Published on November 22, 2008
Tribology : Tribology Science and engineering of interactive surface in relative motion. Presented by: Mukut ch. Medhi Somnath Dey Dhiru Kamal Deka Md Shaifuddin Dept. of Mechanical Engineering Tezpur University Tribology : Tribology Tribology (origin in 1960’s) Tribology= tribos+logos Rub Principle or logic Brown’s first law of applied Tribology : Brown’s first law of applied Tribology IF IT'S RUNNING IT'S WEARING !!! IF IT'S NOT RUNNING IT'S PROBABLY WORN! Tribology : Tribology Two bodies in relative motion . Results Friction Static friction Frictional heat, resistance against movement (friction force), loss of energy. Wear Material loss degradation of surface, decreasing functionality. Examples of Tribology : Examples of Tribology Industrial Tribology Machine parts/engines Lubrication Oil Grease Friction and wear Decreasing performance Wear Definition : Wear Definition Most wear is an combination of several mechanisms Wear Mechanisms : Wear Mechanisms Adhesive Low contact pressures Augmented asperities Abrasive High contact pressures Wear tracks Friction : Friction Origin of friction Deforming of the surface : deformation energy Adhesion of two bodies: non-linear adhesion hysteresis Atomic adhesion model Van Der Waals Capillary forces Electron interactions Dynamic friction –static friction Lubrication : Lubrication Lubrication is the process, or technique employed to reduce wear of one or both surfaces in close proximity, and moving relative to each another, by interposing a substance called lubricant. Types of lubricants : Types of lubricants Liquid lubricants Lubrication with oil Cooling and removal of debris Protection against metal-metal contact Hydrodynamic lubrication Lowering friction=lowering energy input into the surface. Lubrication with grease Oil in wax Low cooling effect/no hydrodynamic lubrication Alternative when oil lubrication is impossible Types of lubricants : Types of lubricants Solid lubricants and self-lubricating materials Plastics, PTFE, MoS2, , Graphite Important properties of lubricants : Important properties of lubricants Wide range of viscosity Little change in viscosity with temperature Chemical stability Sufficient specific heat to carry away frictional heat Low cost Easily available Bearings : Bearings It is mechanical element that permits relative motion between two parts such as shaft and housing. Ball Bearing Classification : Classification Depending on type of friction Sliding contact bearing Rolling contact bearing Depending on type of force Radial Thrust Rolling and sliding contact bearing : Rolling and sliding contact bearing Rolling contact bearing and sliding contact bearing Radial and thrust bearing : Radial and thrust bearing Rolling contact bearing : Rolling contact bearing Deep groove ball bearing Cylindrical roller bearing Angular contact bearing Self aligning bearing Taper roller bearing Thrust roller bearing Rolling bearing : Rolling bearing Different types of bearings : Propeller bearing Water lubricated polymer bearing Water lubricated bearing Different types of bearings Application : Application Industrial Process Tribology in biological science Tribology in engines Industrial process : Industrial process Rolling-Sheet metal Wire drawing Tube expansion Deep drawing Rolling-Sheet metal : Rolling-Sheet metal Rolling-Sheet metal : Rolling-Sheet metal Wire drawing : Wire drawing Tube expansion : Tube expansion Deep drawing : Deep drawing Tribology in biological science : Tribology in biological science Tribology in engines : Tribology in engines Lubrication of engine Lubrication of engine : Lubrication of engine Valve train Sump1 Sump2 Piston assembly Crank shaft Degradation of lubricant : Degradation of lubricant Piston Assembly Sump Sump Piston Piston Assembly : Piston Assembly Extraction of Oil from Top Piston Ring : Extraction of Oil from Top Piston Ring Solutions to tribological problem : Solutions to tribological problem Trial and error method Material selection Parameter selection Lubricant Simulation method Selection of simulation Material selection Parameter selection Field data Conclusions : Conclusions Tribology is a multi-disciplinary science that is based onto experience and common sense. Boiler feed pumps: 49% of the failures causing outages were because of tribological components. Friction, wear and failure of tribological components are costing industry billions of dollars Reference : Reference www.falexint.com www.wikipedia.org lqme.sjtu.edu.cn www.TRIBOLOGY-ABC.com Design of machine elements- V.B BHANDARI Fundamentals of Tribology-Basu, Sengupta, Ahuja Thank You : Thank You Question’s ?....