Patent ID: 6851934
Filing Date: 2005-02-08
Classification: F04B

Abstract:
1. A stroke control apparatus of a reciprocating compressor, comprising: a reciprocating compressor; a current detecting unit for detecting a current applied to a motor of the reciprocating compressor; a stroke detecting unit for detecting a piston stroke by using the current applied to the motor of the reciprocating compressor; a phase difference detecting unit for detecting a phase difference between the piston stroke from the stroke detecting unit and the current from the current detecting unit; an operational frequency determining unit for determining an operational frequency corresponding to an operation region according to the detected phase difference; a frequency/stroke storing unit for storing a piston stroke value based on the determined operational frequency; a reference stroke value determining unit for determining a reference stroke value corresponding to the determined operational frequency by using the stroke value pre-stored in the frequency/stroke storing unit; a control unit for comparing the reference stroke value with a present piston stroke value after a certain time point and outputting a stroke control signal according to the comparison result; and an inverter for varying an operational frequency and a voltage applied to the motor of the reciprocating compressor according to the stroke control signal of the control unit.