Ntn Corporation

Hideki Kondo

Hisaaki Kura

Kenji Terada

Yukihiro Watanabe

Tatsuhiro Goto

Hiroshi Tone

A tripod constant velocity universal joint including an outer joint member having axially extending track grooves formed at three circumferentially equispaced positions in the inner periphery. A tripod member having a trunnion barrel adapted to be fitted to a shaft for torque transmission and trunnion journals radially projecting from three circumferentially equispaced positions in the trunnion barrel. Rollers respectively attached to the trunnion journals for rotation through a plurality of needle rollers and received in the track grooves. Each roller is guided at its outer peripheral surface by roller guide surfaces formed in opposite lateral walls of the track groove. A skew angle of the needle rollers is controlled so that it is within a predetermined specified value.

Tripod constant velocity universal joint

A tripod constant velocity universal joint including an outer joint member having axially extending track grooves formed at three circumferentially equispaced positions in the inner periphery. A tripod member has a trunnion barrel adapted to be fitted to a shaft for torque transmission and trunnion journals radially projecting from three circumferentially equispaced positions in the trunnion barrel, and rollers rotatable around the associated trunnion journal for rotation through a plurality of needle rollers and received in the track grooves. Each roller is guided at its outer peripheral surface by roller guide surfaces formed in opposite lateral walls of the track groove. The torsional strength of the tripod member and the smallest outer diameter portion of the shaft are set to be substantially equal. Also, the surface pressure on the trunnion journals in rolling contact with the needle rollers is allowed up to a predetermined value.

A tripod constant velocity universal joint including an outer joint member having three axial track grooves in an inner periphery and roller guide surfaces formed in opposing side walls of each track groove. A tripod member has three radially projecting trunnion journals and rollers that rotate around respective trunnion journals through a plurality of needle rollers and are received in the track grooves of the outer joint member. Each roller is guided on an outer peripheral surface by the roller guide surfaces. Contact between the roller and roller guide surfaces is circular having a contact ratio that is 1.01 or higher. The contact ratio is defined by a widthwise length of the contact ellipse formed by the roller contacting the guide surface relative to the width of said roller.

A constant velocity universal joint has a ring that is fitted on each trunnion and rotatably supports a corresponding roller so the roller is movable axially of an outer joint member along a roller guide surface. The outer circumferential surface of each trunnion has a straight shape, as viewed in the longitudinal section, and has, as viewed in the cross section, a shape which allows contact with the inner circumferential surface of the ring in a direction orthogonal to the axis of the outer joint member. A generatrix of the inner circumferential surface of the ring forms part of an ellipse having a major axis extending in a direction orthogonal to the axis of the ring or is composed of a central convex circular arc and a tangential line extending from an end portion of the circular arc to an end face of the ring.

Growing community of inventors

Iwata, Japan

Hideki Kondo