METHOD FOR MEASURING RADIAL GAPS BETWEEN THE ENDS OF SCREW BLADES AND THE INTERNAL SURFACE OF STATOR COVER OF NOSE-OVER SCREW VENTILATOR PLANT Russian patent published in 2008 - IPC G01B7/14 

FIELD: measuring equipment, possible use for non-contact measurement of radial gaps between the ends of screw blades and the internal surface of nose-over screw ventilator plant.

SUBSTANCE: method includes mounting a single-coil vortex-current transformer on internal surface of stator cover, which transformer has working sensitive element in form of a length of conductor facing the blade end. The blade end has high electric conductivity. Transformer is positioned in such a way, that working sensitive element is within rotation plane of the screw blade when its static mounting angle is zero. Vortex-current transformer is included in bridged measuring circuit of measuring channel. Output digital code of measurement channel is recorded. By means of software and hardware means, included in composition of stand equipment, motor traction force and screw shaft rotation frequency are recorded. On basis of measured value of traction force and rotation frequency, turn angle of screw blade (φ_b) is modeled. Using the model of resilient bending deformations of screw ventilator plant blades, on basis of measured traction force, values of components of axial displacement of screw blades (X_b) and of shifts in the direction of rotation (Z_b) are determined. On basis of the result of transformation into digital code of measuring channel with vortex-current transformer C and on basis of X_b, Z_b, φ_b modeling results, by means of function, inverse to the family of calibrating characteristics of measuring channel, target value of radial gap (Y_b) is determined.

EFFECT: reduced number of utilized primary transformers, increased reliability of measurement result.

5 dwg