Patent ID: 7726949
Filing Date: 2010-06-01
Classification: F04B

Abstract:
1. A variable displacement compressor having a discharge chamber, a suction chamber and a crank chamber, said compressor comprising a displacement control valve disposed at a position in a discharge pressure supply passageway capable of communicating with said crank chamber from said discharge chamber, and a fixed orifice provided at a position in a pressure relief passageway communicating with said suction chamber from said crank chamber, said displacement control valve being controlled in opening/closing operation to regulate a pressure in said crank chamber to control a piston stroke, wherein said displacement control valve further comprises a pressure sensing member being expanded and contracted by sensing a pressure in said suction chamber or said crank chamber, a valve element one end of which is brought into contact with said pressure sensing member and which has a valve part opening and closing a valve hole formed in said discharge pressure supply passageway in response to an expansion/contraction of said pressure sensing member, a valve chamber in which said valve part is disposed and to which a pressure in said crank chamber acts, a fixed partition wall disposed around said valve element at a position in an axial direction of said valve element, a pressure chamber which is partitioned from said valve chamber by said fixed partition wall and to which a pressure in said suction chamber acts, and a solenoid provided to the other end of said valve element and capable of controlling an opening degree of said valve part by increase/decrease of an electromagnetic force, and said pressure relief passageway from said valve chamber to said pressure chamber is formed by a gap between said fixed partition wall and said valve element for forming a non-contact structure which does not give a sliding resistance relative to a movement of said valve element in its axial direction, wherein said pressure relief passageway continuously is open.