An electric motor uses electrical energy to produce mechanical energy.

A simple electric motor has six parts:

Armature or rotor
The rotor is the non-stationary part of a rotary electric motor which rotates because the wires and magnetic field of the motor are arranged so that a torque is developed about the rotor's axis.

 

Commutator
A switch for reversing the direction of an electric current.


Brushes
The Brushes conducts current between rotating and stationary parts of a generator or motor.


Axle
A non-rotating shaft on which wheels or rollers are mounted.

Field magnet
a magnet that provides a magnetic field in a dynamo or electric motor.

DC power supply
A power unit that supplies direct current only. Examples: battery, transformer etc.

Applications of Electric Motors:

It has various applications in robotics as well in rotating machines such as fans, turbines, the wheels on electric cars, locomotives & drills.

In Kitchen appliances like Blenders, Food Processors, Microwave Ovens, Toasters. They also makes use of electric motors.

Electric Motors Formulas:

Electrical power is in general rated in Watts or Horsepower. A horsepower is a unit of power equal to 746 watts or 33,000 lb.ft per minute (or 550 lb.ft per second).

A watt is a unit of measure equal to the power produced by a current of 1 amp across the potential difference of 1 volt. A watt is 1/746 of 1 horsepower.

Power in Watts
Electric power of a motor can be expressed as:

Power = ηm U I

where ηm = motor efficiency,

U = voltage (V)

I = current (A, amps)
 

Power in Horsepower

Horse power of a motor can be expressed as:

Horsepower = Pw / 746