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What is a Self-lubricating Bearing?

Self-lubricating bearings, as the name suggests, provide their own lubrication during operation without requiring application of grease or oil lubricants.


Due to this, self-lubricating bearings are also referred to as maintenance-free or greaseless bearings as they require no relubrication or grease. An example of a self-lubricating bearing is our GGB-CSM® greaseless bearing.

An important distinction to make is that self-lubricating bearings are not bearings that come pre-applied with grease or oil lubricant – these bearings are instead referred to as prelubricated bearings. Prelubricated bearings will require relubrication at some point in their service life. An example of a prelubricated bearing is our DX® low friction bearing which is marginally lubricated with grease.

Self-lubricating bearings work by having lubricant impregnated within the sliding layer of the bearing. This lubricant can either be liquid (oil) or solid (graphite, MoS2, lead) based on the requirements of the application (such as operating temperature). As the bearing operates, the lubricant is released through pores in the sliding layer, lubricating the bearing surface. The lubricant is uniformly dispersed throughout the sliding layer and thus there is no reduction in low friction bearing performance, even if the sliding layer becomes worn. A “running-in” surface is also usually included at the top of the sliding layer to provide low friction bearing performance at start up before the impregnated lubricant reaches the bearing surface. 


The aerospace industry requires low friction bearings with excellent wear resistance to help reduce labor costs. Additionally, many areas of an aircraft are difficult to access for service and thus benefit from components with long service lives, namely self-lubricating bearings.

Self-lubricating bearings eliminate the need for maintenance, lowering labor costs, and increase the service life of aerospace applications. An amazing example of the versatility of self-lubricating bearings in the aerospace industry is the use of DU® anti friction bearings in NASA’s Curiosity rover, which has been exploring the red planet since 2012.

Learn about more applications of GGB self-lubricating, greaseless bearings in the aerospace industry.

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