kinematics of machine related theory

1. SHRI RAWATPURA SARKAR
INSTITUTE OF TECHNOLOGY,
ATAL NAGAR
KINEMATICS OF MACHINE
4TH SEM MECHANICAL
BY-
NURESH KUMAR KHUNTE
ASST. PROF.
DEPT.OF MECHANICAL ENGG.
 I never want to see the price tag of the thing which i like .
 That’s the my dream………

2. INDEX
Introduction
Elements, pairs, Mechanism
Four bar chain and its inversion
Velocity diagrams
Relative velocity method
Instantaneous centre method.

3. INTRODUCTION
PURPOSE:-
 The purpose of this course is to explore the topics
of kinematics and dynamics of machinery
respect to the synthesis of mechanisms in order
to accomplish desired motions or tasks, and also
the analysis of mechanisms in order to
determine their rigid-body dynamic behavior.

4. KINEMATICS OF MACHINE
 The subject Kinematics of Machines may be
defined as that branch of Engineering-science,
which deals with the study of relative motion
between the various parts of a machine, and
forces which act on them. The knowledge of
this subject is very essential for an engineer in
designing the various parts of a machine.
 We will begin with careful definitions of the
terms used in these topics.

5. BASIC OF THEORY OF M/C & MECHANISM
 Definitions:-
Link(Solid Liquid Gas):- It is a resistant body(any
shape, any size) which taken part in the transfer of
power in a M/c.
 (It should be a resistant body) Need not be a rigid
body.
Resistant body:-Body whose deformation is
negligible during transfer of power(force & motion).
Key point:-Link are identified by their relative
motion.

6. KINEMATICS
 It is that branch of theory of machine which
deals with relative motion between the various
parts of machines.
 Kinematics describes the motion of points
,bodies without consideration of the causes of
motion.

7. DYNAMICS
 It is that branch of theory of machine which
deals with the force and their effects, while
acting upon the machine part in motion.

8. MACHINE
 It is a device which recevies energy in some
avilable form and utilizes it to some particular
work.
 A machine is a tool containing one or more
parts that uses energy to perform an intened
Action.

11. MECHANISM
 It is a device designed to transform input forces
and movement into desired set of output forces
and movement.
 EXM:
 1.Gear and gear trains
 2.Belt and chain drive
 3.Cam and followers
 4.Breaks and clutches

12. Gear and gear
trains

13. BELT AND CHAIN
DRIVE

14. MECHANISM
 TYPES
 1 Planar mechanism
 2 Spatial mechanism
 Planar mechanism: it is a mechanism in which all of
the relative motion of the rigid bodies are in one plane
or in parallel plane.
 It is a mechanical system that is constrained so the
trajectories of stomachs in all the bodies of the system
lie on aeroplanes parallel to a ground plane.

16. SPATIAL MECHANISM
 All the relative motion of the rigid bodies are
not in a same plane or in different planes.
 It is mechanical system that has at least one
body that moves in a way that its point
trajectories are general space curves.

18. Kinematic pair
 The two link or element of a machine, when in
contact with each other, are said to form a
pair.If relative motion between then is
completely or succefully constrained, the pair
is knows as kinematic pair.

19. Classification of kinematic pair
1. Sliding pair : when two elements of pair are
connected in such a way that one can only slide
relative to the other, pair is knows as sliding pair

20. 2. Turning pair : when the two elements of pair are
connect
in such a way that one can only turn or revolve ablout a
fixed axis of
another link,the pair is known as turning pair
Example is a shaft with collars in a circular hole.
3. Rolling pair :when the two element of pair are
connect in such a way that one rolls over another fixed
link, the pair is known as rolling pair

21.  4. Screw pair: when the teo element of pair are
connected in such a way that one element turn about
the other by screw threads, the pair is known as screw
pair
 5. Spherical pair: when the two elements of pair are
connected in such a way that one element turn or
swivels about the other fixed element,the pair formed
is called a spherical pair

22. Contact between the elements
 1. Lower Pair: A kinematic pair is said to be a lower
pair if the links in the pair have surface or area contact
between them.
 2. Higher Pair: A higher pair is a kinematic pair in
which the links have point or line contact. Ball
bearings, cam and follower are examples of higher
pair

23. The type of closure
 1. Self Closed Pair: A pair is said to be self closed if
the links in the pair have direct mechanical contact,
even without the application of external force.
 2. Force Closed Pair: A kinematic pair is said to be
force closed if the links in the pair are kept in contact
by the application of external forces. A good example
of this type of pair is ball and roller bearings.

24. Kinetic chain
 When the kinematic pairs are couple such a way that
last link is joined to the first link to transmit definite
motion, it is called a kinematic chain
 Types of joint in chain
 1. Binary joint
 2. Ternary joint
 3. Quaternary joint

25. Type of kinematic chain
 (i) Four bar chain or quadric cycle chain: That the
kinematic chain is a combination of four or more
kinematic pairs, such that the relative motion between
the links or elements is completely constrained.

26. (ii) Single slider crank chain: A single slider
crank chain is a modification of the basic four bar
chain. It consist of one sliding pair and three
turning pairs. It is usually,found in reciprocating
steam engine mechanism.
.

27.  (iii) Double slider crank chain: A kinematic chain
which consists of two turning pairs and two sliding
pair pairs is knows as double slider crank chain

28. Kinemetic Diagram
And
Kinemetic Inversion
 What is Kinemetics ?
 It is that branch of Theory of Machines which deals
with the relative motion between the various parts of
the machines.
 What is Kinematic diagram
 It is a graphical representation of Displacement
velocity and acceleration with respect to time.

29. GRAPHICAL REPRESENTATION OF
DISPLACEMENT W.R.T. TIME
•When the body moves with uniform velocity,
EQUAL distance are covered in EQUAL
INTERVAL OF TIME.

30. • When body moves with variable
velocity,unequal distance are covered in
equal interval of time.

31. GRAPHICAL REPRESENTATION OF
VELOCITY W.R.T. TIME
•When body moves with zero acceleration,
then body is said to move with a uniform
velocity

32. • When the body moves with constant
acceleration, the body is said to move with
variable velocity

33. GRAPHICAL REPRESENTATION OF
ACCELERATION W.R.T. TIME
• When the body moves with uniform
acceleration

34.  • When the body moves with variable acceleration

35. Kinematic inversion
 Different mechanisms obtained by fixing
different links of a kinematic chain are known
as its inversion.
 A slider-crank chain has the following
inversion

36. First inversion
• This inversion is obtained when link 1 is fixed
and link 2 &4 are made the crank and Slider
respectively

37. Second inversion
• Fixing of link 2 of a slider-crank chain results
in the second inversion

38. THANK YOU
.