Slots are the physical grooves punched or milled into the laminated iron core of an electric machine. They house the insulated copper conductors that make up the armature or field windings. The shape and pitch of these channels dictate the magnetic flux distribution and directly impact the motor's torque, efficiency and cooling.
The rewinder had to carefully pack the slot liners before tapping the new coils into place.
Engineers often skew the rotor slots slightly off-axis to reduce magnetic hum and prevent the motor from locking up during starting.
Related terms
Induction motor
An alternating current motor where the rotor current is induced by the magnetic field of the stator.
Squirrel-cage motor
An AC induction motor featuring a rotor made of parallel conductive bars shorted by end rings.
Field coil
An electromagnet winding used to generate a steady magnetic field in a rotating machine.