Patent ID: 7293965

Claim:
A limiter device provided in a variable displacement compressor capable of compressing a fluid in a cycle and varying a discharge displacement of the fluid per revolution, the limiter device comprising: a sensor for detecting at least one of the following characteristics; a temperature or a vibration at a predetermined portion of the compressor during a compression operation of the compressor; a quantity of wear powder flowing in the compressor with the fluid; a sliding position of a compression member of the compressor; and a discharge side pressure of the compressor; and a solenoid valve for minimizing the discharge displacement when the characteristic obtained by the sensor exceeds a predetermined value, wherein: a current supplied to the solenoid valve is adjusted in response to a detection signal from the sensor and opens or closes a part of a communication passage of the fluid in the compressor to vary the discharge displacement; the sensor is for detecting the quantity of the wear powder and is constructed of a positive pole part and a negative pole part; the positive pole part and the negative pole part have tips that are disposed in the compressor and are arranged to have a predetermined potential difference therebetween; and the positive pole part is separated from the negative pole part in such a manner that they are brought into conduction when a predetermined amount of the wear powder adheres to them.