GB321549A - Improvements relating to electric dynamos or motors - Google Patents

Abstract

321,549. Lucas, Ltd., J., Turner, E. O., and Robinson, E. H. C. Nov. 8, 1928. Magneto-electric machines; dynamos, regulating; motors, controlling.-In a small dynamo for cycle-lighting or the like of the type in which the width of the air gap between the adjacent faces of the magnets and the poles carrying the current windings is adjustable, an axially-adjustable thrust bearing is provided, against which the end of the spindle abuts and which permits adjustment of the air gap. In the form shown, the stationary bar magnets a are carried by plates b, b<1> and the stem g is adjustably carried in an insulated screwed bush h in the plate b for altering the air gap. This plate is screwed into the casing q and abuts on pegs s or an annular rim. The wound rotor poles d are carried by a plate e on a, spindle f having a long bearing o and a cap k insulated from the shaft and bearing against the end of the stem g within a tube m containing an oil-pad n. The rotor is pressed towards the stator by a spring t. One end of the windings is connected to the plate e and the machine casing and the other to the cap k, the external connection being made through the spindle g. A ball may replace the cap and the arrangement of fixed magnet and rotating armature may be interchanged. By the addition of a commutator between the bearing and the rotor coils, the machine may be used on a continuous-current supply as a motor, the number of coils on the rotor being, in this case, optionally different from the number of magnet poles.