RSAW's team of thought-leaders on all things motor repair, sales, storage, and field services contributed this post.
Six Key Components That Make Up Your Industrial Electric Motor
Your industrial electric motor has several critical components that enable it to efficiently and effectively convert electrical energy into mechanical energy. Each one helps drive the critical interaction between your motor's magnetic field, and the electric current in its wire winding, to generate force in the form of shaft rotation. It is the mechanical energy produced by this shaft rotation that helps keep your plant’s operations up and running smoothly.
These six components include:
1) The Rotor
The rotor is the moving part of your electric motor. It turns the shaft that delivers the mechanical power mentioned above. In a typical configuration, the rotor has conductors laid into it that carry currents which then interact with the magnetic field of the stator to generate the forces that turn the shaft. Having said that, some rotors carry permanent magnets and it is the stator that holds the conductors.
2) The Stator (and Stator Core)
The stator is the stationary part of your motor's electromagnetic circuit and usually consists of either windings or permanent magnets. The stator core is made up of many thin metal sheets, called laminations. Laminations are used to reduce energy losses that would result if a solid core were used.
3) The Bearings
The rotor in your electric motor is supported by bearings, which allow it to turn on its axis. These bearings are in turn supported by the motor housing. The motor shaft extends through the bearings to the outside of the motor, where the load is applied. Because the forces of the load are exerted beyond the outermost bearing, the load is said to be “overhung.”
4) The Windings
Windings are wires that are laid in coils, usually wrapped around a laminated soft iron magnetic core so as to form magnetic poles when energized with current. Electric motors come in two basic magnet field pole configurations: salient- and non-salient-pole. In the salient-pole motor, the pole's magnetic field is produced by a winding wound around the pole below the pole face. In the non-salient-pole motor, the winding is distributed in pole face slots. A shaded-pole motor has a winding around part of the pole that delays the phase of the magnetic field for that pole.
5) The Air Gap
Although not a physical component, the air gap is the distance between the rotor and stator. Your motor’s air gap has important effects, and is generally as small as possible, as a large gap has a strong negative effect on performance. It is the main source of the low power factor at which motors operate. Because the magnetizing current increases with the air gap, your air gap should be minimal. Having said that, very small gaps may pose mechanical problems in addition to noise and losses.
6) The Commutator
And finally, the commutator is a mechanism used by your motor to switch the input of most DC motors and certain AC motors. It is made up of slip-ring segments that are insulated from each other and from the shaft. Your motor's armature current is supplied through stationary brushes in contact with the revolving commutator, which causes required current reversal, and applies power to the machine in an optimal manner as the rotor rotates from pole to pole. (The absence of such a current reversal would cause your motor to brake to a stop.)
What Do All of These Components Have in Common?
Each one of them can require needed maintenance, repair or replacement at any given time. That’s where Red Stick Armature Works comes in. We bring over 60 years of organizational excellence around the servicing, storage, and sales of industrial electric motors. Our dedicated and experienced technicians are available on-site 24-7-365 to help you keep your motors – and your operations - up and running smoothly. Contact Us or give us a call today at 800-895-0443 to learn more.