Variable capacity piston- operated refrigerant compressor with an oil separating means

A variable capacity piston-operated refrigerant compressor comprising:

• a cylinder block provided with a plurality of cylinder bores formed therein;
• a housing connected to said cylinder block and defining a crank chamber, a suction chamber for a refrigerant gas before compression, and a discharge chamber for said refrigerant gas after compression, the refrigerant gas containing a lubricating oil and suspending therein;
• a drive shaft supported rotatably about an axis of rotation thereof within said crank chamber;
• pistons movably received in said cylinder bores of said cylinder block and reciprocating to compress the refrigerant gas introduced from said suction chamber and to discharge the compressed refrigerant gas from said cylinder bores into said discharge chamber;
• a cam plate element mounted around said drive shaft to be rotated with said drive shaft and able to change an angle of inclination thereof with respect to a plane perpendicular to the axis of rotation of said drive shaft to thereby cause a change in the stroke of the reciprocating motion of said pistons;
• a gas supply passage extending between said discharge chamber and said crank chamber;
• a gas withdrawal passage extending between said crank chamber and said suction chamber;
• a capacity control valve arranged in said housing to control said angle of inclination of said cam plate;
• and
• an oil separating means for separating said lubricating oil suspended in said refrigerant gas, said separating means being arranged in said gas supply passage between said crank chamber and said capacity control valve.