Patent ID: 7493829
Filing Date: 2009-02-24
Classification: G01F

Abstract:
1. A flow meter for a variable displacement compressor which comprises a housing having a plurality of cylinder bores, a drive shaft provided in the housing, pistons disposed in the cylinder bores and a swash plate provided on the drive shaft, the pistons being driven by the swash plate, an inclination angle of the swash plate being controlled for controlling a displacement of the compressor, the flow meter comprising: a movable body operable to move by differential pressure, wherein the movable body is arranged perpendicularly to the flow passage; a magnet provided in the movable body; a magnetic sensor for detecting change of magnetic flux density of the magnet; a flow passage for refrigerant gas which is discharged from the cylinder bores to flow therethrough; a sealed chamber connected perpendicularly to the flow passage and accommodating therein the movable body; an urging member for urging the movable body into the flow passage; a clearance formed between a movable body and an inner wall surface of the flow passage, wherein the clearance is always provided as a part of the flow passage; a by-pass passage opened and closed as the movable body is moved in an axial direction of the movable body; and a communication passage for introducing into the sealed chamber the refrigerant gas in a downstream flow passage of the flow passage which is located downstream of the movable body.