JPH04254019A - Slide type constant velocity joint - Google Patents

Abstract

PURPOSE:To provide a slide type constant velocity joint which can extremely decrease compelling force at third rotation and surely support a roller even if the roller slides out. CONSTITUTION:A slide type constant velocity joint includes an outside member of the first shaft end, an inside member 26 of the second shaft end, a cage 30 and a roller 32. Three roller grooves 38 are provided at equal spaces on the inner peripheral surface of the outside member, and a rail 36 and a guide surface 40 for a roller groove is provided on each groove. The inside member includes a roller shaft 28 having a projecting spherical surface 29 fitted in each groove. The cage includes a notch 44 for receiving the rail and a recess spherical surface 31 engaged with the projecting spherical surface of the roller shaft. The roller is rotatably supported on each cage through a needle roller 54 and adapted to roll a pair of roller groves of the grooves of the outside member. The roller has a slip-off preventing retainer 52 on the inner peripheral surface similarly to a needle roller support guide. The cage and the roller are capable of relatively moving in the radial direction intersecting perpendicularly to the axis of the first shaft.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding constant velocity joint, and more particularly to a sliding tripod type constant velocity joint suitable for use by being incorporated into a drive shaft of a vehicle.

0002

[Prior Art] A sliding tripod type constant velocity joint is an outer member connected to a first shaft, and three grooves extending in the axial direction of the shaft are formed on the inner peripheral surface at equal intervals in the circumferential direction. 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 to enter each of the grooves. and a roller rotatably supported by each of the tripod shafts and in contact with the outer member.

[0003] 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, A so-called rotational third-order forcing force is generated in the axial direction of the shaft, causing vibrations in the vehicle. This forcing force consists of a rolling component due to rolling friction between the roller and roller groove, a spin component due to spin, and a sliding component due to sliding friction between the tripod shaft or cage and the inner peripheral surface of the roller, and between the outer peripheral surface of the roller and the roller groove. However, in calculations, the slip component has the greatest influence.

[0004] There are many proposals for reducing the above-mentioned forcing force, for example, Japanese Patent Application Laid-Open No. 1-288626, Japanese Utility Model Application Publication No. 64-6425, and Japanese Patent Application Laid-open No. 158327-1983.
However, there are problems in reducing the slip component in both of them. Therefore, a sliding type constant velocity joint that can reduce as much as possible the slip component that affects the rotational third-order forcing force was proposed (Japanese Patent Application No. 2-1773).
No. 47).

[0005] The sliding constant velocity joint according to the above proposal is an outer member connected to a first shaft, and has at least three grooves extending in the axial direction of the shaft and spaced at equal intervals in the circumferential direction. an outer member; and an inner member coupled to the second shaft, the roller shaft extending radially outward of the axis of the second shaft so as to fit into each of the grooves, and having a convex spherical surface on the outer periphery. an inner member having a concave spherical surface on the inner periphery;
a cage whose concave spherical surface is fitted to the convex spherical surface and which is attached to each of the roller shafts; a roller rotatably supported by the cage via a needle roller and in contact with the outer member, the needle roller; When the first shaft and the second shaft rotate at a joint angle, the roller has a guide that supports the needle roller and a retainer that prevents the needle roller from coming off. the cage and the rollers are movable relative to each other in a radial direction perpendicular to the axis of the first shaft.

[0006] In the sliding type constant velocity joint according to the above proposal, the regulating means for keeping the posture of the roller unchanged is provided on the rail extending in the axial direction of the first shaft at the center of each groove, and on the two groove surfaces of each groove. and roller grooves extending in the axial direction. That is, the inner surface of the rail and the end surface of the roller that is radially outward with respect to the axis of the first shaft are brought into contact, while the end surface of the roller that is radially inward with respect to the axis is brought into contact with each of the roller grooves. The roller is supported at three points, making contact with the shoulder.

[0007]

[Problem to be Solved by the Invention] When the roller protrudes from the opening of the outer member, that is, in a so-called slide-out state, the first
When the shaft and the second shaft rotate at a joint angle, depending on the direction of the shaft inclination, the end face of the roller and the shoulder of the roller groove do not contribute to supporting the roller, so the support of the roller may be uncertain. There is a risk of it becoming.

An object of the present invention is to provide a sliding constant velocity joint that can reduce the rotational tertiary forcing force as much as possible and can reliably support the roller even when the roller slides out. It is in.

