GB1022900A - Electric motor construction - Google Patents

Abstract

1,022,900. Electric motors. INTERNATIONAL REGISTER CO. Aug. 24, 1964 [Oct. 10, 1963], No. 34462/64. Heading H2A. An electric, e.g. synchronous motor 10 comprises: a magnetic field structure 11 including a mounting plate 12 from which extends a core 15 and a concentric annular outer pole member 19 having at one end a plurality of pole tips 20 extending radially inwardly above an end of the core 15, an inner pole member 16 having a central portion 17 secured to the core end and along its periphery a plurality of pole tips 18 interspersed with those 20 on the outer pole member, and a winding 37 connectible to an A.C. source; a permanent magnet rotor 23 having a plurality of poles along its periphery, mounted to rotate in the plane of the pole tips 18, 20, and spaced from the inner pole member central portion 17; and a mechanism 40 mounted in the space between the rotor 23 and portion 17 and cooperating with the rotor to ensure that it runs in only one direction. The mechanism comprises a gear 43, e.g. of nylon, driven by a pinion 52 integral with a rotor insert 28 and frictionally engaged by a pivotal arm 47 having a detent 48, Fig. 3, not shown, which when the rotor starts in the wrong direction engages one or the other of two pairs of shoulders 49, 51 on a cam 50 whereupon the rotor rebounds in the correct direction and the detent is removed from the path of the shoulders; the arm may be assembled to provide either direction of rotation. The rotor, of ceramic material, alternatively may comprise, Fig. 6, not shown, a rim cemented to a nylon central portion pinned to the mechanism cam; the rotor insert 28 is secured to a shaft 29 journalled in bearings 30, 31 between which is provided lubricant and is fixed to a pinion 32 driving through a gear train 33 an output shaft 34. The motor may drive timing devices.