Measuring apparatus

An apparatus for measuring a property of a flowing fluid, comprising:

• a support tube connectable in a path of a flowing fluid so as to be axially transversed by said fluid;
• an elongated rotor rotatable in said support tube and spaced inwardly of a wall thereof whereby said flowing fluid passes between said rotor and said wall, said rotor having an exterior configured to be affected by said property of said fluid as said fluid flows past said surface upon transversing said support tube;
• repsective axially magentic rotor members at opposite ends of said rotor;
• respective axially magnetic stator members each paired with one of the rotor members to form a magnetic assembly therewith, axially juxtaposed with the respective rotor member and oppositely magnetically poled with respect to the respective rotor member to generate an attractive axial force between the stator member and the rotor member of each assembly;
• respective supports mounting each of said stator members on said support tube, whereby said attractive axial forces between the stator member and the rotor member of each pair solely position said rotor axially and radially in said tube, at least one of the members of each pair being a permanently magnetic magnet and the other member of each pair being selected from a permanently magnetic magnet poled opposite the respective said one of said members and a magnetic flux guide piece;
• and
• an electromagnetic axially stabilizing device responsive to axial displacement of said rotor for generating a compensatory displacement thereof.