[0009]

[Means for Solving the Problems] A sliding constant velocity joint according to the present invention includes an outer member coupled to a first shaft;
It includes an inner member coupled to the second shaft, a cage, and a roller. The outer member has at least three grooves extending in the axial direction of the first shaft at equal intervals in the circumferential direction on the inner circumferential surface, and each groove extends in the axial direction of the first shaft and has a radius of The roller groove includes a rail projecting inward in the direction, and a pair of roller grooves having a guide surface located on the same plane as the inner surface of the rail. The inner member includes a roller shaft extending radially outward from the axis of the second shaft and having a convex spherical surface on the outer periphery so as to fit into each of the grooves. The cage is provided with a notch and a concave spherical surface on the inner periphery, receives the rail of the outer member in the notch, and is attached to each of the roller shafts by fitting the concave spherical surface into the convex spherical surface of the roller shaft. The roller is annular and rotatably supported by each cage via a needle roller, and rolls in a pair of roller grooves in each groove of the outer member. The roller has a guide that supports the needle roller and a retainer that prevents the needle roller from coming off on its inner peripheral surface. The cage and the rollers are movable relative to each other in a radial direction perpendicular to the axis of the first shaft.

0010

[Operation and Effect] When the first shaft and the second shaft rotate at a joint angle, the roller shaft is displaced by the action of its own convex spherical surface and the concave spherical surface of the cage, and this displacement causes the cage to moves relative to the roller in the radial direction perpendicular to the axis of the first shaft, but since the roller is supported by the rail and roller groove of the outer member, the roller relative to the axis of the first shaft Posture remains unchanged. As a result, while maintaining this attitude, the roller rolls on the outer member and moves in the axial direction of the first shaft.

When the first shaft and the second shaft rotate at a joint angle and the roller slides out, the roller is supported by the inner surface of the rail of the outer member and the guide surface of the roller groove. .

[0012] When the two shafts rotate at a joint angle, the posture of the roller remains unchanged, and as a result, the posture of the cage and needle roller located between the roller shaft and the outer member also remains unchanged, and the rotation The slip component that most affects the third-order forcing force can be extremely reduced. This results in
This makes it possible to significantly reduce force, reduce vibrations applied to the vehicle, and improve ride comfort.

[0013] A guide for supporting the needle roller;
Since a retainer for preventing the needle roller from coming off is provided on the inner circumferential surface of the roller, the outer diameter of the cage can be kept as small as possible, which would otherwise be larger if the cage is provided with a guide. As a 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.

[0014] As long as the roller is in contact with the inner surface of the rail and the guide surface of the roller groove, the roller is reliably supported, so the amount by which the roller slides out from the opening of the outer member can be increased. , the effective sliding amount or effective moving amount can be increased accordingly.

[0015]

[Embodiment] As shown in FIGS. 1 and 2, the sliding constant velocity joint has an outer member 2 connected to a first shaft 20.
2, an inner member 26 coupled to a second shaft 24, a roller shaft 28, a cage 30, and a roller 32.

The outer member 22 has three grooves 34 extending in the axial direction of the shaft 20 on its inner circumferential surface 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.

Each groove 34 includes a rail 36 extending in the axial direction of the shaft 20 and protruding radially inward, and a pair of roller grooves 38 extending along the rail 36 so as to sandwich the rail 36 therebetween. From the shoulder 39 of the roller groove 38 to the guide surface 4
The distance to 0 is slightly longer than the length of roller 32, which will be described later. The guide surface 40 is located on the same plane as the inner surface 37 of the rail 36.

The inner member 26 has a roller shaft 28 extending radially outward from the axis of the second shaft 24 so as to fit 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 42, and the three roller shafts 28 have their axes C extending from the bosses 42 at equal intervals in the circumferential direction.
It protrudes integrally so as to be perpendicular to the center line of 4. A spline 43 is provided on the inner peripheral surface of the boss 42, and a shaft 24 extending in the opposite direction to the shaft 20 is spline-coupled to the boss 42. Boss 42 of inner member 26, roller shaft 28
and shaft 24 passes through an opening in outer member 22 to
You will be guided inside 2.

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 cross section. The cage 30 is provided with two groove-like cutouts 44 in the diametrical direction for receiving the rails 36 provided on the outer member 22, as shown in FIG. When these notches 44 are lined up in the axial direction of the shaft 24 as shown in FIG. 2, the concave spherical surface 31 of the cage fits snugly into the convex spherical surface 29 of the roller shaft and makes sure contact with the convex spherical surface 29.

The rollers 32 are rotatably supported by the cage 30 and roll in a pair of roller grooves 38 in each groove 34 of the outer member 22. The roller 32 is cylindrical and has an end surface 49 facing the shoulder 39 of the roller groove 38 and the guide surface 40, respectively.
, 50 are formed on flat surfaces. The end surface 49 of the roller 32 contacts the shoulder 39 of the roller groove 38, and the end surface 50 contacts the guide surface 40 of the roller groove 38 and the inner surface 37 of the rail 36, so that the posture of the roller 32 with respect to the axis of the shaft 20 remains unchanged. is maintained.

