Considerations on Increase in the Torque of an Electromagnetic Friction-drive Micro-motor

摘要

We have proposed a new electromagnetic micro-motor, in which a vibration excited on a magnet is converted into a rotary movement through a frictional force. This paper describes its basic properties and a trial fabrication for improvement of the torque. First, we fabricated and tested a motor whose stator was an air coil. The revolution speed showed a strong dependence of the excitation frequency. The starting torque was as small as 1.3 x 10~-5Nm. Next, we tried to increase the torque by increasing the attractive force of the rotor. An improved motor using a ferrite core exhibited the maximum torque of 2.5 x 10~-4Nm.