Patent ID: 6599093
Filing Date: 2003-07-29
Classification: F04C

Abstract:
A compressor comprising:a compressor body that is driven by a motor; a motor control mechanism for controlling the rotational speed of said motor; a pressure detector for detecting a discharge pressure of said compressor body; an intake regulation valve provided at the inlet side of said compressor body; and a control operation unit that outputs a motor rotational speed command signal to said motor control mechanism and outputs an open/close command signal to said intake regulation valve, wherein when the rotational speed commanded to said motor control mechanism is not lower than a predetermined threshold, said control operation unit outputs the motor rotational speed command signal to said motor control mechanism, as the control operation unit outputs the open signal to said intake regulation valve, so that said discharge pressure will be maintained at a predetermined target pressure, based on the pressure signal from said pressure detector, and when the rotational speed commanded to said motor control mechanism is lower than said threshold, said control operation unit outputs the open/close signal to said intake regulation valve, in a state that the rotational speed of said motor is being maintained at about said threshold, so that said discharge pressure will be maintained at the predetermined target pressure, based on the pressure signal from said pressure detector, and wherein said threshold is set to such a value that the leakage quantity of gas, compressed by said compressor, into the inlet side of said compressor will not be increased as the rotational speed of said motor is decreased.