Constant velocity joint

Patent metadata

Field	Value
Publication number	US-11796008-B2
Application number	US-201817257593-A
Country	US
Kind code	B2
Filing date	Jul 5, 2018
Priority date	Jul 5, 2018
Publication date	Oct 24, 2023
Grant date	Oct 24, 2023

Abstract

A constant velocity joint comprises an outer joint part with outer ball tracks, an inner joint part with inner ball tracks, wherein respectively an outer ball track and an inner ball track form a pair of tracks with each other; a torque-transmitting ball in each pair of tracks; a ball cage in which the torque-transmitting balls are received; wherein a first articulation angle range is defined comprising articulation angles of less than twenty degrees, and a second articulation angle range comprising articulation angles greater than twenty degrees; wherein an opening angle within the first articulation angle range increases as the articulation angle (β) increases, and wherein a first mean opening angle increase of the first articulation angle range is greater than a second mean opening angle increase of the second articulation angle range.

First claim

The invention claimed is:

1. Constant velocity joint, comprising:
an outer joint part with an outer part longitudinal axis and outer ball tracks, wherein the outer joint part has an attachment side and an opening side,
an inner joint part with an inner part longitudinal axis and inner ball tracks, wherein respectively an outer ball track and an inner ball track form a pair of tracks with each other,
a torque-transmitting ball in each pair of tracks,
a ball cage which is arranged between the outer joint part and the inner part and comprises circumferentially distributed cage windows which each receive at least one of the torque-transmitting balls,
wherein the balls define a joint center plane by the ball cage when the inner part longitudinal axis and the outer part longitudinal axis are coaxially aligned, wherein the inner part longitudinal axis and the outer part longitudinal axis define a joint articulation plane at articulation angles other than zero degrees;
wherein, viewed in the joint articulation plane, in any angular position of the constant velocity joint, an opening angle is formed between an outer tangent, which is applied to the outer ball track in an outer contact point between the outer ball track and the ball, and an inner tangent, which is applied to the inner ball track in an inner contact point between the inner ball track and the ball,
wherein the centers of the balls each define a center point line when moving along the pair of tracks,
wherein, furthermore, a first articulation angle range is defined comprising articulation angles less than twenty degrees (−20°<β<20°), and wherein a second articulation angle range is defined comprising articulation angles greater than twenty degrees (β<−20° and β>20°),
wherein at least some of the pairs of tracks are configured such that:
an attachment-sided opening angle of a ball moving in the joint articulation plane towards the attachment side of the outer joint part increases within the first articulation angle range with increasing an articulation angle, wherein an attachment-sided first mean opening angle increase of the attachment-sided opening angle is defined over the articulation angle within the first articulation angle range,
wherein the attachment-sided first mean opening angle increase of the first articulation angle range is greater than an attachment-sided second mean opening angle increase of the second articulation angle range.

2. The constant velocity joint according to claim 1 ,
wherein the attachment-sided first mean opening angle increase is greater than 0.5, and
wherein the attachment-sided second mean opening angle increase is less than 0.5.

3. The constant velocity joint according to claim 1 ,
wherein the at least some of the pairs of tracks are configured such that:
at an articulation angle of zero degrees the opening angle is at least zero degrees and less than eight degrees.

4. The constant velocity joint according to claim 1 ,
wherein the at least some of the pairs of tracks are configured such that the attachment-sided opening angle is variable over the articulation angle within the second articulation angle range.

5. The constant velocity joint according to claim 1 ,
wherein the at least some of the pairs of tracks are configured such that, for any articulation angle within the second articulation angle range, an opening-sided opening angle of a ball moving in the joint articulation plane towards the opening side of the outer joint part and an attachment-sided opening angle of a ball moving at the same articulation angle in the joint articulation plane towards the attachment side of the outer joint part open in the same axial direction.

6. The constant velocity joint according to claim 1 ,
wherein the outer ball tracks each comprise, over a length thereof, an opening-sided track section and an attachment-sided track section,
wherein the attachment-sided track sections of the outer ball tracks each have at least two segments with different curvature.

7. The constant velocity joint according to claim 6 ,
wherein a first segment of the attachment-sided track sections of the outer joint part has a first radius of curvature,
wherein a ratio of a pitch circle radius to the first radius of curvature of the attachment-sided track section is greater than 1.4.

8. The constant velocity joint according to claim 7 ,
wherein the first radius of curvature of the first segment is formed by a first circular arc section around a first segment center, wherein the first segment center is arranged in the joint center plane and comprises a radial offset from the longitudinal axis in direction towards the ball track.

9. The constant velocity joint according to claim 8 ,
wherein a second segment of the attachment-sided track sections of the outer joint part has a second radius of curvature,
wherein the ratio of the pitch circle radius to the second radius of curvature of the attachment-sided track section is smaller than 1.4.

10. The constant velocity joint according to claim 9 ,
wherein the second radius of curvature of the second segment is formed by a second circular arc section around a second segment center, wherein the second segment center comprises an axial offset from the joint center plane in direction towards the opening side.

11. The constant velocity joint according to claim 10 ,
wherein the at least some pairs of tracks are configured such that the first circular arc section extends over a first track segment angle of 14° to 22° around the first segment center, and
the second circular arc section extends over a second track segment angle of 12° to 20° around the second segment center.

12. The constant velocity joint according to claim 1 ,
wherein the ball cage has a spherical outer face for guiding the ball cage with respect to an inner face of the outer joint part and a spherical inner face for guiding the ball cage with respect to an outer face of the inner joint part,
wherein an axial offset is provided between a center of the spherical outer face and a center of the spherical inner face.

13. The constant velocity joint according to claim 1 ,
wherein a lubricant is provided for lubricating the constant velocity joint, wherein the lubricant has a coefficient of friction between 0.02 and 0.09.

14. The constant velocity joint according to claim 1 ,
wherein at least one of the following applies to the at least some of the pairs of tracks:
a ratio between a pitch circle radius and a ball diameter is between 1.4 and 2.1;
a ratio between a pitch circle radius and an axial offset of the ball cage is between 5.0 and 12.5;
a ratio between a pitch circle radius and an axial offset of the second track segment center is between 4.0 and 8.0;
a ratio between a pitch circle radius and a diameter of a connecting profile of the inner joint part is between 1.0 and 1.25;
a ratio between a pitch circle radius and an outer diameter of the outer joint part is between 0.315 and 0.345.

Assignees

• Gkn Driveline Int Gmbh

Inventors

• Benner Ida
• Cremerius Rolf
• Gremmelmaier Anna
• Hildebrandt Wolfgang
• Maucher Stephan
• Post Hans-Jürgen
• Weckerling Thomas

Classifications

• F16D3/2237 Primary

  where the grooves are composed of radii and adjoining straight lines, i.e. undercut free [UF] type joints · CPC title

• F16D2003/22303

  Details of ball cages · CPC title

• F16D2003/22309

  Details of grooves · CPC title

• Y10S464/906

  Torque transmitted via radially spaced balls · CPC title

• F16D3/223 Primary

  the rolling members being guided in grooves in both coupling parts · CPC title