Kabushiki Kaisha F. C. C.

Nhk Spring Co., Ltd.

Fcc, LLC

Jun Tokumasu

Ichiro Sasuga

Kenjiro Kawanabe

Hirokazu Kojima

Kazuhiro Itonaga

Shouhei Tominaga

Yoichiro Nakano

Yutaka Nishida

Provided is a wet friction plate which can realize a further reduction of drag torque while suppressing a decrease in the total area of frictional sheets. A clutch friction plateis formed by providing frictional sheetsand oil grooveson a flat annular metal core. On a side surface of the metal corefacing a clutch plate, a plurality of small frictional sheetsand oil groovesare alternatingly arranged along the circumferential direction of the metal core. The frictional sheetsare disposed to form frictional-sheet groupseach including five frictional sheetsdisposed successively. Outer and inner peripheral edgesandof the frictional sheetsof each frictional-sheet groupform continuously changing arcuate contoursandsuch that the distances Land Lbetween the outer and inner peripheral edgesandand the center of rotation O of the metal corecontinuously change.

Wet friction plate

A friction clutch device includes clutch plates which are retained through meshing engagement on the inner peripheral surface of an outer case, which is rotatably driven by an engine. Each clutch plate includes a flat, annular pressing element which is pressed against a clutch friction plate for frictional contact therewith. Engagement protrusions are formed on the outer peripheral surface of the pressing element. The engagement protrusions fit into recessed engagement grooves provided on the outer case and mesh with the outer case. Proiectinq portions which project toward the inner peripheral surface of the outer case are formed on the outer peripheral surface of the pressing element.

Plate element, and friction clutch device and brake device provided with the plate element

A compression coil spring is used as a return spring which is stored in the housing of a clutch to urge the clutch piston in its returning direction. The effective number of turns of the compression coil spring is two or less, and the number of turns at an end-turn portion thereof is more than 0.45 and not more than 0.7. The compression coil spring is used in the compressed state throughout the operating stroke of the clutch piston. The number of turns at the end-turn portion is desirably within the range of 0.5 to 0.65, more desirably within the range of 0.55 to 0.62.

Return spring for clutch

Growing community of inventors

Hamamatsu, Japan

Jun Tokumasu