Motor Components

An AC electric motor is comprised of the following components:

• Frame - The frame is a housing that holds all internal and external motor components.
• External Fan - Positioned on the exterior end of the motor assembly, the fan blows air across the outside of the motor to prevent overheating.
• Fan Cover – Protects the fan from foreign object damage and protects people from injury.
• Cast Rotor – Also know of as the armature. The armature is the assembly of windings. These windings interact with the stator to form the magnetic fields necessary for generating rotation energy.
• Stator – Stationary portion of the motor’s electrical field.
• Front Bearing – Shaft support that reduces friction rotation. The front bearing is located at the end where the shaft extends from the motor housing.
• Rear Bearing - Shaft support that reduces friction rotation. The rear bearing is located at the same end as the external cooling fan.
• Base – Also referred to as the foot mount, the base secures the motor housing to the equipment platform.
• Shaft – The shaft runs longitudinally through the center of the stator, and is supported by the front and rear bearings.
• Capacitor – Affixed to the outside of the motor, the capacitor shifts the phase of the incoming current and feeds the starter winding.
• Front End Shield – Located at the end where the shaft extends from the motor, the front end shield encloses the motor frame and supports the front bearing.
• Rear End Shield – Located at the same end as the external cooling fan, the rear end shield encloses the motor frame and supports the rear bearing.
• Internal Fan – Located within the motor housing, the internal fan circulates air internally
• Nameplate – A tag affixed to the motor to designate motor specification parameters.
• Connection Box – A box affixed to the motor housing where motor connections are made with the power supply.
• End Ring – Located at the end of the rotor assembly, the end rings provide a surface to connect the rotor bars.