In order to obtain the spatial distribution of the 3-D static air-gap magnetic field in double-layer solid rotor asynchronous magnetic couplings

the 3-D analytical model of the air-gap magnetic field in the coupling is built based on the equivalent surface current method and the analytical expression of magnetic flux density at any point of the air-gap is derived.The spatial distribution of radial

circumferential and axial magnetic flux density at the average radius of air-gap is obtained through MATLAB programming from a 14-level prototype.The result shows that the radial magnetic flux density changes between-0.36T and 0.36T

the circumferential magnetic flux density changes between-0.6T and 0.6T

and axial magnetic flux density changes between-0.35T and 0.35T.The static magnetic field measurements are tested by 3D Gauss meter.The comparison between the results of analytical method and test show that analytical method is correct and accurate.