Wobble plate type variable capacity compressor with a capacity detector

摘要

A variable capacity wobble plate type compressor having a non-rotatory wobble plate supported on a magnetic material support member to non-rotatively wobble to move compressing pistons in cylinder bores, a steel drive shaft driven by a drive source via a solenoid-operated clutch and causing the non-rotative wobble of the wobble plate at a given angle of inclination that is changed to vary the capacity of the compressor, and a capacity detecting unit provided with a permanent magnet attached to an outer periphery of the wobble plate, a magnetic sensor fixedly attached to the crankcase of the outer casing, for sensing an approach and departure of the permanent magnet of the wobble plate. The magnetic sensor generates electric signals indicating the approach and departure of the permanent magnet of the wobble plate, and a binary circuit electrically connected to the magnetic sensor converts the electric signals of the magnetic sensor into electric binary signals by which the capacity of the compressor is determined. The capacity detecting unit is also provided with an arrangement wherein a magnetic flux delivered from the permanent magnet flows in a direction opposite to that of a magnetic flux leaking from the solenoid-operated clutch through the drive shaft and the support member to prevent erroneous electric binary signals when the permanent magnet attached to the wobble plate is close to the magnetic sensor.