Fixed type constant velocity universal joint

Patent metadata

Field	Value
Publication number	US-9551382-B2
Application number	US-201314439901-A
Country	US
Kind code	B2
Filing date	Oct 10, 2013
Priority date	Nov 5, 2012
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

Provided is a fixed type constant velocity universal joint, in which: each of first track groove portions positioned on an interior side of an outer joint member includes an arc part having a curvature center that is positioned without being offset in an axial direction with respect to a joint center; the first track groove portions are inclined in a peripheral direction with respect to a joint axial line (N-N) and adjacent to each other in the peripheral direction with their inclination directions opposite to each other; each of second track groove portions positioned on an opening side is formed into a different shape from a shape of the each of the first track groove portions so as to increase an effective track length at a maximum operating angle; the each of the first track groove portions and the each of the second track groove portions are connected to each other at a position on the opening side with respect to the joint center; each of track grooves of an inner joint member is formed so as to be mirror-image symmetrical with corresponding one of paired track grooves of the outer joint member with respect to a plane including the joint center and being perpendicular to the joint axial line at an operating angle of 0°; and an axial clearance between the inner joint member and a cage is set to be larger than an axial clearance corresponding to a clearance between each of balls and each of the track grooves.

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 of the outer joint member,
the outer joint member having an opening side and an interior 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 plurality of track grooves of the outer joint member;
a plurality of balls for transmitting torque,
the plurality of balls being interposed between the plurality of track grooves of the outer joint member and the plurality of track grooves of the inner joint member; and

a cage comprising pockets for receiving the plurality of balls,
the cage having a spherical outer peripheral surface and a spherical inner peripheral surface, which are fitted to the spherical inner peripheral surface of the outer joint member and the spherical outer peripheral surface of the inner joint member, respectively,

wherein the plurality of track grooves of the outer joint member comprise:
first track groove portions positioned on the interior side; and
second track groove portions positioned on the opening side,

wherein each of the first track groove portions comprises an arc part having a curvature center that is positioned without being offset in the axial direction with respect to a joint center,
wherein the first track groove portions are inclined in a peripheral direction of the outer joint member with respect to a joint axial line and adjacent to each other in the peripheral direction with their inclination directions opposite to each other,
wherein each of the second track groove portions has a shape that is different from a shape of each of the first track groove portions,
wherein the first track groove portions and the second track groove portions are connected to each other at a position on the opening side with respect to the joint center,
wherein each of the plurality of track grooves of the inner joint member is formed so as to be mirror-image symmetrical with a corresponding one of the plurality of track grooves of the outer joint member with respect to a plane including the joint center and being perpendicular to the joint axial line at an operating angle of 0°,
wherein, at a neutral position under a non-load state at the operating angle of 0°, the outer joint member and the inner joint member being concentric with the joint axial line and centers of the plurality of balls lying in the plane, a first axial clearance at the opening side of the outer joint member and a second axial clearance at the interior side of the outer joint member are defined between the inner joint member and the cage, a third axial clearance is defined between each of the plurality of balls and a corresponding one of the plurality of track grooves of the outer joint member, and a fourth axial clearance is defined between each of the plurality of balls and a corresponding one of the plurality of track grooves of the inner joint member,
wherein the first axial clearance is defined as an axial distance within which the inner joint member is relatively displaceable in the axial direction with respect to the cage from the neutral position toward the opening side of the outer joint member, the second axial clearance is defined as an axial distance within which the inner joint member is relatively displaceable in the axial direction with respect to the cage from the neutral position toward the interior side of the outer joint member, the third axial clearance is defined as an axial distance within which each of the plurality of balls is relatively displaceable in the axial direction with respect to the outer joint member from the neutral position toward one side in the axial direction, and the fourth axial clearance is defined as an axial distance within which each of the plurality of balls is relatively displaceable in the axial direction with respect to the inner joint member from the neutral position toward the other side in the axial direction, and
wherein each of the first axial clearance and the second axial clearance is set to be larger than a sum of the third axial clearance and the fourth axial clearance.

2. The fixed type constant velocity universal joint according to claim 1 , wherein an angle formed between a straight line, which passes through the joint center and a connection point between one of the first track groove portions and one of the second track groove portions, and the plane, which includes the joint center and is perpendicular to the joint axial line at the operating angle of 0° is set to 3° to 10°.

3. The fixed type constant velocity universal joint according to claim 2 , wherein the curvature center of the arc part of each of the first track groove portions is arranged on the joint axial line.

4. The fixed type constant velocity universal joint according to claim 2 , wherein the curvature center of the arc part of each of the first track groove portions is offset in a radial direction with respect to the joint axial line.

5. The fixed type constant velocity universal joint according to claim 2 , wherein each of the second track groove portions comprises an arc part.

6. The fixed type constant velocity universal joint according to claim 2 , wherein each of the second track groove portions comprises an arc part and the arc part of each of the second track groove portions has a curvature center offset to a radially outer side with respect to each of the first track groove portions and offset to the opening side with respect to the joint center.

7. The fixed type constant velocity universal joint according to claim 2 , wherein each of the second track groove portions comprises a linear part, and the linear part is formed with an inclination so as to come closer to the joint axial line as a distance to the opening side becomes smaller.

8. The fixed type constant velocity universal joint according to claim 1 , wherein the curvature center of the arc part of each of the first track groove portions is arranged on the joint axial line.

9. The fixed type constant velocity universal joint according to claim 1 , wherein the curvature center of the arc part of each of the first track groove portions is offset in a radial direction with respect to the joint axial line.

10. The fixed type constant velocity universal joint according to claim 1 , wherein each of the second track groove portions comprises an arc part.

11. The fixed type constant velocity universal joint according to claim 1 , wherein each of the second track groove portions comprises an arc part and the arc part of the each of the second track groove portions has a curvature center offset to a radially outer side with respect to each of the first track groove portions and offset to the opening side with respect to the joint center.

12. The fixed type constant velocity universal joint according to claim 1 , wherein each of the second track groove portions comprises a linear part, and the linear part is formed with an inclination so as to come closer to the joint axial line as a distance to the opening side becomes smaller.

Assignees

• Hirukawa Hiroyasu
• Fujio Teruaki
• Yamazaki Kenta
• Ntn Toyo Bearing Co Ltd

Inventors

• Hirukawa Hiroyasu
• Fujio Teruaki
• Yamazaki Kenta

Classifications

• F16D3/2233

  where the track is made up of two curves with a point of inflexion in between, i.e. S-track joints · 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

• F16D3/2245

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

• F16D2003/22309

  Details of grooves · CPC title