Abstract
According to the static magnetics viewpoint, the no-friction passive magnetic bearings are not stable in their non-load direction. So its position must be limited by certain means for its applications in engineering. Based on the theory of equivalent magnetic charges, the mathematical models for the axial displacement and force of radial passive magnetic bearings were established without any hypothesis and simplifications. In addition, the numerical simulations and the experiments for the axial and radial forces of radial passive magnetic bearing were performed. It shows that the simulations results tally with the experimental results primarily, and the relative axial displacement between the inner ring and the outer ring of the magnetic bearing not only weakens the radial bearing load capacity regularly, but also induces the axial force and makes the bearings unbalance in axial direction. The researches provide an effective approach to study the performance, the load capacity and the structure of the no-friction passive magnetic bearings.