It seems a simple question, yet when asked, the answers are not always similar, or simple.
Some say, “to fight friction” and that is true. We do add grease to an asset’s moving parts to reduce friction. But there’s more to it than that.
Some say, “to reduce heat” and that is also true. The right amount of lubricant does help keep moving parts from getting too hot. But some lube techs, thinking more is better, take it to the extreme. They add more grease — thinking they are doing good — and instead choke the machine’s ability to disperse heat.
The real reason to lubricate assets is to form separation between surfaces. This logic applies to not only motor bearings. The pistons in an engine, chains on a chain drive, gears in a reducer, even linear bearings that do not rotate, but slide back and forth. The primary purpose to lubricate physical assets is to keep moving surfaces from coming into contact with each other. Because when they do, failure modes are initiated, and lifecycle is shortened.
Friction is a force which opposes movement between surfaces. Friction increases wear between surfaces, increases system temperature, and dramatically increases power consumption. The right amount, and type of lubricant creates a thin film between two surfaces. For as long as that film is maintained, it protects the asset from wear and heat while allowing it to produce in an energy efficient way.
Some lubricants offer the additional benefit of controlling corrosion. They contain additives which prevent rust from acid and water attacks.
Grease must be kept free of contaminants, but the very nature of the thickener allows it to pick up dust and grit. Proper storage is therefore crucial, and clean grease applied properly can actually shield machines from the ingress of contaminants.
The science of lubrication continues to evolve for over 4000 years. But the principles remain the same; to maintain separation of two or more surfaces, thus prolonging the reliability of the entire asset.
We welcome you to read the previous blog in this series, “Three Myths About Greasing Bearings.”
Download our Oil & Grease Storage Best Practices for more tips to help outline the best practices for proper lubrication storage.
Lubrication, Maintenance Tips by Allan Rienstra - SDT Ultrasound Solutions