Unit 1

Review of kinematics of planar rigid bodies

Definitions- link, kinematic pair, kinematic chain, mechanism and machines. Degrees of freedom – mobility – Kutzbach criterion – Grashoff’s law. Kinematic inversions – four bar chain and slider crank – mechanical advantage – transmission angle.

Mechanisms – quick return mechanism- pantograph -straight line mechanisms -steering gear for automobiles- Hookes joint – Toggle Analysis of slider crank and four bar mechanisms – Graphical method for position,velocity and acceleration. Instantaneous center – velocity analysis – Kennedy’s theorem.

Shaping machine mechanism – coincident points – Corioli’s component of acceleration – graphical approach for quick return mechanism. Analysis of complex mechanisms

Unit 2

Loop closure method for slider crank, four bar and quick return mechanism –computer programs for analysis of mechanisms – numerical solution of loop closure equations.

Synthesis of mechanisms – dimensional and three position synthesis

Unit 3

Cams – classification of cams and followers, nomenclature, description and analysis of follower motion, pressure angle – Determine of basic dimensions and synthesis of cam profiles, graphical and analytical methods, cams with specified contours.

Gears – terminology, fundamental law of gearing, involute profile. Interference and undercutting, minimum number of teeth, contact ratio, bevel helical, spiral and worm gears. Gear Trains – simple, compound and epicyclic gear trains.

Lab session (ADAMS software/ MAKEIT Tool Kit)

• Modelling and analysis of slider crank mechanism and its inversions
• Modelling and analysis of four bar mechanism and its inversions
• Modelling and analysis of 6 bar chains
• Modelling and analysis of crank and slotted lever and Whitworth quick return mechanism
• Modelling and analysis of Cam mechanism
• Modelling and analysis of gear drives
• Modelling and analysis of practical mechanisms (mini project)
• Demonstration of mechanism using the Tool kit

Course Objectives

This course is expected to enable the students to

• Familiarize with fundamental definitions and classification of mechanisms
• Perform kinematic synthesis and analysis of planar mechanisms with lower and higher pairs
• Perform kinematic analysis using software package

Course Outcomes

• CO1: Classify and solve for mobility of planar mechanisms
• CO2: Perform kinematic synthesis and analysis of planar mechanisms
• CO3: Construct and analyze cam profiles for a specified motion of the follower
• CO4: Analyze different types of gear trains
• CO5: Model and analyze planar mechanisms using software package

CO – PO Mapping

Textbook(s)

• Uicker, John Joseph, Gordon R. Pennock, and Joseph Edward Shigley.Theory of machines and mechanisms.Vol. 1. New York, NY: Oxford University Press, 2011.
• Norton, Robert L. Kinematics and dynamics of machinery.McGraw-Hill Higher Education, 2011.

Reference(s)

• Ghosh, Amitabha, and Asok K. Mallik.Theory of mechanisms and machines. AffiliatedEast-West Press Private Limited, 2002.
• Rattan, Sarjit S. Theory of machines.Tata McGraw-Hill Education, 2014.

Evaluation Pattern