24.
They each have an integral part. The guide 63 and the retainer 64 protrude inward in the radial direction of the roller 62 and extend all around the circumference. These protruding lengths are slightly smaller than the diameter of the needle roller 42, and the needle roller 42 is held by the guide rod 3 and the retainer 64.

The surface 6 of the retainer 64 facing outward with respect to the axis of the shaft 24
5 is on the same surface as the end surface of the roller 62, and this surface 65 contacts the inner surface 37 of the rail 36.

The rail 36 of the outer member 22 and the two fully formed roller grooves 52 of the groove 34 constitute a regulating means 50 that keeps the posture of the roller 62 unchanged. That is, the roller 62 is regulated by the inner surface 37 of the rail 36 and the shoulders 53 of each of the two roller grooves 52, and the action of the sliding constant velocity joint shown in FIGS. 5 and 6 keeps the posture unchanged. is the same as that shown in FIGS. 1 and 2, but since the roller 62 has the retainer 64 integrally,
The following effects can be obtained.

The sliding constant velocity joint shown in Figures 5 and 6 does not require a snap link, so there is a groove for the snap ring and a retainer from the end face of the roller to the groove of the snap ring to provide this groove. The length L of the roller 62 in the axial direction becomes shorter, and the gap S between the roller 62 and the outer member 22 becomes larger, corresponding to the wall portion (see FIG. 4).

This means that the size and weight of the outer member 22 can be reduced accordingly.

Furthermore, since the outer surface 65 of the retainer 64 and the end surface of the roller 62 can be made flush, a wide flat surface can be easily secured in the portion of the roller 62 facing the rail 36. Ru.

By doing so, the movement of the roller 62 can be reliably regulated by the rail 36, and it becomes easy to maintain the attitude of the roller 62 with respect to the outer member 22 unchanged.

Even if the length of the roller 62 is shortened, a flat surface can be ensured in the portion of the roller 62 that faces the rail 36, and a predetermined length of the needle roller 42 can be ensured.
2 and the outer member 22 is the same as that of the constant velocity joint shown in FIGS. 1 and 2, the roller 6
The outer diameter of 2 can be increased. When the outer diameter of the roller 62 becomes larger, it becomes possible to arrange the needle roller 42 outward with respect to the roller shaft 28, and the number of needle rollers can be increased. This can improve strength and life.

By increasing the protruding length of the rail 36 to compensate for the short length L of the roller 62, it is possible to provide a sufficient amount of engagement between the cage 30 and the rail 36 when the joint angle becomes large, thereby increasing the allowable joint. You can increase the angle.

The snap link and the separately manufactured retainer are no longer necessary, and the number of parts can be reduced.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a sliding type constant velocity joint according to the present invention taken along a plane perpendicular to the axis of the shaft, and shows a part of the slide type constant velocity joint according to the present invention.
The figure is a sectional view showing the upper half taken along a plane including the axes of the shafts, showing a state in which the two shafts are at a joint angle. Fig. 3 is an example of the cage, a is a bottom view, and b is a 3B-3B
Figures 4a, b, and c are cross-sectional views of an embodiment of the roller, and Figure 5 is a plane perpendicular to the axis of another embodiment of the sliding constant velocity joint. FIG. 6 is a cross-sectional view taken along a plane including the axis of the constant velocity joint shown in FIG. 5, showing only the main parts.
The figure shows another embodiment of the cage, a is a bottom view, b is 7B of a.
- Sectional views taken along line 7B, Figures 8 to 10
The figure is a schematic diagram illustrating the rotational third-order forcing force. 20: first shaft, 22: outer member, 24: second shaft, 26: inner member, 28: roller shaft, 29: convex spherical surface, 30: cage, 31: concave spherical surface, 32.62: roller, 33 .63 guide, 36: rail, 38: notch, 42: needle roller, 44.64: retainer, 50: regulating means.

Claims (1)

[Claims] an outer member coupled to a first shaft, the outer member having at least three grooves extending in the axial direction of the shaft and equally spaced in the circumferential direction; and an inner member coupled to the second shaft. an inner member having a roller shaft extending outward in the radial direction of the axis of the second shaft and having a convex spherical surface on the outer periphery so as to protrude into each of the grooves; a cage mounted on each of the roller shafts with the concave spherical surface fitted to the convex spherical surface, and a roller rotatably supported by the cage via a rolling element and in contact with the outer member; A roller having a guide for supporting a rolling element and a retainer for preventing the rolling element from coming off on its inner peripheral surface, and when the first shaft and the second shaft rotate with a joint angle, the cage and a regulating means for keeping the attitude of the roller with respect to the axis of the first shaft unchanged; the cage and the roller are movable relative to each other in a radial direction perpendicular to the axis of the first shaft; Type constant velocity joint.