How to Maintain Lab Homogenizer Shaft Bearings

Keeping laboratory and pilot plant homogenizers in proper operating order requires special to critical components located out of sight within the homogenizer shaft tube.  These are the homogenizer shaft bearings that keep the rotor shaft centered in the tube.  While homogenizer shaft bearings and other components are in the tube they are fully exposed to samples being processed.  This post suggests ways on how to maintain lab homogenizer shaft bearings.

Why it’s Important to Maintain Homogenizer Shaft Bearings

Maintaining lab homogenizer shaft bearings is a critical procedure to protect investments in these small but important tools.  You should bear in mind that these bearings support shafts rotating at speeds in excess of 30,000 RPM, depending on model.

Unlike bearings in high-performance engines, homogenizer bearings can often be in contact with abrasive samples being mixed, blended, emulsified, homogenized, dispersed, shredded –  among typical tasks they are called on to perform.

Critical Components of Lab Homogenizers

As automotive engines may signal a need for attention (clacking valves, knocks, missing, smoking) laboratory homogenizers may also send signals alerting operators that maintenance should be looked into.

Here’s a peek inside homogenizer shafts: We’ll cover signals and suggested maintenance steps later in this post.

As noted above, critical components of a lab homogenizer shaft bearings are out of sight.  They are situated in the tube connecting the homogenizer drive motor housing to the generator comprised of a rotor-stator assembly that does the work.

Where they are located is called the stator tube.  Their function is assuring that the rotor shaft is exactly centered in the tube so that the rotor meshes perfectly with the stator.  Seals are included to stop samples from working their way up to the drive motor housing.

Bearing configurations range from the relatively simple– a total of 8 components are found in the CAT T series of lab homogenizers – to the complex exemplified by 14 components in the sealed shaft of the CAT G series of homogenizers.  Here’s a brief description on the T and G series of CAT Homogenizers.

You’ll notice that they are not all that inexpensive – more the reason for homogenizer bearing maintenance.

Maintenance Alerts for Laboratory Homogenizer Bearings

Although relatively small compared to production-scale homogenizers, blenders, emulsifiers and related equipment, lab homogenizers are subjected to sometimes severe working conditions that largely depend on the media being processed.  CAT Scientific describes these in terms of viscosity.

Signal alerts for lab homogenizer maintenance:

  1. A hot stator tube
  2. Vibrations or increasingly noisy operation
  3. Increased  processing time – indicating a worn generator assembly
  4. Unprocessed particles in the sample

 4 Tips for Maintaining Lab Homogenizer Bearings

Standard operating procedures will help minimize wear on your homogenizer bearing assemblies.  All personnel responsible for operating the equipment should be familiar with the procedures.

Here are some suggestions:

  1. Samples should not be allowed to dry or harden on surfaces. Clean all components of the shaft tube, shaft and sealing parts after each use by operating the unit in a mild cleaning solution of formalin or alcohol. Check our recent blog post on cleaning and sterilizing recommendations for an in-depth look at this topic.
  2. Only activate the homogenizer when the generator is immersed in the sample.  The sample serves as a lubricant to keep components from damage due to overheating.  An ideal sample depth is 55 mm, otherwise use slower speeds or shorter cycles. The generator should be ≥10mm from the bottom of the sample container.
  3. Check gasket seals by observing the top cooling port on the shaft tube.  If you see fluids emerging from this port it indicates worn gaskets that can allow sample to reach the drive motor.  Immediately turn off the unit and replace the gaskets.
  4. Use the mounting stand to position the homogenizer at an angle and off center in the sample container.  This helps avoid a vortex that could result in a “dry running” generator and overheated bearings.

More details on maintaining your CAT Scientific homogenizer are provided in the operations manual for the model you are using.  But if you’d like additional information please send us your questions.


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