JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Design of machine members, Fluid Mechanics

Course Objectives:

• To Explain the processes of lubrication in all regimes
• To Explain the friction phenomena
• To Select a suitable lubricant for a specific application
• To Select a suitable material combination for tribological contacts
• To Determine the risk of wear by using simple analyses
• To Suggest an explanation to the cause of a tribological failure Course outcomes: After completing this course, the student should be able to
• Understand the different types of lubrications and relevant theories used in supporting elements.
• Understand the failure mechanisms in different types of supporting elements.

UNIT - I

Selection of rolling element bearings: Nominal life, static and dynamic capacity - Equivalent load, probabilities of survival - cubic mean load - bearing mounting details, pre loading of bearings, conditioning monitoring using shock pulse method.

UNIT - II

Hydrodynamic bearings: Fundamentals of fluid formation – Reynold’s equation; Hydrodynamic journal bearings – Sommerfield number - performance parameters – optimum bearing with maximum load capacity – Friction – Heat generated and Heat dissipated. Hydrodynamic thrust bearings; Raimondi and Boyd solution for hydrodynamic thrust bearings - fixed tilting pads, single and multiple pad bearings - optimum condition with largest minimum film thickness.

UNIT - III

Hydrostatic Bearings: Thrust bearings – pad coefficients - restriction - optimum film thickness - journal bearings – design procedure –Aerostatic bearings; Thrust bearings and Journal bearings – design procedure.

UNIT - IV

Dry rubbing Bearings: porous metal bearings and oscillatory journal bearings – qualitative approach only. Lubrication: Choice of lubricants, types of oil, Grease and solid lubricants - additives - lubrication systems and their selection – selection of pump, filters, piping design - oil changing and oil conservation.

UNIT - V

Failure of Tribological components: Failure analysis of plain bearings, rolling bearings, gears and seals, wear analysis using soap and Ferro graphy. Factors to be considered for life enhancement

TEXT BOOKS:

• 1. Hydrostatic and Hybrid bearing design by Rowe W W & O Dionoghue, Butterworths & Co. Publishers Ltd, 1983.
• 2. Mechanical Fault diagnosis and condition monitoring by Collacott R.A, Chapman and Hall, London R19 M.Tech. ENGG. DESIGN 1977.
• 3. Fundamentals of fluid film lubricant by Bernard J.Hamrock, Mc Graw-Hill Co., 1994.

REFERENCES BOOKS:

• 1. Tribology hand Book by Neale MJ, (Editor), Neumann Butter worths, 1975.
• 2. Standard hand book of lubrication engineers by Connor and Boyd JJO (Editors), ASLE, Mc Graw Hill Book & Co.,1968
• 3. Mechanical Engineering Design by Shigley J, E Charles, McGraw Hill Co., 1989. R19 M.Tech. ENGG. DESIGN M. TECH. I Year II Sem. (ENGG. DESIGN)