What is Elastohydrodynamic theory?
Elastohydrodynamic lubrication (EHL) is a mode of fluid-film lubrication in which hydrodynamic action is significantly enhanced by surface elastic deformation and lubricant viscosity increases due to high pressure.
What is EHL friction?
Elastohydrodynamic lubrication (EHL) is the typical regime for friction pairs having elastic contact under very high pressure in unconformal contact, such as ball bearings and gears. EHL is a development of hydrodynamic lubrication, which takes into account the elastic deflection of solid contacting surfaces.
Where is Elastohydrodynamic lubrication used?
Definition of Elastohydrodynamic Lubrication (EHL) EHL, the same way as HL, is used to decrease friction and wear in tribological contacts. It is achieved by the development of a thin lubricant film between rubbing surfaces, which separates them and decreases friction.
Where can Elastohydrodynamic lubrication be found?
Elastohydrodynamic lubrication can be found in machine elements such as gears, ball bearings and cams. The use of numerical simulation is well established in EHL investigations for predicting the behaviour of EHL contacts.
What is the difference between hydrodynamic and hydrostatic lubrication?
Hydrostatic lubrication depends on the inlet pressure of lube oil and clearance between the metal surfaces, whereas in hydrodynamic lubrication it depends on the relative speed between the surfaces, oil viscosity, load on the surfaces, and clearance between the moving surfaces.
What is boundary lubrication?
Boundary lubrication is defined as that in which the sliding surfaces are separated by a very thin molecular film of lubricant, so that the chemical and physical natures of the surfaces and the lubricant are of major importance.
What is hydrodynamic transmission?
A hydrodynamic transmission is a hydraulic torque converter that sets a fluid in motion internally in order to drive an output element. Hydrodynamic coupling.
What is the principle of hydrodynamic lubrication?
Hydrodynamic lubrication occurs when non-parallel rigid bearing surfaces lubricated by a film-fluid slide over each other, forming a converging wedge of fluid and forming a lifting pressure (Williams, 1994).
What is hydrodynamic and hydrostatic bearing?
Hydrostatic bearings are externally pressurized fluid bearings, where the fluid is usually oil, water or air, and the pressurization is done by a pump. Hydrodynamic bearings rely on the high speed of the journal (the part of the shaft resting on the fluid) to pressurize the fluid in a wedge between the faces.