Scroll-type fluid displacement apparatus including oldham coupling

Abstract

A scroll-type fluid displacement apparatus comprises a housing having an inlet port and outlet port and is made of non-ferrous metal. The housing has a first casing and second casing that is connected to the first casing. A fixed scroll is fixedly disposed within the housing and has a first circular end plate from which a first spiral element entered into the housing. An orbiting scroll has a pair of parallel first grooves formed on a second circular end plate. A second spiral element extends from the second circular end plate such that the first spiral element interfits the second spiral element at an angular and radial offset to make a plurality of line contacts to define a pair of fluid pockets within the housing. A driving mechanism is connected to the orbiting scroll to effect orbital motion of the orbiting scroll. An Oldham ring is coupled to the orbiting scroll for preventing rotation of the orbiting scroll during orbital motion. The Oldham ring has a pair of first key portions and a pair of second key portions. The second key portions are perpendicular to the pair of first key portions. The first key portions engage the parallel first grooves on the second circular end plate. A supporting plate member is disposed between the housing and the orbiting scroll to support the thrust load of the orbiting scroll. The supporting plate member, which is made of ferrous metal, has a pair of grooves formed on one end surface for engaging the second key portions of the Oldham ring.