Effect of slot depth on the permeance of aligned teeth in a doubly‐salient rectilinear toothed structure Available to Purchase

Effect of slot depth on the evaluation of permeance in the aligned position for identically slotted rectilinear tooth geometry can be carried out using conformal transformations. Consequent increase of permeance is related to the airgap proportion ratios; tooth‐width to tooth‐pitch, t/λ; tooth‐pitch to airgap dimension, λ/g; and slot‐depth to slot‐d/s; through two intermediate parameters. Efficient search routine is used to find a suitable combination of these two parameters corresponding to given proportions of tooth and slot. For λ/g larger than 80 and d/s between 0.3 and 1, the effect of slot depth is negligible, but for λ/g equal to or less than 80 a family of permeance correction factor curves is obtained which may be used to correct for finite slot depth in permeance calculations based on infinitely deep slots. This effect is important in stepping and switched reluctance motors, particularly those with multiple teeth per stator pole.