Some aspects of polyphase motor design — The design and properties of the magnetic circuit

IN a preceding paper,¹ an attempt was made to present a design point of view, indicating that the criterion for a design method is its direct ability to provide the construction data whereby desired machine specifications are met. The idea was illustrated by a procedure for polyphase motor design, stripped of refinements, and employing a magnetic circuit of fixed contour. Such a condition arises through the use of standard laminations in which designs are made. The questions naturally, arise as to how these laminations are proportioned and what affect the proportions have on performance. It is with such matters that the present paper is concerned, directed chiefly at motors with semiclosed slots of 50 horsepower or less.