A Spherical Motor Driven by Electro-Magnets Based on Polyhedrons

This paper describes the development of a spherical motor, hereinafter called “14-12 spherical motor.” This spherical motor utilizes two polyhedrons – a truncated regular octahedron and a regular dodecahedron – for the arrangement of permanent magnets on the rotor and electro-magnets on the stator. The 14-12 spherical motor has two types of rotation axes and six rotation axes in all. Five-phase alternating current was applied to the electro-magnets to rotate the rotor. This study also developed a simulation model for the 14-12 spherical motor to numerically simulate the dynamic behavior of the motor. Basic performance was measured and simulated to evaluate (1) the relation between rotation speed and maximum output rotation torque and (2) cogging torque. Waveforms of the five-phase alternating current were improved using the simulation model in order to increase output rotation torque for the rotation axis with the smaller torque.