What are the effects of ineffective lubrication of bearings


Some bearings do not need to be lubricated during use. […]

Some bearings do not need to be lubricated during use. This is called oil-free lubricated bearings, and many bearings need to be lubricated and maintained during use, and it is also very important whether the lubrication is appropriate. It is lubricated, but it is not done properly, which is the so-called ineffective lubrication, which will bring many disadvantages to the bearing.


Rolling bearings are a type of mechanical components that are widely used in mechanical transmission. The movement conditions are mainly rolling and sliding friction. Due to friction, local thermal deformation will be caused, which will accelerate the wear of the surface of the parts, resulting in increased operating errors and even the main shaft will be scrapped.


The reasons for bearing failure are often multi-factors. All the influencing factors of the design and manufacturing process are related to the failure of the bearing. The analysis of the causes of bearing damage shows that about 40% of the bearing damage is related to poor lubrication.


Four major disadvantages of bearing ineffective lubrication

(1) discoloration
Metal-to-metal contact can overheat the bearing, causing discoloration of the raceways and rollers. In mild cases, this discoloration is due to lubricant contamination of the bearing surfaces, while in severe cases, the metal is discolored by high temperatures. In all cases, early detection can avoid costly repairs.

Discoloration due to lubricant contamination of bearing surfaces


(2) Scratches and peeling
Check the bearing for signs of cut metal or peeling metal - these conditions require immediate attention. Scratching and spalling are prone to occur in high-load, low-rpm applications or sustained high temperatures, and problems can be accelerated by a thin or insufficient lubricant film. Insufficient lubrication, the wrong choice of grease, or sudden changes in operating conditions can result in peeling bearing material or scratching of the bearing rib.


(3) Roller overheating
A breakdown of the lubricating film can lead to localized scratches due to direct contact between components. In tapered roller bearings, this can appear as scratches on the big ends of the rollers and the guide ribs. Thermal damage to tapered rollers caused by metal-to-metal contact



(4) The bearing is completely locked
Extreme localized heating can create metal flow in the bearing, altering the original material and geometry of the bearing. This can result in excessive roller tilt, cage damage and complete bearing locking. If catastrophic damage does occur, it is advisable to consult a bearing specialist to determine the root cause of the problem, as factors other than lubrication may be involved.


The role of bearing lubrication
When the bearing is working, in order to ensure the effective and reliable operation of the bearing, there must be sufficient lubrication. The role of bearing lubrication:
Prevent or reduce the direct metal contact between the rolling elements, raceways and cages in the bearing and reduce friction and wear;
An oil film is formed on the friction surface. When the pressure oil film is formed, the contact bearing area of ​​the parts can be increased. Therefore, it can reduce the contact stress and prolong the rolling contact fatigue life.


Lubricant has anti-rust and anti-corrosion effect
Oil lubrication also has the function of dissipating heat and taking away wear particles or intruded pollutants generated during the operation of the bearing;
Grease lubrication can increase sealing to prevent the intrusion of external contaminants;
It has a certain effect of vibration reduction and noise reduction.


Damage caused by ineffective bearing lubrication can vary widely in appearance and impact on bearing performance. In all cases, the amount, type, grade, viscosity, additives and supply system of grease must be properly designed for the bearing system. Grease should be selected based on historical experience, load, rotational speed, sealing system, service conditions and life expectancy. If these factors are not properly considered, bearing performance and application results may be lower than expected.

Contact Us