Continuously variable capacity swash plate type refrigerant compressor

Claim 1

A continuously variable capacity swash plate type compressor for compressing a refrigerant gas used in a refrigerant circuit, comprising: an axially extended cylinder block having front and rear ends thereof; front and rear housings sealingly attached to the front and rear ends of the cylinder block and provided with front and rear suction chambers for the refrigerant before compression and front and rear discharge chambers for the refrigerant gas after compression; a plurality of front and rear axial cylinder bores defined in front and rear portions of the axially extended cylinder block; a plurality of double-headed pistons capable of axially reciprocating in the plurality of front and rear cylinder bores of the cylinder block to thereby compress the refrigerant gas; an axial drive shaft rotatably supported in the cylinder block and having an axis of rotation thereof extending axially in the cylinder block; a swash plate supported on the drive shaft to be integrally rotated with the drive shaft to reciprocate the double-headed pistons at front and rear parallel faces thereof, and shoes, the swash plate being pivotable to change an angle of inclination with respect to a plane vertical to the axis of rotation of the drive shaft about a center located at a peripheral portion of the swash plate which passes through each of the rear cylinder bores during a rotation of the swash plate, to thereby reciprocate each of the plurality of double-headed pistons in such a manner that a top dead center of each of the plurality of double-headed pistons is always located at a fixed position within each of the plurality of rear cylinder bores; control means for controlling the angle of inclination of the swash plate to thereby adjustably vary the compressing capacity of the compressor depending on a change in a cooling load in the refrigerating circuit; front suction passageway means arranged in the cylinder block for permitting a suction of the refrigerant gas before compression from the external refrigerating circuit into the front suction chamber; rear suction passageway means arranged in the cylinder block for permitting a suction of the refrigerant gas before compression from the external refrigerating circuit into the rear suction chamber; fluid passageway means for communicating between the front and rear suction chambers; and suction reducer means for reducing a flow of the refrigerant gas before compression passing through the rear suction passageway while the compressor is in operation at a small compressing capacity while the front cylinder bores are dormant, due to lessening of the angle of inclination of the swash plate, the suction reducer means being operable in association with a change in the compressing capacity of the compressor.