Scroll type fluid displacement apparatus with pressure communicating passage between pockets

摘要

A scroll type fluid displacement apparatus is disclosed. The apparatus includes a housing. A fixed scroll member is fixedly disposed within the housing and comprises a first end plate means from which a first wrap means extends. An orbiting scroll member comprises a second end plate means from which a second wrap means extends, and is supported for orbiting motion within the housing. Both wrap means interfit at an angular and radial offset to make a plurality of line contacts to define at least one pair of symmetrically disposed, sealed off fluid pockets. The first end plate means is formed with two holes which are placed at symmetrical positions to be simultaneously closed by the axial end surface of the second wrap means. These two holes are connected to one another by a passage means. The pressure in the sealed off fluid pockets is thereby equalized at the time the pockets are sealed.