Optimized Design Of High-speed Slotless Permanent Magnet Micro Motor

Because of its small size,fast dynamic response,high power density,high efficiency and no cogging torque,micro slotless permanent magnet motors are widely used in robot joints,precision CNC machine tools,flywheel energy storage,medical devices,aerospace and other fields,and gradually become one of the research hotspots in motor design,robot technology,high-speed and other fields.In this paper,150 W micro slotless permanent magnet motor is taken as the research object,and the optimization design and manufacturing technology of slotless permanent magnet motor are studied.Firstly,the existing research results,main characteristics and working principle of slotless permanent magnet are analyzed.The main dimensions of the motor are calculated by analytic analysis method.The obtained analytical formulas can be used to build not only a slotless motor but also other designs.On this basis,the output characteristics are calculated by two-dimensional finite element method,and various losses of the motor are also calculated.Secondly,a slotted motor was designed,with similar dimension,this model will allow to make comparisons between slotless and slotted motor.The slotless permanent magnet motors and slotted permanent magnet motors are compared and analyzed,and how to select the type of permanent magnet motors under small size constraints is obtained.The slotless permanent magnet motors are optimized.To achieve high torque density,the size of the permanent magnet is maximized as much as possible,and the flux density of the stator core is estimated relative to different magnet volumes.By calculating the back electromotive force(EMF),the area of the winding is approximately determined based on the number of turns of the coil.Finally,on the basis of theoretical analysis and electromagnetic field calculation,two prototypes of slotless motor are made,and load experiments of slotless motor are carried out.The correctness of theoretical analysis is verified by two-dimensional finite element analysis and experimental results.