Ntn Corporation

Yukihiro Watanabe

Hisaaki Kura

Kenji Terada

Hideki Kondo

Keisuke Nishio

Tatsuhiro Goto

Taku Itagaki

Mikio Tomiyama

Atsuto Takemura

Shintaro Harada

A silicone boot for a constant velocity universal joint includes a larger diameter portion attached to an outer joint member of a constant velocity universal joint, a smaller diameter portion attached to a shaft coupled with an inner joint member of the constant velocity universal joint, and a bellows portion, which is arranged between the larger diameter portion and the smaller diameter portion, and has peak portions and valley portions formed alternately with each other. The smaller diameter portion includes a shaft attachment portion having a radially outer surface in which a fitting groove for attachment of a boot band is formed, and a thin portion extending from the shaft attachment portion so as to be coupled with the bellows portion through intermediation of a thick portion and allowing buckling deformation with respect to the shaft attachment portion and the bellows portion.

Silicone boot for constant velocity universal joint and constant velocity universal joint

A boot-mounting structure for a constant velocity universal joint has a configuration which can prevent a crack caused by interference with a boot band while maintaining a stable sealing property. The boot band () is fitted into a fitting groove of a silicone boot (), and is decreased in diameter while being attached into the fitting groove, to thereby fix the silicone boot (). The boot band () is formed into an annular body not provided with a folded-back portion. There is provided a no-interference structure means (S) for preventing interference caused, when the boot band is decreased in diameter, between an axial outer-peripheral-edge portion (or) of the band () and a bottom end portion (or) of the fitting groove () corresponding thereto.

Boot mounting structure for constant-speed universal joint, and silicone boot for the constant-speed 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 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 is disclosed which includes an outer joint member with three axial track grooves and a tripod member with three radially projecting trunnion journals, each of the trunnion journals carrying a roller assembly received in each of the track grooves, a projection being formed at an end of each trunnion for interference with the roller assembly.

Growing community of inventors

Iwata, Japan

Yukihiro Watanabe