Parts of electric motor

Electrical energy is converted into mechanical energy by an electric motor. An electric motor typically has a stator, rotor, winding, bearings, and casing. The force of attraction or repulsion between the stator or rotor fields causes the motor to rotate. The components of a motor are described in detail in this article.

Parts of Electric Motor

1. Stator

2. Rotor

3. Winding

4. Bearing

5. Casing

Stator

The stator is the stationary parts of any electric motor. A permanent magnet or windings may be placed in the stator. In AC motors, the armature is carried by the stator, but in DC motors, the field winding is carried by the stator. The stator cores of AC motors are built of laminated silicon steel, while the DC motor cores do not necessarily need to be laminated.

Typical stator(Ref.-insideevs.com)

Rotor

The rotating parts in any electric motor is known as rotor. Because of the rotary motion it experiences inside an electric motor, the rotor got its name.

Similar to the stator, a rotor can also be a collection of windings (armature) or a single solid component. When windings are involved, they are typically wound around a solid core made of silicon steel or another laminated ferromagnetic material.

Motor rotor(Ref.- lesics.com)

Windings

The term "windings" refers to coils of wire that typically encircle a metallic core comprised of a ferromagnetic material, such as iron or silica steel. The windings' primary function is to produce magnetic fields. These fields may come from an electric current or a permanent magnet via the electromagnetic effect.

Bearings

An electric motor's rotor and shaft are supported by bearings, which reduces the rotational resistance. Bearings prevent the motor from being affected by friction, lowering energy losses. This enables the efficient and effective transfer of mechanical energy from the rotor to the load.
Bearing effectiveness is influenced by design, material composition, load, and environmental factors.

Typical bearings(Ref.- emotorsdirect.ca)

Casing

The major purpose of the casing, an external component, is to safeguard the stator and rotor as well as other components of electric motors. In essence, the casing serves as a barrier between the electric motor's internal structure and the outside world, reducing the impact of physicochemical variables like humidity and temperature on the motor's performance.

Motor casing

Commutator

In the DC motor, to maintain a repulsive force between the poles of the rotor and stator, commutators are utilized to switch the direction of current in the rotor. They can be found in any form of motor that needs a DC source to power its rotors. Carbon brushes with a spring-loaded action that are positioned above the commutator apply voltage to the rotor.

Motor Commutator(Ref.- wiraelectrical.com)

Carbon brush

The primary reason brushes are necessary is to transfer electricity from a stationary source to moving parts. In most cases, an electric motor has two or more brushes. To guarantee that current passes through the motor in the proper direction, these brushes function in conjunction with the terminals (current input points) and commutators. Typically, brushes are made of copper, graphite, or any other material that satisfies the motor's thermodynamic and electrical requirements.

Typical Carbon brush(Ref.- .electronicscuriosities.com)

Poles

Poles can be considered of as a hypothetical or transient element of an electric motor. They are the locations where the rotor and stator's magnetic fields have the greatest magnetic influence. However, pole shoes and pole cores can be used to strengthen the poles in an electric motor. To augment the magnetic affinity of the field windings and the stator core, this section of the stator has ferromagnetic windings installed.

Yoke

The yoke is a portion of the housing that covers or shields particular electric motor components like the rotor and stator. It should be distinct from the casing, which is an all-encompassing external covering that encloses some (or all) of the electric motor's components.

Centrifugal Switch

It is a switch basically, based on the centrifugal force it works. It is used to disconnect either starting capacitor or starting winding in single phase induction motor.

When the motor reaches between 50 and 70% speed, the centrifugal switch is activated to cut off the starting winding.

If the centrifugal switch is unable to open at 50 to 70 percent of its synchronous speed. The starting winding of the motor will overheat and burn out, as a result the motor starting will not be possible.