Slant plate type compressor with variable displacement mechanism

Abstract

A slant plate type compressor with a capacity or displacement adjusting mechanism is disclosed. The compressor includes a housing having a cylinder block provided with a plurality of cylinders and a crank chamber. A piston is slidably fitted within each of the cylinders and is reciprocated by a drive mechanism which includes a slant plate having a surface with an adjustable incline angle. The incline angle is controlled according to the pressure in the crank chamber. The pressure in the crank chamber is controlled by a control mechanism which comprises a first passageway linking the crank chamber and the suction chamber, and a valve device which controls the closing and opening of the first passageway. The valve device includes a valve element which directly controls the closing and opening of the first passageway, a first valve control device which controls the position of the valve element in response to pressure in the crank chamber, and a second valve control device which include a second passageway linking the crank chamber and the discharge chamber and an actuator disposed in the second passageway. The second valve control device controls the predetermined crank pressure operating point of the first valve control device. The operation of the second valve control device is controlled in response to changes in the thermodynamic characteristics of the refrigerant circuit so as to open and close the second passageway.