You know what they say: everything’s better in moderation—including lubrication for your bearings. While you might think there’s no such thing as over-lubricating, using too much grease can lead to serious problems with your machines, including grease churn, overheating, damage to the electric motor, and seal damage.
Thankfully, over-lubrication is one thing that’s easy to avoid, as long as you know what to do and take the time to do things right.
The main causes of over-lubrication
Before I discuss what happens if you over-lubricate your bearings, it’s important that you understand the main causes of over-lubrication so you can avoid them in the future.
In order to prevent over-lubrication, you have to be extra cautious and follow the proper replacement schedule and techniques when re-greasing your bearings. Most of these greasing mistakes are easily prevented with the proper training and knowledge, but when we find cases of over-lubrication, these tend to be the most common causes:
What happens when you over-lubricate your bearings
Most people understand why a piece of equipment breaks down from being under-lubricated, but over-lubrication is a little harder to grasp. That being said, it’s certainly an issue that needs to be taken seriously, and is one that happens a lot more often than you realize. To show you why it’s crucial that you follow the proper greasing techniques, here’s an expanded explanation of what happens when you over-lubricate your bearings:
1. Churned grease
Over-lubricating your bearings will cause the rollers or balls to slide along the raceways, rather than turning. As they push along, they also push the grease out of the way, resulting in a low to no lubrication scenario. This grease churn and accelerated rate of oil bleed will cause your component temperatures to rise, which in turn will cause the grease to harden and hinder lubrication even more—causing oxidation and resulting in bearing failure.
2. Motor failure
In instances where bearings are in an electric motor, over-lubricating those bearings can cause serious damage. If the excess grease reaches the motor windings, the windings will get insulated with grease, causing inefficient performance, overheating, and bearing failure.
3. Seal damage
In addition to damaging your bearings, over-lubrication can also have a significant impact on your equipment’s seals. Excess grease has a tendency to find its way between lip seals, causing them to rupture and allowing contaminants like water and dirt to leak into the bearing housing. This can force you to completely flush your system.
Now that you know the consequences of over-lubrication, it’s your responsibility to ensure it doesn’t happen in your machines. When it comes to preventing over-lubrication, it is key to have a proper training system and lubrication management program (lmp) in place that keeps everyone in line. Start by identifying the best grease to use with your equipment, then train your workers on all the proper re-greasing techniques and processes.
You also need to determine the proper re-greasing frequency and grease amount — you can use vibration or sound analysis to determine the ideal grease level. There are also vendors such as trico that have a grease caddy with a sensor which goes on a specialized grease gun that allows you to fill the bearing, while it’s running, to the optimal grease level.
While this might take some time and effort to get set up, you’ll end up saving a lot of money and machine downtime by improving your plant’s performance and efficiency.