| 摘要 |
PURPOSE:To improve the adhesion of a plating layer by casting a metallic cylinder body of trochoidal shape into a housing body, forming the trochoidal face side of the cylinder body in a convex shape, and providing the same face with a successive formation of a hard plating layer and a nickel-fluorine composite plating layer. CONSTITUTION:A rotor housing 10 is composed of a metallic cylinder body 12 moulded trochoidally into a rotor housing body 11, with the cylinder body 12 being shaped in a convex shape crosswise and a plural number of moulding projections 16 being formed on its periphery. Further, the trochoidal face is provided with the formation of a hard plating layer with a porous surface and of almost uniform thickness, and this layer 13 is provided with a successive formation of a nickel-fluorine composite plating layer 14 of almost uniform thickness. This constitution eliminates honing work in the conventional manufacturing process and improves the adhesion of the composite plating layer 14 at both ends.
|
