Introduction of Kinematics of Machines

1. KINEMATICS OF MACHINES
UNIT-1
BASIC MECHANISM

2. THEORY OF MACHINES
KINEMATICS OF MACHINERY DYNAMICS OF MACHINERY
STATICS KINETICS

3. Kinematics
• Kinematics is the branch of classical
mechanics which describes the motion of
points, bodies (objects) and systems of bodies
(groups of objects) without consideration of
the causes of motion.

4. MACHINE

5. RESISTANT BODY

6. LINK or ELEMENT

7. EXAMPLES FOR LINK

8. TYPES OF LINK

9. RIGID LINK

10. FLEXIBLE LINK

11. FLUID LINK

12. STRUCTURE

13. MACHINE Vs STRUCTURE

14. KINEMATIC PAIR

15. CLASSIFICATION OF KINEMATIC PAIRS
• Based on type of Contact
• Based on type of Relative motion
• Based on type of constraint

16. 1. Based on Nature of contact
or
Type of contact

17. 2. Based on Nature of relative motion between them
or
Type of relative motion

18. 3. Based on Type of constraint

19. BASED ON NATURE OF CONTACT
IN KINEMATIC PAIRS
• LOWER PAIR
• HIGHER PAIR

20. LOWER PAIR

21. HIGHER PAIR

22. DEPEND ON RELATIVE MOTION
IN KINEMATIC PAIRS

23. ii) Turning pair

24. iii) Rolling pair

25. iv) Screw pair (helical pair)

26. v) Spherical pair

27. DEPEND ON CONSTRAINING MOTIONS
IN KINEMATIC PAIR

28. TYPES OF CONSTRAINED
MOTIONS

29. 1. COMPLETELY CONSTRAINED MOTION

30. 2.INCOMPLETELY CONSTRAINED MOTION

31. 3.SUCCESSFULLY CONSTRAINED MOTION

32. KINEMATIC CHAIN

33. HOW TO FIND
KINEMATIC CHAIN OR NOT

34. EXAMPLE .1
ARRANGEMENT OF THREE LINKS

35. SOLUTION

36. EXAMPLE-2
ARRANGEMENT OF FOUR LINKS

37. EXAMPLE – 3
ARRANGEMENT OF FIVE LINKS

38. JOINTS

39. 1.Binary joint
Here,
Number of Links = 4
Number of Binary Joints = 4
If two links are connected at the
same joint, it is called a Binary Joint

40. Checking whether it’s a kinematic chain

41. 2.Ternary joint
If three links are connected at the
same joint, it is called a ternary joint.
For the given Diagram, Apply Kline’s Criterion,
Number of Joints , j = Number of binary joints + 2 ( Number of
Ternary Joints)
= 3 + ( 2 x 2)
= 7

42. 3.Quaternary Joint
Number of Joints ,
j = Number of binary joints + 2 ( Number of Ternary joints) + 3 ( Quaternary
Joints)

43. DEGREES OF FREEDOM (DOF):
It is the number of independent coordinates required to
describe the position of a body.

44. DEGREE OF FREEDOM
OR MOBILITY
Degree of Freedom for plane Mechanism m (mobility):
It is defined as the no of input motions, which must be independently controlled
in order to bring mechanism into useful engineering purpose.

45. (a) Siding pair [DOF = 1]
(b) Turning pair (revolute pair) [DOF = 1]

46. (c) Cylindrical pair [DOF = 2]
(d) Rolling pair [DOF = 1]

47. .
(e) Spherical pair [DOF = 3]
Eg. Ball and socket joint
(f) Helical pair or screw pair [DOF = 1]

48. PROBLEMS

49. FIND THE DEGREE OF FREEDOM(MOBILITY) FOR
THE GIVEN DIAGRAMS

50. EXAMPLE-1

51. EXAMPLE-2

52. EXAMPLE - 3

53. EXAMPLE-4

54. EXAMPLE -5

55. INVERSION MECHANISM
• Inversion of a kinematic linkage or mechanism is observing the
motion of the members of the mechanism with fixing different
links as reference frame. Each time when a different link is
chose as the frame link the mechanism shows different
characteristics of the motion.
• KEEPING ANY ONE OF THE LINK FIXED AND
ROTATING OR OSCILLATING OTHER LINKS-
THIS RESULTS DIFFERENT FORM OF MOTION OUTPUT FOR
DIFFERENT USAGE

56. Inversion of Mechanisms

57. Types of kinematic chain

58. .
How to use
• Drag the red point.
• The red point moves on a line when "Line"
option is selected.
• The red point moves on a circle when "Circle"
option is selected.

