Fig. 1.
Fig. 2. Railway Motor.
CAR EQUIPMENT.
MOTORS.
The voltage most commonly employed by electric railways is 500 to 600; and the motors are 500-volt direct-current series-wound motors, designed especially for railway service. The electric railway motor must be dustproof and waterproof because of the position it occupies under the car. For this reason electric railway motors are made in the form of a steel case ([Fig. 2]), which entirely surrounds the field-magnet poles and takes the place of the yokes or frames that support the fields on stationary motors. Cast steel is the material now usually employed for railway motor cases and fields, on account of its mechanical strength and its high magnetic permeability. The four poles project inwardly from the case, as seen in the open motor case, [Fig. 3], which is that of a Westinghouse No. 69 motor.
Fig. 3. Railway Motor. Upper Field Raised.