1. MECHANICAL DEPARTMENT
Hasumkh Goswami College Of Engineering
Mechanical :C
Governor
GUIDANCE BY
PROF. PARTH SHAH
LECTURER
MECHANICAL DEPARTMENT
HGCE, VAHELAL
PREPARED BY
DIVYESH RUDANI
DEEP PRAJAPATI
ARVIND PRAJAPATI
RAJVEERSINH RATHOD

2. Outline Introduction Demonstration Terms Used in Governor
Types of Governor
Centrifugal Governor
Watt’s Governor
Porter Governor
Proell’s Governor
Characteristics of Governor

3. Introduction function regulate the mean speed of an engine
variations in the load
The primary purpose of a governor for a hydroelectric unit is to control the speed and loading of the unit.
It accomplishes this by controlling the flow of water through the turbine, To control flow of fuel in I.C. Engine for smooth acceleration etc.

4. Demonstration System at rest Begins to rotate Governor at work
Equilibrium established

5. Terms Used in Governors
It is the vertical distance from the centre of the ball to a point where the axes of the arms (or arms produced) intersect on the spindle axis. It is usually denoted by h.
Height of a governor.
It is the speed at which the governor balls, arms etc., are in complete equilibrium and the sleeve does not tend to move upwards or downwards
Equilibrium speed
Mean equilibrium speed
It is the speed at the mean position of the balls or sleeve.
The speeds at the maximum and minimum radius of rotation of the balls, without tending to move either way are known as maximum and minimum equilibrium speeds respectively.
Max and min equilibrium speeds
Sleeve lift
It is the vertical distance which the sleeve travels due to change in equilibrium speed.

6. Spring Controlled Type
Types of Governors
Centrifugal Governor
Pendulum Type
Loaded Type
Watt Governor
Dead Weight Type
Spring Controlled Type
Porter Type Governor
Proell Type Governor

7. Centrifugal Governors

8. Centrifugal Governors
The centrifugal governors are based on the balancing of centrifugal force on the rotating balls by an equal and opposite radial force, known as the controlling force.
It consists of two balls of equal mass, which are attached to the arms as shown in Fig.
These balls are known as governor balls or fly balls. The balls revolve with a spindle, which is driven by the engine through bevel gears.

9. WATT GOVERNOR
Arms of the governor can be connected in three ways as shown:
The pivot P, may be on spindle axis
The pivot p, may be offset from the spindle axis and the arms when produced intersect at O.
The pivot p, may be offset, but the arms cross the axis at O.

10. DERIVATION Let; w = weight of ball in N = m.g,
T = tension in arms in N
ω = angular velocity of arm about the spindle axis in rad/s
r = Radius of the governor
Fc= Centrifugal force acting on the ball in N= m.ω².r
h = Height of the governor in meters

11. DERIVATION
These balls are in equilibrium under the action of three forces:
Centrifugal force on the fly balls.(Fc)
The tension in the arm (T)
The weight of the balls (w)

12. DERIVATION Taking moment at point O we have:
Where ‘g’ is expressed in m/s² , ω in rad/sec and h in meters.
This governor may only work at relatively low speeds i.e. from 60 to 80 rpms

13. Final Equations: Fc x h = W x r Equation of Watt Governor
m r 2 x h = m.g.r
Height of Governor
h = g / 2

14. Porter Governor
In Porter governor central load is attached to the sleeve as shown in Fig .
The load moves up and down the central spindle. This additional downward force increases the speed of revolution required to enable the balls to rise to any predetermined level.
Consider the forces acting on one-half of the governor as shown in Fig.

15. DERIVATION
Consider the force acting on one half of the governor :

16. DERIVATION

17. Relation between ‘h‘ and ‘ω’ of Porter Governor
There are several methods to find this relationship. Here Instantaneous Centre Method is discussed.

18. The instantaneous centre lies at I Taking moments about I:
In this method, equilibrium of the forces acting on the link BD are considered.
The instantaneous centre lies at I
Taking moments about I:

20. Final Equations: 2 1) N2 = (m + M) m x 895 h mg + ( M.g ± F)/2 m.g 2)
Without Friction
mg + ( M.g ± F)/2
m.g 2) N2 = x
895 h
(1+q)
With Friction 3) h =
(m + M) m x g 2

21. Proell Governor

22. The Proell governor has the balls fixed at B & C to the extension of the links DF & EG, as shown. The arms FP & GQ are pivoted at p & Q respectively.
Consider the equilibrium of the forces on one half of the governor. The instantaneous centre (I) lies on the intersection of the line PF produced and the line from the D drawn perpendicular to the spindle axis. The perpendicular BM is drawn on ID

23. Final Equations: 1) N2 =
(m + M) m x
895 h
Since h is in mtrs. FM BM

24. Characteristics of Governors
Stability : A governor is said to be stable when there is one radius of rotation of the balls for each speed which is within the speed range of the governor.
Sensitiveness : The smaller the change in speed from no load to the full load, the more sensitive the governor will be. According to this definition, the sensitiveness of the governor shall be determined by the ratio of speed range to the mean speed. The smaller the ratio more sensitive the governor will be
where N2 – N1 = Speed range from no load to full load.

25. Isochronism
A governor is said to be isochronous if equilibrium speed is constant for all the radii of rotation in the working range. Therefore, for an isochronous governor the speed range is zero and this type of governor shall maintain constant speed.
Hunting
Whenever there is change in speed due to the change in load on the engine, the sleeve moves towards the new position but because of inertia if overshoots the desired position. Sleeve then moves back but again overshoots the desired position due to inertia. This results in setting up of oscillations in engine speed. If the frequency of fluctuations in engine speed coincides with the natural frequency of oscillations of the governor, this results in increase of amplitude of oscillations due to resonance. The governor, then, tends to intensity the speed variation instead of controlling it. This phenomenon is known as hunting of the governor. Higher the sensitiveness of the governor, the problem of hunting becomes more acute.