Fixed type constant velocity universal joint

Patent metadata

Field	Value
Publication number	US-11053986-B2
Application number	US-201716087273-A
Country	US
Kind code	B2
Filing date	Mar 9, 2017
Priority date	Mar 25, 2016
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

Track grooves of an outer joint member include first and second track groove portions. An end portion of the ball raceway center line of each of the first track groove portions is located on the opening side with respect to a joint center and a ball raceway center line of each of the second track groove portions is connected to the end portion. A ball raceway center line of each of the track grooves of the inner joint member is formed to be mirror-image symmetrical with a ball raceway center line of a corresponding one of the paired track grooves of the outer joint member with respect to a plane that includes the joint center at an operating angle of 0° and is orthogonal to a joint axial line.

First claim

The invention claimed is:

1. A fixed type constant velocity universal joint, comprising:
an outer joint member having a spherical inner peripheral surface in which a plurality of track grooves are formed so as to extend in an axial direction, the outer joint member having an opening side and a depth side spaced apart from each other in the axial direction;
an inner joint member having a spherical outer peripheral surface in which a plurality of track grooves are formed so as to be paired with the track grooves of the outer joint member;
a plurality of balls, which are interposed between the track grooves of the outer joint member and the track grooves of the inner joint member, and are configured to transmit torque; and
a cage, which is configured to retain the balls, and has a spherical outer peripheral surface to be fitted to the spherical inner peripheral surface of the outer joint member, and a spherical inner peripheral surface to be fitted to the spherical outer peripheral surface of the inner joint member,
wherein the track grooves of the outer joint member comprise:
first track groove portions ( 7 a ) located on the depth side; and
second track groove portions ( 7 b ) located on the opening side,

wherein the first track groove portions ( 7 a ) each have a first ball raceway center line (Xa) having a first single curvature radius (R 1 ) with a curvature center that is prevented from being offset in the axial direction with respect to a joint center (O),
wherein first planes (M) each including one of the first ball raceway center lines (Xa) and the joint center (O) are inclined with respect to a joint axial line (N-N) such that the first planes of the first track groove portions ( 7 a ) that are adjacent to each other in a circumferential direction are inclined in directions opposite to each other,
wherein an end portion (A) of the first ball raceway center line (Xa) of each of the first track groove portions ( 7 a ) is located on the opening side with respect to the joint center (O),
wherein a second ball raceway center line (Xb) of each of the second track groove portions ( 7 b ) is connected to the end portion (A) of one of the first ball raceway center lines (Xa),
wherein a ball raceway center line (Y) of each of the track grooves of the inner joint member is formed so as to be mirror-image symmetrical with a ball raceway center line (X) formed by one of the first ball raceway center lines (Xa) and one of the second ball raceway center lines (Xb) of a corresponding one of the track grooves of the outer joint member with respect to a second plane (P) that includes the joint center (O) at an operating angle of 0° and is orthogonal to the joint axial line (N-N),
wherein the second ball raceway center line (Xb) of each of the second track groove portions ( 7 b ) has a second single curvature radius (R 2 ) with a curvature center that is offset in a radial direction from the joint axial line (N-N) such that the second single curvature radius (R 2 ) intersects the joint axial line (N-N), and
wherein the second single curvature radius (R 2 ) is set larger than the first single curvature radius (R 1 ).

2. The fixed type constant velocity universal joint according to claim 1 , wherein an angle (( 3 ) formed by a straight line (L) connecting the joint center (O) and the end portion (A) on the opening side of the first ball raceway center line (Xa) of one of the first track groove portions ( 7 a ) with respect to the second plane (P) that includes the joint center (O) and is orthogonal to the joint axial line (N-N) is set to 5° to 8°.

3. The fixed type constant velocity universal joint according to claim 2 , wherein the plurality of balls is eight balls.

4. The fixed type constant velocity universal joint according to claim 1 , wherein the plurality of balls is eight balls.

Assignees

• Ntn Toyo Bearing Co Ltd

Inventors

• Fujio Teruaki
• Funahashi Masashi

Classifications

• F16D3/2245 Primary

  where the groove centres are offset from the joint centre · CPC title

• F16D2003/22309

  Details of grooves · CPC title

• Y10S464/906

  Torque transmitted via radially spaced balls · CPC title

• F16D2003/22306

  having counter tracks, i.e. ball track surfaces which diverge in opposite directions · CPC title

• F16D3/224 Primary

  the groove centre-lines in each coupling part lying on a sphere · CPC title