Constant velocity joint

Patent metadata

Field	Value
Publication number	US-11815138-B2
Application number	US-201817257594-A
Country	US
Kind code	B2
Filing date	Jul 5, 2018
Priority date	Jul 5, 2018
Publication date	Nov 14, 2023
Grant date	Nov 14, 2023

Abstract

A constant velocity joint comprises an outer joint part with outer ball tracks and an inner joint part with inner ball tracks. An outer ball track and an inner ball track respectively form a pair of tracks with one another; in each, a torque-transmitting ball is guided. The torque-transmitting balls are accommodated in a ball cage with circumferentially distributed cage windows. In any angular position of the constant velocity joint an opening angle is formed between an outer tangent to the outer ball track and an inner tangent to the inner ball track. At an articulation angle of zero degrees the opening angle is greater than zero degrees. A central articulation angle range is defined with articulation angles less than fifteen degrees. The opening angle increases by at least two degrees within the central articulation angle range, and is less than twelve degrees for all articulation angles within the central articulation angle range.

First claim

The invention claimed is:

1. A constant velocity joint, comprising:
an outer joint part with a longitudinal axis and outer ball tracks, wherein the outer joint part has an attachment side and an opening side,
an inner joint part with a longitudinal axis and inner ball tracks,
wherein an outer ball track and an inner ball track respectively form a pair of tracks with each other,
a torque transmitting ball in each pair of tracks,
a ball cage arranged between the outer joint part and the inner joint part and comprising circumferentially distributed cage windows, each of which receiving at least one of the torque-transmitting balls,
wherein, with the longitudinal axis of the inner joint part and the longitudinal axis of the outer joint part being coaxially aligned, the balls in the ball cage define a joint center plane, wherein the longitudinal axis of the inner joint part and the longitudinal axis of the outer joint part at articulation angles deviating from zero degrees defining a joint articulation plane;
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 applied to the outer ball track in an outer contact point between the outer ball track and the ball and an inner tangent applied to the inner ball track in an inner contact point between the inner ball track and the ball,
wherein centers of the balls each define a center line when moving along the outer and inner ball tracks, and a first articulation angle range is defined that includes articulation angles β that have an absolute value of less than fifteen degrees (−15°<β<15°),
wherein for at least one of the pairs of tracks:
the opening angle is greater than zero degrees, for an articulation angle of zero degrees,
the opening angle increases by at least two degrees within at least a portion of the first articulation angle range, and
the opening angle is less than twelve degrees for all articulation angles within the first articulation angle range.

2. The constant velocity joint of claim 1 ,
wherein the opening angle at the articulation angle of zero degrees is greater than one degree.

3. The constant velocity joint according to claim 1 ,
wherein the opening angle at the articulation angle of zero degrees is less than eight degrees.

4. The constant velocity joint according to claim 1 ,
wherein the opening angle increases by at least four degrees within the first articulation angle range.

5. The constant velocity joint according to claim 1 ,
wherein the at least one pair of tracks has a second articulation angle range comprising articulation angles that have an absolute value of greater than or equal to 15° (β≤−15° or β≥15°, wherein at least one opening angle within the second articulation angle range is greater than a largest opening angle of the first articulation angle range.

6. The constant velocity joint according to claim 1 ,
wherein eight pairs of tracks and eight balls are provided, wherein the opening angle in the first articulation angle range is at most six degrees.

7. The constant velocity joint according to claim 1 ,
wherein six pairs of tracks and six balls are provided, wherein the opening angle in the first articulation angle range is at most twelve degrees, and the opening angle increases by at least four degrees within the first articulation angle range.

8. The constant velocity joint according to claim 1 ,
wherein the at least one pair of tracks is configured such that, at any articulation angle within the first articulation angle range, an opening-sided opening angle at a ball moving in the joint articulation plane to 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 to the attachment side of the outer joint part open in the same axial direction.

9. The constant velocity joint according to claim 8 ,
wherein the outer ball track is configured such that the center line in the attachment-sided track section of the outer joint part runs radially outside a circular arc section defined by a reference radius,
wherein the reference radius extends from a reference radius center to the center plane intersection of the center line with the joint center plane, wherein the reference radius center is offset with respect to the joint center plane towards the opening side of the outer joint part.

10. The constant velocity joint according to claim 1 ,
wherein the outer ball track is configured such that the center line in the opening-sided track section of the outer joint part runs radially outside a circular arc section defined by a reference radius,
wherein the reference radius extends from a reference radius center to the center plane intersection of the center line with the joint center plane, wherein the reference radius center is offset with respect to the joint center plane towards the opening side of the outer joint part.

11. 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.

12. The constant velocity joint according to claim 1 ,
wherein each center line respectively has at least two track sections with different curvature along their length.

13. The constant velocity joint according to claim 1 ,
wherein each center line respectively has at least one curvature change point within the first articulation angle range.

14. The constant velocity joint according to claim 1 ,
wherein all ball tracks are configured such that within the second articulation angle range the opening angles of all balls open in the same axial direction, viewed respectively in the joint articulation plane.

15. The constant velocity joint according to claim 1 ,
wherein all ball tracks are configured such that the opening angles at all balls are greater than zero degrees when the joint is aligned.

16. The constant velocity joint according to claim 1 ,
wherein the outer ball track is configured such that the outer center line has a central outer section formed by an outer circular arc about an outer central section center, the outer central section center having an axial offset in a first axial direction relative to the joint center, and
wherein the inner ball track is configured such that the inner center line has a central inner section formed by an inner circular arc about an inner central section center, the inner central section center having an axial offset in a second axial direction relative to the joint center point.

17. The constant velocity joint according to claim 1 ,
wherein the inner ball track is configured mirror symmetrical to the outer ball track with respect to an angle bisecting plane between the longitudinal axis of the outer joint part and the longitudinal axis of the inner joint part.

Assignees

• Gkn Driveline Int Gmbh

Inventors

• Maucher Stephan
• Gremmelmaier Anna
• Hildebrandt Wolfgang
• 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

• F16D3/223 Primary

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

• F16D2003/22309

  Details of grooves · CPC title

• Y10S464/906

  Torque transmitted via radially spaced balls · CPC title