MAGNETICALLY MOUNTED ROTOR

• US 3,845,995 A
• Filed: 02/27/1973
• Issued: 11/05/1974
• Est. Priority Date: 03/08/1972
• Status: Expired due to Term

• Current Assignee: Heinz Wehde
• Original Assignee: Heinz Wehde
• Inventors: Wehde, Heinz
• Primary Examiner(s): Budd, Mark O.
• Application Number:
  US05/336,215
• Time in Patent Office: 616 Days
• Field of Search: 310/156,263,12,166,13 308/10 74/5.46 324/151
• US Class Current: 310/90.5
• CPC Class Codes: F16C 2370/00 Apparatus relating to physics, e.g. instruments in general G01 - G12
• CPC Class Codes: F16C 2380/26 Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators in general H02K
• CPC Class Codes: F16C 32/0444 Details of devices to control the actuation of the electromagnets
• CPC Class Codes: F16C 32/0493 integrated in an electrodynamic machine, e.g. self-bearing motor
• CPC Class Codes: G01C 19/08 electrically driven G01C19/14 takes precedence
• CPC Class Codes: G01C 19/24 using magnetic or electrostatic fields
• CPC Class Codes: H02K 29/06 with position sensing devices H02K29/03 takes precedence
• CPC Class Codes: H02K 7/09 with magnetic bearings
• CPC Class Codes: Y10T 74/125 by magnetic field

Abstract

A rotational magnetic device, such as those used in flywheels, includes a stator and a rotor. A plurality of permanent magnets are mounted on the rotor, arranged around the circumference of the rotor and alternating in polarity along the circumferential direction. A plurality of windings are arranged on the stator within the magnetic field produced by the permanent magnets. Current which is supplied to these windings produces forces on the rotor which control the positioning and movement of the rotor. This arrangement provides for a rotational magnetic device in which the drive mechanism and the bearing are combined into a single unit and the rotor can be freely suspended in any desired position so that it is in effect magnetically mounted.

Claims

1. A magnetic device comprising, in combination:

a stator;

a rotor disposed for rotation relative to said stator;

a plurality of permanent magnets mounted on, and spaced around the circumference of, said rotor to be in the form of a ring with the magnets alternating in polarity around said rotor circumference in a manner such that the magnetic field lines extend substantially parallel to a surface of said rotor between said rotor and said stator in regions between adjacent magnets and extend substantially perpendicular to such rotor surface in the region of each magnet;

a plurality of windings disposed on said stator and composed of first and second conductor groups distributed around the circumference of said stator to intersect said field lines, with the conductors of said first group being transverse to the conductors of said second group, the conductors of both said groups being substantially parallel to such rotor surface, the conductors of said first group being oriented transverse to the field lines in regions between adjacent magnets, and the conductors of said second group being oriented transverse to the field lines in the region of each magnet; and

current generating means connected to said windings for providing currents in said windings which create forces acting on the rotor in the axial, radial and tangential directions, relative to the direction of rotor rotation, for driving and positioning said rotor with respect to said stator.

2. A magnetic device as defined in claim 1 further comprising:

sensing means connected to said current generating means and located on said stator for detecting the position of said rotor with respect to three orthogonal axes and its three associated rotatory degrees of freedom and providing to said current generating means an output indicative of the position of said rotor.

3. A magnetic device as defined in claim 1 wherein said permanent magnets consist of material having poor electrical conductivity.

4. A magnetic device as defined in claim 1, wherein said rotor is an external rotor;

said permanent magnets are radially magnetized and circumferentially spaced around the inner surface of said rotor;

said first group of conductors is arranged substantially axially with respect to said rotor; and

said second group of conductors is arranged substantially tangentially with respect to said rotor.

5. A magnetic device as defined in claim 1, wherein said rotor has an annular shape;

said permanent magnets are axially magnetized;

said first group of conductors is arranged substantially radially with respect to said rotor; and

said second group of conductors is arranged substantially tangentially with respect to said rotor.