Scroll fluid compressor with surface finished flat plates engaging the wraps

Claim 1

A scroll fluid compressor comprising: an orbiting member including an end plate and a wrap in vortical form integral with said end plate and located in an upstanding position on the end plate; a stationary scroll member including an end plate and a wrap in vortical form substantially of the same construction as said end plate and said wrap of said orbiting scroll member, said wrap in vortical form being in mesh with said wrap of said orbiting scroll member when the two scroll members are assembled with each other; a crankshaft having a shaft portion for supporting said orbiting scroll member for orbiting movement, said crankshaft having a balance weight formed integrally therewith; a frame including a bearing means for journalling said crankshaft and formed so as to enclose said orbiting scroll member on an inner side thereof and bring the same into contact with said stationary scroll member; means for preventing said orbiting scroll member from rotating on its own axis connecting said frame to said orbiting scroll member; a rotor of a motor secured to said crankshaft; a sealed vessel for housing said orbiting scroll member and having secured thereto a stator of said motor in a sealed condition and formed with an oil sump in a lower portion thereof; oil feeding means located in an end portion of said crankshaft and immersed in said oil sump; a fluid inlet line and a fluid outlet line communicating with spaces defined between said end plates of said orbiting scroll member and said stationary scroll member; flat plates in vortical form each fitted in a valley between the outer wraps and the inner wraps of the oribiting scroll member and the stationary scroll member, said flat plates having surface finishes of higher precision than said end plates of said two scroll members, whereby said wrap of said orbiting scroll member can move in orbiting movement while having forward ends of the two scroll members maintained in sliding contact with the surfaces of the flat plates; and stepped portions are formed on a bottom of the valleys so as to stably hold the flat plates in place.