Variable displacement compressor

Abstract

A variable displacement compressor the displacement of which is externally controlled is provided. The compressor has basically the same structure as prior art compressors except for simple differences. A pressure sensing chamber of a displacement control valve is connected to a suction chamber by an outlet passage. A bellows is located in the pressure sensing chamber. The bellows expands and contracts in accordance with the pressure in the sensing chamber. A valve chamber forms part of a displacement control passage, which is used to control the pressure of a crank chamber. A valve body is located in the valve chamber. The valve body is moved by the bellows to open and close the displacement control passage. Highly pressurized gas from the discharge chamber is supplied to the pressure sensing chamber through an inlet passage. The gas in the pressure sensing chamber is released to the suction chamber through the outlet passage. An electromagnetic valve is located in the outlet passage to regulate the flow of refrigerant gas from the sensing chamber. The outlet passage also includes a bypass passage. The bypass passage bypasses the electromagnetic valve and constantly communicates the pressure sensing chamber with the suction chamber.