Abstract: A reluctance motor has salient teeth on both the stator and the rotor. The reluctance motor includes electrical coils that are usable to generate magnetic flux to drive rotation of the rotor. Concentrated coil windings are wound around each stator tooth. The electrical coils are arranged across all the stator teeth of the reluctance motor to enable the reluctance motor to be driven by alternating current. The electrical coils are arranged so that, when excited with alternating current, the number of magnetic half-poles is equal to the number of teeth on the rotor. The reluctance machine can operate using an inverter instead of an asymmetric bridge.

Abstract: Various embodiments are described herein for a double-rotor switched reluctance machine with segmented rotors. In one example embodiment, the double-rotor switched reluctance machine comprises an interior rotor, an exterior rotor spaced from the interior rotor and concentrically disposed outside the interior rotor, and at least one stator disposed concentrically with the interior rotor and the exterior rotor. The interior rotor, the exterior rotor and the at least one stator are disposed within one machine set to provide an interior switched reluctance machine and an exterior switched reluctance machine. In the various embodiments described herein, at least one of the interior rotor and the exterior rotor comprises an array of magnetically isolated segments and filler segments. The interior switched reluctance machine and the exterior switched reluctance machine can operate as two motors, two generators, or a motor and a generator simultaneously.

Abstract: A reluctance motor has salient teeth on both the stator and the rotor. The reluctance motor includes electrical coils that are usable to generate magnetic flux to drive rotation of the rotor. Concentrated coil windings are wound around each stator tooth. The electrical coils are arranged across all the stator teeth of the reluctance motor to enable the reluctance motor to be driven by alternating current. The electrical coils are arranged so that, when excited with alternating current, the number of magnetic half-poles is equal to the number of teeth on the rotor. The reluctance machine can operate using an inverter instead of an asymmetric bridge.

Abstract: The present invention relates to a multi-stage vacuum pump having a plurality of compression stages 12, 14, 16, 18 20 and a booster stage 22. The pump 10 is arranged to pump a chamber 24. The pumping stages include respective rotors supported for rotation on one or more common drive shafts 26. A recirculation valve 28 is associated with the booster stage 22 for selective recirculation of pumped fluid from an outlet 32 to an inlet 30 of the booster stage above a predetermined pressure.

Abstract: Various embodiments are described herein for a double-rotor switched reluctance machine with segmented rotors. In one example embodiment, the double-rotor switched reluctance machine comprises an interior rotor, an exterior rotor spaced from the interior rotor and concentrically disposed outside the interior rotor, and at least one stator disposed concentrically with the interior rotor and the exterior rotor. The interior rotor, the exterior rotor and the at least one stator are disposed within one machine set to provide an interior switched reluctance machine and an exterior switched reluctance machine. In the various embodiments described herein, at least one of the interior rotor and the exterior rotor comprises an array of magnetically isolated segments and filler segments. The interior switched reluctance machine and the exterior switched reluctance machine can operate as two motors, two generators, or a motor and a generator simultaneously.

Abstract: A double-rotor switched reluctance machine includes a stator, a first rotor, and a second rotor. The stator and the first rotor operate as a first electric machine and the stator and the second rotor operate as a second electric machine. Each electric machine has an output torque profile that fluctuates periodically between a maximum and a minimum instantaneous torque. The double-rotor switched reluctance machine is configured so that when the first and second electric machines are operated at a common electrical frequency, the first and second maximum instantaneous torques are temporally offset, thereby reducing the overall torque ripple of the switched reluctance machine. Additionally, or alternatively, a double-rotor switched reluctance machine is configured so that the first and second rotors are radially offset from each other to reduce a net radial force imposed on the stator by the operation of the first and second electric machines.

Abstract: A double-rotor switched reluctance machine includes a stator, a first rotor, and a second rotor. The stator and the first rotor operate as a first electric machine and the stator and the second rotor operate as a second electric machine. Each electric machine has an output torque profile that fluctuates periodically between a maximum and a minimum instantaneous torque. The double-rotor switched reluctance machine is configured so that when the first and second electric machines are operated at a common electrical frequency, the first and second maximum instantaneous torques are temporally offset, thereby reducing the overall torque ripple of the switched reluctance machine. Additionally, or alternatively, a double-rotor switched reluctance machine is configured so that the first and second rotors are radially offset from each other to reduce a net radial force imposed on the stator by the operation of the first and second electric machines.

Abstract: This invention relates to a superconductor device, comprising: a superconductor; a former which supports the superconductor; and, an intermediate electrical connector attached to the former for coupling the superconductor to a power source, wherein the intermediate electrical connector is connected to the superconductor via a deformable portion in the intermediate electrical connector, wherein the deformable portion allows relative movement between the superconductor and former.

Abstract: A system and method are provided for controlling a permanent magnet synchronous generator without rotor position information, utilizing sensor-less hysteresis control and brushless direct current switching scheme. The present invention controls the current and torque of the permanent magnet generator without information of the rotor position in respect to the stator.

