The Contributing Variables to Bearing Performance
November 7, 2022Manufacturers in nearly every industry — food processing, steel fabrication, aerospace, and medical devices, to name a few — are steadily increasing the performance expectations they have for rolling-element bearings while at the same time subjecting them to a wide variety of operating and environmental conditions. Although excellent performance is always expected, one thing that is sometimes neglected is that harsh circumstances significantly influence bearing life, reducing the basic rating life by as much as ninety per cent.
Estimated Life of a Bearing
Bearing life estimations have traditionally been based on a statistical method that uses the bearing manufacturer’s dynamic load rating. Following the selection of a bearing type, loads, speeds, and duty cycle are evaluated to provide a basic rating life, which is then compared to the required design life to establish an acceptable size.
However, bearing life might be drastically shortened when exposed to extreme operating situations. Typically, design alterations are necessary to preserve life expectancy (i.e. changes may include materials for rings and rollers, coatings, seals, retainer materials and lubricants). There is seldom a one-size-fits-all answer. Designers must examine all environmental elements before making necessary changes to make the best suitable alteration.
High temperature, corrosive chemical exposure, and vacuum settings are three typical and demanding working situations that affect bearing life. Manufacturers must account for these factors to appropriately prepare for and fulfil production objectives and milestones.
Affected By Corrosive Environments
Bearings are susceptible to damage from both water and chemicals, which can significantly reduce their lifespan. Bearings, for example, are constantly treated to high-pressure water in food processing factories. On the other hand, Irrigation systems are exposed to water and fertilisers. Bearings and lubricants are vulnerable in either of these settings.
When working in corrosive situations, you should consider using nitrogen-enhanced martensitic stainless steel since it offers five times the corrosive resistance of standard stainless steel. Stainless steel is often used to make rings and components. Similarly, ceramic may be utilised for rolling components, which give remarkable performance when exposed to corrosive conditions.
Impact of Temperature
Bearings made to order may withstand temperatures of more than 350 degrees Celsius. When designing a bespoke bearing that will function properly in such conditions, producers must consider both the bearing material and the lubrication.
Chrome steel grade 52100 is frequently used for ball and roller bearings because it can endure temperatures up to 125 degrees Celsius. Therefore, while working with greater temperatures, you should seek materials that are heat-stabilised and can function in temperatures higher than 350 degrees Celsius.
Additionally, an increase in temperature causes a reduction in the viscosity of the oil, which in turn affects the load-carrying capacity of the lubricant layer. Bearing greases that are considered standard can normally withstand temperatures of up to 175 degrees Celsius. Choose a grease or oil that can withstand temperatures up to 285 degrees Celsius, and put it to use.
Finally, Vacuum
Outgassing compounds condensing on optical devices in vacuum settings, including those found in space, impact retainers, and lubricants (lenses, solar cells, navigation sensors). At higher temperatures, the outgassing rate rises, necessitating solid lubricants such as gold, silver, molybdenum disulphide, and polytetrafluoroethylene. Furthermore, austenitic stainless steel AISI 304 cages are favoured in retaining materials since they reduce torque between the rolling element and the cage.
Contact us today for more information, or visit our list of available bearing products online!
Optimized by: Netwizard SEO