1982 Volume 48 Issue 12 Pages 1608-1613
A new type induction motor with a built-in torque sensor has been developed in order to monitor grinding torque. Its rotor shaft consists of a hollow shaft and a torsion-bar, each of which has a disc with equally separated magnets, and torque output is calculated by microcomputer from time delay of pulses generated in detecting coils. This torque sensor has good linearity in torque and rotation speed output. Torque ripple and zero-point drift caused by rotation speed change are estimated less than 1 N·m. It is so sensitive that it can detect torque ripple driven from belts' rotation error on the grinding machine. And using a low path filter it can surely monitor grinding torque without such torque ripple. It can also estimate the timeconstant of the grinding-wheel and workpiece system in transient torque situation of a grinding cycle. As a grinding-wheel motor the developed one has as good property as a usual one.
