Swash plate type compressor

A swash plate type refrigerant compressor comprising:

• a pair of axially combined front and rear cylinder blocks forming therein a plurality of cylinder bores and a swash plate compartment,
• a pair of front and rear housings arranged at axial ends of said combined cylinder blocks, each housing having therein a suction chamber and a discharge chamber,
• valve plates interposed between said front and rear housings and said axial ends of said combined cylinder blocks, respectively,
• a drive shaft extending axially through said swash plate compartment of said combined cylinder blocks,
• a swash plate in said swash plate compartment supported on said drive shaft and rotatable therewith,
• a plurality of double-headed pistons engaged with said swash plate so as to be reciprocated in said cylinder bores, each piston having a pair of head portions at the opposite ends thereof connected together by an intermediate portion of said piston,
• said swash plate having formed on and throughout its circumferential periphery an annular groove,
• an annular ring member received in said annular groove, said ring member having an outer diameter larger than the diameter of said swash plate and forming with the bottom annular surface of said groove a substantially annular clearance at least during the operation of the compressor.