Research On The Structure Design And Electromagnetic Performance Of A New Type Of Motor Rotor Based On Metal 3D Printing

With the application of motors in various occasions,higher requirements have been put forward for their electromagnetic performance.The motor core is an important part of the motor,and the production of the core is also an important indicator to measure the performance of the motor.The motor core of a traditional motor is made by laminating silicon steel sheets or winding steel strips.This process is more complicated,and the versatility of the mold is not high,which limits the design of the motor.The metal 3-dimension(3D)printing technology has a simple printing process and strong operability.It can accurately and quickly manufacture parts with any complicated shape.It provides new ideas for the design and manufacture of motors.However,after using metal 3D printing,the motor core is printed as a whole,which increases the eddy current loss of the motor and reduces the performance of the motor.Moreover,after the Fe-Si soft magnetic powder is formed by metal 3D printing at high temperature,the electromagnetic properties of the material will also change.In order to explore the application of 3D printing in the motor field,this article chooses to start with the motor rotor with less eddy current loss,and gradually start the research.In this paper,the metal 3D printing process is used to make the rotor core.The main research content is divided into the following three parts:First,the air gap flux density simulation and Fourier analysis are carried out on four common rotor structures of permanent magnet synchronous motors(PMSM).The fundamental wave amplitude and total harmonics distortion(THD)value of the air gap magnetic density of the four rotor structures are compared.Therefore,a permanent magnet synchronous motor structure suitable for metal 3D printing is selected.Secondly,the reasons for the eddy current loss in the rotor core are analyzed and the calculation process of the core block eddy current loss is deduced.Then,the influence of slot-pole fit,air gap length and rotor core segmentation on the eddy current loss of the metal 3D printed rotor are analyzed.The eddy current loss of the motor is reduced through the design of the rotor air magnetic barrier.And integrated segmentation method,so that the rotor core eddy current loss is further reduced.Taking into account the mechanical strength of the motor and the difficulties in the actual printing process,the rotor structure is further optimized,and the basic electromagnetic parameters of the optimized motor model are calculated.Finally,the basic principles,experimental procedures and precautions of the metal 3D printing process are introduced.Summarized the problems encountered in the experiment and provided solutions.The experimental parameters suitable for 3D printing of Fe-Si soft magnetic powder metal are obtained.On this basis,the rotor core is printed.The basic magnetization curve and density of Fe-Si soft magnetic powder after printing were tested.A motor test platform is built,the basic electromagnetic parameters of the traditional rotor motor and the printed rotor motor are tested and compared,and the correctness of the simulation results is verified,which fully demonstrates the feasibility of the metal 3D printing process in the motor industry.