Ntn Corporation

Kenji Terada

Hisaaki Kura

Tatsuro Sugiyama

Tatsuhiro Goto

Kenta Yamazaki

Shigeyoshi Ishiguro

Akio Sakaguchi

Kazuhiko Yoshida

Yukihiro Watanabe

Hideki Kondo

Takeshi Ikeda

Shin Tomogami

Yoshikazu Fukumura

Masayuki Kuroda

Shinichi Takabe

Masuo Takaki

Junichi Izumino

Katsuhiro Suzuki

Yoshimasa Ushioda

Tatsurou Sugiyama

Toshiyuki Oki

Takuya Katou

Masaru Komatsu

Yasunori Kawasaki

A power transmission mechanism () includes left and right drive shafts (L,R) that transmit rotational torque from a drive source to drive wheels provided on left and right sides of a vehicle. In the right drive shaft (R) and the left drive shaft (L), the numbers of rolling elements () included in plunging type constant velocity universal joints (L,R) are different from each other.

Power transmission mechanism and vehicle

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

The tripod member has three trunnions which are projected radially. Each of the trunnions carries a roller, and this roller is accommodated in one of the track grooves in the outer joint member. The outer peripheries of the rollers and the roller guideways make angular contact with each other. Support rings are fitted onto the outer peripheries of the trunnions. These support rings and the rollers are assembled (unitized) via a plurality of needle rollers to constitute roller assemblies capable of relative rotations. In longitudinal sections, the outer peripheries of the trunnions have straight shapes parallel to the axes of the trunnions. In cross sections, the outer peripheries are elliptic in shape, with their respective major axes perpendicular to the axis of the joint. The inner peripheries of the support rings have arcuate convex sections.

Constant velocity universal joint

A fixed constant velocity joint is provided, which is suitable for an application where a rotational backlash should be avoided. A pressing member is attached to a shaft, and simultaneously a receiving member is attached to a cage. Then, an elastic force of an elastic member elastically bring a pressing part of the pressing member in contact with a receiving part of the receiving member. As a result, an inner race and a cage relatively travel in the axial direction, balls are pushed toward a direction along which wedge-shape ball tracks narrow, and consequently a track clearance in the axial direction decreases.

Fixed constant velocity joint

An annular support ringis fitted onto the outer periphery of each trunnion. This support ringand the rollerare unitized via a plurality of needle rollersto constitute a roller assembly capable of relative rotations therebetween. In longitudinal section, each trunnionhas an outer periphery of straight shape, parallel to the axis of the trunnion. In cross section, the trunnionhas a generally ellipse shape with the major axis orthogonal to the axis of the joint. The inner periphery of each support ringis arcuate and convex in section. This combines with the general elliptic cross sections of the trunnionsand the provision of predetermined clearances between the trunnionsand the support rings, to allow the support ringsto move along the axial directions of the trunnionsas well as make tilting movements with respect to the trunnions

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.

An annular support ring is fitted onto the outer periphery of each trunnion . This support ring and the roller are unitized via a plurality of needle rollers to constitute a roller assembly capable of relative rotations therebetween. In longitudinal section, each trunnion has an outer periphery of straight shape, parallel to the axis of the trunnion . In cross section, the trunnion has a generally ellipse shape with the major axis orthogonal to the axis of the joint. The inner periphery of each support ring is arcuate and convex in section. This combines with the general elliptic cross sections of the trunnions and the provision of predetermined clearances between the trunnions and the support rings , to allow the support rings to move along the axial directions of the trunnions as well as make tilting movements with respect to the trunnions

A constant velocity universal joint with a further reduction in inductive thrust and slide resistance. The constant velocity universal joint comprises: an outer joint member having three track grooves each having circumferentially-opposed roller guideways ; a tripod member having three radially-projecting trunnions ; a roller inserted in each of the track grooves ; and a ring fitted on each of the trunnions to support the roller rotatably, the roller being movable in axial directions of the outer joint member along the roller guideways . Here, the inner periphery of the ring is shaped arcuate and convex in section. The outer periphery of each of the trunnions is shaped straight in longitudinal section, as well as formed in cross section so as to make a contact with the inner periphery of the ring along a direction perpendicular to the axis of the joint and create a clearance with the inner periphery of the ring in an axial direction of the joint.

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Shizuoka-ken, Japan

Kenji Terada