Hitachi, Ltd.

Motohiro Satoo

Toshihiro Yamada

Hirotaka Kameya

Tatsuo Natori

Akihiko Yamamoto

Katsumi Matsubara

Mitsuru Fujiwara

Kotaro Naya

Kazuaki Shiinoki

Kazuaki Shinoki

A screw-type rotary fluid machine such as a compressor or a vacuum pump has male and female rotors which rotate within a casing, with or without mutual contact. At least one of the male and female rotors being surface-treated to have a treated surface structure. The treated surface structure is a multi-layered structures composed of a plurality of layers including a non-electrolytic Ni plating layer and at least one covering layer of organic resin. The organic resin may be one or more kinds selected from a group of engineering plastics, so as to improve mechanical strength.

Screw-type rotary fluid machine including rotors having treated surfaces

A method treating a surface of rotors in a screw-type rotary fluid machine, with the method comprising the steps of: conducting a non-electrolytic Ni plating on the surface of each rotor so as to form a first layer of non-electrolytic Ni plating layer; heating the rotor having the first layer at a temperature not lower than 500.degree. C.; and forming, at least, a second layer of an organic resin so as to cover the first layer.

Method of treating surfaces of rotors of the screw type rotary machine

Growing community of inventors

Ibaraki, Japan

Motohiro Satoo