A positioning apparatus includes a beam which is driven in a first direction that is perpendicular to the longitudinal direction of the beam, a movable member which surrounds at least a part of the beam and moves with the beam moving in the first direction, an actuator which generates a force in the first direction between the beam and the movable member to control a positional relationship in the first direction between the beam and the movable member, and a position regulator arranged between ...

A motor includes a rotor and a stator. A shaft of the rotor is received in a sleeve. A face of the sleeve and a face of the shaft, that are opposed to each other, form a bearing supporting the rotor in a rotatable manner relative to the stator. A sleeve-retaining portion that retains the sleeve has a bottom portion opposed to an axial end of the sleeve. A magnet holder is arranged in the bottom portion to accommodate an attracting magnet magnetically attracting the axial end of the shaft. The ma...

A magnetic bearing has two bearing members each of which carries a set of bearing elements. The bearing elements carried by one member are interleaved with the bearing elements carried by the other member to define three or more substantially parallel interleaf gaps between successive elements, so that bearing forces can be developed as a result of magnetic shear stresses acting across those gaps. The magnetic bearing achieves its bearing forces as the sum of force contributions from a number of...

The symmetry properties of a magnetic levitation arrangement are exploited to produce spin-stabilized magnetic levitation without aligning the rotational axis of the rotor with the direction of the force of gravity. The rotation of the rotor stabilizes perturbations directed parallel to the rotational axis.

An aligning apparatus includes a moving member, a magnetic member arranged vertically above the moving member, a stator unit which is arranged vertically below the moving member and has a plurality of coils, a first magnet unit which is provided to the moving member and generates a force with the magnetic member, and a second magnet unit which is provided to the moving member and generates a force with the stator unit.

A magnetic bearing assembly for levitating a movable member in either rotation or linear translation comprises a three-loop magnetic circuit in which permanent magnets establish a quiescent or fixed flux across four magnetic gaps arranged to provide restoring forces transverse to the direction of gap flux; the resulting inherent instability in the longitudinal direction is overcome by an electric feedback control system which supplies control currents in a pair of coils associated with the magne...

An axial electromagnetic bearing for supporting the end of a shaft rotating a high speed of the type comprising an armature in the form of a disc attached to the shaft and a fixed annular armature disposed facing the disc armature a short distance from the former so as to define a small axial air gap therebetween, the said fixed armature comprising excitation windings and a ferromagnetic core, the bearing being characterized in that radial grooves are provided in the peripheral portion of the di...

A mounting for an elongate horizontal shaft, for example a rotor shaft of a turbine or compressor, comprises two radial end bearings, and at least one intermediate radial bearing. The intermediate bearing is an electromagnetic bearing and is controlled by a detector responsive to the radial position of the shaft. The use of such an intermediate electromagnetic bearing enables relatively long shafts to be mounted satisfactorily.

Improved apparatus is disclosed for use in a magnetic suspension system for developing signals representative of the rate of displacement of a magnetically suspended body along one or more axes thereof for use in applying forces to the body to restore it to a desired stable position. Specifically there are provided a plurality of thin, closely-spaced discs of permanent magnet material affixed to the body and a plurality of conductive windings respectively cooperating with the magnetic fields pro...

A magnetically suspended rotor system is provided capable of operating at rotational speeds of 100,000 rpm or greater. The system comprises a rotor assembly and electric motor means for producing rotation of the assembly about an axis thereof. Electromagnetic means disposed near one end of the rotor is energized to exert an attractive force on the rotor to support it and preferably cooperates with permanent magnet means affixed to the rotor assembly near one (the upper) end thereof. An additiona...