A study on design and manufacturing of a micro brushless DC motor

The reduction of size and weight is very often one of the most important requirements in product design. Many applications in robotics, automation, medicine systems etc require powerful micro motor and actuator. In this paper, a design and fabrication result of an ultra-small brushless DC motor is presented. The outer diameter of the designed motor is 2 mm. This motor is designed to 3-phase slotless winding type, and operated with both a synchronous type driver and a sensorless type one. The experimental results for back EMF value and speed characteristics are presented and discussed.