JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Overview

Course Overview: The aim is to teach students in the undergraduate and postgraduate levels basic concepts about friction, lubrication and wear applicable to design and operation of mechanical systems used in engineering, industrial, and modern applications. Examples of these systems are lubrication of internal combustion engines, gearboxes, artificial hip/knee joints, and micro/nano electromechanical systems.

Course Objectives:

Design of surfaces in contact is a critical problem for mechanical engineering. Tribology & lubrication (ME6009) is an interdisciplinary course which deals with fundamentals of surface contact, friction, wear and lubrication. Topics in ME 6009 include description and modeling of engineering surfaces, popular surface contact theories, major modes of friction, wear, lubrication and adhesion. The tribology challenges in micro system will be discussed as well.

UNIT - I

Historical Background - Viscosity - Viscometry - Effect of temperature onviscosity - Effect of pressure in viscosity - Other physical properties of mineral oils - The generalized Reynolds equation - Flow and shear stress - The energy equation - The equation of state - Mechanism of pressure development.

UNIT - II

Circumferential Flow - Oil flow through a bearing having a circumferential oilgroove - Heat generation and lubricant temperature - Heat balance and effective temperature - Bearing design: Practical considerations - Design of journal bearings - Parallel surface bearing - Step bearing - Some situations under squeeze film lubrication - The mechanism of hydrodynamic instability - Stiffness and damping coefficients - Stability.

UNIT - III

Elasto Hydrodynamic Lubrication: Theoretical consideration - Grubin typesolution - Accurate solution - Point contact - Dimensionless parameters - Film thickness equations - Different regimes in EHL contact - Deep-groove radial bearings - Angular contact bearings - Thrust ball bearings - Geometry - Kinematics - Stress and deformations - Load capacity.

UNIT - IV

SURFACE TOPOGRAPHY - Surface characterization - Apparent and real area ofcontact - Derivation of average Reynolds equation for partially lubricated surface - Effect of surface roughness on journal bearings

R16 B.TECH MSNT.

UNIT - V

Laws of Friction - Friction theories - Surface contaminants - Frictional heating -Effect of sliding speed on friction - Classification of wear - Mechanisms of wear - Quantitative laws of wear - Wear resistance materials.

TEXT BOOKS:

• 1. Rowe WW & O Dionoghue, Hydrostatic and Hybrid bearing design ― Butterworth’s & Co. Publishers Ltd, 1983.
• 2. Collacott R.A, Mechanical Fault diagnosis and condition monitoring, Chapman and Hall, London 1977.

REFERENCES BOOKS:

• 1. Neale MJ, (Editor) ― Tribology hand Book Neumann Butterworth’s, 1975.
• 2. Connor and Boyd JJO (Editors) ― Standard hand book of lubrication engineers ― ASLE, Mc
• 3. Introduction to Tribology of Bearings by Majumdar, B.C R16 B.TECH MSNT.