Roller Bearing Lubrication

Viscosity Ratio (k) for Roller Bearing Lubrication

Know what the Viscosity Ration (k) is. Information about the different results to know if you have an adequate Kappa factor for your bearing application.

The Kappa factor (K) is the ratio of the oil viscosity at the bearing operating temperature divided by the oil viscosity required by the bearing.

The ideal lubrication is when we have 1-4 of the K factor. When it is closer to 4 the bearing life reaches the maximum. When it is less than 1, there may be contact between the components, so the use of EP additives is indispensable. Our greases have EP additives, so if the value is less than one, there would not be a serious problem. The ideal is to have it higher than 1

When we have 4 to 10 there is more resistance to movement and could cause increases in fluid friction. We will have rolling elements rotating inside the tracks but with higher resistance. There is a higher energy consumption of up to 25% which is undesirable.

When it is greater than 10 and the base oil is very viscous. The rolling element may not roll and may slide affecting the tracks. There will be increased internal friction which ultimately generates more heat, friction and energy consumption.