The document discusses the functions of flywheels and governors. It defines a flywheel as an inertial energy storage device that absorbs and stores mechanical energy to smooth out fluctuations in shaft speed from varying torque. Governors are used to regulate the mean speed of an engine under varying load conditions by automatically controlling the fuel supply. Common types of governors include the Watt, Porter, and Hartnell governors. The Watt governor uses centrifugal force of weights on arms, while the Porter governor adds a central load. The Hartnell governor uses a spring to control the sleeve position based on speed. Flywheels and governors both aim to maintain consistent engine speed but flywheels only regulate speed within each cycle, while governors regulate mean

1. *FUNCTION OF FLYWHEEL- A flywheel is an inertial
energy-storage device. It absorbs mechanical energy and
serves as a reservoir, storing energy during the period
when the supply of energy is more than the requirement
and releases it during the period when the requirement of
energy is more than the supply.
The main function of a fly wheel is to smoothen out
variations in the speed of a shaft caused by torque
fluctuations. If the source of the driving torque or load
torque is fluctuating in nature, then a flywheel is usually
called for.
5.Flywheel & Governors (8marks)

2. Turning moment diagram for 4-stroke
internal combustion engine:-

3. * Coefficient of Fluctuation of Speed (CS) -
The difference between the maximum and minimum speeds during a
cycle is called the maximum fluctuation of speed. The ratio of the maximum
fluctuation of speed to the mean speed is called the coefficient of fluctuation of
speed.

4. *Coefficient of Fluctuation of Energy (CE)-
It may be defined as the ratio of the maximum fluctuation of
energy to the work done per cycle.
CE =
𝑴𝒂𝒙𝒊𝒎𝒖𝒎 𝒇𝒍𝒖𝒄𝒕𝒖𝒂𝒕𝒊𝒐𝒏 𝒐𝒇 𝒆𝒏𝒆𝒓𝒈𝒚
𝑾𝒐𝒓𝒌 𝒅𝒐𝒏𝒆/𝒄𝒚𝒄𝒍𝒆
=
𝚫𝑬
𝐖
△ 𝑬 = 𝑴𝒂𝒙𝒊𝒎𝒖𝒎 𝒆𝒏𝒆𝒓𝒈𝒚 − 𝑴𝒊𝒏𝒊𝒎𝒖𝒎 𝒆𝒏𝒆𝒓𝒈𝒚
W=
𝑷∗𝟔𝟎
𝑵
Where,
P = Power
N = Number of working strokes /min
=N, for two stroke cycle
= N/2, for four stroke cycle
E = I * ω²
I = Mass moment of Inertia
ω= Angular speed=
𝟐𝜫𝑵
𝟔𝟎

5. GOVERNORS

6. INTRODUCTION
Function of Governor- The function of a governor is to
regulate the mean speed of an engine when there are
variations in the load . The governor automatically
controls the supply of working fluid to the engine with
the varying load conditions and keeps the mean speed
within certain limits.

7. Working principle
 When the load of an engine increases , its speed
decreases , therefore it become necessary to increase
the supply of working fluid . On the other hand when
the load on the engine decreases, its speed increases
and thus less working fluid is required.

8. Types of governor
 Watt governor : It is the simplest type of a centrifugal governor . If N is the speed of
arm and ball about the spindle axis , then the height of the governor (h) is given by
h=895/N^2
 Porter governor : It is a modification of the watt governor , with a central load
attached to the sleeve.
 The ratio of height of a porter governor to the height of a watt’s governor is
= m+M /m
 Hartnell governor : It is a spring controlled governor.in a hartnell governor , the
compression of the spring or lift of the sleeve (h) is given by
h=(r2-r1) y/x
 Stiffness of the spring
s=s2-s1/h
Where, r1= minimum radius of rotation
r2= maximum radius of rotation
s1= spring force exerted at the minimum radius of rotation
s2= spring force exerted at the maximum radius of rotation
x = length of vertical or ball arm of the lever
y = length of horizontal or sleeve arm of the lever

9. 1.Centrifugal Governor

10. It consists of two balls
of equal masses
attached to yhe two
arms . the upper ends
of the arm are pivoted
to a spindle,which is
driven by the engine
through bevel gear. The
lower arms connected
to a sleeve which is
connected to the
spindle. The sleeve
revolve with the
spindle but can slide up
and down . the two
stops s1 and s2 on the
spindle prevents the
upwards and
downward motion of
sleeve . the sleeve is
connected by a bell
crank lever to a throtle
valve,which controls
the supply of the
working fluid..

11. WATT GOVERNOR
OPEN-ARM TYPE =In
the first fig. the upper
links are conncted by a
horizontal link and the
governor is known as
open arm type watt
governor .
CROSSED –ARM TYPE
=In the second fig the
upper links cross the
spindle and are
connected by another
link and the governor is
known as crossed-arm
governor.

12. 2.Porter Governor

13. 3.Proell Governor

14. 4.Hartnell Governor

15. 5.Wilson-Hartnell Governor

16. 6.Hartung Governor

17. 7.Pickering governor

18. POSITION AT DIFFERENT SPEED

19. PORTER GOVERNOR
Porter governor : it
is a modification of
the watt governor ,
with a central load
attached to the
sleeve.
The ratio of height
of a porter governor
to the height of a
watt’s governor is
=
m+M /m

20. Hartnell Governor
Hartnell governor
: it is a spring
controlled
governor . In a
hartnell governor
, the compression
of the spring or
lift of the sleeve
(h) is given by
h=(r2-r1) b/a
Stiffness of the
spring
s=s2-s1/h

21. Mechanical Governor OperationMechanical Governor Operation at low engine speed

22. Mechanical Governor Operation at medium engine speed

23. Mechanical Governor Operation at high engine speed

24. FLYWHEEL GOVERNOR
 It controls speed
variation caused by
engine turning
moment during cycle.
 It stores energy and
gives up the energy
whenever required.
 It regulates speed
during one cycle only.
 It regulate the mean
speed of engine when
there is variation in
load.
 It regulate the speed
by regulating the
quantity of charge.
 It regulates speed
over period of time.
FLYWHEEL Vs GOVERNOR

25.  It has no control over
quantity of charge.
 It is not essential if
cycle fluctuation are
not present as in multi
cylinder engine.
 Governor takes care of
quantity of charge.
 It is very essential
element as it regulates
the fuel supply as per
demand
FLYWHEEL GOVERNOR

26. IMPORTANT TERMS RELATED TO GOVERNOR
 Isochronous governors :A governor is said to be
Isochronous when the equilibrium speed is constant
for all radii of rotation of the balls .
 Hunting : A governor is said to be hunt if the speed
of the engine fluctuates continuously above and
below the mean speed.
 Stability of a governor :A governor is said to be stable
when for very speed within the working range there
is a definite configuration