Design Of Dual-Rotor Unequal Number Of Poles PM Torque Motor For NC Table

Modern CNC rotary table is one of the most important assemblies in multiaxial linkage NC machine. The direct drive NC table abolishes the worm wheel and worm mechanical transmission chain, using of direct-drive ring structure torque motor, which compares with traditional drive has performance advantages has a high torque, high accuracy and fast response. In recent years, the research hot spot in multiaxial linkage high-grade NC machine field is the direct drive CNC table assembly. In the sub-topics of National Science and Technology Major Projects and the Technology Council of Liaoning Province Major Projects, the thesis studies a novel e torque motor—dual-rotor unequal number of poles PM torque motor for NC table. The motor maintain the advantages of high density and high accuracy, at the same time, which has a good processing technology.Firstly, According to the motor application place, and practical design experience, this paper introduces the designing idea and structural characteristics the mathematical expression of main inductance magnetic flux leakage coefficient is deduced on the motor. Get the finite element model, obtained inner and outer motor no-load back EMF, the synthesis back EMF, analyses the both inner and outer motor no-load voltage harmonic and torque by ANSYS, which is more accurate finite element analysis software.Secondly, as the number of poles of inner and outer motors is unequal, inner and outer rotors are rigid connection and rotate with the same speed. The expression of cogging torque is deduced in order to reduce the cogging torque of the motor as the same time ensure the motor has a high servo accuracy, the method of evenly auxiliary slots opening on the every tooth top of the inner motor is carried, so that the cogging torque curve fluctuations of inner and outer motors have the same frequency. According to the dual-rotor PM ring torque machine, these method for reducing the cogging torque amplitude and leading a reverse phase torque curve by suitable selection of the inner and outer slot opening widths and change the relative angle of inner and outer slot opening is proposed.Finally, on the basis of fundamental theory research, the electromagnetic field of the motor has been analyzed by FEM software, These design methods are verified to be effective.