1.What are the properties of alumina ceramic shafts?
Thirty years ago, Grundfos in Denmark was a pioneer in this field by using alumina ceramic shafts in their central heating circulator pumps. Since that time, Grundfos alone has built around 30 million pumps using ceramic shafts and bearings, most of which are still running today – so we can say quite safely that these materials work well in this application!
The parts in the picture are pump shafts made of 95% pure alumina which Aegis supply for use in small pumps. The applications for these pumps varies from chemical handling to heating water circulation, garden pond and fountain pumping and even for use in aquariums. Shown in the picture are shafts centreless ground to 3.0, 4.0 and 8.0mm diameter, some having anti-rotation features and some without. Sometimes the shafts run in ceramic bearings of the same grade and sometimes they run in small plastic bearings or Glacier-type composite bearings with a non-metallic contact surface. Other grades of alumina can also be supplied, but for most purposes the high strength and low cost of the pink 95% grade make it the first choice.