Lubrication

Lubricant selection is of critical importance for the performance of a ball bearing. It affects Life, Torque, Speed, Noise, Grease migration, Outgassing, Temperature effects and rust prevention. In most cases NMB supplies ball bearings as a complete unit, pre-lubricated with grease. It is not normal to re-lubricate ball bearings as they are "sealed for life".

The two basic types of lubricants available are oil and grease.

Applications that require extremely low torque or narrow range of torque variation, are suited to use oil as a lubricant.

Depending on the application, it is possible that an oil lubricant may not meet a specific requirement. Please contact to NMB for the proper oil selection.

Greases are comprised of a base oil and a thickener.

The life obtained from greases is considerably greater than that of just oil. This is because of a continuous mechanism of lubrication by base oil separation coming from the construction of the thickener.

Grease additives include rust inhibitors, EP (extreme pressure) additives, oxidation preventatives, etc. Because of the wide variety and complexity of additives, the characteristics of similar greases change considerably from one manufacturer to another.

Calculating grease life and performance in sealed-for-life ball bearings includes many complicated factors, such that grease life calculation formulas in the industry at this time will likely show different results than actual life.

In recent years, using plastic material around the bearing has become more common, so the proper selection of lubricant is even more critical to prevent compatibility issues.

Miniature and instrument ball bearings are typically filled with a 30% (±5%) by volume fill quantity. However, depending on the application and specific performance requirements, NMB can also offer the following: