JPS5768646A - Formation of corrugated disc-shaped element coil from hollow conical trapezoid coil including annular coil - Google Patents

Abstract

PURPOSE:To obtain the disc-shaped element coil having a small air gap with an excellent workability by a method wherein a hollow conical trapezoid coil, the measurements for each section of which will be determined by a specific formula, is formed and then a corrugated conical trapezoid coil is fabricated by folding it to the front and back sides repeatedly at a specific angle. CONSTITUTION:When the vertical angle of the disc-shaped element coil to be obtained finally is set at delta, the larger diameter at 2K1, the smaller diameter at 2K2, the number of corrugated conductors at 2n and the width of the corrugated conductors at B, firstly, a hollow conical trapezoid coil is formed with the vertical angle of which can be determined at delta, the diameter of the larger bore at d1 and the inner bore diameter at d2 using the formula d1=K1sin(pi/n).sin(delta/2)/[sinphi2.sin[pi/2n. sin(delta/20)]]or K2sin(pi/n).sin(delta/2)[sinphi1.sin[pi/2n.sin(delta/2)]]{provided that phi1=tan<-1>[sin(pi/n)/[K1/K2-cos(pi/2)]],phi2=phi1+pi/n, d2=d1-2betasin(delta/2)}. Then, this hollow conical trapezoid coil is evenly divided into 2n along the circumference, bent to the front side at the angle of phi1 and bent to the back side at the angle of phi2 at the adjoining evenly-divided point for the entire circumference, and the conical trapezoid element coil consisting of a corrugated conductor can be formed.