Lowe, Price, LeBlanc & Becker
Clean pump
 In a clean pump of the present invention, a magnetic coupling is formed by a permanent magnet attached to a rotor and a permanent magnet attached to an impeller, with a combined electromagnet arranged to be opposed to a soft iron member of the impeller at the side opposite to the rotor. The combined electromagnet is provided with a permanent magnet arranged at one side of its core and two coils wound around the permanent magnet. These coils are zero-power controlled by a control circuit based on outputs of position sensors such that the impeller is supported approximately at the center of a casing by an attracting force of the permanent magnets and an attracting force of the permanent magnet of the combined electromagnet. 
NTN Corporation
H F F F F F H H F F H F H
H02K F04D F04D F04D F16C F16C H02K H02K F04D F04D H02K F16C H02K
inventional inventional inventional inventional inventional inventional inventional additional inventional inventional inventional inventional inventional
Tsugito Hiroyoshi
Nakazeki Ito