Linear Drive Systems and their Related Technologies. Analysis for Static Characteristics of Magnet Wheels.

Abstract

Characteristics of “tilt type” and “partial overlap type” magnet wheels with revolving permanent magnets, which were proposed by authors, are analyzed respectively at standstill condition for linear running. First, eddy current distribution, three directional components of generated forces and variation of instantaneous forces are shown respectively by three-dimensional numerical analysis. The analysis is proved by comparison between computed results and measured results. It is found that the lateral force of magnet wheels operates to move away from conducting plate, but the force in the “tilt type” is very small. It becomes clear that the lift force and lateral force of the “partial overlap type” have, respectively, relative large cyclical change with number of poles in a rotation. Second, the simplified two-dimensional analysis is described. The equivalent magnetomotive force of permanent magnet is corrected according to the flux density on the magnet surface in order to consider the effect of circular arrangement of magnets and the edge effect of eddy current. It is confirmed that the forces in the “tilt type” are estimated by using the model of horizontal revolving magnet wheel with various air gaps, the forces in the “partial overlap type” are estimated by considering only the overlap region between the area of revolving magnets and conducting plate.