What is wedge film lubrication?
Oil Wedge: An oil film formed as the result of hydrodynamic lubrication. A result of temperature, speed, load and oil viscosity. Often a consideration in turbine plain bearing lubrication as the wedge will provide lift for the turbine shaft.
What is squeeze film?
A squeeze film damper is a layer of film between the bearing and the housing that softens the bearing support to increase damping effectiveness. This film is in addition to the hydrodynamic film between the bearing and the shaft.
What are the types of lubrication mechanisms?
There are three different types of lubrication: boundary, mixed and full film. Each type is different, but they all rely on a lubricant and the additives within the oils to protect against wear. Full-film lubrication can be broken down into two forms: hydrodynamic and elastohydrodynamic.
What is fluid film lubrication used for?
description. In lubrication: Fluid-film lubrication. Interposing a fluid film that completely separates sliding surfaces results in this type of lubrication. The fluid may be introduced intentionally, as the oil in the main bearings of an automobile, or unintentionally, as in the case of water between a smooth rubber…
What are the 3 regimes of lubrication?
Lubricants operate under three common lubricating regimes: Hydrodynamic (full-film) Elasto-Hydrodynamic.
What is difference between hydrodynamic and elastohydrodynamic lubrication?
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.
What is wedge journal bearing?
In a wedge film journal bearing, the bearing carries a steady load and the journal rotates relative to the bearing. But in certain cases, the bearings oscillate or rotate so slowly that the wedge film cannot provide a satisfactory film thickness.
What are the 5 types of lubricants?
Here given are the common lubricants and their uses:
- Penetrating Lubricants.
- Dry Lubricants.
What are the four types of lubricants?
Lubricants are classified into four types: oil, grease, penetrating lubricants, and dry lubricants. The two most common lubricants you’ll encounter on a daily basis are oil and grease, but your facility will still use dry and penetrating lubricants.
What is thick film lubrication mechanism?
When the load is applied, the pressure developed in the lubricant is sufficient to keep moving surfaces apart and hence it known as hydrodynamic lubrication. It occurs in journal bearing. This type of lubrication is used in watches, clocks, electric motors, turbines etc.
What is full film lubrication?
Hydrodynamic or full film lubrication is the condition when the load carrying surfaces are separated by a relatively thick film of lubricant. In this lubrication regime, the load is sufficiently high enough for the surfaces to elastically deform during the hydrodynamic action.
Why does lubricant film have a low surface deformation?
The hydrodynamic pressure generated in the lubricant film due to the relative motion and inner film friction is too low to cause surface deformation. The flow of the lubricant film is laminar, but at thicknesses above 20 μ m it becomes turbulent and that leads to undesirable friction losses.
How to assess the lubrication regime of ultra-flat solid surfaces?
Using the lubricant film parameter, the lubrication regime can be assessed as elastohydrodynamic lubrication (EHL) or hydrodynamic lubrication (HL) if λ ≥ 3, as mixed lubrication if λ ranges from 1 to 3, and as boundary lubrication (BL) when λ is smaller than 1. The above-mentioned methods are not applicable to ultra-flat solid surfaces.
What is hydrodynamic lubrication?
Hydrodynamic lubrication: The tool and the workpiece are separated by a liquid lubricant which is thick enough to avoid any direct contact between their surfaces.
What is boundary lubrication and how does it work?
Boundary lubrication usually does involve wear and antiwear additives are commonly employed. Most antiwear additives are believed to react with or adsorb onto the contacting surfaces, affording a contact surface that is more resistant to wear. Many real life applications involve both hydrodynamic and boundary lubrication.