Particles are like a virus, invisible to the naked eye but packing a powerful punch. The most destructive particles are typically less than ten microns in size (for comparison, a thousandth of an inch is roughly 25 microns).
The microscopic size of these destructive particles makes them hard to measure and count. Over time, they keep accumulating in the oil. Even in relatively high concentrations, their presence can remain hidden from view and undetectable to the touch. This explains why they are often referred to as "ghost riders".
Think of ultrafine sandpaper at 1000 grit. The size of abrasive particles that are bound to the paper range from 6.8 - 9.3 microns in diameter. Lubricants with high populations of suspended particles of that size range effectively form a medium with the potential to exact considerable harm to the machine.
Compared to larger particles, small silt-size particles easily evade even the finest filters, and larger particles are often quickly crushed into many smaller particles (comminution). As shafts rotate or slide against opposing surfaces (bearings, seals, gears, pistons, cams), microscopic excavations occur (dents, gouges, scratch marks), producing even more particles. Over time, the concentration of these small particles forms a medium that is functionally equivalent to liquid sandpaper.
Think of a belt sander. Even fitted with fine 1000-grit paper, it can polish away vast amounts of metal in short order. Now imagine a heavily loaded shaft rotating at high speed against a journal bearing lubricated with contaminated oil. It's the same thing, and the shaft and bearing get polished. This is called three-body abrasion.
The Causes of Liquid Sandpaper
この記事は MACHINERY LUBRICATION INDIA の March - April 2024 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です ? サインイン
この記事は MACHINERY LUBRICATION INDIA の March - April 2024 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です? サインイン
The Secrets For Implementing A Clean lubricant Program
If you could find an investment that guaranteed a return 40 times greater than your initial investment, you probably wouldn't pass it up.
MAINTAIN? REPAIR? REPLACE?
When considering the life of any asset, the question arises: what types of interventions should be planned to keep it operating or to restore operation in the event of its failure?
Engineering Reports Should Be Like Bad Movies
I'm frequently asked to review engineering reports, and I'm continually baffled by how many engineers want to take their readers on a journey instead of getting to the point.
WHY SCHEDULED OIL CHANGES AREN'T ENOUGH TO MITIGATE LUBRICANT CONTAMINATION
There are few problems more insidious or damaging to large industrial machinery than contaminated lubricant.
LUBRICATION CONTAMINATION PREVENTION
How many articles have you read, or seminars listened to, that tout the value of contamination control? If you are like me, they number in the hundreds—if not thousands. One thing about these articles and seminars that bothers me is the word “control”.
LUBRICANT CONTAMINATION PREVENTION AND MITIGATION: A Guide For Maintenance Professionals
Lubricants are essential for the smooth and efficient operation of many types of machinery, from engines and turbines to gears and bearings.
TASK-BASED TRAINING | INSPECTING A SINGLE-POINT LUBRICATOR
A single-point lubricator is a device engineered to attach to a single unit to regularly and automatically deliver a small amount of clean grease or lubricating oil to a specific area.
TOP LEADERSHIP FOCUSES FOR IMPROVED RELIABILITY AND COST REDUCTION
Here’s a scenario that may sound eerily familiar – you have a new reliability initiative.
4 KEY ELEMENTS FOR INTERPRETING AN OIL ANALYSIS REPORT
Years ago, a customer came into my office, visibly upset. He had just received his second oil analysis report for one of his Caterpillar gas engines.
ASTM ENHANCEMENTS TO MICROSCOPIC PARTICLE IDENTIFICATION AND DOCUMENTATION
In 1982, Daniel Anderson published his influential book, \"Wear Particle Atlas\", which describes, sizes, and classifies particles found in oil.