Study On Permanent Magnet Coupler With Large Inertia Load

The starting torque of large inertia load is very large.If the motor is used to carry the load directly,it will cause the starting current of the motor to be too large or even burn the motor.Permanent magnet coupler is a kind of product which combines the transmission technology,the mechanical manufacturing technology,the permanent magnetic material technology and so on.It not only can greatly improve the operating efficiency of the motor and respond to the slogan of energy saving and emission reduction in China,but also can realize the soft start of the motor.In this paper,a permanent magnet coupler has designed for the large inertia load transmission system.The main work is as follows:Firstly,the calculation formula of the eddy current loss of the permanent magnet coupler was derived by magnetic circuit analysis.Through the MATLAB programming calculation and transmission system performance indicators,the structural dimensions of the main components of the permanent magnet coupler were determined.Secondly,the three-dimensional transient finite element model of the coupler was established by ANSOFT software with reference to the size determined by magnetic circuit method.The output torques with different rotation speeds and different air gap lengths were simulated respectively.The simulation results were compared with those obtained by the magnetic circuit method to verify the accuracy of the magnetic circuit method.Thirdly,the temperature field of the permanent magnet coupler was analyzed by ANSYS WORKBENCH software.The heat source,thermal conductivity and heat dissipation coefficient of the coupler under different working conditions were determined.Through software calculation,the temperature of the conductor disc and permanent magnet under rated working condition and working condition of maximum load was obtained.It was ensured that permanent magnet wouldn't be irreversibly demagnetized when the coupler worked normally.Finally,the ANSYS WORKBENCH software was used to simulate the stress field of the aluminum permanent magnet disk which was the most easily deformed in the coupler.It ensured that the conductor plate and the permanent magnet plate would not rub at maximum load and the coupler would work normally.