Lubrication is a critical component to extending bearing life. Without it the wear and heat caused by friction will quickly cause a bearing’s life to come to a catastrophic end. Lubrication reduces friction between bearing components by providing a film that separates contacting surfaces. The thickness of this fluid film can directly correlate to the fatigue life of a bearing. A thick film will keep components separated and help increase life, but if the film thickness is too thin the rolling surfaces will contact and cause life threatening friction.
The method of lubrication can also extend bearing life in other ways. Circulating lubrication may be used to dissipate heat by transferring it away from the bearing. This will keep the bearing cool and reduce lubricant deterioration. Lubrication can also help prevent contaminants from entering the bearing and guard against corrosion.
Grease and Oil Lubrication
Either grease or oil lubrication can be used to ensure bearings run optimally and to reduce wear. The application and operating conditions have to be taken into account when choosing the type of lubrication. Different parameters and the recommended method of lubrication are listed in the table below [article with the table is linked below].
- Grease Lubrication – Increasingly high-performance machines need rolling bearings which fulfill the most exacting output and quality requirements. In order to meeting the increasing demands and requirements of industry there are often a multitude of properties to consider when selecting a grease for your application.
- Oil Lubrication- Oil lubrication is most suitable for high limiting speeds. Generally speaking, oil lubrication systems are more complex and need careful maintenance. The lubricating oils used for rolling bearings are normally highly refined mineral and synthetic oils with high levels of oil film strength, plus excellent resistance to oxidation and corrosion. When choosing a lubricating oil, it is important to consider its viscosity in the relevant operating conditions. If the viscosity is too low, a proper oil film will not be able to form, which can cause abnormal wear and smearing. However, if the viscosity is too high, the lubricant can cause excessive friction, leading to an increase in bearing temperature and a considerable loss of energy.
This information is a guideline to help select a starting point for bearing lubrication in your equipment. To read the full Technical Insight from NSK Americas, click here.
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