JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Design of Machine Elements

Course Objectives:

• To study design concepts in order to enhance the basic design.
• To study behaviour of mechanical components under fatigue and creep.
• To study statistical techniques and its applications in mechanical design. Course outcomes: After completing this course, the student should be able to
• Ability to analyze behaviour of mechanical elements under different loads
• Understand the design of different transmission elements of automobile
• Ability to analyze mechanical elements critically.

UNIT - I

Shafts and Axles: Introduction, Causes of failure in Shafts and Axles and Stresses in Shafts, Materials for Shafts and Axles, Methods of Manufacturing of Shafts, Designing of Straight Shafts, Pure Torsional Load, Designing for Rigidity and Stiffness, Design of Axles, Flexible Shafts.

UNIT - II

Rope drive: Fibre ropes, rope drives for power transmission, fibrous Ropes used in Hoisting Tackle, Wire Ropes, Materials, Wire Rope Construction, Applications of Ropes, properties of various types of Ropes, Approximate wire Diameters and Effective Cross- section of Ropes: Fiber cores for steel wire ropes, Working loads, Friction and Efficiency wire rope, sheaves and Drum, rope fasteners, Selection of wire rope, design procedure.

UNIT - III

Chain drives: Types of Chain drives, construction of Chains, Roller Chains, Silent Chains, selection of a chain, Design of the chain Drive, Good design practice.

UNIT - IV

Gear drives: Design calculations for helical gears, Definitions, double helical, Gear tooth proportions, Design calculations, forces acting in a Bevel gear, Worm gear drives, worm wheel, designation of a worm gear drive, Materials, efficiency of Drive, Heat Dissipation, Design of worm Gearing, Forces on worm gears, advantages and disadvantages of worm gear drives.

UNIT - V

Power screws: Friction, Types of Power screws, Multiple threads, Comparison of square and trapezoidal threads, Power screw drive, Efficiency of screws, square threads, Trapezoidal Threads, stresses in screws design calculations, design procedure, other types of screws, differential and compounds screws, ball baring screws.

TEXT BOOKS:

• 1. Machine Design by Dr. P.C. Sharma, S.K.Kataria & sons
• 2. Machine Design by Maleev and Hartman, C.B.S Publishers

REFERENCE BOOKS:

• 1. Machine Design by Schaum series
• 2. Mechanical Engineering design by J.E. Shigley. M. TECH. I Year I Sem. (ENGG. DESIGN)