Goavernor characteristics

1. BULE HORA UNIVERSITY
 COLLEGE OF ENGINEERING AND TECHNOLOGY
 DEPARTMENT OF MECHANICAL ENGINEERING
 COURSE TITTLE :- MECHANISMS OF MACHINERY
 COURSE CODE :- MEng3071
 GROUP ASSIGNMENT
 GROUP MEMBER NAME
 NAME IDNO
 1 ROBEL DESTA ……………….RU0043/12
 2 YONAS DEREJE ……………….RU1943/12
 3 ROBA BOBE …………………….RU2283/12
 4 OLANA FIKADU …………………RU2423/12
 5 FIRAOL KEBEDE ……………….RU0501/12
 SUBMITTED TO:- TESFAYE
 SUBMISSION DATE :- 27/5/2014

2. content
 Introduction
 classifications of governors
 governor characteristics
 stability
 Sensitiveness
 controlling force
 isochronism
 Hunting
 porter governor
 hartnel governor
 centrifugal shaft governor
 centrifugal governor working
 inertia governors

3.  Introduction
 the function of a governor is to regulate the speed of an engine,
when there are variation in in the load. when the load on an engine
increases, its speed decreases, therefore it becomes necessary to
increase the supply of working fluid on the other hand
 the governor automatically controls the supply of working fluid
to the engine with the varying load condition and keeps the mean
speed within certain limits.
 the governor automatically controls the supply of working fluid
to the engine with the varying load condition and keeps the
mean speed within certain limits.
 GOVERNORS

4.  CLASSIFICATION OF GOVERNORS
Governors are broadly classified into two categories
depending on the controlling force acting on the governor.
1,centrifugal governors(loaded governors) and
2,inertia governors
 Centrifugal governors, the controlling force is due to the
centrifugal force acting on the control element- are two
types:-
1,dead weight governors
2,spring loaded governors
 Inertia governors, the control is achieved by means of
inertia force acting on the control element.

5.  governor characteristics
 To regulate speed, a governor must posses certain qualities.
 the main characteristics of a governing system is there fore the
reletionship between the generated load of the controlled machine
and speed which is the prime governor input .
 The characteristics that are related to the proper functioning of a
governor are stability and sensitivity. These characteristics affect the
controlling force of the governor.
 At the same time, it must readily respond to changes of speed.

6.  Controlling force
 is centrifugal governors is the equivalent inward redial
force that controls ball movement. Wich is due to sleeve
weight , spring force etc…
Depend on the horizontal radial position of the balls ,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.
 Stability
 Stability is 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.

7. Sensitivity
 Sensitivity is define as the extent of sleave movement for a change
in speed of the governor.
 as a governor is used to limit the change of speed of the engine
between a minimum to full load conditions the sensitiveness is also
defined as the ratio of the range of speed to the mean equilibrium
speed.
Isochronous Governors
 A governor is said to be isochronous when it is infinitely
sensitive.
 isochronism a governor is said to be isochronous if equilibrum
speed is constant for all the radii of rotation in the working range.
 hunting
 hunting an excessivelyfast too and fro motion of the sleeve between the
stopper due to resonance condition is knoun as hunting of governor.

8. The Porter Governor
 The Porter governor is a dead weight governor and is illustrated.
 As the speed of the shaft increases, the balls move outward
raising the sleeve height, and viceversa.
 The controlling load is attached to the sleeve.
in porter governor two balls are located at the top and load is
attached to the sleeves.

9.  hartnell governor
hartnell governors consists two bell cranks situated the
different points of the frame.
a frame is attached to the spindle each lever carries a ball
to the horizontal roller at the end of vertical arm.
the helical ring is provided to maintain the equal level
force on the rollers and arrangement of the screw is there
to adjust a force of the spring

10. centrifugal shaft governor
it consists of two ball of equal the centrifugal shaft 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.
Shaft governors are classified into two as
1 centrifugal flywheel governors, and
2 inertia governors
Both shaft governors operate by a combination of radial and
transverse accelerating forces.

11. centrifugal governor working
 the main working principle behind these types of governor is the
balancing of the centrifugal force.
 these balls will be revolving around the spindle which is driven by
the engine.
 A ball crank lever is connected to the sleeve and the other end of it
also will be connected to throttle valve located in the fuel supply
passege .

12.  inertia governors
 Inertia governors are operated by the rate of change of speed in
stead of the finite change of speed.
 For some rate of change of speed, the link carrying the two balls will
start to move causing the spring to deflect
 inertia governor are less frequently used than centrifugal governors.
 the function of a governor is to regulate the mean speed of an
engine.
 a speed control device utilizing suspended masses that respond to
speed changes by reason of their inertia.