Abstract: This invention relates to a superconductor device, comprising: a superconductor; a former which supports the superconductor; and, an intermediate electrical connector attached to the former for coupling the superconductor to a power source, wherein the intermediate electrical connector is connected to the superconductor via a deformable portion in the intermediate electrical connector, wherein the deformable portion allows relative movement between the superconductor and former.

Abstract: An apparatus in an example comprises a stator and a rotor. The stator comprises one or more coils. At least one coil of the one or more coils comprises one or more windings about a hollow spool. The hollow spool comprises a stator conveyor. The stator conveyer comprises a coolant that is located on an inner surface of the hollow spool. The rotor is electromagnetically coupled with the stator. The rotor comprises a plurality of permanent magnets.

Abstract: A vacuum pumping arrangement is described for evacuating a load lock chamber. A booster pump comprises a molecular drag stage and a multi-stage centrifugal compressor mechanism. A backing pump comprises a multi-stage centrifugal compressor mechanism exhausting pumped fluid at atmospheric pressure. Such arrangements can reduce noise, size and vibration levels associated with conventional load lock pumping arrangements.

Abstract: A regenerative pumping mechanism comprises a rotor having a series of blades positioned in an annular array on one side of the rotor, and a stator having an annular channel within which the blades rotate. In order to control the axial clearance between the rotor and the stator, an axial magnetic bearing actively controls relative axial movement between the rotor and the stator. This can allow the pumping mechanism to provide controllable axial sealing between the rotor and the stator, as opposed to radial sealing.

Abstract: A differentially pumped mass spectrometer system comprises a mass spectrometer having a plurality of pressure chambers; a vacuum pump attached thereto and comprising at least three pump inlets, a first pumping section, a second pumping section downstream from the first pumping section, and a third pumping section downstream from the second pumping section, an outlet from a first, relatively low, pressure chamber being connected to a first pump inlet through which fluid can enter the pump from the first chamber and pass through the first, second and third pumping sections towards a pump outlet, an outlet for a second, medium pressure chamber of the spectrometer being connected to a second pump inlet through which fluid can enter the pump and pass through, of said sections, only the second and third pumping sections towards the pump outlet, and an outlet for a third, highest pressure chamber of the spectrometer being connected to a third pump inlet through which fluid can enter the pump and pass through, of sai

Abstract: A turbomolecular pump comprises a pumping mechanism and an electric motor (10) for driving the pumping mechanism. The electric motor comprises a rotor (14), a stator and stator windings (20). The stator comprises a yoke [18(1), 18(2)] and a plurality of teeth (16) projecting from the yoke and carrying the stator windings. The yoke and the teeth are made of a non-sintered magnetic powder material in which the powder particles are bonded by an electrically insulating binder.

Abstract: A method of monitoring the condition of a pump (10) or at least one component of a system that includes a pump which component or components are not a part of the pump, includes the step of generating a pre-determined test condition in the pump or system component or components. During a period in which such a test condition is present, signals indicative of the pump or system component or components are obtained. Wear in the pump bearings, the build-up of deposits in the pump or in pipework forming a part of the pump system can be detected or predicted and corrective action taken before the pump or system fails. By providing a method of monitoring pump or system condition in-situ, it is possible to reduce the likelihood of pump failure in use and the need to carry out over frequent servicing of the pump.

Abstract: A vacuum pumping system comprises a vacuum pumping arrangement comprising: a drive shaft; a motor for driving said drive shaft; a molecular pumping mechanism comprising turbomolecular pumping means; and a backing pumping mechanism. The drive shaft drives said molecular pumping mechanism and said backing pumping mechanism. The system also comprises evacuation means, such as a load lock pump, for evacuating at least, said turbomolecular pumping means.

Abstract: A vacuum pumping arrangement comprises a drive shaft, a motor for driving said drive shaft, a molecular pumping mechanism and a regenerative pumping mechanism. The drive shaft is arranged for simultaneously driving the molecular pumping mechanism and the regenerative pumping mechanism. The drive shaft is supported by a lubricant free bearing associated with the molecular pumping mechanism.

Abstract: A vacuum pumping arrangement comprises a turbomolecular pumping mechanism and a molecular drag pumping mechanism connected in series. A rotor of the molecular drag pumping mechanism is supported by the rotor blades of the turbomolecular pumping mechanism.

Abstract: A vacuum pumping arrangement (10) for controlling pressure in a chamber, the arrangement comprising a molecular pumping mechanism (12) and a backing pumping mechanism (14). The backing pumping mechanism (14) is rotatable by a motor (34), the motor being arranged to rotate the molecular pumping mechanism (12) simultaneously with the backing pumping mechanism (14). Means are provided for controlling the rotational speeds of the backing pumping mechanism and the molecular pumping mechanism.