The function of governor is to regulate the speed of an engine when there are variation in the load . And its Applications.

1. Submitted By: Submitted to:
Name:Abhishek Singh Mr.Amit Kumar Singh(AP)
Branch: Mechanical Engg. ( Seminar Incharge )
Roll No.: 1442340006

2. INTRODUCTION:
 The function of governor is to regulate the speed
of an engine when there are variation in the load .
 Eg. When the load on an engine increases, its
speed decreases, therefore it is necessary to
increase the supply of working fluid & vice-versa.
Thus, Governor automatically controls the speed
under varying load.

3. Characteristics of Governors
Different governors can be compared on the
basis of following characteristics.
 Stability :
A governor is said to be stable when for every
speed within the working range there is a
definite configuration i.e. there is only one radius
of rotation of the governor balls at which the
governor is in equilibrium. For a stable governor,
if the equilibrium speed increases, the radius of
governor balls must also increase.

4.  Sensitiveness of Governor
If a governor operates between the speed limits
N1 and N2, then sensitiveness is defined as the
ratio of the mean speed to the difference
between the maximum and minimum speeds.

5.  Isochronous Governors
A governor is said to be isochronous when the
equilibrium speed is constant (i.e. range of speed
is zero) for all radii of rotation of the balls within
the working range, neglecting friction.The
isochronism is the stage of infinite sensitivity.

6.  Effort and Power of a Governor
The effort of a governor is the mean force exerted at the sleeve for a
given percentage change of speed (or lift of the sleeve). It may be
noted that when the governor is running steadily, there is no force at
the sleeve. But, when the speed changes, there is a resistance at the
sleeve which opposes its motion. It is assumed that this resistance
which is equal to the effort varies uniformly from a maximum value to
zero while the governor moves into its new position of equilibrium. The
power of a governor is the work done at the sleeve for a given
percentage change of speed. It is the product of the mean value of the
effort and the distance through which the sleeve moves. i.e., Power =
Mean effort × lift of sleeve

7.  Compensation:
A mechanical and/or hydraulic action that
prevents over correction of the fuel supply is
called compensation. Compensation in a
governor produces transient speed droop i.e. a
momentary speed droop during a speed
correction.
Dead band:
A narrow band of speed variation through which
the governor makes no correction of fuel supply.

8.  Hunting:
When the load on an engine changes the governor
tends to over-control or under-control. This causes a
fluctuation in rpm, which is called hunting. For
example, if load is removed from an engine, the speed
increases some amount above normal and the governor
comes into operation and reduces fuel supply. Due to
friction and time lag, the governor causes the fuel
reduction to be in excess of that required and the fall in
speed is too much. This causes the governor to increase
fuel and the engine rpm goes slightly above normal.
This swing in speed above and below the mean
operating rpm for that load continues until equilibrium
is reached and hunting ceases. The more sensitive a
governor is, the greater will be the tendency to hunt.

9.  Isochronous:
Constant speed i.e. the same average speed regardless
of load.
 The governors may broadly be classified as
1)Centrifugal governors
2)Inertia governors

10.  Centrifugal Governors :
 In centrifugal governors, multiple masses know
as governor balls, are responsible to revolve
about the axis of a shaft, which is driven through
suitable gearing from the engine crankshaft.
Each ball is acted upon by a force which acts in
the radially inward direction and is provided by
dead weight, a spring or a combination of two.
This force is commonly called as the controlling
force and it will increase as the distance of the
ball from the axis of rotation increases.The
inward or outward movement of the ball is
transmitted by the governor mechanism to the
valve which controls the amount of energy
supplied to the engine.

11. The centrifugal governors may further be classified as follows:
Centrifugal governor
Pendulum type Loaded type
Watt governor
Dead weight
governor
Spring controlled
governor
Porter governor Proell governor
Pickering
governor
Hartung
governor
Wilson - Hartnel
governor
Hartnell
governor

12. Watt Governor:

13. It is the simplest form of centrifugal
governor. It is basically a conical pendulum with
links attached to a sleeve of negligible mass. This
governor was used by James Watt in his steam
engine. The spindle is driven by the output shaft
of the prime mover. The balls are mounted at the
junction of the two arms. The upper arms are
connected to the spindle and lower arms are
connected to the sleeve.

16. Graph between height & Speed

17. Applications
 The application of this device to the steam engine has a great
importance in the technology history because it was the founder of
a great family of devices for the installations automatic control.
 It was commonly used to maintain the engine’s speed of trucks or
other vehicles.
 It is still use in Ships and trains engine.
 They are seen on steam engines, internal combustion engines and
variously fuelled turbines.
 We can use it on ac generators to maintain the electricity supply
with the load increases on it.
 They are used in automobiles to restrict/maintain engine RPM, total
speed.
 Governors protect engine from excessive rotational speed.
 We can use it on those systems where working fluid and speed of
the system are main issue.