Nikola Tesla - Free-Energy Devices

POLYPHASE CURRENT*. 69cured in position to surround both the armature and the polesc c'. The armature is detachable from its shaft, the latter beingpassed through the armature after it has been inserted in position.The operation of this form of motor is the same in principleas that previously described and needs no further explanation.One of the most important features in alternating currentmotors is, however, that they should be adapted to and capableof running efficiently on the alternating circuits in present use,in which almost without exception the generators yielda veryhigh number of alternations. Such a motor, of the type underconsideration, Mr. Tesla has designed by adevelopment of theprinciple of the motor shown in Fig. 56, making a multipolarmotor, which is illustrated in Fig. 57. In the construction ofFIG. 56. FIG. 57.this motor he employs an annular magnetic frame j,with inwardly-extendingribs or projections K, the ends of which allbend or turn in one direction and are generally shaped to conformto the curved surface of the armature. Coils F F are woundfrom one part K to the one next adjacent, the ends or loops ofeach coil or group of wires being carried over toward the shaft,so as to form y -shaped groups of convolutions at each end of thearmature. The pole-pieces C C', being substantially concentricwith the armature, form ledges, along which the coils are laidand should project to some extent beyond the the coils, as shown.The cylindrical or drum armature D is of the same constructionas in the other motors described, and is mounted to rotate withinthe annular frame j and 1 Jetween the U-shaped ends or bends of