A new method for boring of non-circular holes

Abstract

A revolving electromagnetic actuation mechanism composed of an electromagnetic stator and an electromagnetic rotor has been developed for boring non-circular holes. The main component of the rotor is a flexure-hinged based flexible body. There are four pole-pair coils in the stator supplying actuation currents. The micro-displacement between the stator and rotor can be controlled by changing the currents applied in the pole-pair coils. Through linearization of the actuation force near the static action point, a linear relationship between the control current and the actuation force was established, and the synchronizing control method of the electromagnetic actuation mechanism is presented here. With two-factor analysis of the linearization error of the actuation force, the influences of control current and micro-displacement to the linearization error of the actuation force were studied. Then, the principle for designing the basic parameters of the magnetic actuation mechanism is put forward. The calibration of the mechanism indicates that the relationship between the micro-displacement of the rotor and the control current has linear characteristics in the required micro-displacement range. Simulation tests show that the turning radius of the rotor changes with the control current. The proposed mechanism can feasibly supply a controllable micro displacement to the boring bar.