Maintenance and Care of Bearings for Large 3-Phase Commercial Evaporative Coolers


Applicable Models: Large 3-Phase Commercial Evaporative Coolers with a plumber's block and grease nipple (zerk fitting).


Step-by-Step Guide

  1. Regular Inspection:
    • Visual Check: Regularly inspect the bearings for any signs of wear, damage, or leakage. Look for discoloration, cracks, or deformation.
    • Listen for Noise: During operation, listen to any unusual noises such as grinding, squeaking, or knocking, which could indicate bearing issues.
  1. Clean Surrounding Area:
    • Remove Debris: Keep the area around the bearings clean and free from dust, dirt, and debris. Use a brush or compressed air to remove loose particles.
    • Wipe Down: Use a clean, dry cloth to wipe down the bearing housing and surrounding components.
  1. Monitor for Corrosion:
    • Check for Corrosion: Inspect the bearings for signs of corrosion caused by water exposure. Look for rust, pitting, or discoloration.
    • Preventive Measures: Ensure filter pads are well-maintained, and the unit operates with adequate bleed-off to prevent mineral buildup. Avoid over-watering pads to reduce water pull-off.
  1. Check for Proper Installation:
    • Alignment: Ensure the bearings are properly aligned and securely mounted to prevent uneven wear and premature failure.
    • Tightness: Verify that all bolts and fasteners are tight and secure.
  1. Replace When Necessary:
    • Signs of Wear: Replace the bearings if you notice any signs of wear, damage, or unusual noises. Check for excessive play or movement in the bearing.
    • Regular Monitoring: Regularly monitor bearing performance and replace them if there is a noticeable decline in efficiency or increase in operational noise.
  1. Grease Bearings Using a Grease Gun:
    • Preparation: Use the correct grease (e.g., SKF LGWA 2) and clean the area around the grease fitting. Ensure the grease gun is loaded with the appropriate grease.
    • Locate the Grease Fitting (Zerk fitting): Identify the grease fitting on top of the bearing housing. It is usually a small, protruding metal fitting.
    • Attach Grease Gun: Securely attach the nozzle of the grease gun to the grease fitting. Ensure a tight connection to prevent grease leakage.
    • Apply Grease: Pump the handle to inject grease into the bearing. Continue pumping until fresh grease appears around the seals or until resistance is felt.
    • Avoid Over-Greasing: Do not over-grease to prevent heat build-up and seal damage. Stop once you see fresh grease or feel resistance.
    • Clean Up: Wipe off excess grease from the fitting and housing. Use a clean cloth to ensure no grease is left on the surface.
    • Regular Maintenance: Repeat this process during each maintenance visit as per the schedule. Keep a log of greasing activities for reference.

Important Notes:

  • Grease bearings every visit.
  • Avoid over-greasing.

 

 

Common Issues and Solutions

  1. Contaminated Grease:
    • Issue: Dirt or debris can enter the grease fitting if the area is not properly cleaned before greasing, leading to contamination and potential bearing damage.
    • Solution: Always clean the area around the grease fitting before applying grease. Use clean, lint-free cloth and ensure the grease gun is free from contaminants. Consider using a grease fitting cap to protect the fitting from dirt and debris when not in use.
  1. Blocked Grease Fittings:
    • Issue: Grease fittings can become clogged with hardened grease or debris, preventing new grease from entering the bearing.
    • Solution: Remove the grease fitting and clean it with a solvent or use a small wire to clear the blockage. If necessary, replace the fitting. Regularly check and clean grease fittings to prevent blockages.
  1. Incorrect Grease Type:
    • Issue: Using the wrong type of grease can lead to inadequate lubrication and potential bearing failure.
    • Solution: Always use the manufacturer's recommended grease. Check the maintenance manual for the correct type and ensure compatibility with existing grease. SKF LGWA 2 is a premium quality mineral oil-based, lithium complex grease with extreme pressure (EP) performance.
  1. Over-Greasing:
    • Issue: Excessive greasing can cause seals to rupture, leading to grease leakage and contamination.
    • Solution: Follow the recommended amount of grease for your bearing. Use a grease gun with a pressure gauge to avoid over-pressurizing. Stop greasing once you see fresh grease or feel resistance.
      • When greasing an SKF YET208 40mm bearing using a grease gun on a Zerk fitting, it's important to follow the manufacturer's guidelines. SKF generally recommends applying grease until you see a slight bead of grease coming out of the bearing seals. This ensures that the bearing is adequately lubricated without overfilling, which can cause excessive heat and potential damage.
  1. Under-Greasing:
    • Issue: Insufficient greasing can result in inadequate lubrication, causing increased friction and wear.
    • Solution: Establish a regular greasing schedule based on the manufacturer's recommendations and monitor the bearing's performance. Adjust the frequency of greasing based on operating conditions and usage.
  1. Inconsistent Greasing Schedule:
    • Issue: Not following a regular maintenance schedule can lead to periods of inadequate lubrication, increasing the risk of bearing failure.
    • Solution: Implement a consistent greasing schedule and track maintenance activities to ensure timely lubrication. Use maintenance logs to record greasing intervals and any issues observed.
  1. Improper Grease Gun Use:
    • Issue: Incorrect use of the grease gun, such as not securely attaching the nozzle or not pumping enough grease, can result in ineffective greasing.
    • Solution: Ensure proper use of the grease gun by following the manufacturer's instructions. Regularly calibrate the grease gun to ensure accurate grease delivery. Train maintenance personnel on the correct use of grease guns and the importance of proper greasing techniques.


Monitoring for Corrosion

  1. Water Damage from Poorly Maintained Filter Pads:
    • Issue: Poorly maintained filter pads can cause water damage, leading to corrosion on the shaft and bearings.
    • Solution: Regularly inspect and clean filter pads. Replace them if worn or damaged to prevent water leakage.
  1. Incorrect Bleed-Off Settings:
    • Issue: Incorrect bleed-off and water management settings can cause calcium and mineral deposits on internal parts, especially the shaft and bearings.
    • Solution: Ensure bleed-off is set or water management system is operating properly to prevent excessive calcium and mineral build up.
  1. Over-Watering of Pads (Flow rate from pump to water spreaders):
    • Issue: Over-watering pads can cause water pull-off, leading to excessive moisture and corrosion.
    • Solution: Follow manufacturer guidelines for setting water flow from pump to filter pads. Monitor and adjust water flow as required to prevent water pull-off.



By following these detailed guidelines, you can ensure the efficient and long-lasting operation of your commercial evaporative coolers. Regular maintenance and timely replacement of bearings are key to preventing breakdowns and maintaining performance.