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Hydrodynamic, hydrostatic plain bearings

What are hydrodynamic and hydrostatic plain bearings?

Cross section of a bearing position with a hydrostatic plain bearing

Functionality of hydrodynamic plain bearings

A hydrodynamic plain bearing is a type of bearing in which there is minimal clearance between the bearing and the shaft. This gap is filled with lubricant. When at rest, the shaft also rests on the plain bearing.

When the shaft starts to rotate, lubricant is drawn into the constriction between the bearing and shaft and the pressure in the lubricant increases as the rotational speed increases. This forms a so-called lubrication wedge underneath the shaft, which lifts the shaft. As a result, the plain bearing and shaft no longer touch and are separated from each other by a lubricating film.

Advantages of hydrodynamic bearing points

Wear-free continuous operation is possible thanks to hydrodynamic lubrication
Ideal for large bearing forces and diameters as well as high speeds
Oil film has a dampening effect
Simple installation

Hydrodynamic plain bearings are used here

Hydrodynamic plain bearings are often used in the automotive industry, where they are used in thermal management. They are also widely used in ships and subsea turbines, as they provide optimum performance when operating in humid environments. They also play an important role in power generation, particularly in wind turbines and hydroelectric power stations. In addition, hydrodynamic plain bearings are used in industrial machinery, such as large machine tools and pumps. Their ability to carry high loads with low friction makes them the ideal choice for these applications.

Cross section of a bearing position with a hydrodynamic plain bearing

How hydrostatic plain bearings work

A hydrostatic plain bearing is a type of bearing in which a pump is used to pump lubricant between the shaft and the bearing. In contrast to hydrodynamic bearings, there is therefore permanent full lubrication.

Hydrostatic plain bearings are used when it is necessary for the shaft to run in the centre. However, as the oil supply or oil pressure represents a safety risk, hydrodynamic bearing points are generally favoured.

Advantages of hydrostatic bearing points

Permanent oil film means there is no sliding resistance when starting up and running down
Low wear of the bearing point
Low frictional power

This is where hydrostatic plain bearings are used

Hydrostatic plain bearings have similar areas of application to hydrodynamic plain bearings. However, as they have a higher true-running accuracy, they are often used where high-precision operation is required. For example, in measuring equipment or machine tools. Like hydrodynamic plain bearings, they are also used in power generation. Here they are used in turbines and generators, among other things.

Our plain bearings for hydrodynamic applications

igus offers various plastic bearings that are suitable for use in hydrodynamic lubrication. These differ primarily in the various application parameters, such as e.g. temperature or chemical resistance, for which they were developed.

UW plain bearings - information and dimensions

UW160 plain bearings - information and dimensions

UW500 plain bearings - information and dimensions

H1 plain bearings - information and dimensions

H370 plain bearings - information and dimensions

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iglidur plain bearings sample box from igus

Free iglidur plain bearing sample box

Convince yourself of the quality of our products. The iglidur improves sample box contains:

✅ 39 iglidur plain bearings made from the most important materials
✅ Templates for finding the perfect material for your application
✅ iglidur bearing technology catalogue with information about our plain bearings

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