APPARATUS FOR DETECTING ABRASION OF AXIAL BEARING OF CANNED MOTOR

摘要

PURPOSE: An apparatus is provided to accurately display the axial abrasion of the bearing and the direction and degree of the abrasion. CONSTITUTION: An apparatus comprises an axial detection coil mounted at the axial both ends of a stator of a canned motor; a differential amplifier circuit for differentially amplifying the voltage which is detected by the axial detection coil and rectified and smoothed, and outputting a voltage signal in accordance with the direction and position of axial movement of a rotor with respect to the stator; a blind zone circuit(77) including a polarity inversion circuit(71) for inverting the polarity of the voltage signal output from the differential amplifier circuit, a comparing signal generating circuit(76), the first comparator circuit(72) for outputting a signal corresponding to the size of the voltage signal when the voltage signal output from the polarity inversion circuit is larger than the comparing signal output from the comparing signal generating circuit, and the second comparator circuit(74) for outputting a signal corresponding to the size of the voltage signal when the voltage signal output from the differential amplifier circuit is larger than the comparing signal output from the comparing signal generating circuit; and an axial abrasion display for displaying the degree of axial abrasion of the canned motor in accordance with the signals output from the comparator circuits of the blind zone circuit.