Compressor assembly

Claim 1

A compressor for use in an air conditioning system, comprising: a pair of axially aligned cylinder blocks, each having a cylinder bore therein, a valve plate mounted at the distal end of each cylinder block, having an exhaust and an intake valve formed therein, a housing enclosing each valve plate in sealing relationship with said cylinder bores, an axle rotatably mounted axially of said cylinder bores, valve plates and housings, a swash plate secured to said axle for rotation therewith, a double acting piston slidably, reciprocably mounted within said bore of said cylinders and being actuated by said swash plate for effecting a compressing action, said piston being formed in one piece and having an annular groove in the periphery thereof having a rectangular cross section, a piston ring seal fitted into said groove and having a rectangular cross section, said piston being made of fluorine-containing olefin polymer having a higher coefficient of thermal expansion than that of said cylinder block and said piston, the outer diameter of said piston ring seal being smaller than the diameter of said cylinder bore and also the thickness and the width of said piston ring seal being respectively smaller than the depth and the width of said groove at ambient temperature, whereby said piston ring seal expands in all directions so as to completely fill said groove and be in contact with the inner wall defining said cylinder bore during normal operation of the compressor.