Bearing Maintenance: all you need to know

A pillar is a column that supports a building’s structure. To do so, it needs to be strong and resistant to the wear that comes with time. If the pillars are weakened, the house falls down.

But why are we talking about constructions? Well, because every industrial plant also has its pillars – the bearings. Essential for the operation, these components act as fixed support to the machine’s rotating elements, ensuring that the mechanical transmission systems work properly.

Like a pillar for a house, the bearing supports all the loads projected onto a constantly rotating shaft. And because of its constitution and hard work, this piece suffers damages that, when not monitored, can jeopardize production. 

TRACTIAN prepared this article to help you learn more about your bearings and improve their care, implementing in your maintenance plan some fundamental techniques in order to preserve these assets and ensure that they continue to sustain the machinery. Enjoy your reading!

What are bearings used for?

As previously mentioned, the primary function of the bearing is to support the rotating shafts of machines. Sliding or rolling, they carry loads while in contact with the shaft surface – and are always exposed to the frictional forces caused by rotation.

You may be aware that industrial machinery can only operate if the mechanical transmission systems are working properly and efficiently. This is why bearings are such an essential part of the industry. A single unexpected failure in a bearing can interrupt the operation of the equipment in which it is located, leading to great damage to the production.

Therefore, the proper maintenance of these components is more than necessary and should prioritize strategies that detect failures that have not yet arrived and repair them before they can affect the bearing.

There are two main types of bearings: plain or sliding bearings and rotary or rolling bearings. 

The first group uses a bushing attached to the bracket and supports heavy machines and low-rotation equipment since the reduced speed prevents the machines, which are exposed to friction, from overheating.

The second group of bearings, on the other hand, is used when higher speed and lower friction are required, limiting the energy losses produced by friction.

Plain bearing

As we have said above, plain bearings consist of a bushing fixed on a bracket. Their function is precisely to support rotating shafts, and they are always subject to the frictional forces created by shaft rotation – which makes them susceptible to many kinds of damage and failure. 

Some of the plain bearings used in industry are:

• Hydrodynamic bearings;
• Hydrostatic bearings;
• Aerostatic bearings;
• Magnetic bearings.

Despite the friction, a major advantage of the plain bearing is that it is easy to assemble and disassemble. It also adapts well to the circumstances and comes in different shapes that allow a greater variety of applications.

On the other hand, it has some disadvantages that must be taken into account when designing the maintenance plan. Some of them are the high temperature that this type of bearing produces when it is in operation, the lubrication deficiencies, and the rigidity that does not allow misalignments.

To extend the service life of this equipment, it is important to ensure that the plain bearings have an efficient lubrication system, that their application is compatible with the environment, and that the load limit is supported by the bearing dimensions is respected. In addition, these components must be constantly monitored and analyzed through predictive maintenance and some preventive inspections, to anticipate failures and reduce unexpected downtimes.

Rolling bearing

The second type of bearing consists of two concentric rings with rolling elements between them, such as balls, rollers, or needles. It is used to reduce the sliding friction caused by the rotation of the machine shaft inside the bore. In this way, the bearing facilitates control of the relative motion between two or more parts, limiting the energy losses due to friction.

Because of their higher speed and reduced friction, rolling bearings do not require as much special maintenance as plain bearings, but this does not mean that they do not come with some disadvantages.

Unlike the first group, this one is very sensitive to shocks, has a higher manufacturing cost, presents low tolerance for housing and shaft seat, does not support very heavy loads, and occupies a larger radial space.

On the other hand, it also has its advantages, such as the absence of friction and overheating (as already mentioned), the lower need for lubrication, the preservation of the shaft, and the lack of clearances during its lifetime.

Even though they are more resistant, rolling bearings can also present failures that could be harmful to production, and should therefore be monitored and verified continuously.

For assessing the spinning process, it is necessary to rotate the bearing slowly, checking whether there are difficulties or not.

The hearing evaluation is also important and, to do so, the bearing must rotate through reduced revolutions while the operator analyzes the noise. It can be scraping, thumping, or metallic, indicating that the raceways are dirty, peeling, with clearances, or unlubricated.

The bearing maintenance

Because of its characteristics and hard work, it is only natural that the bearing suffers from wear processes and develops a greater need for special care and constant maintenance.

