Research On Permanent Magnet Torque Motor With Unequal Tooth Structure Mixed Material

In this thesis,a new type of unequal tooth width mixed material motor is proposed.The stator adopts unequal tooth width and tooth top width structure to increase the winding factor of the motor,and the armature teeth wrapped with windings are changed to oriented silicon steel sheets and the other parts of stator use traditional non-oriented silicon steel sheets.The high magnetic permeability in the rolling direction of the oriented silicon steel sheet is combined with the long magnetic circuit of the tooth of the motor with similar number of poles and slots to reduce the magnetic resistance of the magnetic circuit.The saturated magnetic density of the oriented silicon steel sheet in the rolling direction is relatively high,usually up to 2.0T,which can increase the air gap magnetic density of the motor to increase the output torque of the motor.Taking the 10P12 S motor as an example,the finite element calculation method is used to compare the output torque of unequal tooth width mixed material motor,unequal tooth width non-oriented silicon steel motor and traditional equal tooth motor.The average output torque of the three structural motors at rated load and 2 times rated load is compared and analyzed.At rated load,the unequal tooth width mixed material motor has the highest average output torque;at 2 times the rated load,the high average output torque advantage of the unequal tooth width mixed material motor is more obvious.The analytical method and the finite element method are combined to analyze the influence of the additional air gap caused by the process error on the joint of the armature tooth and the stator yoke on the torque performance of the motor.Firstly,the influence of additional air gap on the cogging torque of the motor is compared.Secondly,the influence of different additional air gaps caused by armature tooth on the cogging torque period and size of the motor is analyzed.Finally,the influence of the additional air gap on the output torque is compared,and the advantageous working conditions for motors with unequal tooth width mixed material is founded,which provides a reference for the design of the unequal-width mixed material motor.