Poor Lubrication Leads to Most Bearing Failures. Here Are Tips for Proper Grease Maintenance.

Maintenance Tips to Keep Bearings Operating Properly

This article is based on a webinar by the Grain Handling Safety Coalition as part of the Stand Up for Grain Safety Week, April 13-17, 2020. The presenter was John Lee, director of safety, health, and environmental services at the Grain and Feed Association of Illinois, Springfield (217-787-2417). The webinar can be viewed for free at grainnet.com/webinars-archive.

Poor lubrication is responsible for 80% of bearing failures. Proper grease application is essential to equipment protection.

For proper grease gun performance, know the output per stroke of the grease gun to measure the appropriate amount of grease according to equipment manufacturer recommendations. Output can vary significantly with each pump and also can be affected by the age of the gun.

Hand-grip and lever-grip grease guns put out different levels of grease per pump. No two grease guns are equivalent. This is important to understand to avoid undergreasing a bearing, which can lead to overheating, breakdown, or an explosion.

Bearings should have just a little bit of grease coming out, providing the right amount of lubrication without overdoing it. Too much grease can cause churning, which pushes the grease out of the way, resulting in energy loss and a hotter-running bearing.

Chemical degradation and oil bleed can cause crusty residue that won’t allow grease into the bearing, leading to premature failure and a fuel/fire hazard.

Bearings need to be cleaned of debris and excess grease. Wipe down bearings as part of a regular maintenance program.

Grease compatibility. Mixing greases can cause them to break down. Ensure the equipment’s grease is compatible with the grease being used during lubrication.

Polyurea grease, for example, is used in electric motors, but it is incompatible with most other greases and will break down if mixed.

One method to prevent this is to put different grease fittings on motors and have a specific grease gun dedicated for each fitting.


Greasing Summary

  • Grease while the bearing is rotating, if it is safe to do so.
  • Clean the tip of the zerk (the fitting that allows lubrication on a bearing or wheel) and grease gun.
  • Pump the proper grease into the zerk until fresh, clean grease is seen purging under and past the seal lip.
  • Clean up the excess grease found around the bearing.
  • Follow up with additional cleaning, if grease continues to purge.

Regular and proper application of grease is an important task. Make sure employees know how to use grease guns and how to apply grease properly to the equipment.

A good maintenance program, which includes greasing, will save money with less downtime and fewer repairs. Take these steps, so equipment will run at peak capacity when it’s needed most:

  • Follow your preventive maintenance program.
  • Record your findings.
  • Document any actions.

To view John Lee’s webinar at no charge, go to grainnet.com/bearing or scan the QR code.

From the September/October 2020 Grain Journal

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