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Thordon Sewage Treatment & Wastewater Applications

Thordon Sewage Treatment & Wastewater Applications

Dotted around the countryside at large and small towns and cities are oxidation ponds at the local wastewater treatment plant

Nearly all of these ponds will have aerators of some form or another – pictured below is a brush aerator


Many of these aerators will be running rolling element bearings

The self aligning bearings on the aerator above only lasts 18 months before they are rusted out and need replacing. They also need grease lines and regular greasing.

More often than not the greasing doesn’t get done as it should and when the bearings rust out they seize onto the shaft resulting in a major and costly repair.

Using Thordon SXL flat top or split bearings in this application as pictured below will do the following:

  • You will eliminate grease lines and the need to regularly grease.
  • Extend out the life of the bearings. 
  • Split bearings offer easy maintenance as gear box & motor do not have to be taken off the shaft to replace the bearing. 
  • Splashing of the water by the aerator will lubricate the bearing.


Thordon SXL bearings are split & the worn bottom can be interchanged with the top. 


Alternatively when the bearing is worn on the lower side, the bearing housing can be rotated 180˚ and the unworn top half can be used. 


A worn bottom section of the bearing can be swapped with unworn top section.


No grease is used, just plenty of pond water splashing on the bearings for lubrication. 


The housings themselves are off the shelf items.


There is an initial wear in period where we see up to 1mm wear in the first month to accommodate any alignment issues.

After that the wear is immeasurable and we are expecting at least 2 years running before the need to swap the top half of the bearing with the bottom half.


  1. The motor and gearbox should be supported on preferably adjustable mounts 
  2. The revolving brush must be balanced 
  3. The shaft must be aligned

*The set up is very similar to a Marine driveline.

If the above requirements are not attended to then excessive bearing wear can be the result


Other types of aerators can also be fitted with Thordon bearings


Auger bearings in primary sedimentation tank














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