What is a Squirrel Cage Motor?

Question

What does it do, what industry is it from, and what is it mainly used for by industries?

Answer 1

An AC induction motor with a squirrel cage rotor is sometimes called a squirrel cage motor.
In overall shape it is a cylinder mounted on a shaft. Internally it contains longitudinal conductive bars of aluminium or copper set into grooves and connected together at both ends by shorting rings forming a cage-like shape.
The name is derived from the similarity between this rings-and-bars winding and the wheel on which pet rodents (including squirrels) run.

The core of the rotor is built of a stack of iron laminations. The drawing shows only three laminations of the stack but many more are used.


The field windings in the stator of an induction motor set up a rotating magnetic field around the rotor. The relative motion between this field and the rotation of the rotor induces electrical current flow in the conductive bars. In turn these currents flowing lengthwise in the conductors react with the magnetic field of the motor to produce force acting at a tangent to the rotor, resulting in torque to turn the shaft.

This type of motors should be employed whenever possible because of their simplicity,robustness,lowerred cost and lower maintenance compared with slipring motor.
Squirrel cage motor may be employed when the starting torque is sufficient to run the drive upto speed and when the starting current to do this is not too high for the conditions of the supply.
Because of the high initial peak-up current, the squirrel cage motor has to be started on reduced voltage. For that star-delta connection, auto transformer or primary resistance starting is used to reduce the starting torque.

All types of pumps,compressors,agitators and many more equipments in chemical industries are using these type of motor.

Answer 2

A squirrel cage rotor is the rotating part commonly used in an AC induction motor. An electric motor with a squirrel cage rotor is sometimes called a squirrel cage motor. In overall shape it is a cylinder mounted on a shaft. Internally it contains longitudinal conductive bars of aluminium or copper set into grooves and connected together at both ends by shorting rings forming a cage-like shape. The name is derived from the similarity between this rings-and-bars winding and the wheel on which pet rodents (including squirrels) run.

Answer 3

The standard every-day induction motor is a "squirrel cage" motor.

The term originates from the placement of rotor bars equally around the rotor, and then shrting the ends of the bars together with a conductive ring of some form. This makes it look like a "squirrel wheel" or "hamster wheel".

It is one of many different types of machines built by electric motor/generator manufacturers (others include wound-rotor induction machines, synchronous machines, permanent magnet machines, and direct current machines, and "linear" machines).

It is by far the most commonly seen version of an electric motor in the world; it has been used historically for processes that require high starting torque, single speed, and relatively high stall capability. Also, since the majority of the world's utilities generate AC power, it uses the available power directly (unlike a DC machine). With the increased popularity of power electronics and the development of frequency converters, the induction machine is now used in processes that require variable speed as well.

Typical processes include all those that are 'flow' specific; compressors for refrigerant and coolant, fans for airflow, water (or other liquid) pumps, high-speed drills (like oil rigs), and so on.

Answer 4

A squirrel-cage rotor is the rotating part (rotor) used in the most common form of AC induction motor. It consists of a cylinder of steel with aluminum or copper conductors embedded in its surface. An electric motor with a squirrel-cage rotor is termed a squirrel-cage motor.

Answer 5

The only squirrel cage that I am aware of is used in air conditioning for the blowers. The squirrel cage is a cylindrical arrangement of vanes with the squirrel cage spun about its center by a motor either direct drive or belt driven. Even most central heat and air systems have a squirrel cage for the air moving blower. I am sure there are other air movers out there. For instance, your hair dryer has a small squirrel cage in it directly driven by a small motor.