Three-dimensional characteristic analysis of micro BLDC motor according to slotless winding shape

The winding of slotless BLDC (SLBLDC) motor has a rhombic shape or hexagonal shape in its axial direction. So, its shape is not uniform in its axial direction. The analysis and design of slotless brushless dc (SLBLDC) motor must consider the three-dimensional (3-D) shape of the winding. In particular the magnetization distribution of PM as well as the shape determines the output characteristics of SLBLDC motor, which has a 3-D pattern because of the overhang. For the analysis, a new numerical method is developed. The analysis results of this method have been compared with the measured results.