Patent ID: 9513117
Filing Date: 2016-12-06
CPC Classification: F01D,F05D,G01B,G01M,G01N

Claim Text:
1. A method for measuring gas turbine blade tip and turbine ring segment radial clearance gap, comprising: providing a gas turbine including: a turbine casing having an inner circumferential ring segment that fully circumscribes a rotatable rotor oriented within the casing, the rotor having a row of turbine blades radially aligned with the ring segment, each blade having an airfoil that defines an airfoil outer surface and a radially outwardly projecting tip in opposed, spaced relationship with the circumscribing ring segment, each respective blade tip defining a radial clearance gap between itself and the circumscribing ring segment at a plurality of rotational angular positions of the blade and rotor; coupling on an airfoil surface of a first one of said blades at least one non-contact displacement sensor that generates a displacement data set of distance between the displacement sensor and the ring segment; coupling on the airfoil surface of the same first one of said blades a rotor rotational position sensor that generates a rotational position data set indicative of rotational angular orientation of said first blade relative to the circumscribing ring segment; rotating the rotor so that the blade tip of said first blade sweeps at least a portion of the circumscribing ring segment, while generating the displacement data set with the displacement sensor and a rotational position data set with the rotor rotational position sensor at plural angular positions along the blade tip sweep; acquiring the displacement and rotational position data sets with a data acquisition system that is coupled to the displacement and rotational position sensors; and correlating blade tip and circumscribing ring segment radial clearance gap relative to angular rotational position of said first blade, with the displacement and rotational data sets, at plural angular positions along the blade tip sweep, in a data analyzer system that is coupled to the data acquisition system.