Thursday, 20 July 2017

TERMINOLOGIES OF FRICTION AND LUBRICATION (PART-1)



1.)ABSOLUTE VISCOSITY – Force per unit area required to move a surface at unit velocity, when it is separated by a fluid of unit thickness from a stationary surface.

2.)ADDITIVES – Chemical compounds used to alter the characteristics of lubricating oils.

3.)ANGLE OF REPOSE – The minimum inclination which a plane can have consistent with the body on it sliding down the plane by the force of gravity. It is the same as the friction angle.

4.)ANTI OXIDATION ADDITIVES – Chemical compounds added to decrease oxidation of the oil. These have a greater affinity for oxygen than does the oil.

5.)BATH LUBRICATION – Lubrication system in which the bearing contains a space filled with oil, which is in contact with a portion of the journal.

6.)BEARING OIL CLEARANCE – The space purposely provided between the revolving shaft and the bearing in which it rotates. Through this space lubricating oil can flow.

7.)CENTIPOISE – A unit of viscosity of a fluid used in figuring pressure drop etc.

8.)CRITICAL SPEED – The limiting or critical speed corresponding to a given pressure is that speed at which surface irregularities may intervene and so lead to seizure.

9.)FILM LUBRICATION – Type of lubrication in which the two metallic surfaces are separated by a continuous film of liquid oil of measurable thickness which forces itself between them.

10.FIRE POINT OF OIL – The temperature at which the oil vapour on the oil surface ignites and burns for at least five seconds, when heated gradually, under specified test conditions.


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