The Importance of Lubrication

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Protect Your Bearings “By The Numbers”

In agriculture, the leading cause of bearing failure is improper or inadequate lubrication and contamination ingression. For applications such as tillers, planters, harvesters and other equipment where bearings are routinely subjected to (or submerged in) dirt, sand and other contaminants, proper lubrication is critical to bearing service life.

Let’s look at what proper lubrication accomplishes:
  1. It separates bearing contact surfaces to reduce friction and wear.
  2. It protects internal parts from corrosion.
  3. It purges contaminants that infiltrate the bearing.
Now, let’s look at why lubrication fails:
  1. Improper re-lubrication interval, which occurs when recommended lubrication schedules are not followed.
  2. Insufficient lubricant quantity, which occurs during re-lubrication, when an insufficient amount of grease is added, inhibiting its ability to expel degraded or contaminated grease from inside the bearing.
  3. Contaminated lubricant, where environmental contaminants such as dirt, sand or moisture enter the bearing and damage internal parts.
  4. Application conditions exceed lubricant capability, which occurs when temperatures exceed the grease capability or other environment conditions exist. (Unfortunately, there is no one perfect grease that can be used in all situations.)
  5. Incorrect lubricant, which means the lubricant was mixed with incompatible grease thickeners.

Simply put, greases should only be mixed with materials made from the same base thickeners. Mixing incompatible grease thickeners will result in bearing failure.
The standard grease for all types of mounted ball and spherical roller bearings is an NLGI Grade #2 lithium complex-based thickener type, which is effective to 225oF (107oC).
All bearing manufacturers provide standard lubrication charts, and these recommendations are good starting points. However, the presence of contaminants and other environmental factors (i.e., operating temperature) warrant a more frequent interval than what is listed for your bearing. That said, we suggest using the “CLEAR” method to achieve proper lubrication frequency and quantity:
Clean the area around the seal prior to lubrication;
Lubricate the bearing until grease purges from the seal;
Examine and evaluate the condition of the purged lubricant;
Adjust the frequency of lubrication based on grease condition; and
Repeat this process until the purged lubricant has little or no contamination.
Using the CLEAR method, you’ll achieve a satisfactory frequency interval with the right amount of grease that will extend your bearing service life. In the agricultural industry, with its severe operating environments, it’s not uncommon to re-lubricate your bearings daily -- if not twice a day – especially during unusually dry periods.
Consistent lubrication frequency extends bearing service life. Here are two more tips to consider:
  1. For long-term idle equipment, lubricate all bearings and rotate them to coat all surfaces.  Additional information on proper bearing storage can be found here.
  2. Prior to adding lubricant to a bearing, clean all grease guns and fittings to prevent introducing contaminants during relubrication.

Lubrication is arguably the most important factor toward longer bearing life. By actively incorporating the preventative measures we’ve outlined here, you can considerably extend your bearing's service life, reduce unscheduled downtime, and increase overall workplace productivity.
If you have questions or would like to discuss this issue with one of our application engineers, call (317) 273-5781 or email  [email protected]. For videos and other demos, visit our YouTube channel.

Jason  Ludwig

Jason Ludwig is the Application Engineering Manager for Rexnord's Bearing Division. He has been with Rexnord since 2005 in roles of increasing responsibility. Jason works closely with Rexnord’s customers helping to troubleshoot issues, provide onsite support, train personnel, and select bearings that fit the customer’s needs. As the Application Engineering Manager for Rexnord Bearings, he is an expert on all bearing products that Rexnord provides.