Abstract: Computation of axial stiffness of permanent magnet bearings is very important in the design process of permanent magnet bearings. There exists a certain error in the calculation results of several kinds of existing models in comparison to the measured result. The equivalent surface currents method is employed to analyze the stiffness of axial permanent magnet bearing, but the solution cannot be obtained easily for a quadruplicate integral. Monte Carlo method is used to solve the equation to simplify the calculation of the stiffness of axial permanent magnet bearing. Thus the equivalent surface currents method can be easily used in engineering. The stiffness of the permanent magnet bearing with the equivalent surface currents method is verified by comparing the simulating result obtained by using the finite element method. The conclusion is that the equivalent surface currents method can be used to calculate the axial stiffness of permanent magnet bearings, and the application of the equivalent surface currents to engineering is not difficult by using the Monte Carlo method.

Key words: Axial stiffness, Equivalent surface currents method, Finite element method (FEM), Monte Carlo method, Permanent magnet bearings