Riken Piston Ring Kogyo Kabushiki Kaisha

Masayuki Maruyama

Joichi Watanabe

Yoshitugu Hamada

Ryoichi Yamauchi

A rotary piston engine has a pair of side housings made of high silicon aluminum alloy and a rotor made of iron-based material. The side surfaces of the rotor are subjected to a surface treatment called 'Sulfinuz' to form surface layers rich in sulphur and nitrogen for minimizing scuffing between the side surfaces of the side housings and the side surfaces of the rotating rotor due to thermal expansion of the side housings and vibration of the rotor.

Sulphur and nitrogen treated iron based rotor for rotary piston engine

An oil seal ring is obtained which can maintain its oil scraping performance at a satisfactory level despite the frictional wear it undergoes. It is formed with a tapered sliding surface having a hardness maximized at its oil scraping edge and decreasing with the distance therefrom. It can be manufactured by casehardening a ring blank through one end surface thereof which is oppositely tapered and subsequently finishing the end surface to shape.

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Kashiwazaki, Japan

Masayuki Maruyama