Flywheel | Function, types, Advantages, Application
A flywheel is a heavy rotating body which acts as a reservoir of energy. It acts as a bank of energy between the
energy source and machinery.
Energy stored in a flywheel is in the form of kinetic energy.
Fu nc ti on s of f ly wh ee l
• It is used to store energy when available and supply it when required.
• To reduces speed fluctuations.
• To reduce the power capacity of an electric motor or engine.
• Applications of the flywheel can be broadly divided into two parts based on the source of power
available and the type of driven machinery.
Wor k of f ly wh ee l
1. When the power available at a variable rate but is required at a uniform rate. For e.g. the machinery is driven
by the reciprocating internal combustion engine.
2. When the power is available at a uniform rate but we need it at a non-uniform rate. For e.g. power required in
punching press. In this case, we need sudden power at punching stroke.
Types of flywheels
On the basis of angular velocity, flywheels can be divided into two types.
1. High-Velocity Flywheel
The angular velocity of these type of Flywheels comes between 30000 rpm to 60000 rpm which may even be
adjusted up to 100,000 rpm. They contain magnetic levitation bearings and need less maintenance. They are
lighter in weight if compared size/capacity wise to low-velocity flywheels. They are costly in comparison to
Low-velocity Flywheels.
2. Low-Velocity Flywheel
The angular velocity of these type of Flywheels comes up to 10000 rpm. They are bulky and heavy if compared
to high-velocity Flywheels. They need periodic maintenance and does not use magnetic levitation bearings. Their
installation needs special concrete construction to support its weight. They are cheaper in comparison to high-
velocity Flywheels.
Flywheels-Function need and Operation
Fl ywhe els- Fu nc ti on n ee d an d Op er at io n
The main function of a fly wheel is to smoothen out variations in the speed of a shaft caused by torque fluctuations.
If the source of the driving torque or load torque is fluctuating in nature, then a flywheel is usually called for. Many
machines have load patterns that cause the torque time function to vary over the cycle. Internal combustion engines
with one or two cylinders are a typical example. Piston compressors, punch presses, rock crushers etc. are the other
systems that have fly wheel.
Flywheel absorbs mechanical energy by increasing its angular velocity and delivers the stored energy by decreasing
its velocity.
