The simplest type of Centrifugal Governor is the Watt governor. In the previous article, we have discussed the Centrifugal governer in detail. In this article, we are going to discuss the Watt Governor in more detail.
The main working principle behind Watt governor is the balancing of the centrifugal force. So these come under the Centrifugal Governors.
We have to assume that the mass of the arms and links and the sleeve is negligible compared to the mass of the balls.
The working principle of this governor is also the same as the Centrifugal Governor, so it is already explained in detail, read it here
- m = Mass of the ball in kg
- w = weight of the ball in newton = m.g
- T = Tension in the arm in newtons,
- ω = Angular velocity of the arm and ball about the spindle in radians/seconds
- r = Radius of the path of rotation of the ball i.e. horizontal distance from the centre of the ball to the spindle axis in metres
- FC = Centrifugal force acting on the ball in newtons = m.ω2.r
- h = Height of the governor in metres
Due to the action of centrifugal force (FC) acting on the ball and tension (T) in the arm and the weight (w) of the ball, the ball is in equilibrium.
Let’s take the moments about the point O
FC × h = w × r = m.g.r
m.ω2.r.h = m.g.r
h = g / ω2
We can also write this in the following form
h = 895/ N2 ( ∵ ω = 2 π N/60 , g = 9.81 m/s2 )
from the above equation, we can say that as the speed is inversely proportional to the height of the governer. Therefore at the high speed, the value of the h is small.
Due to the small height of the governer, at very much high speeds of the engine, the change in the value of h corresponds to the small variation in the speed is insufficient to make a governer to operate the mechanism to give necessary change in the fuel supply.
Because of this reason, this type of governer only prefered for the engine speeds such as 60 to 80 rpm.
We have discussed the watt governor, the centrifugal governor working principle is already explained in the previous article. If you have any further thoughts on this topic, let us know in the comment section below.