Study of a Five-Phase AC Driven Spherical Motor with Oscillatory Movement

Abstract

The conventional motor is driven with one degree of freedom, whereas the spherical motor is driven with three degrees of freedom. As a result, compared to conventional motors, control to the target posture is easier in a mechanism using spherical motors. In addition, the difficulty of achieving ultra-high accuracy due to assembly errors and difficulty of maintenance will be reduced. Because of these features, spherical motors are expected to be used for robot eyes, joints, reaction wheels, and stirrers. In the culture of cells in biotechnology, it is necessary to constantly stir the solution containing cells, but currently the stirring is conducted by one-dimensional movement. There is a need for a rotation motion with sinusoidally changing the tilting angle of rotation axis. This study proposes a spherical motor to realize the rotation motion and has developed a prototype spherical motor of this type. The proposed spherical motor is driven by the electromagnets excited by five-phase alternating currents. This paper describes the structure of proposed spherical motor, its driving principle and rotation experiments of the developed prototype of spherical motor.