59. examples

60. Inversions of Grashof’s chain

61. Inversions of Grashof’s chain

62. Inversions of Grashof’s chain

63. INVERSIONS OF FOUR BAR
CHAIN

64. INVERSIONS OF FOUR BAR
CHAIN

65. INVERSIONS OF FOUR BAR
CHAIN

66. INVERSIONS OF FOUR BAR
CHAIN

67. INVERSIONS OF FOUR BAR
CHAIN

68. FIRST INVERSION -

70. SECOND INVERSION

71. COUPLING ROD OF A LOCOMOTIVE – USED TO
TRANSMIT ROTATION FROM ONE WHEEL TO ANOTHER WHEEL
EXAMPLE --- IN TRAIN
• .

72. THIRD INVERSION

73. WATT INDICATOR MECHANISM- USED TO SHOW THE
STEAM PRESSURE IN THE CYLINDER

74. PANTOGRAPH
- USED TO ENLARGE THE SMALL GIVEN DIAGRAM

75. WORKING --- PANTOGRAPH

76. "Pantograph" is a drawing instrument to magnify figures.
Tracing the original figure by moving the red point, we can automatically
obtain the magnified figure with the pen at the blue point. Find the ratio of
magnification when the lengths of the arms are defined in the right figure.

77. ACKERMAN STEERING

78. INVERSIONS OF SINGLE SLIDER
CRANK CHAIN

79. First Inversion

80. Second Inversion

81. .

82. .

83. Third Inversion

84. .

85. .

86. Crank and slotted lever quick return motion
mechanism

87. Application of Crank and slotted lever quick return
motion mechanism

88. Fourth Inversion

89. Pendulam pump or Bull Engine

90. Hand Pump

91. INVERSIONS OF DOUBLE SLIDER
CRANK CHAIN

92. ,

93. Second Inversion

94. Third Inversion

95. .

96. .

97. Toggle mechanism,
UNIT - I

98. Toggle mechanism

99. toggle mechanisms
• The toggle mechanisms can be used in the
situation when one needs to output large
force subject to a short stroke, for example,
the stone crushers and mechanical presses,
etc. The shown mechanism has a toggle
position when the two lower links arrange to
be aligned. At this position, the slider can
produce an extremely large power to press
workpiece.

100. .
.

101. Intermittent motion mechanisms
Ratchet and pawl mechanism

102. Application of Ratchet Pawl mechanism

103. ,
.

104. .
.

105. Intermittent motion mechanisms
Geneva wheel mechanism

106. Snap Action Mechanism
.
• Its known as toggle mechanism or flip flop
mechanisms

107. Hooke’s joint

108. Straight line generators
Unit -1

109. Scott Russell straight line Mechanism

110. Arrangement
• The green link is 2 times greater than the length
of blue link. This blue link is pinned as shown in
fig with green link.
• One more requirement is that the slider's
connection pin needs to be sliding in a line that
would intersect the static pivot end of the short
link.

111. Scott Russell straight line Mechanism
The complexity of the mechanisms to generate
exact straight lines can be reduced by introduction
of one or more slider crank linkages. It is possible
to generate an exact straight line using the slider
crank mechanism but the range of motion is limited.
Based on the geometry of the linkage the output
motion is a simple sine function of the drive link or a
simple harmonic motion. It is evident from the figure
that this mechanism is made up of isosceles
triangles, AB, AC and AO2 are of equal lengths.

112. Peaucellier Exact Straight Line Mechanism
• Peaucellier linkage can convert an input circular
motion to the exact straight line motion.
• The construction of this mechanism is such that the
point which is connected to the crank moves in a
circular path and the point traversing the straight
line is selected as the output point.
• The linkage has a rhombic loop formed of the equal
length members, 5, 6, 7 and 8. Two equal length
links are connected to the opposite corners of the
rhombus at one end and to a common fixed point
O4 at the other ends.
• The point A of the rhombus is connect to fixed
point O2 through the link 2. The length of the link 2
is equal to the distance between points O2 and O4.
• By the constraints of the geometry point A moves in
a circular path and as the point A moves in a circle
point P traverses an exact straight line path normal
to the line joining O2 and O4.

113. Peaucellier Apparatus
• --- For drawing straight lines

114. MECHANICAL ADVANTAGE OF
MECHANISM
-------- a quality measure
• Due to more usage of 4 bar mechanism, its necessary to study
some of the advantages of mechanisms.
• Which tell whether the mechanism is good one or not.
• It’s a quality measure of all mechanism

115. MECHANICAL ADVANTAGE
• It’s the ratio of output torque to the input torque
• M.A(ideal) =
• M.A (Actual) =
TA = Driving link torque
TB = Driven link Torque
A
B
A
B
T
T



 
A
B
A
B
T
T




116. Transmission Angle
• The angle between
Coupler and the follower


117. Effect of Transmission angle
on mechanical advantage
.