Patent ID: 6572341
Filing Date: 2003-06-03
Classification: F04B

Abstract:
A variable displacement type compressor comprising:a housing having cylinder bores, a crank chamber, a suction chamber and a discharge chamber formed therein; a suction passage for introducing refrigerant gas from an outer refrigerant circuit into the suction chamber; a discharge passage for discharging refrigerant gas from the discharge chamber to the outer refrigerant circuit; pistons slidably arranged in the cylinder bores; a drive shaft extending through the crank chamber; a cam plate mounted on the drive shaft for rotation with the drive shaft and for tiltable motion with respect to the drive shaft and operatively coupled to the pistons to convert the rotation of the drive shaft into the reciprocating motion of the pistons; a pressure control device for controlling the pressure in the crank chamber to change an inclination angle of the cam plate to change the displacement of the compressor; a first valve arranged in the suction passage for opening and closing the suction passage, the first valve having a valve element, a pressure chamber applying a pressure to the valve element, and a spring urging said valve element in the valve closing direction, said first valve being arranged such that said valve element can hermetically close the suction passage when the refrigerant gas is introduced into said pressure chamber, wherein when said first valve is closed, refrigerant gas lubricating oil is prevented from dissipating through said suction passage and therefore maintained within the compressor; a first passage for introducing the refrigerant gas from the discharge chamber into the pressure chamber; a second passage branched from the first passage at a branch point and leading to the crank chamber; and a control device arranged such that the refrigerant gas can be introduced from the second passage into the crank chamber when the refrigerant gas is introduced from the discharge chamber into the pressure chamber and that the flow of the refrigerant gas from the crank chamber to the first passage is blocked when the introduction of the refrigerant gas from the discharge chamber into the pressure chamber is stopped.