. The street railway review . gs and are provided with end plates of a design whichfurnishes ventilating ducts to dissipate the heat generated in thefield coils. These end plates are tapped and retaining bolts passthrough the frames accurately clamping the pole core into a posi-tion of rigid contact with the inner circumference of the yoke rings,liy removing these bolts the pole pieces and field coils can thenreadily be taken off. In machines of this type up to 60 h. p. it is not necessary to in-troduce ventilation into the center of the armature as the losses inthese machines are exceptionall
. The street railway review . gs and are provided with end plates of a design whichfurnishes ventilating ducts to dissipate the heat generated in thefield coils. These end plates are tapped and retaining bolts passthrough the frames accurately clamping the pole core into a posi-tion of rigid contact with the inner circumference of the yoke rings,liy removing these bolts the pole pieces and field coils can thenreadily be taken off. In machines of this type up to 60 h. p. it is not necessary to in-troduce ventilation into the center of the armature as the losses inthese machines are exceptionally low. The foregoing characteristicof the Lundell Universal motor enables it to save space whichother types of motors must use, and the extremely low losses alsomake it possible to enclose these motors at lower temperature risesthan is possible with motors in which the losses are greater and thetemperature rise consequently higher. The armature coils are formwound and are separately insulated independently of slot LUNDELL UN1VERS.\L MOTOR. The commutators are built on the lines of the standard street rail-way practice giving a rigid support to the bars. The commutatorshells are ventilated through their centers, which construction aidsin securing cool running of the commutators. A new principle is involved in the brush device of this motor,namely: the placing of two carbon brushes in tandem on one he total brush surface in this construction is the same as thoughthe brushes were side by side, hut as any irregularity in the commu-tator does not lift both tandem brushes from the commutator atthe same time a better contact and therefore, a cooler, smootherrunning commutator is obtained. For variable speed work the brushat the leaving edge is made of high resistance carbon to Uke careof the sparking conditions and the other brush of high conductivityto care for the current, which combination is successful. The Birmingham Railway, Light & Power Co. has in force amo
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Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
