For both grease and oil systems, the viscosity of the base oil is one of the most important considerations in selecting the proper lubricant.

Vibrating screens create operating conditions in which bearings have to perform at high temperatures. The load zone of a screen bearing can be 30ºF (17ºC) higher than the sump temperature and 40ºF (22ºC) higher than the housing temperature.

Consider why the bearing’s operating temperature matters: It is critical because it affects lubricant viscosity and lubricant life. As a general rule, a lubricant should maintain a minimum viscosity of 105 SUS (21.8 cSt) at the bearing operating temperature for adequate lubrication.

With the improved analytical tools that exist today, Timken’s engineers are able to suggest the required viscosity based on the load, speed and temperature conditions of a particular screen.

The most common types of lubrication systems used by vibrating screen manufacturers are manual grease, automatic grease feed, oil splash and circulating oil systems. Oil mist and drip feed systems are also used, but to a lesser extent.

Vibration Analysis

With appropriate product considerations in place, it is also important to incorporate condition monitoring to keep conveyors running smoothly. Vibration analysis provides valuable data to help operators optimize their performance of their systems and avoid costly downtime. The service detects potential problems in equipment, allowing operators to address them before they cause a breakdown.

Timken points to an example from a pipeline transportation and energy storage company that was troubled by inconsistencies in its operation, involving large conveyors for seaward vessels loaded with mineral and ore products.

After meeting with the customer, Timken dispatched one of its own field experts to conduct in-depth vibration analysis on the bearings throughout the entire system.

“The findings showed two imminent failures on the first trip and two more on the second trip,” said Vern Couch, senior field engineer. “So far, we’ve caught five damaged bearings that were close to causing catastrophic failures – damage that another service provider wasn’t able to find.”

After being replaced, the damaged bearings – which were manufactured by a Timken competitor – were immediately sent to Timken for damage analysis.

 The damage analysis prompted adjustments to the customer’s bearing settings and maintenance procedures to avoid similar problems in the future, and helped to save the company substantial costs, thanks to downtime averted.

About The Timken Company

The Timken Company (NYSE: TKR, http://www.timken.com) keeps the world turning, with innovative friction management and power transmission products and services, enabling our customers’ machinery to perform more efficiently and reliably. With sales of $5.7 billion in 2008 and operations in 26 countries, Timken is Where You Turn™ for better performance.