GB1303993A - - Google Patents

Abstract

1303993 Measuring shaft displacements electrically ENGLISH ELECTRIC CO Ltd 25 March 1970 [1 April 1969 22 Aug 1969 9 Dec 1969] 17045/69 42001/69 and 60015/69 Heading G1N Apparatus for measuring displacement of a shaft 10 relative to a frame bearing the shaft and in a direction perpendicular to its axis comprises a collar 11 of non-magnetic material with a plurality of cylindrical magnets 12 embedded in it, spaced apart arcuately of it and disposed parallel to the shaft, and a pair of pick-up loops 13 in series opposition which supply a pulse train to circuits including a trigger circuit19 and a meter 24 whereby the time intervals between successive pulses are indicative of radial shaft displacement. A further pair of loops (60-61) Fig.4 (not shown), radially displaced from the pair 13 are selectively connected to the circuit for calibration. Alternatively the outputs from diametrally opposed pairs (13, 13') Fig. 5 (not shown) are combined so as to compensate for thermal expansion. To detect lateral displacement of the shaft, loops (80, 81) Fig. 6, (not shown) are provided at diametrally opposed points adjacent the collar, the plane of each of the loops being disposed parallel to the shaft. Fig. 8 (not shown) illustrates an embodiment utilising a plurality of loops thereby increasing the frequency of pulses.