Everything you need to know about bearing failure

The bearing is an essential component in the operation of many rotating machines. It is present not only in industrial plants, but also in cars, planes, and many common gadgets in our daily lives. These components were designed to enable rotary motion in a way that prevents wear on the rest of the connected machinery.

However, bearings are susceptible to many kinds of failures. The causes are diverse, and they can originate from mechanical compression or physical wear of the parts.

Failure classification and ISO 15243

There are many causes for bearing failure, and they can be produced both by pre-operational errors and errors made during the operation. Among the pre-operational faults are electrical erosion, caused by excessive tension, and plastic deformation, caused by incorrect handling and installation.

The rest of the categories concern operating faults, that is, all faults that occur after the bearing is installed. In this context, the most recurrent failures are fatigue, corrosion, current leakage, and thermal cracking.

ISO 15243 classifies each of these faults into groups and describes their characteristics and causes. See the standard for more information.

Main causes of bearing failure

There are many causes for bearing failure; they can occur in isolation or simultaneously. In any case, it is necessary to be alert to any indication of a defect in these components.

The origin of bearing-related problems is linked to pre-operational factors and operational failures. The most common causes include:

• Inadequate lubrication

This is the most common cause of bearing failure. Whether it is insufficient or excessive, lubrication is the most recurrent cause of bearing failure. For this reason, it is necessary to be sensible when choosing a lubricating oil, always opting for a good quality product, indicated by the manufacturer itself.

• Contamination

Material waste such as dust, sand and water can easily contaminate bearings and their lubricant. This waste reduces the efficiency of the parts by increasing friction between them and oxidation of the component. Thus, generating wear and overheating of the bearing.

• Misalignment

Misalignment in bearing installation, or in the bearing housing, causes wear from mechanical compression in the radial and axial direction of the rotation axis. Therefore, paying attention to bearing installation and machine alignment is critical in maintaining the useful life of the bearing.

• Overload

Even though it is very resistant, each bearing is designed to support a certain amount of load. Thus, avoiding overloading in the bearing reduces exposure to excessive vibration.

• Installation

Incorrect installation, impact or incorrect storage of components can lead to premature failure due to component deformation.

How to detect bearing failure

Now that you know the main causes of bearing failure, it is important to pay attention to the warning signs of damage in these types of components. Being one step ahead in the detection of anomalies in your component prevents operational damage, and vibration analysis can be an important ally in the early detection of failures.

Bearing anomalies are generally detected when analyzing the high-frequency components in vibration spectra, as well as impact signals in the waveform.

It is also possible to identify faults through demodulation using the spectral envelope technique that widens the periodic frequencies, further evidencing the defects in the component.

Also, the waveform graph allows visualizing the impacts and modulations, RMS, crest factors (CF), and kurtosis (KURT). Thus, it is a widely used tool in the detection of cage failures.

Differences in vibration analysis

There are several data collection techniques for vibration analysis, from wired to wireless sensors. New analysis techniques are increasingly emerging to support the planning and execution of equipment maintenance in the industry.

Through wireless sensors, it is possible to monitor the condition of the equipment on your laptop or cell phone screen. The DynaPredict Solution, Dynamox’s remote asset condition monitoring system, is an alternative for those considering relying on predictive maintenance of equipment.

In the case of the DynaPredict system, the collection intervals can be set from 1 to 60 minutes. Through this technique, it is possible to get a much larger number of samples, and there are advantages in terms of cost and safety.

In addition to providing global trend graphs and spectra, the DynaPredict Web Platform also has a frequency bank (BPFO, BPFI, BSF, and FTF) of almost 70.000 bearings of all major brands and models to facilitate data interpretation and speed up the analysis of potential failures.

And there is more!

The DynaPredict system, besides signaling the detected anomalies on the monitoring panel, also issues alerts via e-mail to those responsible for monitoring the company’s assets. As a result, there is more time to focus on maintenance.

Want to know more about how to identify bearing failures? Read How to Identify failures in rolling bearing cages.