Abstract: A Wiegand-effect shaft position sensor is excited by an alternating magnetic field generated by stationary magnets or solenoids interacting with a high-strength, toothed wheel that is fixed to the rotor. A set of three stationary poles are situated proximate to the rotor and are connected together by a yoke. The magnets or solenoids are mounted in the outside poles of the set of three stationary poles. The central stationary pole contains a Wiegand-effect device. In operation, a flux reversal in the Wiegand-effect device occurs at twice the frequency at which the poles of the toothed wheel pass the stationary poles, resulting in the generation of sharp voltage pulses indicative of rotor position.

Abstract: A vibratory linear motor system employs a comb-shaped electromagnet to excite transverse mechanical oscillations of a relatively thin, spring-like beam. The electromagnet establishes an approximate standing wave on the beam for which brakes mounted on either side of the beam provide independently established boundary conditions and produce rectified linear motion thereof. The brakes may be electromagnetically, magnetostrictively, or piezoelectrically actuated. An electronic control provides modulated currents to the exciter electromagnet and the brakes in order to control the rectified linear motion of the beam.

Abstract: An electric motor driven blade pitch varying system for the fan blades of an unducted fan type aircraft gas turbine engine utilizes permanent magnet alternating current motors located in the oil sump region of the engine. An alternator driven by the engine generates unregulated variable frequency, variable amplitude power which is rectified and placed on a DC bus. Controlled inverters convert the DC power on the bus to appropriate AC power for the motors. The system incorporates redundancy without significant weight penalty by providing alternators and motors dividing into two independent operating sections on common shafts. Separate electronic circuits are provided to supply power for each sectionalized motor or to rectify power from each alternator section. A common power bus may be used to couple the multiple motors and alternators. The common bus may alternatively receive power from tbe aircraft 400 Hz system or from on-board batteries.

Abstract: An electromagnetic actuator includes a moving element comprising a plurality of permanent magnets oriented in alternating magnetic pole position so as to present a sequence of alternating north-south magnetic poles. The magnets can be angularly oriented within a magnetic structure serving to concentrate magnetic flux and focus such flux at the surface of the structure. Alternatively, the magnets are surface mounted within a structure of non-magnetic material. The actuator includes opposed electro-magnetic stators between which the moving element is positioned.

Abstract: A circuit is provided comprising a plurality of series connected superconductive coils. Each of a plurality of series connected shunt resistors is connected in parallel with at least one corresponding series connected superconductive coil. A superconductive switch, which includes a length of superconductive wire, is connected in parallel with the series connected superconductive coils. The switch further includes a first and second heater means which are thermally coupled to the superconductive wire. The first heater means is connectable to an external power supply. The second heater means has a plurality of different sections with each of the shunt resistors connected in parallel to one of the sections so that a quench in any of the superconductive coils causes a section of the second heater means to warm and drive the superconductive switch normal.

Abstract: A method of applying a pre-tensioned, metal containment shroud to a rotor of a permanent magnet machine where pressure is applied to the inside of the shroud to stretch it so that the rotor may be inserted. This pressurization can also be used to size the shroud if the yield strength of the containment shroud is exceeded during the stretching process. The containment cylinder is proportioned such that on the removal of the pressure, the cylinder will have the required tension to clamp the permanent magnets to the rotor.

Abstract: Superconductive conductors, having as many as thousands of filaments, are joined together to form a true superconductive joint. The method is particularly applicable in the situation in which superconductive filaments are embedded in an overlying or surrounding matrix of resistive material such as copper or aluminum. The resistive material is removed by chemical dissolution to expose a length of superconductive filaments. The filaments are juxtaposed within a sleeve of superconductive material which is crimped about the exposed filaments. The connection may be completed by thermally fusing the exposed ends of the filaments.

Abstract: Electrical switches used in conjunction with high energy superconductive windings must be able to quickly absorb large amounts of electrical energy since switching of the superconducting current is accomplished by means of transition to the resistive state in the switch portion of the superconducting current loop. Furthermore, to minimize the heat generated during the transition to the resistive state, the switch itself should exhibit a relatively high resistance while at the same time exhibiting a low external magnetic field. The switch should also exhibit minimal stray magnetic fields, especially in those applications requiring field uniformity. These objectives are achieved in a persistent current switch which includes a length of superconductive material disposed in a compact, thermally insulated volume which also includes a mechanism for heating at least a portion of the superconductive conductor in the switch in order to return it to its resistive state.

Abstract: A permanent magnet rotor is provided having a stack of disk laminations, each of the laminations having a plurality of pole piece sections connected to one another by circumferential bridges situated on the disk periphery. Radial ligaments connect the core portion of the disk to the bridges. The core portion and pole piece sections define the radial thickness of the magnet slots. Magnets are situated in the magnet slots and the bridge positions of the rotor are inwardly deformed causing the radial ligaments to collapse, thereby holding the magnets in their respective slots.

Abstract: The resistor assembly includes a plurality of resistor sections each in the form of resistive plates in which slots have been cut to provide a continuous resistive element of low inductance. The resistor sections are stacked together with thin insulating sheets separating adjacent resistor sections. The resistor sections are serially interconnected. Taps are provided on selected resistor sections to form a plurality of serially connected resistors in which each resistor is electrically isolated from an adjacent resistor but closely thermally coupled thereto. The resistive plates are bound together by discrete bands of an insulating material such as glass cloth tape. Epoxy impregnation allows the resistor assembly when connected in shunt with series connected superconductive coils to be immersed in the liquid helium of a magnet cryostat without causing excessive pressure rise during a quench event.

