Numerical calculation for axial force of Adjustable Speed Asynchronous Magnetic Coupling

As the speed regulating and energy saving of the Adjustable Speed Asynchronous Magnetic Coupling (ASAMC) is realized by changing the contact area of the air gap magnetic field through the axial movement of the squirrel cage rotor, while the axial force is generated. In order to calculate the axial force which plays a very important role in the design of the speed regulating mechanism. Firstly, the magnetization of the cage rotor is equivalent by using mirror method of electromagnetic field theory; the axial force theoretical analysis model is solved by the equivalent magnetic charge method. Then, the axial force of the cage rotor in different axial direction is obtained by using ANSYS 3D-finite element analysis. Finally, a 22kW ASAMC prototype was manufactured and tested for its axial force. The axial force experimental results show that is in agreement with the theoretical and finite element analysis, specific test results are as follows: the axial force in the moving process of the inner rotor firstly increases and then decreases, its maximum value occurs in the axial direction of the rotor 30 mm, at this time the axial force is 1123 Nm. The study provides reference for the design of ASAMC series and speed regulating mechanism.