THEORY OF MACHINES – II

Course Objectives

1. Compute, both analytically and graphically forces and couples for reciprocating parts and dynamically equivalent system.

2. Understand the theory of inertia force and apply to four-bar linkage mechanism.

3. Understand types of balancing and its need.

4. Apply the theory of balancing to reciprocating and Rotating masses.

5. Understand the types of both tooth gear and the nomenclature of gears.

6. Understand the concepts of interference in gears, and its removal.

7. Compare the cycloid and involute tooth profile.

8. Understand the various types of gear trains.

9. Apply the theory of gear trains to solve simple numerical problems.

10. Understand gyroeffect on moving bodies

11. Understand techniques of kinematic synthesis

Detailed Contents

1. Static force analysis: Static equilibrium of mechanism, concept of force and couple, free body diagram, condition of equilibrium, methods of static force analysis of simple mechanisms and power transmission elements, considerations of frictional forces

2. Determination of forces and couples for a crank, inertia of reciprocating parts, dynamically equivalent system, analytical and graphical method, inertia force analysis of basic engine mechanism torque required to overcome inertia and gravitational force of a four bar linkage.

3. Balancing: Classifications, need for balancing, balancing of single and multiple rotating masses, static and dynamic balancing, primary and secondary balancing for reciprocating masses, partial balancing of locomotives, swaying couple, hammer blow, variation in tractive effort, balancing of V-engine, concept of direct and reverse crank, balancing of machines, rotors, reversible rotors.

4. Gears : Toothed gears and spur gears, types of toothed gears, definitions, pitch circle diameter, pitch surface, pitch point, circular pitch, module pitch, diametrical pitch, addendum,. Dedendum clearance, outside and internal diameters, root diameter, base circle diameter, face and flank of tooth, pressure angle, path of contact, arc of contact, conditions for correct gearing, forms of teeth, involute and its variants, interference and methods of its removal. Calculation of minimum no of teeth on pinion/wheel for involute rack, helical/spiral/bevel/worm gears. Center distance for spiral gears and efficiency of spiral gears

5. Gear Trains : Types of gear trains, simple, compound and epicyclic gear trains, problems involving their applications, estimation of velocity ratio of worm and worm wheel.

6. Gyroscopic motion and gyroscopic couples: Effect on supporting and holding structures of machines, Effect on 2 and 4 wheeled vehicles,

7. Kinematic synthesis of Mechanism: Freudenstien equation, Function generation errors in synthesis, two/three point synthesis, Transmission angles, least square techniques,