Tripod type constant velocity joint

Patent metadata

Field	Value
Publication number	US-12313129-B2
Application number	US-201917775919-A
Country	US
Kind code	B2
Filing date	Nov 18, 2019
Priority date	Nov 18, 2019
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

A constant velocity joint comprises a male element having arms, a female element having a central axis and defining a pair of symmetrical tracks and an outer roller which can roll on one or other of the two tracks via a peripheral rolling surface. The female element comprises at least one bearing surface which limits the rotation of the outer roller around an axis perpendicular to the axis' of the female element and of the arm. With respect to each arm the cross-section profile of each track comprises either two circular arcs having centers of radii offset one from another, or one single circular arc extending over a female element median plane, and the rolling surface has a part spherical shape or a part torical shape. Each track and the rolling surface are capable of contacting each other at a first and second contact points spaced radially from one another. The tilting of the roller is controlled by proximal and distal rails on the female element and by proximal and distal breaking surfaces on the outer roller.

First claim

The invention claimed is:

1. A constant velocity joint, comprising
a male element having multiple arms;
a female element having a female element central axis and defining, for each of the arms, a pair of opposed tracks which are arranged on either side of said arm and which are symmetrical in relation to a radial longitudinal plane of the female element, wherein mounted on each arm there is a mechanical transmission unit comprising an outer roller which is mounted so as to plunge and slide in relation to the respective arm and which rolls on one or other of the corresponding two tracks via a peripheral rolling surface, the female element further including at least one bearing surface which prevents or limits the rotation of the outer roller around an axis perpendicular to the female element central axis and to the axis of the arm;
wherein, with respect to each of the arms:
the cross-section profile of each track comprises either two circular arcs having centers of radii offset one from another;
the rolling surface has a part spherical shape or a part torical shape; and
each track and the rolling surface are capable of contacting each other at first and second contact points spaced radially from one another;
wherein in case the rolling surface has a part spherical shape its cross profile, taken along a plane comprising a revolution axis of the outer roller, is circular with the center of a circle, defining the spherical shape of the surface, being arranged on the central axis;
wherein in case the rolling surface has a part torical shape the degree of toricity T=RT 2 /RT 1 is between 0.8 and 1;
wherein the dimension RT 1 is the radius of the rolling surface which is the distance between the central axis taken in a median plane of the outer roller and the rolling surface, and the dimension RT 2 is the radius of the rolling surface taken in a plane containing the central axis.

2. The constant velocity joint of claim 1 , wherein with respect to the first and second contact points, the tangent planes of the track and of the rolling surface are oblique to the radial longitudinal plane.

3. The constant velocity joint of claim 1 , wherein
the cross-section profile of each track has the two circular arcs and their radii are bigger than the radius of the cross section of the rolling surface.

4. The constant velocity joint of claim 1 , wherein
the outer roller comprises a distal braking surface, adjacent the rolling surface and oblique with respect to a central axis of the outer roller;
each track has a distal rail surface; and
the distal braking surface and the distal rail surface are adapted to cooperate and to limit a pivoting of the outer roller with respect to the track around an axis parallel to the female element central axis.

5. The constant velocity joint of claim 4 , wherein
the distal rail surface has a plane or convex cross section;
the distal braking surface has a plane or convex cross section; and
the distal rail surface and the distal braking surface define a single point of contact.

6. The constant velocity joint of claim 1 , wherein
the outer roller comprises a proximal braking surface, adjacent the rolling surface and inclined with respect to a central axis of the outer roller;
each track comprises a proximal rail surface; and
the proximal braking surface and the proximal rail surface are adapted to cooperate and to limit a pivoting of the outer roller with respect to the track around an axis parallel to the female element central axis.

7. The constant velocity joint of claim 6 , wherein
the proximal rail surface has a plane or convex cross section;
the proximal braking surface has a plane or convex cross section; and
the proximal rail surface and the proximal braking surface define a single point of contact.

8. The constant velocity joint of claim 6 , wherein the proximal braking surface and proximal rail surface are adapted to limit a proximal displacement of the outer roller with respect to the female element.

9. The constant velocity joint of claim 1 , wherein
the mechanical transmission unit comprises an inner ring arranged within the outer roller, with a coupling of the inner ring and the outer roller enabling them to pivot relatively on a common axis of revolution and the inner ring is mounted so as to plunge and rotate on said arm and the inner ring is mounted axially fixed relative to the outer roller with respect to the axis of the outer roller.

10. The constant velocity joint of claim 9 , wherein the coupling of the inner ring and the outer roller comprise a crown of needles and two support rings, each support ring being arranged on one of two axial sides of the crown of needles and maintaining the needles, and in particular also the inner ring, with respect to the outer roller.

11. The constant velocity joint of claim 10 , wherein the outer roller comprises two grooves on its inner side and each of the two support rings is arranged in one of the two grooves.

12. The constant velocity joint of claim 1 , wherein the outer roller presents a flat front surface arranged perpendicularly to the axis of the outer roller and adapted to contact a bearing surface of said at least one bearing surface of the female element, and the bearing surface of said at least one bearing surface is formed by a bearing area which has a cross profile substantially orthogonal and convex to the radial longitudinal plane corresponding to the contact locations with the flat front surface.

13. The constant velocity joint of claim 12 , wherein, with respect to each arm, the bearing area is formed by two bearing surfaces which extend on either side of the radial longitudinal plane, and the two bearing surfaces are separated by a radially outwardly recessed portion of the female element.

14. The constant velocity joint of claim 12 , wherein, with respect to each arm, the bearing area is formed by a single bearing surface which extends on either side of the radial longitudinal plane and the bearing surface is separated from each operatively associated track by a radially outwardly recessed portion of the female element.

Assignees

• Gkn Driveline Int Gmbh

Inventors

• Francois Marc
• Post Hans-Juergen

Classifications

• Y10S464/905

  Torque transmitted via radially extending pin · CPC title

• F16D2003/2026

  with trunnion rings, i.e. with tripod joints having rollers supported by a ring on the trunnion · CPC title

• F16D3/2055 Primary

  having three pins, i.e. true tripod joints · CPC title