The Guide To Gear Oil Maintenance

~ An effective oil maintenance program boosts productivity and profit ~

The first mathematical equation many of us learn is that 1 + 1 = 2. While this might seem logical and straightforward, it actually takes over 300 pages of complex mathematical sums to prove. This is just one of many seemingly simple tasks that are actually deceptively complex. The same is true of changing the gear oil in your machinery, as Mark Burnett, VP of the Lubricants and Fuel Additives Innovation Platform at NCH Europe, explains.

NCH Mark BurnettGear oil is the cornerstone of industrial manufacturing machinery. Without effective gear oil, machinery is at an increased risk of break down as the result of poor lubrication. This results in expensive repairs and replacements, with a loss of productivity further exacerbating costs.

Unplanned downtime is clearly not desirable and the current economic climate across Europe only makes matters worse. A recent analysis of European industrial markets found that production is nine percent below what it was prior to the recent recession. While some sectors such as machinery and equipment are keeping a positive CAGR (Compound Annual Growth), sectors such as mining and metalworking are experiencing negative growth rates. European businesses are now in a position where it is vital that they avoid downtime.

However, the process of lubricating gears is not as straightforward as simply buying an effective oil and putting it into a system. When inexpertly administered, the danger is that the oil becomes contaminated, potentially in just a few hours, and can be rendered ineffective. This would lead to elevated energy consumption and higher operating temperatures, which would normally lead in turn to a reduction in oil life.

This vicious cycle of fluid replacement becomes very expensive over time and isn’t sustainable environmentally or financially. Fortunately, while the procedure is more complicated than just refilling machinery, it doesn’t have to be too taxing. By following a three-step process, an effective oil maintenance program can be as simple as one, two, three.

Good time for a change

The first step in ensuring that gear oil is changed effectively is establishing the best time to run the process. This is another example of a task that seems obvious, but it is alarming that only 20 percent of oil changes actually happen at the right time. That leaves the majority of businesses either changing their oil too soon or too late.

On the surface this may not seem like a major issue, as changing oil too soon simply leads businesses to spend on new oil more frequently. However, replacing oil too late can be dangerous and expensive, causing increased gear wear that results in machine damage and the need for further maintenance.

So how do you know when the best time to change your gear oil is? While many engineers top up a machine with oil and expect it to last a long time without changing, it is not the longevity but the quality of the oil itself that must be measured.

As such, maintenance engineers must take into account oil condition and contamination level, testing samples where necessary. For example, oxidation is a naturally occurring process that affects oil over time. In the presence of oxygen, the oil begins to break down and this reduces the service life of the oil itself. In addition to this, it also produces sludge that makes equipment work harder and drives up operation costs.

If left long enough, the acidity of oxidised oil will steadily increase and result in corrosion and pitting. While this is problematic if left for extended periods of time, this acidity can be used to accurately assess oil condition. By measuring increases in the system’s total acid number (TAN), maintenance engineers and plant managers can identify acceptable limits of oil acidity and act accordingly.

However, TAN is only one factor in a gearbox’s overall condition and there are many other considerations such as the operational health of the machinery itself. It is crucial that engineers consider all aspects to ensure optimum performance.

This is why NCH Europe developed the NCH Oil Service Program (NOSP), which allows us to analyse gear oil and identify the right time to change oil. NOSP also provides businesses with accurate reports each time a change is due, breaking down the results of the analysis and comparing the current sample with historical data.

By using advanced insight into gear oil, engineers can ensure that changes happen at the right time to avoid damaging machinery. However, in order to extend oil life and maximise performance, engineers must first clear away contaminants.

NCH Gear Oil Maintenanc

Flush and clean

One of the most commonly forgotten stages of the oil change process is cleaning the system before refilling with fresh oil. In fast-paced environments, it can be tempting to cut corners and opt for just refilling without cleaning.

However, this leads to oil that is ineffective and heavy with contaminants mere hours after use. These contaminants quickly form deposits on metal surfaces in the system, raising operating temperature and reducing power transmission through the gearbox.

While the ideal solution may initially appear to be eliminating contaminants, that is easier said than done. Any plant responsible for the processing of materials such as metal and wood will find that dust is an unavoidable consequence of production. This dust frequently enters the system oil, contaminating it and impacting machine performance.

To prevent this from occurring, it is imperative that engineers remember to clean their systems before replacing machinery oil. The most efficient and effective way is to use a cleaning product to dissolve the deposits and neutralise any acidic contaminants.

An effective system cleaning product, such as NCH Europe’s Flush & Clean, works by being allowed to run through the system during a brief period of operation. This separates the deposits from the system surface, leaving them suspended in the old oil so they are removed during the oil change.

The right stuff

With the system flushed, the final step is the simple process of replacing the fluid with an effective gear oil. In order to choose an effective product, engineers must consider both the traits of the oil and the problems the application faces.

For example, if the gearbox is prone to accumulating condensation and rusting, it is important that the oil can address this. In this instance, we would recommend our Top Blend CS product. Top Blend CS employs a higher percent of calcium-sulphonate technology that mops up acidity as a result of oxidation, it also contains demulsifiers that separate water from oil to keep gears properly and safely lubricated.

Similarly, problems such as foaming and oil oxidation can also be addressed by choosing a product that contains anti-foam agents and oxidation inhibitors, respectively. It is important that maintenance engineers consider the operating environment and do not focus solely on the condition of the oil itself.

Even if one gear oil is suited to a piece of equipment, it may not necessarily suit the operating environment. Several industries are subject to strict regulations that govern the products that can be used to maintain equipment and machinery, so engineers must ensure that products comply with the relevant standards.

In the food sector, for example, there are a number of NSF categories for lubrication products. These categories denote what applications the product is suitable for, with NSF H1 certified gear oils safe for use in equipment where there is a chance of incidental food contact, while H2 indicates that a product cannot come into direct contact with food.

NCH Oiled Gear

Therefore, if a maintenance engineer is replacing the gear oil in a food conveyor system, they must use an effective food-grade oil with NSF H1 certification. It is also important to check the NSF rating of the other products used, such as the system cleaning product, to ensure regulatory compliance.

Regardless of whether it is from a practical or a legal perspective, consideration must be paid at every step of the process to determine the best  lubrication products for an application. This treatment should then be repeated for every subsequent refill.

It might not need a 300-page explanation, but it is clear that oil changing is notthe simple process many consider it to be. With the right knowledge and solutions, boosting machine efficiency can be as easy as one plus one.


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