What is Governor in Automobile? How Does it Works?

Governor is a mechanical device which is used to regulate
the mean speed of the engine, when there are variations in the load. When load
on the engine varies, the configuration of the governor changes and it controls
the supply of the fuel to the engine. How does it controls the supply, this
question arises in our mind, so let’s find out what happens in the governor’s
configuration when load varies on the engine. 

When load on the engine increases, its speed decreases, so
it becomes necessary to increase the supply of the working fluid (ex petrol or diesel)
to the engine. On the other hand when the load on the engine decreases, the
governor’s speed increases, so it requires to decrease the supply of the fuel.

When the speed of the governors increases, its sleeve moves in
upward direction, which is connected to a throttle valve through a bell crank
lever. This upward motion of the sleeve operates the valve to decrease the supply
of the fuel. And when the speed of the governor decreases due to the increase
in the load, the sleeve move downward, this made the valve to open to a larger
extent and increases the fuel supply.