If ω is the angular speed of rotation and g is acceleration due to gravity, the height h of a watt governor is expressed as

Concept:

Governor:

• It is a device which controls the mean speed of the engine over a long period due to load fluctuation.
• Governor has no influence over cyclic speed fluctuation

Watt Governor:

• It is a type of centrifugal governor.
• It is the simplest pendulum-type governor.
• It is unsuitable for high-speed Engine.

The above figure shows the simple watt governor,

Let, m = mass of each ball, h = height of the governor, w = weight of each ball, ω = angular velocity of the arm ball and sleeve, T = tension in the arm, r = radial distance of ball-centre from spindle axis

Assuming the link to be massless and neglecting the friction of the sleeve, the mass m at A is in static equilibrium under the action of.

• Weight w
• Centrifugal force mrω²
• Tension T in the upper link

The equilibrium of the ball provides

T × cos θ = mg

T × sin θ = mrω²