Design and experimental analysis of a high force piezoelectric linear motor

In this paper, the design and experimental analysis of a piezo-motor for applications requiring compact size, high blocking and driving forces are presented. Mechanical design addresses difficulties associated with high integration flexibility and high blocking force for the motor. The technology is inspired from a real inchworm motion and is based on Piezoelectric Actuators (PAs). The proposed Inchworm Motor (IM) consists of an extending mechanism (EM) and two doubled clamping mechanisms (CMs). Theoretically and by using Finite Element Analysis (FEA), the CM is designed in order to obtain high clamping forces between rotor and stator (2500N), while the EM is designed for large displacement (free stroke of 0.01mm) and high force (500N) using PAs. Practically and by using a preliminary low power supply (80V, 1Hz), the working principle of the motor is validated under testing conditions of 300N as a clamping force and 5N as a driving force. The fabricated IM achieves speed of 2.25μm/s. Experimental methods for verifying the theoretical force, calibrating the pre-stressing force and measuring the friction coefficient between the stator and the rotor are proposed. A motor with a weight of 78g and dimensions of 100mm×16mm×7mm ensures full clamping ability when not electrically activated.