Question

4. Name three types of lubrication in addition to hydrodynamic lubrication and explain each of them briefly. (3 points)

Answer 1

(*) Lubrication is the control of friction and wear by inserting a friction - reading film between two moving surfaces in contact. The lubricant used can be a fluid, solid or plastic substance. Main features of lubricant is to (*) rightarrow Reduce friction (*) rightarrow Prevent wear (*) rightarrow Protect the equipment from corrosion (*) rightarrow control temperature (*) rightarrow control contamination (*) rightarrow Transmit power Three types of lubrication including boundary, mixed, and full fil. Full film lubrication are of two types (*) Hydrodynamic and (*) elasto hydrodynamic rightarrow Hydrodynamic lubrication occurs when the surfaces are in sliding motion rightarrow Elasto Hydrodynamic lubrication is similar but occurs when surfaces are in rolling motion. The film layer is much thinner than hydrodynamic lubrication and pressure on the film is greater. It is called elasto hydrodynamic because the film elastically deforms the rolling surface to lubricate it. Rightarrow Boundary lubrication is found