Electric Motor Working and Its Applications

The conversion of energy from electrical to mechanical was explained by Michael Faraday, a British scientist in the year 1821. The energy conversion can be done by arranging a current carrying conductor within a magnetic field. So the conductor starts rotating because of the generated torque from the magnetic field and electrical current. A British scientist William Sturgeon was designed a DC machine in the year 1832 based on his law. However, it was expensive and doesn’t suitable for any application. So finally, the first electric motor was invented in the year 1886 by Frank Julian Sprague.

What is an Electric Motor?

An electric motor can be defined as; it is one kind of machine used to convert the energy from electrical and mechanical. Most of the motors work through the communication among the electrical current and magnetic field of the motor’s winding for generating force in the form of shaft rotation. These motors can be triggered by a DC source or AC source. A generator is mechanically the same to an electric motor, however, works in the opposite direction by changing mechanical energy to electrical energy. The electric motor diagram is shown below.

The classification of electric motors can be done based on considerations like the type of power source, construction, motion output type, and application. They are AC type, DC type, brushless, brushed, phase type like single phase, two or three phases, etc. The motors with typical characteristics & dimensions can provide suitable mechanical power to use in industries. These motors are applicable in pumps, industrial fans, machine tools, blowers, power tools, disk drives.

electric-motor
electric motor

Electric Motor Construction

The electric motor construction can be done using the rotor, bearings, stator, air gap, windings, commutator, etc.

electric-motor-construction
electric-motor-construction

Rotor

The rotor in an electric motor is the moving part, and the main function of this is to rotate the shaft for generating the mechanical power. Generally, the rotor includes conductors which are laid to carry currents, and communicate with the magnetic field in the stator.

Bearings

The bearings in the motor mainly give the support to the rotor to activate its axis. The shaft of the motor expands with the help of the bearings to the load of the motor. As the load forces are used outside of the bearing, then the load is known as overhung.

Stator

The stator in the motor is the inactive part of the electromagnetic circuit. It includes permanent magnets or windings. The stator can be built with different thin metal sheets which are known as laminations. These are mainly used for reducing energy losses.

Air gap

The air gap is the space among the stator and the rotor. The effect of the air gap mainly depends on the gap. It is the major source for the low power factor of the motor. Once the air gap increases between the stator & rotor then magnetizing current also increases. Because of this reason, the air gap should be less.

Windings

Windings in the motors are wires that are laid inside of the coils, generally covered around a flexible iron magnetic core so as to make magnetic poles while energized with the current. For motor windings, copper is the most frequently used material. Copper is the most common material for windings and aluminum is also used although that should be solid to carry a similar electrical load securely.

Commutator

The commutator is a half ring in the motor which is fabricated with copper. The main function of this is to link the brushes toward the coil. The commutator rings are used to ensure the flow of current direction within the coil reverses each half time thus the one surface of the coil is frequently pushed upwards & the other surface of the coil is pushed downwards.

Working of Electric Motor

Basically, most of the electric motors work on the electromagnetic induction principle, however, there are different types of motors which uses other electromechanical methods namely piezoelectric effect and electrostatic force.

The basic working principle of electromagnetic motors can depend on the mechanical energy that works on the conductor using the flow of electric current & it is placed within the magnetic field. The mechanical force direction is perpendicular toward the magnetic field and the conductor and the magnetic field.

Types of Electric Motor

Nowadays, most commonly used electrical motors mainly include ac motors and dc motors

AC Motor

AC motors are classified into three types namely induction, synchronous, and linear motors

  • Induction motors are classified into two types namely single phase and three phase motors
  • Synchronous motors are classified into two types namely hysteresis and reluctance motors

DC Motor

DC motors are classified into two types namely self-excited and separately excited motors

  • Self-excited motors are classified into three types namely series, compound and shunt motors
  • Compound motors are classified into two types namely short shunt and long shunt motors

Applications of Electrical Motor

The applications of electrical motor include the following.

  • The applications of electrical motor mainly include blowers, fans, machine tools, pumps, turbines, power tools, alternators, compressors, rolling mills, ships, movers, paper mills.
  • The electric motor is an essential device in different applications like HVAC- heating ventilating & cooling equipment, home appliances, and motor vehicles.

Advantages of Electrical Motor

Electric motors have several advantages whenever we compare with normal engines which include the following.

  • The primary cost of these motors are low compared with the fossil fuel engines, but the horsepower rating of both are similar.
  • These motors include moving parts, so the lifespan of these motors are longer.
  • The capacity of these motors is up to 30,000 hrs as we maintained properly. So each motor requires little maintenance
  • These motors are extremely efficient & automatic control permits for automatic start & stop functions.
  • These motors don’t use fuel because they don’t require the maintenance of engine oil, otherwise, battery service.

Disadvantages of Electric Motor

The disadvantages of these motors include the following.

  • Large electric motors are not easily movable, and consideration should be made for the exact voltage and current supply
  • In some situations, expensive line expansions are mandatory for isolated areas where electrical power is not accessible.
  • Usually, the performance of these motors is more efficient.

Thus, this is all about the electric motor, and the main function of this is to convert the energy from electrical to mechanical. These motors are very quiet and convenient, which uses alternating current otherwise direct current. These motors are available in everywhere where the mechanical movement can be occurred using alternating current or direct current. Here is a question for you, how to make an electric motor?

Add Comment