Gas turbine engine tip clearance control system

A system for controlling tip clearance between tips of rotor blades and a surrounding outer gas path wall in a gas turbine engine, the rotor blades mounted to an engine shaft for rotation about a shaft axis, the system comprising:

• a thrust bearing disposed in a bearing housing, the thrust bearing supporting the engine shaft and located at a fixed axial position thereon;
• and
• a rotary actuator driving a rotary-to-linear motion mechanism, the rotary-to-linear motion mechanism axially translating the thrust bearing relative to the bearing housing and thereby axially translating the engine shaft and the rotor blades mounted thereto within the gas turbine engine;
• wherein the outer gas path wall is non-parallel to the shaft axis, and the tip clearance changes due to the axial translation of the rotor blades and the engine shaft by the rotary-to-linear motion mechanism.