Abstract: A turbomolecular vacuum pump utilizes a virtually zero power magnetic bearing assembly with a single axis sevo control and has an optimized L/D ratio and an optimized number of pole faces. In such a structure, radial stiffness is low and radial damping is high so that single axis control is possible. A frusto-conical mechanical bearing structure is shown as a fail-safe back-up for the magnetic suspension system taught.

Abstract: 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 produced by said magnets, pairs of said windings being interconnected so that currents induced therein by the fields of the magnets tend to reinforce each other and so that currents induced therein by stray fields tend to cancel. The resultant currents induced in the windings are representative of rate of displacement of the suspended body and may be combined with separately derived signals representative of displacement of the body for use in applying forces to the body to restore it to its desired stable position.

Abstract: 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 additional permanent magnet affixed to the rotor near the opposite (lower) end thereof cooperates with another permanent magnet disposed in juxtaposition thereto to exert an attractive force on the rotor tending to oppose the force exerted by electromagnetic means and produces a radial constraining force on the rotor tending to center the lower end of the rotor assembly.

Abstract: An electric motor system comprising a rotor including permanent magnets providing a plurality of correspondingly directed magnetic poles angularly displaced around said rotor, a stator comprising first and second windings adapted to cooperate with the poles of said rotor, each of said windings having transversely disposed conductive portions for intercepting the magnetic fields of said poles during rotation of said rotor, and an amplifier having its input coupled to said first winding so as to be energized by alternating voltage induced in said first winding during rotation of said rotor, and having its output coupled to said second winding to supply alternating current therethrough in synchronism with the interception of the magnetic fields of said poles by the transverse portions of said second winding.

Abstract: A magnetic suspension system for efficiently supporting a rotor of relatively large radius and high available moment of inertia includes concentric stator and rotor elements spaced apart by narrow gaps of relatively large diameter and very small axial extent. A pair of spaced discs in the stator are oppositely polarized by a permanent magnet, their peripheral magnetic field strength being selectively augmented or diminished in predetermined sectors by electromagnet windings thereon. The rotor includes narrow ring faces juxtaposed to said discs, a permanent magnetic polarization being provided between the narrow ring faces. Means are provided for varying the relative electromagnetic contributions in the different sectors to maintain stability of rotor positioning with minimized electric power. SUThe present invention relates to magnetic suspension systems.Magnetic suspension systems have been described in various prior patents including, inter alia, the following U.S.

Abstract: A rotary stepping motor having high torque and low rotor inertia wherein the rotor is of a disk type configuration having a plurality of uniformly spaced rotor poles and the stator has a plurality of stator pole pairs which are formed in separate groups, the spacing between the stator poles in each group being equal to the rotor pole spacings and the spacings between the stator pole groups being not equal to the rotor pole spacings. The stator may be formed of laminated stator elements to provide a magnetic path with the laminations oriented so as to prevent delamination thereof due to the magnetic forces present during operation. The laminated stator elements are appropriately affixed to the motor housing so that the pole pieces thereof are maintained at preselected positions relative to a reference planar surface of the housing. The rotor poles may be tapered to further reduce the rotor inertia and increase motor speed operation.

Abstract: A method is described for producing permanent magnets, in accordance with which magnetic material in finely divided or powdered form, comprising an alloy of a rare earth metal and cobalt, is first premagnetized by subjecting it to a high-intensity magnetic field to magnetize the individual particles thereof, the particles are then introduced into a hardenable resinous material and caused to be distributed substantially uniformly throughout at least a region of said resinous material. While said particles are being introduced into and distributed throughout said resinous material, they are subjected to a magnetic field to align them magnetically. The resinous material is then hardened to form a body thereof in which said particles are maintained in magnetic alignment to form an effective permanent magnet structure. In preferred forms of the invention, fibrous material and/or fiberglass cloth or mat may be embedded in the matrix to enhance its strength.

Abstract: Rotor balancing apparatus and a system comprising balance probes for measuring unbalance at the ends of a magnetically suspended rotor are disclosed. Each balance probe comprises a photocell which is located in relationship to the magnetically suspended rotor such that unbalance of the rotor changes the amount of light recorded by each photocell. The signal from each photocell is electrically amplified and displayed by a suitable device, such as an oscilloscope.

Abstract: A linear magnetic bearing provides magnetic support by means of permanent magnets and control by means of electromagnets and an electronic control system such that virtually zero power is required to maintain the bearing in suspension. Persisting net force producing electric energization of the electromagnets resulting from displacement of the bearing causes the energization to be augmented to reposition the bearing to an oppositely displaced position of substantial equilibrium with minimized net force producing electric energization of the electromagnets. The linear magnetic bearing is effectively utilized in one application to significantly reduce the power requirements for magnetic levitation vehicles.