GB504800A - Improvements in or relating to laminated magnetic elements - Google Patents

Abstract

504,800. Dynamo - electric machines. RAWLINGS, G. W. Nov. 1, 1937, No. 29780. [Class 35] [Also in Group XXII] A laminated magnetic element for an imbricated type armature or field core or other magnetic circuit comprises a number of laminations nested one within another to form a yoke with polepieces so constructed that in each polepiece the ends of the laminations progressively overlap and collectively form a tegulated pole surface. Fig. 1 shows one pole element of an armature core comprising five laminations a ... e each having a central hole f for the passage of the spindle. The element is manufactured preferably by assembling the laminations on a locating pin at the end of a conical plug and forcing the plug first into a taper forming die and then through a ring shearing die. The cylindrical pole-surface is finished by grinding. The pole faces may be further subdivided by a longitudinal slot. In Fig. 5, the magnetic circuit is completed independently of the spindle by inwardly turned flanges i<1>, j<1> which may abut as shown at k or which may be interleaved as shown at k<1>. In the case of the magneto shown in Fig. 7, the armature and the magnet are of the imbricated type, the permanent magnet o being magnetized axially and embraced by laminated pole elements n<1>, n<2>. The polepieces may be parallel-sided or tapered. Specification 481,585 is referred to.