A passive permanent magnetic bearing with increased axial lift relative to radial stiffness

Four different magnet bearing configurations, with varying numbers of combined radially and axially magnetized rings, are studied both experimentally and using the modeling framework MagTense. First the optimal vertical position of the radially magnetized ring is determined using the numerical model. Then the model is validated using experimental data. Finally, we show that a bearing where the rotor and the stator each consist of a single ring of axially magnetized magnets and a single ring of radially magnetized magnets has the smallest radial force per axial lift force at an axial air gap of 1 mm. For this bearing, the ratio of the radial force per axial lift here is 0.383 times that of the same bearing without the radially magnetized ring.