THE DYNAMO. 



69 



38. Special designs of dynamos. The essential features of a 

 dynamo are the same whatever the use for which the dynamo is 

 intended ; whether it is to be used as a generator or as a motor ; 

 whether it is to be driven as a generator by a belt or by being 

 directly connected to an engine or to a water-wheel ; or whether 

 it is operated as a motor and drives a machine by a belt or by being 

 constructed as an integral part of the machine which it drives. 



There are, however, important special points in the design of a 

 generator which is to be directly connected to an engine or to a 

 water-wheel, and in the design of a motor which is to be directly 

 connected to the machine which it drives. These special points 



iiiuiJiilJ yiPlpr'^ 



Fi. 59. Westing'iouse Va iable Speed Motor Driving a 48-iuch Lathe. 



in design relate chiefly to the arrangements of the shaft, bearings 

 and pedestals, and to the shape of the frame which serves as a 

 base for the machine. 



Thus Fig. 41 shows a typical belted generator, Fig. 45 shows 

 a typical generator mounted on the crank shaft of the driving 

 engine, and Fig. 59 shows a lathe with a specially designed 

 motor geared directly to it. 



