5 reasons for bearing failure and proper lubrication
When bearings fail to achieve their expected life or performance, the consequences can include increased downtime, high maintenance costs, lost revenue, and missed deliveries.
Although precision ball bearings are designed for long and useful life, this can only be achieved through proper installation, lubrication, and maintenance. This is especially important in harsh environments, such as humid or dust-laden areas.
Most importantly, you must also ensure that you have selected the correct bearing for the application. If in doubt, always ask your supplier.
Below are some tips to avoid bearing failures
Excessive loads
Excessive loads on a bearing are another common cause of failure.
What to look for
You may see undulating rolling element wear paths, indicating overheating and widespread fatigue.
How to fix it
Reduce the load or consider using a larger capacity bearing.
If you’re looking for durable bearings that can withstand high speeds and loads, don’t hesitate to check out our range of bearings.
Lubrication failure
According to a recent study, up to 80 percent of bearing failures are due to improper lubrication. This includes inadequate lubrication, the use of unsuitable lubricants, or excessive temperatures that degrade the lubricant.
What to look for.
Look for discolored rolling elements (e.g., blue or brown) and rolling element marks, as well as overheating or excessive wear in the bearing.
How to fix it
Use the correct type and amount of lubricant, avoid grease loss, and maintain appropriate relubrication intervals.
For this reason, we carry only a wide range of lubricants, from the most trusted brands on the market.
Overheating
Overheating is usually the result of excessive operating temperatures and improper lubrication. High temperatures can cause grease to leak (oil flushing), which reduces the efficiency of the lubricant. At high temperatures, oxidation can cause loss of lubricating oils from the grease and leave a dry, crusted soap that can seize the bearing. Higher temperatures also reduce the hardness of the metal, leading to premature failure.
What to look for
Look for any discoloration of the rings, rolling elements, and cages. In extreme cases, bearing components will deform. Higher temperatures can also degrade or destroy the lubricant.
How to fix it
Thermal or overload controls, adequate heat paths, and additional cooling are among the best options to mitigate overheating.
Overheating can also be the result of poor installation. With the right tools, this can be avoided in the future. Check out our comprehensive SKF tools now.
Improper mounting and installation errors
In most cases, bearings should be mounted with an interference fit on the rotating ring.
What to look out for
A number of conditions can lead to dents, wear, cracked rings, high operating temperatures, premature fatigue, and premature failure of bearings. These include mounting bearings on shafts by pressure or impact on the outer ring, mounting bearings in housing by pressure on the inner ring, loose shaft fits, loose housing fits, fits that are too tight, out-of-round housings, and a poor bearing seat surface.
How to fix it
Follow proper assembly instructions and conduct training to ensure all employees understand the difference between proper and improper assembly.
To fix this problem, we strongly recommend using our SKF Maintenance Tools product range to help you assemble and troubleshoot.
Contamination
Improper storage and handling can expose bearings to contamination caused by foreign matter entering the bearing lubricants or cleaning solutions. This includes dirt, abrasive grit, dust, steel chips from contaminated work areas, and dirty hands or tools.
Improper handling can also cause damage to the bearing, through scratches and indentations. This can render the bearing unusable or cause premature failure of the bearing.
What to look for
Look for dents on rolling elements and raceways that cause vibration.
How to fix them
Filter the lubricant and clean work areas, tools, fixtures, and hands to reduce the risk of contamination.
Corrosion
Moisture, acid, low-quality or degraded grease, poor coatings, and condensation caused by excessive temperature changes can cause corrosion that attacks the finely machined surfaces of the ball and roller bearings.
What to look for
Look for red and brown spots or deposits on rolling elements, raceways, or cages, as well as increased vibration with subsequent wear, an increase in radial internal clearance, or a loss of preload.
How to fix it
Divert corrosive fluids away from bearing areas. Select integrally sealed bearings and consider external seals for particularly harsh environments. If you can’t avoid a corrosive environment, using a bearing material such as stainless steel can help.
The right lubrication
Are you using the right lubrication for your bearings? Not sure what type of greases and oils to use? Don’t worry, we can help you find the right lubrication for your machine.
Keeping your bearings lubricated is critical to extending the life of your bearings, but is it also necessary to maintain them? Yes, of course! Bearing failure can be more expensive than the cost of lubrication, maintenance, or parts replacement. The costs can add up quickly, as bearing failure can lead to lost production due to machine downtime and replacement and maintenance costs.
Did you know?
One of the main causes of bearing failure is inadequate or improper lubrication, which leads to contamination and excessive heat buildup!
Over time, the loss of lubrication from bearings can contribute to equipment failure if not relubricated at the proper time. Remember to always clean your bearings of dirt and dry them thoroughly before relubricating. If these steps are not done thoroughly, it can cause dirt and dust to penetrate deeper into the bearings during lubrication, which can lead to bearing failure later.
Oil or grease?
Lubricants for bearings come in the form of oil or grease, and choosing the right lubricant can be a challenge because there are over thousands of different bearings. Lubricating with the right oils and greases can extend the life of these mechanical elements, keeping your machinery running longer without incurring many maintenance costs.
Oil is ideal for rolling bearing elements. There are several types of oil lubrication systems, depending on the type and application of the bearing. Oil is often chosen to lubricate bearings in systems that operate constantly at high temperatures. It can help protect the bearing from rust and corrosion and control viscosity when dilution may occur.
Grease is a semi-fluid to solid thickener in combination with lubricant. It is generally preferred to oil lubrication in applications of bearings operating at moderate speeds where the temperature is not as high. For example, the use of grease lubrication would be used for bearings operating in wind turbines where oil reserves would be difficult to handle, and for conveyor belts where shock loads are frequent. Grease lubricants should be used for bearings that need additional protection from vapors or dirt.
Looking for a specific type of oil or grease? Visit our website now to see our range of lubricants.
Too much lubrication
Caution. Too much lubrication can cause bearings to deteriorate and overheat as the excess grease and oil increase the temperature in the bearing. Not all greases are the same and not all are compatible with each other. For the life of the bearing, it is highly recommended to stick with the same grease or a compatible substitute. However, this depends on several factors, such as the type of bearing, the design of the bearing, and the application of the bearing.
Condition and maintenance
Remember that lubrication of your bearing should not depend on time, but on the condition of the bearing. Bearings only need to be lubricated to reduce friction in the application of the mechanical element. If the amount of lubricant is doing the job well, it should not be necessary to change it. Friction levels should be monitored and measured so that you know when is the right time to relubricate your bearings.
There are a number of maintenance tools that can help you measure and monitor your bearings, and we have selected a few to help you. The TKTI21 thermal imaging camera is a tool that allows you to measure how much heat is being radiated from the bearing. The TMSP1 sound pressure meter is a handheld device that allows you to measure sound levels in machinery. In addition, the TMST3 electronic stethoscope should be used to easily locate machine noise and detect annoying machine and noise vibrations. For details on bearings and products that help maximize their efficiency, please visit our homepage