A small piezoelectric stack motor designed for vacuum and micro-dust environment

Abstract

With the development of moon exploration, higher requirements have been proposed for the adaptability of small motors under vacuum and micro-dust conditions. In this paper, a rotational motor based on piezoelectric stacks is proposed, which can be driven by a single-phase direct current with a simple drive circuit. The motor dimensions are 24 mm × 24 mm × 24 mm (length × width × height), and the mass is 11.4 g. In air environment, the maximum output rotational speed of the motor is 1372 rpm, and the maximum stall torque is 3.2 mN m at 40 V DC and 5.93 kHz. An open-loop control system is established to drive the stepping motion of the motor, and the minimum stepping angle is measured as 0.122 mrad. An environmental experiment of the motor is conducted in a lunar simulator module, which can simulate a high vacuum (6.7 × 10−5 Pa) and micro-dust (average 75 μm) environment of the lunar surface. The result shows that the motor can work steadily in the vacuum and micro-dust environment with an average speed of 1723 rpm, which demonstrates its potential applications in the space environment.