抄録
An outer-rotor-type multidegree-of-freedom (MDOF) spherical ultrasonic motor (SUSM) is proposed. This type of an MDOF SUSM can be applied directly as a MDOF joint of robot and manipulator. The SUSM consists of a spherical shell as outer rotor, a rotation shaft and two stator vibrators with the same structure. Three kinds of vibration modes can be excited by both of the stator vibrators, and the outer rotor can rotate around the stators on three axes by combining the different vibration modes. This paper describes the construction and the operating principle of an outer-rotor-type MDOF SUSM, modal analysis results of the stator, and some measurement results from trial manufacturing. The outer-rotor-type MDOF SUSM has the possibility of realizing a simple, lightweight, compact and flexible actuator system, and a large torque-to-weight ratio is expected to be realized.
