Lubrication: Difference between revisions

Latest revision as of 11:20, 15 February 2025

Lubrication[edit]

Lubrication is the process or technique of using a lubricant to reduce friction and wear in contact between surfaces in relative motion. It is an essential aspect of mechanical engineering and plays a critical role in the operation and longevity of machinery.

Types of Lubrication[edit]

There are several types of lubrication, each suited to different applications and conditions:

Hydrodynamic Lubrication[edit]

In hydrodynamic lubrication, a full fluid film separates the surfaces in motion. This type of lubrication is common in journal bearings and other applications where a continuous film of lubricant can be maintained.

Boundary Lubrication[edit]

Boundary lubrication occurs when the lubricant film is not thick enough to completely separate the surfaces. This type of lubrication is typical in conditions of high load and low speed, where the lubricant film is reduced to a thin layer.

Mixed Lubrication[edit]

Mixed lubrication is a combination of hydrodynamic and boundary lubrication, where parts of the surfaces are separated by a fluid film, while other parts are in direct contact.

Lubricants[edit]

Lubricants can be classified into several categories based on their physical state and composition:

Liquid Lubricants[edit]

Liquid lubricants, such as mineral oil and synthetic oil, are the most common type of lubricants used in machinery. They provide excellent cooling and cleaning properties in addition to reducing friction.

Grease[edit]

Grease is a semi-solid lubricant composed of a thickener dispersed in a liquid lubricant. It is used in applications where liquid lubricants would not stay in place, such as in bearings and gears.

Solid Lubricants[edit]

Solid lubricants, such as graphite and molybdenum disulfide, are used in extreme conditions where liquid lubricants would evaporate or degrade.

Applications of Lubrication[edit]

Lubrication is crucial in a wide range of applications, from small engines to large industrial machinery. It is used to:

Reduce friction and wear
Dissipate heat
Protect against corrosion
Seal against contaminants

Lubrication in Steam Engines[edit]

In steam engines, lubrication is vital to ensure the smooth operation of moving parts such as pistons, cylinders, and bearings. The image on the right illustrates the lubrication of a steam engine, highlighting the importance of maintaining a proper lubrication system to prevent wear and overheating.

Related Pages[edit]

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-'''Lubrication''' is a process or technique employed to reduce wear of one or both surfaces in close proximity, and moving relative to each another, by interposing a substance called lubricant between the surfaces to carry or to help carry the load (pressure generated) between the opposing surfaces. The interposed lubricant film can be a solid, (e.g. [[Molybdenum disulfide|MoS2]]) a solid/liquid dispersion, a liquid, a liquid-liquid dispersion gasses.
+== Lubrication ==
-==Types of Lubrication==
+[[File:Steam_engine_lubrication.jpg|thumb|right|Lubrication of a steam engine]]
-There are three distinct types of lubrication: boundary, mixed, and full-film.
-===Boundary Lubrication===
+Lubrication is the process or technique of using a lubricant to reduce friction and wear in contact between surfaces in relative motion. It is an essential aspect of [[mechanical engineering]] and plays a critical role in the operation and longevity of [[machinery]].
-In [[Boundary lubrication]], the bodies come into closer contact at their asperities; the heat developed by the local pressures causes a condition which is part of the boundary lubrication state.
-===Mixed Lubrication===
+== Types of Lubrication ==
-[[Mixed lubrication]] is a condition in which a lubricant film (oil film) does not completely separate the friction surfaces, but significantly affects the friction and wear rates.
-===Full-film Lubrication===
+There are several types of lubrication, each suited to different applications and conditions:
-In [[Full-film lubrication]], the motion of the contacting surfaces, and the design of the bearing is used to pump lubricant around the bearing to maintain the lubricating film.
-==Lubrication Theory==
+=== Hydrodynamic Lubrication ===
-[[Lubrication theory]] is the science of studying lubrication – its type, flow and the lubricants. It is a discipline that is guided by the principles of fluid dynamics and tribology.
-==Lubricants==
+In hydrodynamic lubrication, a full fluid film separates the surfaces in motion. This type of lubrication is common in [[journal bearings]] and other applications where a continuous film of lubricant can be maintained.
-[[Lubricants]] are typically used to separate moving parts in a system. This separation has the benefit of reducing friction and surface fatigue, together with reduced heat generation, operating noise and vibrations.
+=== Boundary Lubrication ===
+Boundary lubrication occurs when the lubricant film is not thick enough to completely separate the surfaces. This type of lubrication is typical in conditions of high load and low speed, where the lubricant film is reduced to a thin layer.
+=== Mixed Lubrication ===
+Mixed lubrication is a combination of hydrodynamic and boundary lubrication, where parts of the surfaces are separated by a fluid film, while other parts are in direct contact.
+== Lubricants ==
+Lubricants can be classified into several categories based on their physical state and composition:
+=== Liquid Lubricants ===
+Liquid lubricants, such as [[mineral oil]] and [[synthetic oil]], are the most common type of lubricants used in machinery. They provide excellent cooling and cleaning properties in addition to reducing friction.
+=== Grease ===
+Grease is a semi-solid lubricant composed of a thickener dispersed in a liquid lubricant. It is used in applications where liquid lubricants would not stay in place, such as in [[bearings]] and [[gears]].
+=== Solid Lubricants ===
+Solid lubricants, such as [[graphite]] and [[molybdenum disulfide]], are used in extreme conditions where liquid lubricants would evaporate or degrade.
+== Applications of Lubrication ==
+Lubrication is crucial in a wide range of applications, from small [[engines]] to large industrial [[machinery]]. It is used to:
+* Reduce friction and wear
+* Dissipate heat
+* Protect against corrosion
+* Seal against contaminants
+== Lubrication in Steam Engines ==
+In [[steam engines]], lubrication is vital to ensure the smooth operation of moving parts such as pistons, cylinders, and bearings. The image on the right illustrates the lubrication of a steam engine, highlighting the importance of maintaining a proper lubrication system to prevent wear and overheating.
+== Related Pages ==
-==See Also==
-* [[Hydrodynamic lubrication]]
-* [[Elastohydrodynamic lubrication]]
-* [[Lubrication theory]]
 * [[Tribology]]
+* [[Friction]]
+* [[Wear]]
+* [[Bearing (mechanical)]]
+* [[Gear]]
 [[Category:Mechanical engineering]]
-[[Category:Tribology]]
+[[Category:Lubrication]]
-[[Category:Lubricants]]
-[[Category:Friction]]
-{{stub}}
-{{dictionary-stub1}}