What You Need to Know About Oil Maintenance for Industrial Gear Drives

Author: Matthew Finco

Category: Gear

Article Tags:

Gear

Gearbox

gears

oil maintenance

Lubrication is critical for ensuring the health of your industrial gear drive. For an industrial gear drive to function properly, you need:

Proper sealing
Proper lubrication

The gear drive sealing systems keeps the lubrication—in this case, oil—in and keeps all other contaminants out. Lubrication keeps the pieces of the gear drive moving smoothly and efficiently. Without the right lubrication:

Components become oil-starved (dry)
Friction increases
Gearboxes wear down
Operating temperatures increase (leading to mechanical failure)

Proper oil maintenance for gear drives is critical to avoid downtime and ensure your equipment runs smoothly and efficiently.

What You Need to Know About Oil Maintenance for Industrial Gear Drives

For almost any gear drive application, oil maintenance is crucial to long-term performance. If your gear drive runs too hot, there are methods to cool your gear drive and bring down the operating temperature, including fan cooling and water cooling.

For most of us, when we think of checking our oil, we probably think of checking the oil in our car. Although industrial gear drives are often larger and more complex, the principles are similar.

When you perform oil maintenance, you check a sample of the oil to make sure it's free of contaminants, and the level is appropriate for the performance of the gear drive. With industrial gear drives, heat is extremely detrimental. The objective of proper lubrication and oil maintenance is to keep your gear drive running as cool as possible. Lubrication prevents friction and carries contaminants away from your gear drive components.

To test the oil, you’ll take samples from your gear drive periodically as recommended by your manufacturer. Check with your Rexnord representative for the best guidelines for your particular drive setup. Typically, you should perform oil maintenance every three months. Be sure to request all of the tests recommended by your gear drive manufacture when requesting the oil analysis.

Oil samples are sent out for analysis, and when the results come back, you should check that the results are within the recommended standards. If it isn't within the right parameters, much like the oil in your car, it will need to be changed. In some cases, cleaning or filtering the oil may be an option. For most applications, the oil will need to be replaced entirely.

When you send your oil out for analysis, what are you checking? Oil analysis can look at the following factors:

Water

We all know water and oil don’t mix. When you have your oil sample analyzed, be sure to check the water content.

Sediment

Sediment and containments are outside particles that end up in your oil. Silicon (dust and dirt) is an example of a common contaminant. Anything that wasn’t in the original oil formulation is considered contamination.

ISO Rating

Your oil sample analysis should include an ISO rating--a cleanliness standard rating determined by automatic particle counting (APC). Using laser or pore blockage, the APC is determined at the micron level.

Viscosity

One of the most important properties for oil to function properly is viscosity. Viscosity changes with temperature, so it's important to ensure oil sample measurements are compared to reference values at the same temperature.

Acid Number

The acid number will increase over the life of the lubricant as the additives oxidize. The acid number is an indirect but effective way to measure lubrication oxidation.

Oil maintenance plays a vital role in keeping your gear drive cool. If you lower the sump temperature in your gear drive by 10 degrees Celsius, it will extend your oil life. In some cases, it may even double the oil life. The lubricant you use should always match the specifications of your gear drive manufacturer.

These specifications look at:

Needs of the bearings and gears (light or heavy lubrication requirements)
Viscosity—film thickness and strength
Formulation of the lubrication

Your gear drive manufacturer may recommend EP lubricants, which use synthetic hydrocarbons. They may also provide guidance for selecting food-grade lubricants for applications needing this class of lubricants. It's essential to follow the recommendations to get the proper lubricant for your drive specifications.

There are also additive packages made up of chemical compounds for oil that increase lubrication properties. These additives are determined by your application. It’s important to note that, over time, additive packages oxidize. The interaction with the environment slowly degrades the additives.

The warmer your oil is, the faster the oxidation process happens. Lowering your oil temperature by 10 degrees (Celsius) makes a huge impact, including fewer oil changes and longer maintenance intervals. Better yet, it will extend the life of your drive equipment as well.

While regular sampling is essential, your gear drive oil will still steadily degrade. Even with regular oil maintenance and sampling, some damage will occur due to constant degradation. Slowing the degradation will ensure that your oil life is as long as possible and enable you to plan predictable maintenance. The less time there is poor oil in your gear drive, the longer your drive will last. Bearings and gear teeth will hold up longer, and you will have less need to buy or replace components for the gear drive over time.

When it comes to gear drives and cooling, size matters. The larger the gear drive, the more effectively it will cool. The key is to find the best drive sized for your application that can offer the coolest run temperatures possible.

The Falk V-Class Gear Drive: Built to Stay Cool

The Falk V-Class gear drive is built to stay cooler than the competition. We’ve enclosed the high-speed head inside the housing, rather than designing an external head, as with most other standard gear drives. The DuraPlate heat exchanger option wraps the gearbox in steel to draw heat away from the head and provides more surface area to disburse heat. This design results in a cooler temperature at high speeds and a longer gear drive life.

Size-for-size, the V-Class cools more effectively. In addition to the patented DuraPlate cooling system option, V-Class drives feature fins that run along the outside of the housing. These fins maximize the surface area of the housing and help lower the temperature inside the drive.

Oil level requirements in the V-Class tend to be lower than the competition. With the Splash Lubrication System, oil level needs are reduced. Most gear drives run an oil level at the midline of the drive, so every bearing is dipped, and every gear is pushing through the oil. With lower oil levels needed, the amount of gear churn is lessened, resulting in even lower heat generation.

Multiple oil ports in the V-Class gear drives allow for fast, easy oil changes. The V-Class uses EP oils and features a specialized “no-leak” design, making oil maintenance reliable and simple.
Oil maintenance is a necessary part of gear drive care. With the Falk V-Class Drive, you can rest assured your drive life is maximized, and maintenance is minimized. When it comes to increasing uptime and reducing downtime, the Falk V-Class Drive delivers.

For more information on the Falk V-Class drive with optional DuraPlate cooling system, contact your Rexnord representative today.

The Advantages of Condition Monitoring and Oil Quality

A lot can happen in between regular oil samplings and changes. Many facilities have implemented condition monitoring systems in order to monitor oil quality in real time, thus reducing the risk of unplanned downtime or maintenance as a result of poor oil quality or elevated temperatures. With condition monitoring, maintenance schedules evolve from being route-based to preventative because real-time information from the monitoring system gives actual performance of the asset. Many facilities have found this useful for not only optimizing maintenance schedules, but for helping to meet reliability, productivity and safety KPIs.

For more information on the Falk V-Class drive with optional DuraPlate cooling system, or the Rexnord Smart Condition Monitoring System powered by DiRXN, contact us today.

Matthew Finco

Matthew is a Senior Engineer in New Product Development at Rexnord Industries, Gear Group. In 2010, Matthew joined Rexnord and has previously worked in the Engineering Technical Services as an Applications Engineer. Matthew holds a Bachelor of Science in Mechanical Engineering from the Milwaukee School of Engineering.