Laminated core for rotary electric machine - has triangular wedge slots enclosing sharp angle and forming rounded apex

摘要

The object of the punching design is principally to improve tool life and also to avoid sharp points on the core plate. This object is achieved by making the notch (1) for the wedge groove with an angle (alpha) less than 90 deg., typically 70 deg. The radius (r1) at the base of the notch can then be relatively large, for example 1.5 mm, without effectively reducing the load bearing surface of the notch. Similarly radii (r2, r3) at the open end of the notch can be given values of approximately 0.5 mm. The part (5) above the notch can be tapered (beta/2) to assist coil insertion.