Lubricating the bearings in your motor in the correct manner is essential to ensuring that it continues to run smoothly. Lubrication helps retain rolling elements during assembly, prevents corrosion, acts as a barrier against contaminants, reduces heat generated by friction, removes excess heat generated by friction, separates rolling surfaces to reduce wear, and removes excess heat generated by friction. Incorrect lubrication is the cause of more than fifty percent of all bearing & seals failures. If that isn't a compelling reason for you to keep reading this article, I don't know what is.
All greases that are currently available on the market are made up of a base oil (either mineral or synthetic), a thickener (such as polyurea or lithium, for example), and various additives (such as anti-oxidants, rust inhibitors, anti-foaming additives, and so on). Even under ideal operating conditions, grease will degrade over time due to the complex interaction of its myriad constituent chemicals. As a result, you will need to re-grease the majority of your bearings at some point. Oxidation, oil bleeding, mechanical working, and evaporation are the four most important factors that contribute to the degradation of grease.
The following is a brief list of some of the most well-known lubricants that can be found on the market today:
Calcium soap-based grease is superior when it comes to its resistance to water, but it performs poorly when it comes to its resistance to heat.
Grease that is not soap-based has an excellent resistance to heat.
As a result of its high temperature performance, inherent anti-oxidative properties, and high shear stability, polyurea grease has become the industry standard for use in electric motor bearings. This grease works best in bearings that are completely sealed.
Oilil companies use a wide variety of additives, some of which may not be suitable for use with other kinds of oil. It is in your best interest to always relubricate using the oil that is recommended by the original equipment manufacturer. If you absolutely must use a different oil, you should get in touch with the manufacturer to make sure that the two oils can coexist.
What are the steps to relubricating?
The relubrication of bearings can be accomplished in just eight easy steps, which are as follows:
It is important to thoroughly clean the areas around the fill and drain fittings so that contaminants do not make their way into the bearing cavity.
Remove the drain fitting to make room for any excess grease that may have accumulated in the bearing.
During the entire process of greasing the machine, you should keep the drain plug out.
While the motor is running at its operational temperature, the recommended amount of grease should be added, or the grease should be added slowly until it begins to move into the relief tube.
Immediately after installation, a baseline should be established by monitoring the motor's noise and vibration. Check these measurements at predetermined time intervals; if there is a sudden or appreciable shift, an inspection of the bearing suppliers lubrication should be performed.
(When mounting a replacement bearing, one of the final operations that should be completed is filling the bearings distributor with grease. This will ensure that there is the least amount of contamination possible.)
What kind and how much lubricant should I use?
These bearings help to keep grease where it belongs and keep larger particles and contaminants out of the bearing suppliers cavities. It is necessary to re-grease single-shielded bearings in accordance with the instructions provided by the manufacturer; however, double-shielded bearings are typically designed to be "Lubricated for Life" and do not typically need to be re-greased.
What About Bearings That Are Sealed?
These bearings are suitable for use in environments with a high level of contamination. Sealed bearings are typically only used in motors with horsepower ratings of 75 or less and have an expected lifespan of only three years. Sealed bearings are generally reserved for lower speed motors. It is not necessary to re-grease these particular kinds of bearings because they have been given the "Lubricated for Life" designation.