Method of treating surfaces of rotors of the screw type rotary machine
AssigneeHitachi, Ltd.
InventorsAkihiko Yamamoto, Toshihiro Yamada, Tatsuo Natori, Kotaro Naya, Motohiro Satoo, Mitsuru Fujiwara, Katsumi Matsubara, Kazuaki Shiinoki, Hirotaka Kameya
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Abstract
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.
Claims8
A method of treating a surface of rotors disposed in a screw rotary fluid machine having at least one male rotor and at least one female rotor rotatable in a casing, 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 a non-electrolytic Ni plating layer;
- heating said rotor having said 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 said first layer.
A method of treating a surface of rotors disposed in a screw rotary fluid machine having at least one male rotor and at least one female rotor rotatable in a casing, 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 a non-electrolytic Ni plating layer;
- heating said rotor having said first layer at a temperature ranging between 300.degree. C. and 500.degree. C.;
- cooling said rotor to generate cracks in said non-electrolytic Ni plating layer;
- heating said rotor having said non-electrolytic Ni plating 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 said first layer.
A method of treating a surface of rotors disposed in a dry screw rotary fluid machine having at least one male rotor and at least one female rotor which rotate within a casing in contact with each other, the method comprising:
- forming a non-electrolytic Ni plating layer on the surface of each rotor, and heat-treating the rotor surface carrying said non-electrolytic Ni plating layer at a temperature ranging between 500.degree. C. and 650.degree. C., thereby producing fine crystal grain structure in the non-electrolytic Ni plating layer which allowing a diffusion of constituents of both the Ni plating layer and the main body of the rotor at a boundary layer between the rotor surface and said non-electrolytic Ni plating layer.
A method of treating a surface of a rotor disposed in a dry screw rotary fluid machine having at least one male rotor and at least one female rotor which rotate within a casing in contact with each other, the method comprising the steps of:
- conducting a non-electrolytic Ni plating on the surface of each rotor so as to form a non-electrolytic Ni plating layer;
- heating said rotor having said first layer at a temperature ranging between 300.degree. C. and 500.degree. C.;
- causing cracks to be generated in said non-electrolytic Ni plating layer;
- heating said rotor having said non-electrolytic Ni plating layer at a temperature not lower than 500.degree. C., and impregnating said non-electrolytic Ni plating layer with a solid lubricant.
Dependencies are inferred from the claim text.