GB646528A - Improvements in or relating to laminated magnetic structures - Google Patents

Abstract

646,528. Cores for dynamo-electric machines. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN. March 25, 1948, No. 8822. Convention date, March 29, 1947. [Class 35] The core of a small dynamo, e.g. cycle dynamo is composed of two or more superimposed laminations having a disc or annular form save for tongues which initially were approximately tangential to the lamination circumference but have been bent to form polepieces in planes which are edge-on to the lines of force of the magnetic field such that the edges of the inner and/or outer polepieces lie on a surface of a revolution. Figs. 1, 2 show plates 1, 2, 3 provided with tags 4, 6, 7 respectively, each of which extends more or less tangentially. The tags 4, 6, 7 are bent over dotted lines 5 so as to extend perpendicularly to the plane of Fig. 1, which results in the form shown in Fig. 2. The position of the lateral edges of the bent-over tags depends upon the endwise direction of the tags. With truly tangentiallydirected tags the lateral edges of the same side of the bent-over tags lie on the surface of an imaginary cylinder, whereas with tags, e.g. directed as those 17, the said edges would lie on the surface of a truncated cone. Fig. 6 shows a section of a hub dynamo having six rings 1-3 each pair of which is provided with a cylindrical part 23. Imbricated pole-pieces are formed by the bent-over tags 18, 26 projecting from righthand side and left-hand side rings respectively. An annular permanent magnet 27 with two annular plates 28 provided with alternate polepieces 29 surrounds the magnetic structure built from the plates 1, 2, 3.