Abstract: A rotor for a permanent magnet machine comprises an even plurality of pole pieces joined together by intermediate nonmagnetic segments to form a hollow cylinder. A plurality of magnets is situated adjacent to the interior portion of the pole pieces, with the magnets defining a central axial opening. A rotor core has a plurality of saucer shaped elements arranged in a stack situated inside the central opening. Means for providing opposing axial forces to the rotor core tend to flatten the saucer shaped elements and thereby cause radial expansion of the rotor core holding the magnets against the interior of the hollow cylinder.

Abstract: A permanent magnet rotor has a north and a south pole piece each separated into two sections by a central nonmagnetic insert to reduce the quadrature flux. The pole piece sections are welded to the central nonmagnetic insert, two nonmagnetic segments are welded to either end of the north pole piece and two magnetic segments are welded to either end of the south pole pieces to form two half rings. The half rings are secured about a solid shaft of magnetic material having a central portion with a rhombic cross section. The centerline of the half rings is aligned with the diagonal of the square central portion. The half rings are bolted to one another. The sides of the shaft and the inner faces of the half rings form four apertures extending the axial length of the pole pieces. A magnet which adds no structural strength to the rotor is positioned in each of the apertures, respectively.

Abstract: A rotor for a permanent magnet machine comprises laminated pole pieces held in position by interpolar nonmagnetic clamp pieces bolted to a solid rotor core having central portions with a polygonal cross section. Magnets are situated between the pole pieces and the faces of the central portion of the rotor and held in place by the clamping of the pole pieces. Pole piece bars are situated in axial extending apertures circumferentially arranged at the periphery of the pole pieces. Clamp piece bars are situated in channels in the clamp pieces. End rings electrically and structurally connect the clamp piece bars and pole piece bars at either axial end of the rotor forming a uniformly distributed starting cage.

Abstract: A permanent magnet rotor has a stack of disk laminations, each lamination having a plurality of pole piece sections connected to one another by circumferential bridges situated on the disk periphery. Radial ligaments connect the core portion of the disk to the bridges. The core portion and pole piece sections define the radial thickness of the magnet slots. Magnets are situated in the magnet slots and the bridge positions of the rotor are inwardly deformed, causing the radial ligaments to collapse, thereby holding the magnets in their respective slots.

Abstract: A permanent magnet rotor has a north and a south pole piece each separated into two sections by a central nonmagnetic insert to reduce the quadrature flux. The pole piece sections are welded to the central nonmagnetic insert, two nonmagnetic segments are welded to either end of the north pole piece and two magnetic segments are welded to either end of the south pole pieces to form two half rings. The half rings are secured about a solid shaft of magnetic material having a central portion with a rhombic cross section. The centerline of the half rings is aligned with the diagonal of the square central portion. The half rings are bolted to one another. The sides of the shaft and the inner faces of the half rings form four apertures extending the axial length of the pole pieces. A magnet which adds no structural strength to the rotor is positioned in each of the apertures, respectively.

Abstract: A rotor for a permanent magnet machine comprises an even plurality of pole pieces joined together by intermediate nonmagnetic segments to form a hollow cylinder. A plurality of magnets is situated adjacent to the interior portion of the pole pieces, with the magnets defining a central axial opening. A rotor core has a plurality of saucer shaped elements arranged in a stack situated inside the central opening. Means for providing opposing axial forces to the rotor core tend to flatten the saucer shaped elements and thereby cause radial expansion of the rotor core holding the magnets against the interior of the hollow cylinder.

Abstract: Means for developing a plurality of chromatograms simultaneously without prior equilibration are disclosed. When the means of the invention are used, the chromatograms are vertically positioned with their lower ends in developing fluid, their vertical edges equidistant from a solid wall member, and spacing between chromatograms to permit air flow. The means comprise a rack for use in a developing tank and in which the chromatograms are vertically supported in spaced slits, the ends of which are equidistant from a wall member when in the developing tank.

Abstract: A permanent magnet rotor uses a magnetic shaft having a rhomboidal cross section. Fastening means secure clamp pieces which in turn retain pole pieces and the permanent magnets.

Abstract: A two-pole rotor of increased flux concentration factor employs two pole pieces of magnetic material which are separated from each other by non-magnetic segments. The pole pieces and non-magnetic segments are joined together to form a cylinder with an aperture extending axially through the central portion. Two magnets forming a V shaped configuration and polarized such that the inner faces of the magnets have like polarity are positioned in the central portion of the cylinder with the outer sides of the magnets adjacent to one of the pole pieces. The magnets are located symmetrically about the d axis and asymmetrically about the q axis. The magnets extend above and below the q axis. A prism shaped segment of magnetic material is positioned between the magnets with the base of the prism adjacent to the other pole piece to hold the magnet in place. A stub shaft is mounted on each face of the cylinder.

Abstract: A plural bag dust collector filter apparatus for filtering air to remove dust and similar contaminants therefrom including a plurality of vertically elongated tubular cylindrical upwardly opening filter bags and respective associated shape-maintaining skeletal cylindrical wire cages inwardly lining the filter bags arranged in transversely plural longitudinal rows of plural filter bags each in a box-like chamber, and a shake-down mechanism comprising vertically elongated beater rods located respectively within and depending substantially throughout the vertical height of the respective filter bag cages and their associated filter bags. Rotatable crank arms pivotally coupled to the opposite ends of supporting bars for the beater rods and a powered drive therefor are provided to impact the beater rods inwardly against their associated cages and develop sufficient force to dislodge dust build-up on the surfaces of the filter bags.