METHOD OF MEASUREMENT OF RADIAL CLEARANCES AND AXIAL DISPLACEMENTS OF END FACES OF TURBINE WHEEL BLADES Russian patent published in 2015 - IPC G01B7/14 

FIELD: instrumentation.

SUBSTANCE: invention is used for measurement of clearances and axial displacements of end faces of working blades of turbines. The essence of the invention consists in that with the end face of the monitored blade the distributed cluster is made to interact which is formed by two high-temperature single-turn eddy current transducers with sensitive elements (SE) designed as a linear piece of the conductor installed on a stator shell with rated shift with reference to each other in the direction parallel to the axis of the driving wheel (X axis) to the distance equal to the expected displacement of the blade end face Δx₀, and the cluster of transducers is placed on X axis to the left of the outlet edge of the blade to the half of SE length (λ_SE/2), and also SEs of transducers are oriented parallel to the tangent to the centreline of the profile of the blade end face in the point of its intersection with the rotation plane passing through the geometrical centre of the cluster of transducers (the middle of the line connecting centres of transducer SEs); from the set of results of conversion of parameters of the first SE with face edges of back and trough of each monitored blade the least of extreme values of codes is selected, and from the set of results of conversion of parameters of the second SE with face edges of back and trough of each monitored blade the greatest of extreme values of codes is selected.

EFFECT: improvement of sensitivity of single-turn eddy current transducers with sensitive elements designed as a linear piece of conductor at measurement of radial clearances and axial displacements of end faces of turbine blades with a large bend angle of the profile and U-shaped longitudinal section of its feather.

2 cl, 2 dwg