Types of Bearing Lubricants
Oil or Grease? Which Lubricant is Right for Your Application?
Applying an oil or grease lubricant between the rolling and sliding parts of a bearing will help to improve speed and reduce service life.
Other benefits of lubrication include:
- Reduction of noise and vibration
- Heat dissipation
- Corrosion protection
- Maintenance-free operation over a long period of time
But which type of lubricant should you choose? Oil or Grease? The tables below can help guide you on the best lubricant for your application.
Choose The Best Lubricant for Your Application
Selection Chart: At-A-Glance
Quick comparison of grease vs oil lubrication.
|General Speed suitability in n * dm||+++
~3 - 4 MM
|Design / system costs||+++++ (low)||+ (higher)|
|Operating costs||+++++ (low)||+ (higher)|
|Running in procedure||++||+++|
|Pollution||+++++ (low)||+ (higher)|
+++++: very good +: poor
Reference Speed Factor: Grease Lubrication
Selecting a suitable grease for high precision bearings is based on the max operating speed and temperature.
The reference speed factor n * dm calculates the operating rotational speed from the center line of the bearing ball diameter and indicates the max speed capacity of the lubricant being specified.
Below is a standard Reference Speed Factor Industry Guide. This Reference Speed Factor Guide helps compare the entire application for grease versus a general shaft or housing RPM.
|Reference speed factor : n * dm|
Using this reference speed factor will help you select a lubricant that will not prematurely degrade the bearings performance.
In comparison to grease-lubricated bearings, oil lubrication enables long-term reliable operation at maximum speeds. There are three main oil lubrication methods:
- Oil-mist lubrication
- Oil-Air / Air-Oil lubrication (minimized lubrication consumption)
- Oil injection lubrication (greater cooling effects)