Patent ID: 9647517
Date: 2017-05-09
CPC Classifications: H02K,Y10T

Claim:
1. A manufacturing method of a helical core for a rotating electrical machine, the method comprising: forming a yoke portion and a plurality of tooth portions protruding toward a width direction of the yoke portion from a first side edge of the width direction; forming a notch by punching processing at a position between the tooth portions of the yoke portion, wherein the yoke portion, the plurality of tooth portions and the notch are formed on a belt-shaped metal plate; heating the belt-shaped metal plate; and bending the heated belt-shaped metal plate from a linear configuration into a helical shape so that the belt-shaped metal plate is curved toward the width direction sequentially from a portion in which the notch is formed, wherein, during bending, a distance between a position at which application of the bending starts and a position at which the notch is formed is set to be 10 mm or more and 1000 mm or less.