Nippon Piston Ring Co., Ltd.

Osamu Hirakawa

Genkichi Umeha

Shigeru Urano

Shunsuke Takegushi

Shunsuke Takeguchi

Abrasion resistant sintered alloy

Shaft member

A hollow cam shaft of the type wherein lubricating oil is distributed to the cam portions includes a rod member positioned inside the shaft pipe member and spaced from the inner pipe surface by shaft end members and guide strips to form a reduced, annular volume to be filled with oil during engine start-up. The method of making the hollow cam shaft includes forming the rod member from a resinous material by injection molding, using a removable mold positioned in the pipe through-hole, and, in a preferred embodiment, flowing the resin through the mold cavity and into a recess located in the distal shaft end member, which recess has an enlarged portion for capturing the hardened resin rod end and facilitating mold removal.

Method of making a cam shaft

Cam shaft and method of manufacture

Camshaft with lubricating oil supplying function

A composite camshaft having a plurality of ferrous fitting members, such as cam lobes and journals, firmly bonded to a steel shaft by sintering in the presence of a liquid phase. The fitting members are fabricated as a green compact from metal powders and pre-sintered to axially shrink the compact by one-half a preselected allowance of shrinkage. Thereafter the pre-sintered fitting members are fitted on the shaft and sintered to axially shrink the compact by the remaining allowance of shrinkage and metallurgically join the shaft.

Method for manufacturing camshaft

A rotary seal improved in quality by providing relatively movable seal surfaces in the form of a hardened, wear resistant layer covering only a part of the seal body surface. In particular the hardened layer may be formed in a helical fashion such that upon relative rotation of the seal surfaces, entering abrasives and the like may be shunted to the outside periphery of the seal, per se.

Rotary seal with linear wear resistant treated layer

Growing community of inventors

Saitama, Japan

Osamu Hirakawa