How to Properly Lubricate Bearings (Problems and Solutions)

How to Properly Lubricate Bearings (Problems and Solutions)

Lubrication mistakes:

When it comes to lubrication, the most common reasons for bearing failure can be summed up in three words: 'over', 'under' or 'wrong'. Here are Andrew Howards thoughts on the subject:

1. Over-lubrication must be the number one reason for premature bearing failure that I see in my daily work. Too much grease or oil increases the friction and heat for the bearing, leading to seal damage and eventual bearing failure. It is usually easy to spot over-lubrication when it gets to this stage, as there will be grease leakage, an increased temperature during operation or additional noise.

2. Conversely, under-lubrication is almost as bad for bearing longevity, as insufficient amounts of grease or oil leads to metal-to-metal contact that inevitably leads to wear and overheating. The tell-tale signs of under-lubrication are a high operating temperature, unusual vibration and premature wear.

3. Third on the list is using the wrong lubrication for the application or mixing incompatible thickeners or base oils. With different grease or oil viscosities and base types there is no guarantee that they will be able to handle the speeds, loads or temperatures thrown at them during normal operating conditions. The signs of the wrong lubricant use will usually be accompanied by excessive wear, noise, machine or grease breakdown and/or clogged lubrication paths.

Avoiding lubrication mistakes:

1. So, how is it possible to avoid these common mistakes and get bearing lubrication right?  Firstly, it is important to pay attention to OEM's specifications for grease type, quantity and lubrication intervals, that are usually based on bearing size, speed, operating temperature, load and environmental conditions. If the manual advice isn't specific enough, then calculations for grease volume from leading bearing companies are readily available.

2. Correct lubrication reapplication is equally as important. Manufacturer charts – based on operational conditions, online calculators and lubrication schedule spreadsheets – are good. Also, using ultrasound or vibration analysis, infrared thermography, or checking grease colour changes are useful indicators of lubrication needs. Another thing to take into consideration is lubrication application method.