Lubrication method

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Splash lubrication on the cross head of the steam engine of a paddle steamer

Lubrication process is a term of tribology and is used to convey the respective lubricant in the right amount at the right time to a point of friction and, if necessary , to divert it again. Lubrication methods can be classified according to various criteria.

Loss lubrication (consumption lubrication)

Loss lubrication refers to the exclusive supply of lubricant to the lubrication point. The feeding can be done manually, semi-automatically or automatically. Old lubricant is continuously or cyclically replaced by new, unused lubricant. The old, used lubricant must be removed, provided it does not evaporate by itself.

Example: coating sliding surfaces with grease , oiling joints with an oil can, two-stroke engine (use of two-stroke oil )

Circulating lubrication

Circulating lubrication refers to a lubricant cycle. It consists of the reservoir (e.g. oil pan), the feed to the friction point and the return. A lubricant preparation (e.g. oil filter ) can also be interposed.

Recirculating lubrication requires less lubricant as it is reused. Due to the closed system, no (or only very little) lubricant gets into the environment.

Circulating lubrication is mostly implemented with lubricating oil . The best-known example is the four-stroke internal combustion engine.

Splash lubrication

It is used for less loaded gearboxes. The oil level in the housing reaches at least to the lower teeth. The rotating gears take the lubricant with them into gear mesh. A low oil level can keep splashing losses in the gearbox low. However, it must be ensured that all lubrication points are adequately supplied. Thanks to the favorable component and housing design, the oil that drips off again can also be transported to higher-lying, non-submerged lubrication points, such as roller bearings. In piston engines, cantilevers on the lower connecting rod eye can also serve to "fling" oil to higher-lying lubrication points.

Splash lubrication was known as "excavator oiling" on historic Opel cars.

Lifetime lubrication

Under lifetime lubrication means the unique equipping a friction point with lubricant, which until the end of the planned useful life is not replaced or renewed needs.

It is often used in rolling bearings , but is also used, for example, in linear guides . These systems are provided with a lubricating grease filling during production, which is held in the bearing or in the guide by sealing rings.

Lifetime lubrication becomes problematic when the application profile or the service life deviates significantly from the conditions assumed for the design. In such cases, lubrication can fail. It is usually not possible to fill the lubricant reservoir as there are no access points.

Self-lubrication

Self-lubrication describes the property of a friction point to work without external lubricant. This can be done by choosing very low-wear friction partners with a low coefficient of friction. This means that the service life is achieved even without additional lubricant. One area of ​​application is, for example, graphite or plastic bearings. Another variant consists in embedding solid lubricant (e.g. graphite) in bearing shells (e.g. brass). As a result of bearing wear, lubricant is repeatedly released.

According to the number of lubrication points

Single lubrication

Individual lubrication is used if there is only one lubrication point, a central lubrication system is too complex or the lubrication points cannot be reached by a central lubrication system.

Manual individual lubrication

Pump oil can

Manual individual lubrication is always consumption lubrication.

Keywords: hand application, brush, spatula, oil can , grease gun , grease nipple , Stauffer bushing , point oiler

Semi-automatic individual lubrication

Fat box lubrication , wick oiler , oiler , Pen oiler

Automatic individual lubrication

Keywords: splash lubrication, spray + spray lubrication

Central lubrication

Central lubrication systems are ideal when several lubrication points need to be supplied.
One advantage is the reduction in maintenance costs. Regular lubrication and correct dosing reduce lubricant consumption and wear. In the past it was often installed in automobiles ( central chassis lubrication ), which saved the need for greasing with a grease gun and oil can. Another classic case is the central lubrication of all steam lubrication points in steam engines and locomotives with superheated steam oil that is very viscous at room temperature.

literature

  • Berthold Schlecht: Machine elements 2. Gears - gears - bearings, Pearson Education, Munich 2010, ISBN 978-3-8273-7146-1 , pp. 161–163.
  • Richard Ascher: The lubricants, their type, testing and use. A guide for the business man, 2nd edition, published by Julius Springer, Berlin 1931.
  • H. Wittel, D. Jannasch, J. Voßiek, C. Spura: Roloff / Matek machine elements. Springer Vieweg, Wiesbaden 2019, ISBN 978-3-658-26280-8 .

Individual evidence

  1. ↑ It's going well. (accessed on August 10, 2018)
  2. ↑ Environment-and-material-sparing loss lubricants (accessed on August 10, 2018)
  3. ^ EW Steinitz: Correct machine lubrication. Published by Julius Springer, Berlin 1932, pp. 45–47.
  4. ↑ Lubrication, cooling and instrumentation. P. 79. (accessed on August 10, 2018)
  5. ↑ The Science of Self-Lubrication (accessed August 10, 2018)

See also

Web links