US Patent 10323535 Blade tip clearance systems

A blade tip clearance system includes first and second control rings. The first control ring has a first coefficient of thermal expansion (CTE) and a first thermal response rate. The second control ring is located radially outward of and operatively connected to the first control ring and has a second CTE that is different from the first CTE and a second thermal response rate that is different from the first thermal response rate. Thermal expansion and contraction of the first and the second control rings controls a radial position of the blade tip clearance system relative to a rotating blade component.