Reason Why Bearings Fail & Preventative Measures
Operational situations in the bearing industry and production installations occur in many equipments. Operational and production units keep operations up and running. Despite the significant responsibilities being undertaken in the manufacturing process, they are at a critical stage in the process, but before failure occurs. Bearings are often not noticeable until a facility fails.
What is a bearing failure?
Simply put, bearing failure occurs whenever a bearing fails to live up to its expected life or calculated performance level. When a bearing fails to live up to its expected life or performance level, this often leads to machine shaft failure, and the machine it’s in can fail.
The consequences of bearing failure can have far-reaching consequences for your facility. These can include increased downtime, high maintenance costs, missed deliveries, and lost revenue. In some extreme cases, workers can be injured.
A most common cause of bearing failure
In practice, damage or failure of bearings is often the result of the simultaneous operation of multiple mechanisms. Failures can be due to improper assembly or maintenance or manufacturing errors in the bearing or its adjacent components.
★ Improper lubrication procedure
This should be one of the first reasons to consider when inspecting a failed bearing. To ensure proper lubrication, there must be sufficient viscosity at operating temperature. Lubrication prevents metal-to-metal contact, prolongs service life, and prevents contaminants from entering the bearing housing.
However, using too much grease is as bad as not using lubricant at all. Over-lubrication is often the culprit in bearing failure as it leads to increased energy loss, elevated temperatures and oil seepage.
★ Lubrication failures can also occur when the operator
☆ Using the wrong type
☆ Not enough
☆ Allows lubricant to come in contact with water or other contaminants
It is also important to consider the service life of the grease, which is referred to as “how long a specific quantity and class of grease will maintain normal bearing function”. This is especially important in pumps, compressors and motors.
★ Corrosion and pollution
Contamination is caused by foreign matter entering the bearing lubricant or cleaning solution. Contaminants such as dirt, sand, water and chemical compounds can cause many problems in bearing assemblies.
For example, they can degrade lubricants or corrode/erode bearing surfaces, all of which can lead to premature failure. Moisture, acids, poor or damaged grease, poor packaging and condensation from excessive temperatures can cause corrosion, which can erode the finished surfaces of the ball and roller bearings.
Overheating is usually caused by excessive operating temperatures and improper lubrication. High temperatures can cause grease to bleed (remove oil), reducing the efficiency of the lubricant. At high temperatures, oxidation can cause the oil in the grease to run off, leaving behind a dry crusty soap that can seize the bearings. Higher temperatures also reduce the hardness of the metal, leading to early failure.
★ Improper installation
When installing bearings, be sure to use the correct tool and verify shaft and housing tolerances. When the fit is too tight, too much preload is created. When the fit is too loose, too little preload is created, causing the shaft to rotate in the bearing. Misalignment or shaft deflection should also be avoided.
★ Bad fit
It is critical that the bearing is properly installed on the dimensionally accurate shaft. If not, it can cause problems in two ways:
- If the shaft is oversized or expanded, it will result in an overtight fit, reducing the bearing’s internal clearance (see below for details).
- If the shaft is undersized or the fit is too loose, the bearings will creep on the shaft and wear and generate heat, eventually causing vibration and runout problems.
Bearing Failure Prevention Measures
Bearings have a fairly long life under normal operating conditions, but since they do have a fixed life, it is inevitable that bearings will eventually fail. Knowing why bearing failures occur makes it easier for industry professionals to implement appropriate measures to avoid them.
Why it is important to install and align bearings correctly?
Proper tools, ovens and induction heaters must be used during bearing installation and installation. Consider avoiding misalignment or shaft deflection as this is important when mounting bearings with separate parts. If the components are not properly aligned, the bearings will eventually experience abnormal wear.
The best practice to keep in mind is to solid flush the bearing and clean it with lubricant. Also, be sure to apply the last proper amount of grease before using the machine.
Lubricate according to manufacturer’s guidelines
Lubrication is used on bearings to completely cover rolling and sliding surfaces with a thin oil film to prevent metal-to-metal contact. Grease is more commonly used because it is easier to handle, while oil lubrication is often used for high temperature or high-speed applications.
Correct and effective application of lubrication can help reduce problems such as friction and wear, transfer heat from friction, extend service life, prevent rust and corrosion, and keep foreign objects and contaminants away from rolling elements.
Prevent operating pressure
Operating pressure on the bearing can affect bearing life. If the load on the bearing is too low, it will result in rolling element slippage and improper loading. If the load is too high, overloading and early fatigue may result.
Often the first sign of such a problem is unusual noise and/or high temperature. The ideal bearing temperature is below 100 degrees Celsius. It is important to note that bearing temperatures typically increase with startup and remain flat at slightly below startup temperatures (10 to 40 degrees Celsius above room temperature).
This is why it is crucial to ensure that vibrations are isolated in the associated equipment, as if not isolated, they can cause abnormal noise and uneven operation.
Why choose Yuanhe to meet your bearing needs?
Bearings are an essential part of many industrial equipment and systems, so proper selection and maintenance of them are critical. Otherwise, the facility may experience unexpected failures resulting in lost productivity and profits. Since bearing applications vary from company to company, it can be difficult to choose the right product. Fortunately, the experts at Yuanhe Bearing are here to help you.
The Yuanhe team is fully committed to ensuring that every customer gets the right bearing at the right price to meet their needs. To learn more about our bearing products and services, please contact us today. To discuss your application requirements with one of our experts, please request a quote.