DEVICE FOR MONITORING AXIAL DISPLACEMENT OF SHAFT Russian patent published in 1999 - IPC

FIELD: measurement technology; automatic monitoring for maximum allowable axial displacement of rotating parts including turbine shafts. SUBSTANCE: device has three pairs of linear- displacement transducers 1-1, 1-2 through 3-2, voltage adders 4, 5 through 9, analog-to-digital converters 10, 11 through 15, measuring data processing units 16, 17, 18, OR gate, and switch. Transducers 1- 1, 1-2, 2-1, 2-2, and 3-1, 3-2 are arranged symmetrically relative to monitored shaft axis at 180 deg. to the latter so that ac components of measuring signals are relatively compensated for during their addition by means of adders 4 through 9 and do not produce any impact on precision of measurement data processing; this procedure results in generation of alarm signal in case shaft has displaced beyond permissible limit. Device incorporates hardware redundancy provision and ensures double confidence check of measurement information entered in units 16, 17, 18; measurement codes are checked in the beginning of each cycle for identity of increments relative to preceding cycle and alarm signal is generated only in case readings of linear-displacement transducers are within preselected limits of their measurement range. EFFECT: improved precision of measurement data processing and operating reliability of device. 2 cl, 10 dwg