Abstract: A tripod constant-velocity joint including: an inner ring; three trunnions protruding from the inner ring; three roller units supported by the trunnions; and an outer ring storing the roller units. Each roller unit includes: an inner roller that is in contact with a convex outer-circumferential surface of the corresponding trunnion at a tangent point; an outer roller supported by the inner roller through rolling elements that are interposed between the inner and outer rollers; and a limiting portion protruding from the outer roller, so as to limit movements of the rolling elements and the inner roller. A clearance between the inner roller and the limiting portion is smaller than an axial length of a crowned end portion of each rolling element, and is larger than a stroke distance of reciprocating movement of the tangent point when a joint angle of the tripod constant-velocity joint is a predetermined value.

Abstract: A tripod constant-velocity joint including: an inner ring; three trunnions protruding from the inner ring; three roller units supported by the trunnions; and an outer ring storing the roller units. Each roller unit includes: an inner roller that is in contact with a convex outer-circumferential surface of the corresponding trunnion at a tangent point; an outer roller supported by the inner roller through rolling elements that are interposed between the inner and outer rollers; and a limiting portion protruding from the outer roller, so as to limit movements of the rolling elements and the inner roller. A clearance between the inner roller and the limiting portion is smaller than an axial length of a crowned end portion of each rolling element, and is larger than a stroke distance of reciprocating movement of the tangent point when a joint angle of the tripod constant-velocity joint is a predetermined value.

Abstract: A tripod constant-velocity joint including: an inner ring; three trunnions protruding from the inner ring; three roller units supported by the trunnions; and an outer ring storing the roller units. Each roller unit includes: an inner roller that is in contact with a convex outer-circumferential surface of the corresponding trunnion at a tangent point; an outer roller supported by the inner roller through rolling elements that are interposed between the inner and outer rollers; and a limiting portion protruding from the outer roller, so as to limit movements of the rolling elements and the inner roller. A clearance between the inner roller and the limiting portion is smaller than an axial length of a crowned end portion of each rolling element, and is larger than a stroke distance of reciprocating movement of the tangent point when a joint angle of the tripod constant-velocity joint is a predetermined value.

Abstract: A sliding-type tripod-shaped constant-velocity universal joint that can reduce induced thrust force by preventing the tangent-point back-surface side of rollers from contacting with roller grooves in the case where the rollers and the roller grooves make an angular contact at two locations. An outer peripheral surface of the rollers makes an angular contact with respect to the roller grooves at two locations, and an inner peripheral surface of the rollers is formed as a convex-shaped curve that is directed to the inner side in an axially cross section of the rollers. And, the rollers are made swingable with respect to tripod-shaft portions.

Abstract: A constant velocity universal joint includes an inner race having an outer peripheral face on which inner grooves are formed, an outer race having an inner peripheral face on which outer grooves are formed, a plurality of balls each engaging with each pair of inner groove and outer groove, and an annular cage disposed between the inner race and the outer race and including window portions for retaining respective balls. A coefficient of sliding friction between the ball and a rolling face on the inner groove with which the ball is in contact, and a coefficient of sliding friction between the ball and a rolling face on the outer groove with which the ball is in contact are larger than a coefficient of sliding friction between the ball and a sliding face on the window portion with which the ball is in contact.

Abstract: A constant velocity universal joint includes an inner race having an outer peripheral face on which inner grooves are formed, an outer race having an inner peripheral face on which outer grooves are formed, a plurality of balls each engaging with each pair of inner groove and outer groove, and an annular cage disposed between the inner race and the outer race and including window portions for retaining respective balls. A coefficient of sliding friction between the ball and a rolling face on the inner groove with which the ball is in contact, and a coefficient of sliding friction between the ball and a rolling face on the outer groove with which the ball is in contact are larger than a coefficient of sliding friction between the ball and a sliding face on the window portion with which the ball is in contact.