How to grease a bearing

Bearings depend on grease to reduce friction levels. Too much friction in a bearing causes component failure and shortened life. Whether your bearings are subjected to extreme temperatures, high loads, or high speeds, understanding the unique grease requirements for your bearings can ensure the continued performance and longevity for your application. We have put together a simple 4-step guide to follow when lubricating your bearings. It should be noted that each bearing is different, so for more specific technical guidance contact a member of our team.

Clean/Remove existing oils, greases anti-corrosion coatings
- Cleaning and removing any existing oils, greases and coatings will eliminate any potential incompatibilities that may occur between the existing product and the new lubricant. Additionally, a clean contact surface inside the bearing will enhance the wetting capability and performance of the new lubricating film.
- Many bearing companies will provide their products pre-coated with oil film or anti-corrosion coating. If this coating has a micro-thickness and is compatible with your chosen lubricant, then you may not need to pre-clean the bearing.
- Should you need to remove the existing lubricant or clean the bearing you may use a non-residual solvent-based product to clean the bearing surfaces.
Calculate the required fill quantity for your bearing
- The correct lubricant quantity is determined by the design, operating speeds, reservoir volume and extent of sealing or shielding found in the application. Calculating the correct volume is imperative as over lubrication can be just as detrimental to bearing life as under lubrication.
- In most instances the correct grease quantity will be specified in the equipment IOM manual or the bearing manufacturing information. In the absence of this information there are several formulas that you can use to calculate grease fill, and we would be happy to help you. Contact a member of our technical team for help with your specific bearing and application, and we will help you determine your fill quantity.
Fill the bearing
- Now that you have cleaned the bearing and calculated the fill quantity, it is time to fill and run-in the bearing. It is important to always lubricate your bearings with clean, fresh grease and that the environment is clean and dry to minimise the risk of moisture or debris damaging the bearing. Once ready, your chosen bearing grease can then either be applied by hand, via graduated syringe or with a grease gun. On larger bearings the grease may be applied though centralised systems where power guns may be used.
Run-in the bearing
- Once filled, it is vital to run-in the bearing to ensure its performance and longevity.
- Start the bearing at a low speed. Aim for about 20% of the maximum operating speed.
- Increase speed incrementally closely monitoring the temperature of the bearing ensuring a stable operating temperature.
- Continue to increase the speed whilst monitoring the temperature until an equilibrium temperature is reached at the maximum operating speed. (ideal equilibrium operating temperature is approximately 35°C to 40°C)
- If the temperature spikes at any point during the run-in process, stop the application. Allow the system to cool to room temperature before restarting the process.