From bearing management to the big picture

ROTATING EQUIPMENT including motors, compressors and a multitude of other machinery, is the beating heart of the manufacturing industry. The ultimate aims of manufacturing – efficient production and maximum output – are delivered by reliable machinery. At the same time, it is vital to minimise total cost of ownership over the life of any machine. Modern equipment is built to the finest tolerances but must be well maintained in order to manage ongoing costs.

This has traditionally been achieved by paying close attention to the component level, such as through careful management of bearings. However, the emerging digitalisation of manufacturing, encompassing everything from interconnected machinery to ‘big data’, can also help towards achieving the same goal. Using elements from both these approaches helps to raise rotating equipment performance (REP), which in turn can improve the availability, performance and quality of machinery.

Optimise performance

Improving REP starts at a company-wide level, with an assessment of the overall manufacturing operation. How does your company compare with other organisations? And what can be done to correct any shortcomings? Assuming that this has already been done, and operations are running effectively, it’s time to focus on the machinery level.

Here, it all starts with measurement: knowing how machinery is performing, and working out how to return it to maximum performance. There are many ways to assess the ongoing health of machinery. Condition monitoring, for instance, can detect early faults, allowing them to be corrected before they become more serious. This has been revolutionised by the advent of digital technology, which is explained in greater detail later.

On an everyday basis, general maintenance is vital, and doing it correctly can save time and money. This includes operations such as alignment, balancing and bearing installation. Bearings are critical to REP and as such deserve special attention.

Bearing management

While many bearings last for the lifetime of a machine, others do not, due mainly to factors such as contamination and incorrect mounting. In any case, it is vital to stay on top of bearing maintenance, through operations such as mounting, lubrication, alignment, basic condition monitoring and dismounting.

The logic is simple: extending the bearing life cycle helps to do the same for the machinery itself. Applying correct maintenance practices, using the proper tools, helps extend bearing life, leading ultimately to increased plant productivity and efficiency.

Bearing mounting and dismounting should be carried out with the correct tools. Unfortunately, there is a legacy of using general tools, such as hammers, to remove old bearings using brute force. This can cause irreparable damage to components such as the shaft and shorten the life cycle of the new bearing. Rather than using brute force, technicians should treat bearings delicately. For instance, they should use dedicated tools such as grippers and heaters, to remove bearings with greater care. The same approach should be taken when fitting a new bearing, using gentle heat or even hydraulic techniques as required.

Preventing failure

Bearing failure is rarely down to by defects in the bearing itself. Instead, it is caused by errors in fitting and lubrication, overloading the bearing, or contamination.

Lubrication is another basic function that is often neglected or rushed. As with mounting and dismounting, the principle of lubrication is simple and follows the ‘5R’ approach. “The right lubricant, in the right amount, reaches the right point at the right time using the right method.” The simple plan, however, needs to be carried out in practice.

Bearing lubrication, like fitting, needs to be done methodically and carefully. Rather than treating it as an afterthought, as is often the case, lubrication needs to be properly managed. Taking such a proactive approach means thinking about all aspects of lubrication, including selection, storage, delivery, application and disposal.

Selecting the correct lubricant is fundamental. Different machines will run at a variety of speeds and temperatures, under varying conditions. They may use various sizes and types of bearing. Choosing the correct lubricant for each individual application is critical and can help to increase machine reliability.

Other aspects of lubrication management, such as dispensing, are equally important. Large, complex machinery may benefit from automatic lubrication dispensing systems, rather than manual lubrication. This helps to dispense exact quantities when needed, while freeing up staff to perform other tasks.

Digital breakthrough

Focusing on the component level will always help to improve maintenance procedures. This focus can be intensified through increased use of digital technologies such as condition monitoring equipment. Other digital techniques the ability to collect large amounts of process data, for instance, can also raise manufacturing and production efficiency.

Manufacturers are often tempted to digitalise their entire operation. However, a better approach is to create a digital ‘toolbox’ – and select from the available technologies to achieve specific goals.

A traditional toolbox stores physical tools, such as a screwdriver and hammer, that are needed in order to complete a piece of work. Similarly, a ‘digital toolbox’ includes products and services, such as measurement equipment and sensors, that can be selected to improve overall performance and efficiency.

A good example is condition monitoring, which uses sensors to extend machine life by keeping a constant watch on bearing health, for instance. The sensors are reliable, easy to install and relatively inexpensive. To get maximum value from them, they should be incorporated into a wider digital framework. Taking full advantage of condition monitoring requires enhanced data gathering, interconnectivity and analysis – all aspects of digitalisation.

Adding value

Increased digitalisation can help to raise efficiency, quality and productivity. However, as with anything in manufacturing, the relevant technologies must be introduced in a way that delivers real, measurable value.

Unfortunately, this is not always achieved: there is often too much attention on developing a system solution, rather than looking at specific needs. As with any investment, digitalisation should focus on raising performance. So, the first task for any potential user should be to determine the real meaning of “value” – and of all key performance indicators (KPIs).

A typical KPI for customers is higher output. The most obvious way of raising performance value would be to minimise unplanned downtime as it is very costly. For this reason, discussions about digitalisation should avoid maintenance schedules and instead focus on maximising asset performance and availability. This is where digitalisation can add real, concrete value.

Information under control

Big data is effectively the collection of large amounts of information, such as process data, that can be usefully analysed in order to improve performance.

Collecting this information, which would once have been impossible, is now straightforward, thanks to the availability of affordable, reliable sensors. On top of this, huge amounts of data can now be stored in the cloud, making the information remotely accessible.

However, big data must be properly interpreted in order to be of any use. While digitalisation is vital when gathering and analysing data, it is remote diagnostics – using human experts – that can provide real time feedback, such as during production. This expertise helps to transform raw data into effective maintenance recommendations.

Even with these tools, the amount of data generated can still be overwhelming. For this reason, it pays to plan exactly how the data will be used. Carrying out a process audit is critical in understanding how a machine is currently performing and how this might be improved for the future. It helps to identify exactly which type of data needs to be collected and analysed.

Rotating equipment performance underpins industrial performance. By focusing on fine detail – at the component level – is one way of improving it. However, increased digitalisation can also help manufacturers gather and analyse critical information – and take efficiency to a new level.

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