The strong friction, especially in plain bearings, makes these components require a lot of lubrication, one of the primary forms of bearing care. But as we can see from the many differences between bearing types, the maintenance of these items depends on their function and operation – which is why it is important to keep up with the bearings in your industrial plant, getting to know them thoroughly and implementing techniques that will extend their useful life.

Despite the importance of constant predictive maintenance, it is possible to stipulate certain intervals for the preventive maintenance of bearings:

• Once a month if it is applied to electric motors;
• Every 2 months if it is a support bearing;
• Once a month if it is a shaft bearing (responsible for supporting pulleys);
• Every 15 days (twice a month) if it is a cylinder head bearing.

In the previous topic about the two main types of bearings, we outlined some care and evaluation techniques for each group. In order to help you take better care of the pillars of your industry, we have also selected some important general guidelines for the bearing maintenance process. Have a look:

1. Define a strategic maintenance plan for your bearings

You may already know that an action is only successful if it has been planned with care and attention. So, to ensure the good performance of your bearings, the first step should be to develop an intelligent schedule of preventive inspections – that is, a schedule that uses predictive maintenance as a tool for preventive maintenance.

Preventive maintenance is only useful and profitable when set according to the demands of each piece of equipment, which becomes clearer when detected by a constant asset monitoring technology.

Thus, the maintenance manager can design a strategic plan using reliable and precise information, such as the bearings’ manufacturers’ recommendations and the data collected and analyzed by the predictive tool employed.

2. Analyze its physical conditions

The job of the bearings to support all the load placed on the shaft means that they suffer a lot of stress and wear during operation. With this in mind, when analyzing a bearing, technicians should always look for apparent damage caused by friction.

Of course, it is also important to always be aware of the “invisible” symptoms of bearing failure, such as noise, temperature increase, excessive vibration – but almost all of these are identified and diagnosed right away by online monitoring, which releases the staff to concentrate on more important activities.

3. Observe friction and lubrication levels

As already noted, efficient industrial lubrication is extremely important for bearings, since most of their defects are friction-related. By applying lubricants such as oils and greases, friction during shaft rotation is reduced and the bearing’s service life is extended.

The lubrication levels of the part must be constantly checked by the maintainers, who must also check if there is any contamination in the lubricant used and if it meets the quality levels required to reduce friction in that bearing.

4. Always check and follow safety standards

It seems obvious, but it is always important to remember. When performing bearing maintenance, professionals are very close to industrial machines, their substances, and fluids, which presents some dangers to the staff’s safety.

Each equipment, in its manual, has its own safety rules indicated, and these must always be checked and followed. The correct use of PPE is also extremely necessary.

Predictive maintenance and the benefits of online bearing monitoring

Nowadays, there is no maintenance management strategy more effective and profitable than the use of online asset monitoring software, including bearings. A survey by ITIC (Information Technology Intelligence Consulting) showed that 98% of American companies had losses of about $100,000 due to equipment downtime, which in turn is reduced by predictive maintenance.

By analyzing vibration, temperature, alignment, and other bearing data, this type of technology detects failures even before they happen and alerts the maintenance manager about the component’s condition, guiding him also about what intervention should be done, where, and when.

TRACTIAN is an example of software that collects and analyzes bearing data in real-time. It automatically sends insights to the team, keeping them aware of what is happening in the pillars of the industry.

Some problems often identified in bearings through predictive maintenance are:

By combining technology with maintenance, the manager and his staff increase the reliability of the bearings, which in turn benefits the performance of the entire machinery. As a result, the number of unexpected breakdowns decreases, as does the waste of time and resources on emergency corrective maintenance and random preventive inspections.

The pillars of your industry also deserve some support

They are there for all types of equipment, withstanding the heavy loads and ensuring that everything goes according to plan. So it stands to reason that bearings should also count on the right support to extend their life and improve their performance – and who else could fulfill this role but predictive maintenance?

A bearing failure can jeopardize the entire production, which often happens in maintenance managements that turn a blind eye to the failure and insist on the tiresome (and expensive) work of repairing the machine only after it breaks down.

By tracking your bearings with online monitoring software like TRACTIAN, you get ahead of the fault, optimize staff work, and improve productivity, while also boosting the organization’s profitability. All this with a single tool.

Now that you know a little more about the pillars that support your industrial plant and the importance of good maintenance management of these items, it is time to make a move – and TRACTIAN is here to help you. For more information on how to take better care of your bearings and reduce unexpected downtime in production, talk to our team or shedule a demonstration of our solution.