GB564865A - Improvements in or relating to permanent- or electro-magnet motor or generator structures - Google Patents

Abstract

564,865. Dynamo-electric machines. HITCHCOCK, S. I. April 21, 1943, No. 6370. [Class 35] A permanent magnet motor or generator has permanent magnet 15, Fig. 2, provided with a leakage path comprising a number of magnetic portions 16 separated by material 18 of high reluctance. This leakage path extends between laminated polepieces 19. In the motor shown, the permanent magnet forms the rotor and the stator poles 2 are similarly provided with leakage paths 24, 25. Exciting coils 4 surround each pole and these are switched off, or reversed, by a cam-operated switch surrounding one end of the rotor shaft 10. The position of the switch relative to the cam can be altered by the handle 11a for adjustment of the speed and direction of rotation. The cam mechanism is generally of the same kind as that shown in Specification 547,668. Fig. 3 shows a section of the form shown in Fig. 1. In a modification, the permanent magnet may be surrounded by cast material and such material may also be deposited on the inside of the magnet. In a further modification, the permanent magnet is replaced by a soft iron core excited by an axial solenoid. To improve the attraction between the rotor poles and the stator poles when the poles are approaching the leakage, elements may be inclined with r.espect to the axis so that while the poles are approaching the attracting force is great, but as soon as the poles are separating the restraining force falls to a minimum. Specifications 13886/15, [Class 35], and 545,583 also are referred to.