The roller 32 is attached to the cage 30 via a needle roller 54. On the inner periphery of the roller 32, in a portion radially inward with respect to the axis of the shaft 24,
A guide 5 that protrudes inward in the radial direction of the roller 32 and extends over the entire circumference of the roller 32 to support the needle roller 54.
1 is provided. In addition, the shaft 24 is
A retainer 52 for preventing the needle roller 54 from coming off is provided at a portion radially outward with respect to the axis of the roller. The protruding length of the guide 51 and the retainer 52 is slightly smaller than the diameter of the needle roller 54.

Since the outer peripheral surface of the cage 30 is a cylindrical surface, the roller 32 is cylindrical, and the guide 51 and retainer 52 of the roller 32 are smaller in size than the diameter of the needle roller 54, the cage 30, the roller 32, and The needle roller 54 is movable relative to the roller 32 in the axial direction.

As shown in FIG. 2, when the roller 32 is inside the outer member 22, the inclination of the roller 32 is determined by the contact between the shoulder 39 of the roller groove 38 and the end surface 49 of the roller 32;
and the inner surface 37 of the rail 36 and the end surface 50 of the roller 32
prevented by contact with. In this case, the effect of preventing the roller 32 from tilting in the spin direction (direction A or B in FIG. 3) due to the contact between the end surface 50 of the roller 32 and the guide surface 40 of the roller groove 38 is due to the This is smaller than the effect of preventing inclination due to contact with the end surface 50, so it virtually does not occur.

As shown in FIG. 3, when the first shaft 20 and the second shaft 24 rotate at a joint angle and the roller 32 slides out, the spin in the A direction , the shoulder 39 of the roller groove 38 and the end surface 4 of the roller 32
9 and the contact between the guide surface 40 of the roller groove 38 and the end surface 50 of the roller 32 prevents the roller 32 from tilting. In addition, with respect to the spin in the B direction, contact between the guide surface 40 of the roller groove 38 and the end surface 50 of the roller 32,
and the inner surface 37 of the rail 36 and the end surface 50 of the roller 32
The contact with the roller 32 prevents the roller 32 from tilting.

As described above, the guide surface 40 of the roller groove 38 can supplementally prevent the roller 32 from tilting when the roller 32 slides out significantly. However, when the roller 32 is in its normal position, , roller 3 due to contact between inner surface 37 of rail 36 and end surface 50 of roller 32
2 is prevented from tilting in the spin direction (direction A or B in FIG. 3), even if the guide surface 40 is provided in the roller groove 38,
Slide resistance etc. at the normal position do not substantially increase.

[Brief explanation of the drawing]

FIG. 1 is a sectional view taken along a plane perpendicular to the axis of a sliding constant velocity joint according to the present invention.

FIG. 2 is a sectional view taken along a plane including the axis of the sliding constant velocity joint according to the present invention.

FIG. 3 is a sectional view taken along a plane including the axis of the sliding constant velocity joint according to the present invention, showing the action when the roller protrudes from the opening of the outer member.

[Explanation of symbols]

20 First axis 22 Outer member 24 Second axis 26 Inner member 28 Roller shaft 29 Convex spherical surface 30 Cage 31 Concave spherical surface 32 Roller 34 groove 36 Rail 38 Roller groove 44 Notch

Claims (1)

[Claims] Claims: 1. An outer member coupled to a first shaft, having at least three grooves extending in the axial direction of the shaft on an inner peripheral surface at equal intervals in the circumferential direction; an outer member comprising a rail extending in the axial direction of the first shaft and protruding radially inward, and a pair of roller grooves having a guide surface located on the same plane as an inner surface of the rail; , an inner member coupled to the second shaft, the inner member comprising a roller shaft extending radially outward of the axis of the second shaft so as to enter each of the grooves and having a convex spherical surface on the outer periphery. a cage having a notch and a concave spherical surface on an inner periphery, the cage receiving the rail in the notch and fitting the concave spherical surface into the convex spherical surface to be attached to each of the roller shafts; a ring-shaped roller rotatably supported by the cage via a needle roller and rolling in the pair of roller grooves of each groove of the outer member, the guide supporting the needle roller; and a guide for supporting the needle roller; a roller having a retainer on its inner peripheral surface to prevent
The cage and the roller are sliding constant velocity joints that are movable relative to each other in a radial direction perpendicular to the axis of the first shaft.