| 摘要 |
FIELD: measurement technology. SUBSTANCE: procedure can be employed for contact-free test of radial clearances between butts of blades and jacket of fan and of angular positions of blades in process of operation of fan during tests and operation. In compliance with first variant dependence of length of path S in which blade interacts with eddy-current converter on angular position alpha. of blade is established first. Inverse relationship alpha = f(S) is constructed by obtained dependence, eddy- current converter is placed on frame of turbo-machine. In process of operation of turbo-machine eddy- current converter is excited in zone of clearance measurement with alternating magnetic field and values of signals measured in passage of blades through sensitive zone of eddy-current converter are recorded. Length ttp of pulse during which blade interacts with eddy-current converter is measured, linear velocity of motion of peripheral section of blade V is measured too. Length of path S in which blade interacts with eddy-current converter is calculated by multiplication of length ttp of pulse by linear velocity of motion of peripheral section of blade V by which angular position of blade is established with use of relationship alpha = f(S) obtained earlier. In correspondence with second variant dependence of length of path S during which blade interacts with eddy-current converter on angular position alpha, of blade is found beforehand. Obtained dependence is used to construct inverse relationship alpha = f(S). In process of operation of turbo- machine pulse repetition period T is measured, length ttp of pulse during which blade interacts with eddy-current converter is measured. Relative pulse duration is computed as relation of pulse repetition period T to length ttp of pulse during which blade interacts with eddy-current converter. Length S of path in which blade interacts with eddy-current converter is computed by division of value of spacing between blades into pulse repetition period Q and angular position of blade is established by substitution of obtained value of length S of path into relationship alpha = f(S) obtained before. EFFECT: reduced number of pickups required for establishment of angular positions of blades. 4 cl, 1 dwg |
