Theory of Machines-I (ME2L001)
Lecture 1 : Introduction
Dr. Soham Roychowdhury
School of Mechanical Sciences
Indian Institute of Technology Bhubaneswar
Text/Reference Books:
• Theory of Mechanisms and Machines by A. Ghosh and A.
K. Malik, East-West Press.
• Design of Machinery by R. L. Norton, McGraw-Hill.
• Theory of Machines and Mechanisms by J. E. Shigley, and
J. J. Uicker, McGraw Hill, Inc.
Theory of Machines is a branch of Engineering, which deals with the
study of relative motion between the various parts of a
mechanism/machine, and forces which act on them.
Kinematics: Study of geometric aspect of motion of the
mechanism/machine without considering the forces.
Dynamics: Study of the effect of forces acting upon the
mechanism/machine parts in motion.
• In earlier days, the scientists believed that all machines are composed of six basic
components known as simple machines.
• The true beginning of the theory of mechanisms started by the development of a four
bar mechanism by James Watt for guiding a point along an approximate straight line
path.
• German engineer Franz Reuleaux first proposed that the kinematic pairs are the
true building blocks for all mechanical devices. He is often considered as the father of
Kinematics.
Mechanism: An assemblage of rigid bodies connected by movable joints
to form a closed kinematic chain with one link fixed and having the
purpose of transforming/transferring motion from input(s) to output(s).
Machine: A device that uses mechanism(s) to transform/transfer motion
and force from input(s) to output(s) to perform useful mechanical work.
Slider Crank Mechanism Internal Combustion Engine Model
Types of Motion:
• Linear: Motion that moves an object in
a straight line.
• Rotary: Motion that turns the object in
a complete 360° circle around an
axis, often repeatedly.
• Reciprocating: Motion that pivots an
object back and forth in a linear direction.
• Oscillating: Motion in which an object
is rotating back and forth in a arc.
Types of Mechanisms:
• Planar: The relative motions of the
links are confined in one plane or in
parallel planes.
Planar Mechanism
• Spatial: The links can have relative
motions in three-dimensional space
and not constrained to move in a
particular plane.
Spatial Mechanism
Examples of Different Mechanisms
Mechanism for Drawing Specific Curves:
Scott Russel Mechanism Roberts Four Bar Mechanism
Mechanisms for Holding Objects:
Pliers
Parallel Jaw Pliers
Mechanism used in Shaping Machine:
Whitworth Quick Return Mechanism
Mechanisms used in Automobiles:
Rack-Pinion Mechanism in Wiper Mechanism used in Brakes
Mechanisms to Transfer Intermittent Motion:
Geneva Mechanism Ratchet Mechanism
Cam Follower Mechanisms:
Translating Follower Oscillating Follower
Speed/Flow Control Mechanism:
Mechanical Governor
Gear Mechanisms:
Bevel Gears
Spur Gears Helical Gears
Rack and Pinion
Worm Gears
Robots (Open Kinematic Chain):
Robotic Arm Manipulator Parallel Kinematic Machine
Parallel Robots:
Stewart Platform Flight Simulator
Scope of Study:
1.Analysis: (Forward Problem)
(a) Kinematics: Position, velocity and acceleration analysis of
mechanisms
(b) Dynamics: Force analysis of mechanism
2. Synthesis: Geometric design of the mechanism (Inverse
Problem)
References:
• Norton R.L., Design of Machinery, McGraw-Hill
• Myszka D.H., Machines and Mechanisms: Applied Kinematic Analysis, Prentice Hall
• Shigley J.E., and Uicker J.J., Theory of Machines and Mechanisms, McGraw Hill, Inc
• Ghosh A., and Malik A.K., Theory of Mechanisms and Machines, East-West Press
• Wilson C.E., and Sandler J.P., Kinematics and Dynamics of Machinery, Pearson Education
• Waldron K. J., and Kinzel G. L., Kinematic, Dynamics, and Design of Machinery, Wiley
• Vinogradov O., Fundamentals of Kinematics and Dynamics of Machines and Mechanisms, CRC
Press
• NPTEL Course on Kinematics of Machines, Prof. A. K. Malik
• NPTEL Course on Kinematics of Mechanisms and Machines, Prof. A. DasGupta
• Respective sources from internet for different figures
• https://www.youtube.com/user/thang010146
