Motional characteristics of ultrasonic motor using Λ (lambda)-shaped stator

In this study, characteristics of novel ultrasonic motor with lambda shaped stator were investigated. A thin metal plate was used as a Λ(lambda)-shaped stator and four ceramic plate were attached on upper and bottom surface of the metal plate. From the stator, elliptical displacements of the contact line were obtained. When two sinusoidal sources with phase difference of 90° were applied to the ceramics, the symmetric and anti-symmetric displacements were combined at the contact line of the stator to make the elliptical motion. A finite element analysis (ATILA) was used for simulating the motional pattern of contact line of the stator. Stator characteristics depending on changes of ceramic size and thickness of metal were analyzed. The motor was fabricated by using results of FEA. Characteristics of the motor such as frequency, speed, torque, and pre-load were measured by using the driving system and measurement equipment.