Scroll compressors with annular sealed high pressure thrust producing member

Claim 1

A scroll compressor including a casing, a frame provided in the casing, a motor and a compressor assembly mounted on opposite sides of said frame, said compressor assembly having a stationary scroll member and a movable scroll member respectively having spiral wraps engaging with each other so that the movable scroll member is driven by said motor eccentrically around the center of a spiroid spiral of said stationary scroll member, said movable scroll member having a planar portion with a lower surface facing said frame, said stationary scroll member having a peripheral portion secured to said frame, said scroll compressor further comprising: an annular member formed adjacent said lower surface and separated therefrom by a gap, said annular surface having radially outer and inner walls and a bottom wall for defining an annular high pressure chamber therebetween, said radially outer and inner walls of said annular member having internal surfaces tapered radially outwardly and inwardly from said bottom wall, respectively; passage means for supplying a portion of a quantity of compressible fluid delivered from said compressor assembly into said high pressure chamber for reducing a thrust force applied to said movable scroll member; a radially outer resilient seal ring having at least one part of a radially outer surface thereof tapered to be slidable along said tapered outer wall of said high-pressure chamber; and a radially inner resilient sealing ring having at least one part of a radially inner surface thereof tapered to be slidable along said tapered inner wall of said high-pressure chamber, said inner and outer sealing rings sealing said annular high-pressure chamber to said lower surface of said planar portion by closing said gap, each of said outer and inner resilient sealing rings including a sealing surface sealingly contacting said lower surface; and means for maintaining said seal between said annular high-pressure chamber and said lower surface upon a change in the width of said gap, said maintaining means including diameter varying means for resiliently increasing and decreasing the diameters of said inner and outer sealing rings when said sealing rings slide along said respective tapered inner and outer walls.