Turbine blade clearance controller

In a turbine engine having an engine housing with a chamber therein, a shaft located in said engine housing and extending into said chamber, a plurality of blades attached to said shaft and rotatable within said chamber, each of said blades having a tip that extends to a position adjacent the engine housing to define a desired clearance therebetween, said clearance being affected by operating engine parameters comprising temperature, pressure, engine speed, the improvement comprising:

• a first source of fluid having a fluid pressure (P.sub.1);
• a valve housing having a supply chamber connected to said first source of fluid, said valve housing having first and second exit ports;
• a nozzle having a head with a first cavity connected to said first exit port and a second cavity connected to said second exit port, said head having a first opening for connecting said first cavity with a recess in said chamber of the engine housing and a second opening for directly connecting said second cavity with said chamber of the engine housing, said first exit port restricting the flow of said first fluid from said supply chamber to establish a fluid pressure (P.sub.2) in the fluid communicated to said first cavity, said first fluid continually flowing from said first cavity into said first recess;
• a valve located in said supply chamber and movable with respect to said second exit port to control the flow of said first fluid therethrough to said second cavity, each tip of said blade restricting the flow of said first fluid from said opening to establish a fluid pressure (P.sub.2 ') in said second cavity, said fluid pressure (P.sub.2 ') being directly dependent on the clearance between the tip of said blade and said engine housing and the position of said valve with respect to said second exit port;
• and
• means responsive to a difference in fluid pressure (P.sub.2 -P.sub.2 ') in said first and second conduits for producing an operational signal, said valve being responsive to a change in said operational signal created as the fluid pressure P.sub.2 ' changes by moving to modify the flow of said first fluid through said second exit port to substantially nullify said difference in pressure (P.sub.2 -P.sub.2 ') by allowing the fluid pressure (P.sub.2 ') to equal the fluid pressure (P.sub.2), said valve controlling the flow of a second fluid to a manifold surrounding said engine housing, said second fluid counteracting the affect of said engine parameters by cooling said engine housing and reestablishing said desired clearance.