Wet vacuum cleaners
The main requirement for this type of vacuum cleaner is to ensure safety from electric shocks for the user should the motor fail.
SKF bearings are designed to optimize performance in this application. Two deep groove ball bearings support the motor shaft. The internal radial clearance will depend on the design requirements for speed and running temperature. Bearings are usually fitted with heavy contact rubber seals incorporating a steel insert. Cages are made of glass fibre reinforced plastic.
Lubrication is often special grease designed for good performance at high speed and temperature together with good resistance to contamination and condensation.