Linear Piezoelectric Motor for Topography Detector of Diamond Wire

In topography detection procedures for diamond wire, precision motion control is one of the key preconditions; the motion control unit of detection needs both micron resolutions and centimeter strokes. In this paper, a linear motor with four sets of multilayer piezoelectric actuators was developed to achieve an actuator with high resolution and a large stroke. The stroke depended on the guideways of the system, which mar enlarged the stroke of a single multilayer piezoelectric actuator. The mechanism of differential actuation was analyzed by dividing an operation cycle into several states. A symmetrically arranged four-foot design was proposed, and a corresponding excitation method was devised. A prototype was fabricated to conduct a proof-of-concept operation test. Experimental results validated the feasibility of the prototype with a 10 mm stroke. The speed of the prototype increased when the amplitudes of driving voltage signals increased from 30 V to 100 V. Within the frequency range of 1 Hz to 120 Hz, the speed increased initially then decreased with driving frequency, the maximum of which was at 100 Hz. With an excitation voltage signal of 100 V and 100 Hz, the speed reached a maximum of 740 μm/s. With an excitation voltage signal of 30 V and 120 Hz, the resolution of the prototype reached 0.26 μm. The prototype satisfies precision motion control of topography detection for diamond wire. This work also provides an option for automatic systems that require high resolutions and large strokes.