Effects of airgap and magnet shapes on permanent magnet reluctance torque

This paper examines the permanent magnet reluctance torques produced by thr ee different configurations of permanent magnet, airgap, and iron. These co nfigurations are briefly described here as rectangular magnet/triangular ai rgap, rectangular magnet/sinusoidal airgap, and sinusoidal magnet/sinusoida l airgap, The analysis of the torques is achieved by developing analytical solutions. Equations for magnet reluctance torque are obtained by finding t he derivative of the stored held energy with respect to position. The trian gular airgap configuration is shown to produce a torque waveform which appr oximates a triangular waveform, and both the sinusoidal airgap configuratio n are shown to produce torque waveforms which approximate sinusoids.