Patent ID: 7165947

Claim:
A screw compressor equipped with an internal volume ratio adjusting slide valve and a capacity adjusting slide valve, wherein the capacity adjusting slide valve having a cut in the discharge side end part thereof for defining radial port and having a center female screw hole is screwed on a male screw thread part of a valve driving shaft, the internal volume ratio adjusting slide valve having a center hole is supported for sliding on said valve driving shaft in the suction side from the capacity adjusting slide valve, the internal volume ratio adjusting slide valve is pushed toward the capacity adjusting slide valve by an elastic member supported in the suction side bearing housing, and a fixing means for securing the internal volume ratio adjusting slide valve in place is provided, and wherein internal volume ratio is adjusted through securing in place the internal volume ratio adjusting slide valve by means of said fixing means and capacity is adjusted through sliding the capacity adjusting slide valve by rotating said valve driving shaft.