Patent ID: 7393179

Claim:
A turbomachine for extracting mechanical energy from a compressed gas, comprising: a rotor portion including a rotor having a plurality of rotor blades; a nozzle portion having a plurality of rotatable nozzle vanes, a stationary shroud, and a movable wall, said movable mall having a first, higher pressure side and a second, lower pressure side opposite the first side; one or more pneumatic bellows, each of said one or more pneumatic bellows defining an internal cavity for selectively varying a pressure exerted on the lower pressure side of the movable wall; each of said one or more bellows including an inlet for selectively increasing pressure within said internal cavity for urging the movable wall to a closed position wherein the nozzle vanes are clamped between the movable wall and the stationary shroud; and each of said one or more bellows including an outlet for selectively reducing pressure within said internal cavity for retracting the movable wall to an open position permitting rotation of the nozzle vanes.