Development of an integrated type slotless BLDC motor with a 15-mm-outer diameter

Recently, slotless BLDC(brushless DC motor) motors have been used as the small sized motors which are suited for precision mechanism such as robot. Moreover, miniaturization precision mechanism requires BLDC motors to be smaller than before. The BLDC motors are required to be driven with high power density. This paper presents the development of an integrated type slotless BLDC motor with a 15-mm-outer diameter. We design the slotless BLDC motor using FEM(finite element method). Especially, COB (chip on board) type driver is used for small in size. The mechanical structure of the development model is extremely miniaturized not only by eliminating the unnecessary space and but also by using COB type driver. Also, we design planetary gear heads. The planetary type gear heads have advantages that same-axle structure, high torque transmission, low noise in comparison with spur gear heads. And the characteristics of the development motor are analyzed by performing experimentation.