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Adjustable Speed Drive
Armature
Ball Bearing Motor
Brush
Brushed DC Motor
Brushless DC Motor
Commutator
DC motor
Direct Torque Control
Direct on Line Starter
Doubly-fed machine
ESC
Electrostatic Motor
Enameled Wire
Induction Motor
Inverter AC/DC
Linear Motor
Lynch Motor
Motor Controllers
Motor Soft Starter
Outrunner
Parvalux
Piezoelectric Motor
Repulsion motor
Shaded Pole Motor
Slip Ring
Squirrel-Cage Rotor
Stepper Motor
Traction Motor
Ultrasonic Motor
Vibrators
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Asynchronous Traction Motors
Traditionally, traction
motors are DC series-wound motors, usually running on approximately
600 volts. The availability of high-powered semiconductors (such as
thyristors and the IGBT) has now made practical the use of much
simpler, higher-reliability AC induction motors known as asynchronous
traction motors. Synchronous AC motors are also occasionally used, as
in the French TGV.
A traction motor is a type of electric motor used to power the driving
wheels of a vehicle such as a railroad locomotive, electrical
multi-unit train (such as a subway or light rail vehicle train), a
tram, or an automobile.
Before large scale dieselization in the mid-20th century, a single
large motor was often used to drive multiple driving wheels through
connecting rods that were very similar to those used on steam
locomotives. It is now standard practice to provide one traction motor
driving each axle through a gear drive.
Usually, the traction motor is simply suspended between the truck
(bogie) frame and the driven axle; this is referred to as a
"nose-suspended traction motor". The problem with such an arrangement
is that a portion of the motor's weight is unsprung, increasing forces
on the track. Occasionally, other mounting arrangements are made. In
the case of the GG1, two truck-mounted motors drove each axle through
a quill drive.
The "Bi-Polar" electric locomotives built by General Electric for the
Milwaukee Road had gearless motors. The rotating shaft of the motor
was also the axle. In the case of the TGV power units, a motor mounted
to the power unit’s frame drives each axle; a "tripod" drive allows a
small amount of flexibility in the drive train allowing the trucks
(bogies) to pivot. By mounting the relatively heavy traction motor
directly to the power unit rather than to the truck (bogie), better
dynamics are obtained allowing much-improved high-speed operation.
Because of the high power levels involved, traction motors are almost
always cooled using forced air.
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