Canned pump with dry rotor compartment

Abstract

An electric pump for a liquid has a rotor surrounded by a stator which is disposed in the flow path of the liquid, the rotor being disposed in a rotor compartment, which is sealed from the flow path of the liquid and is predominantly filled with a mixture of air and vaporized liquid. The rotor compartment is in communication with the ambient atmosphere through a vent orifice. A vent system in the form of a labyrinth seal and a liquid-tight, gas-permeable membrane is interposed between the vent orifice and the ambient atmosphere. The rotor bearings are lubricated in one embodiment by leakage liquid and its vaporized product within the rotor compartment. In another embodiment the rotor bearings are disposed in the liquid flow path outside seals between the rotor and the rotor compartment.

Dependencies are inferred from the claim text.