Be wary of the four stages of insufficient bearing lubrication

The environment in which the bearings work is often very harsh, and the harsh working conditions will continue to increase. As original equipment manufacturers and heavy equipment operators become more demanding on equipment performance and productivity, bearings need to withstand higher loads at higher speeds and operating temperatures. Thus, the important role of proper lubrication in avoiding bearing damage that may result in shutdown is becoming apparent.

Most bearings (about 80%-90%) use grease as a lubricant, and most of the bearing damage is mainly due to insufficient lubrication. During use, when the grease is insufficient to separate the rolling element from the raceway contact surface, different levels of bearing damage occur, which poses a threat to production efficiency and safety.

Dr. Kuldeep Mistry, Timken's research and development technologist, summarizes the gradual damage caused by insufficient bearing lubrication in four stages that are clear and easy to understand. It can help you find these warning signs and timely respond when inspecting and repairing bearings. Suffering from it.


First stage: discoloration

Metal-to-metal contact can cause the bearing temperature to be too high, causing discoloration of the raceways and rollers. In mild cases, this discoloration is due to lubricant contamination of the bearing surface, and in severe cases, the metal discolors due to high temperatures. In all cases, early inspection can avoid costly repairs.

Second stage: scratches and flaking

Check the bearings for traces of cut metal or metal peeling - these conditions require immediate attention. Scratches and flaking are prone to occur at high load and low speed applications or at high temperatures, and thin or insufficient lubricant film can accelerate the problem.

The third stage: roller overheating

Cracking of the lubricating film can result in direct contact between the components and localized scratches. In tapered roller bearings, this can be manifested as scratches on the big end of the roller and on the leading rib.

The fourth stage: the bearing is completely locked

 Extreme local heating creates metal flow in the bearing, changing the original material and geometry of the bearing. This can result in excessive roller tilt, damage to the cage, and complete bearing lockup. If catastrophic damage does occur, it is advisable to consult a bearing specialist to determine the root cause of the problem, as it may be a factor other than lubrication.

A small damaged bearing can cause critical equipment to suddenly stop – regular inspection and relubrication are still the best way to prevent unscheduled maintenance.

Damage caused by insufficient lubrication varies greatly in appearance and impact on bearing performance. In all cases, the amount, type, grade, viscosity, additive and supply system of the grease must be properly designed for the bearing system. Grease should be selected based on historical experience, load, speed, sealing system, conditions of use and life expectancy. If these factors are not properly considered, bearing performance and application effects may be lower than expected.

This is where the lubrication specialist's expertise can work. Find a partner who is proficient in materials science and tribology to analyze bearing damage and determine the best grease to apply. Or, if you just need to help set new lubrication guidelines, experienced professionals can work with you to develop a plan and provide in-depth training.

The world of bearings is complex, but improved bearing lubrication can help the business move forward more smoothly. Be sure to check the bearings carefully and take extra care. If excessive friction affects your operations, don't hesitate to contact the bearing specialist immediately.

Reprinted from the network