HISTORY OF TRIBOLOGY DOWSON PDF

For example, the joint mechanisms in vertebrates or the mucus layer of fish are perfect tribological systems that originated through evolutionary processes. As early as the Stone Age, humans were familiar with friction and tribology: If one patiently rotated a dry wooden stick back and forth in the hollow of a limb, it was possible to kindle a fire after some time. In this case, friction provided an effective means to an end. Man began using the first tools such as levers, stone axes and similar tools as far back as , to , years ago.

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Invention of Wheel: The invention of wheels helped vehicles to move along by transferring and reducing friction. The wheel was probably invented around 8, B. The oldest known wheel found in an archaeological excavation is from Mesopotamia, and dates to around BC.

This period was known as the Bronze Age. The period of early civilization post BC , saw many advances in the field of tribology including stone sockets, lubricants to reduce friction, and different surface materials to reduce wear. Possible lubricants used were water, mud, and rendered fat from sheep or cows. The picture of transportation of an Egyptian statue to the grave of Tehuti-Hetep, El-Bersheh indicates the concept of lubrication was already used by ancient Egyptians.

The picture depicts slaves are dragging a large statue along sand or ground. Specimens of Egyptian Chariots from around B. During the times of the Greeks and Romans approximately BC to AD , advancements in machine elements, lubrication and theories regarding friction and wear were all evident.

These advancements included Archimedes gears, and roller bearings on Roman ships for rotating platforms. A list of lubricants was published, which included vegetable and animal oils. The middle ages The Middle Ages was not known for its advancements, and the same is true regarding the field of tribology.

One possible exception is the Cathedral of Wells clock, which incorporates metal gearings and brass bearings.

Leonardo Da Vinci was one of the first scholars to study friction systematically. His work on friction originated in studies of the rotational resistance of axles and the mechanics of screw threads. He focused on all kinds of friction and drew a distinction between sliding and rolling friction. Leonardo da Vinci understood the important role friction played in the workings of machinery and how friction limited efficiency.

His ideas included the thought that friction was the result of the roughness of the material and smoother materials resulted in less friction. Specifically, da Vinci noted that friction is not dependent of contact area, friction resistance is directly proportional to the applied load, and friction has a constant correlation.

Prior to the First Industrial Revolution Developments in the period prior to the First Industrial Revolution of was mainly confined to Britain, as Britain did not allow the export of machinery, skilled workers, or manufacturing techniques, as they were aware of their superiority in these areas.

The revolution brought about much advancement in the areas of bearings, gearings, lubricant application, and theories regarding friction and wear. Christian Huygens invented the pendulum clock and patented the pocket watch while Robert Hooke invented the universal joint. The monumental work done by Sir Isaac Newton in his Principia from laid down the foundations of Viscosity and was able to bring out the concept of Newtonian and Non-Newtonian Fluids.

John Theophilus Desaguliers became the first person to propose the adhesion concept of friction. He stated that friction is fundamentally caused by the force it takes to overcome adhesive forces or to breakdown adhesion.

French physicist Guillaume Amontons rediscovered the rules of friction after he studied dry sliding between two flat surfaces Amontons, He postulated three laws which is only applicable to dry friction: The force of friction is directly proportional to the applied load. The First Industrial Revolution The Industrial Revolution from to saw rural societies in Europe and the United States change into industrialized, urban societies. Goods that were formerly produced by hand were now produced in mass quantities by machines in factories.

This was the era of James Watt, a Scottish inventor and mechanical engineer who created the Watt steam engine, which was fundamental to the period and the changes it brought about.

John Harrison who was a self-educated English carpenter and clockmaker, invented caged roller bearing as part of his work on chronometers. Advancements were also made in the field of gearings, journal bearings, and roller bearings.

Many patents for lubricants were granted during this time. Lubricants included mixtures of graphite and pig tallow, as well as mixtures of olive oil and lime in water.

George Rennie, Charles Hatchett, and George Gabriel Stokes were active scientists during this time, promoting their theories regarding friction, wear, and hydrodynamic theory. Era of Osborne Reynolds The years of to saw amazing improvements in machine elements including the electromotor locomotive and the axle gear drive for the automobile. Vegetable and animal oil lubricants were replaced with distilled and refined lubricants such as compressor oils and refined cylinder oils.

The first additives were also invented during this time period. In this manuscript, the famous equation of thin fluid film flow in the narrow gap between two solids was formulated.

This equation is the basis of the classical lubrication theory. In Richard Stribeck was a German scientist and engineer, living from to , published the Stribeck curve, a plot that related friction with viscosity, speed and load. Modern tribology Philip Bowden and David Tabor gave a physical explanation for the laws of friction. They determined that the true area of contact is a very small percentage of the apparent contact area. The true contact area is formed by the asperities.

The term tribology was mentioned for the first time in in the Jost Report, a study commissioned by the British government to investigate damage from wear.

The committee headed by Peter Jost, estimated that application of basic principles of tribology could save the UK economy approx. After s development of bio-based lubricants generally made from a variety of vegetable oils, such as rapeseed, canola, sunflower, soybean and popularly known as bio-lubricant began.

In the s, development of Nanotribolgy branch of tribology that studies friction, wear, adhesion and lubrication phenomena at the nanoscale and Biotribology the tribological phenomena occurring in either the human body or in animals began. Tribology continues to grow in importance to modern society, especially as green tribology emerges in response to the growing environmental crisis.

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He also observed that the force needed to overcome friction doubles as weight doubles. They state that: [3] the force of friction acting between two sliding surfaces is proportional to the load pressing the surfaces together the force of friction is independent of the apparent area of contact between the two surfaces. Although not universally applicable, these simple statements hold for a surprisingly wide range of systems. In a study commissioned by the Privy Council of the UK , they used a simple reciprocating machine to evaluate the wear rate of gold coins. They found that coins with grit between them wore at a faster rate compared to self-mated coins.

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