摘要:
A method of detecting a vibration node between a non-collocated sensor-actuator pair of a rotatable component includes applying an excitation signal to an actuator of the sensor actuator pair. The method also includes obtaining frequency response data from the sensor-actuator pair. The method further includes analyzing the frequency response data to ascertain a resonant frequency of the rotatable component. The method includes identifying a resonance/anti-resonance peak pair in the frequency response data for the non-collocated sensor-actuator pair. Furthermore, the method includes determining whether the vibration node is located between a sensor and the actuator of the non-collocated sensor-actuator pair based on the resonance/anti-resonance peak pair.
摘要:
Die Erfindung betrifft ein Verfahren zum Kompensieren mindestens einer niederfrequenten mechanischen Stör-Schwingung, die in einem Rotor eines aktiven Magnetlagers durch Einwirken einer Stör-Kraft auf den Rotor verursacht wird. Die mechanische Stör-Schwingung weist eine Stör-Schwingungs-Frequenz unterhalb einer Dreh-Frequenz des Rotors auf. Das Verfahren weist folgende Verfahrensschritte auf: a) Analysieren der niederfrequenten mechanischen Stör-Schwingung, b) Bestimmen einer Kompensations-Kraft zum Erzeugen einer der mechanischen Stör-Schwingung entgegenwirkenden mechanischen Kompensations-Kraft im Rotor und c) Einbringen der Kompensations- Kraft in den Rotor, wobei die Verfahrensschritte a), b) und c) mit Hilfe mindestens eines von einem Magnetlager-Regel-Kreis zum Regeln des aktiven Magnetlagers entkoppelten Kompensations-RegelKreises des aktiven Magnetlagers durchgeführt werden. Darüber hinaus wird ein entsprechendes aktives Magnetlager mit einem Rotor, mindestens einem Magnetlager-Regel-Kreis zum Regeln des aktiven Magnetlagers und mindestens einem vom Magnetlager-Regel-Kreis entkoppelten Kompensations-Regel-Kreis zur Kompensation mindestens einer niederfrequenten mechanischen Stör-Schwingung angegeben. Verwendung finden das aktive Magnetlager sowie das Verfahren in einem Turboverdichter.
摘要:
Ein magnetisches Radiallager mit geringen Wirbelstromverlusten soll kompakt und leicht ansteuerbar bereitgestellt werden. Dazu wird ein Radiallager mit vier Spulen (S1, S2, S3, S4) vorgeschlagen, die sich paarweise auf zwei Achsen (X, Y) gegenüberstehen. Die Spulen werden mit einem drei-phasigen Strom (U, V und W) angesteuert. Die Amplituden der Ströme der Phasen (U, V und W) werden jeweils mit einer untereinander um 120° phasenverschobenen Sinusfunktion bewertet. Die Ansteuerung erfolgt durch eine Ansteuereinrichtung in einem variablen Arbeitspunkt, der für die einzelnen Phasen entsprechend der jeweiligen Sinusfunktion den Wert für die Bewertung der Amplituden festlegt.
摘要:
An electromagnetic actuator with flux feedback control includes two poles located on opposite sides of a soft-magnetic target. A bias flux is introduced that flows into both poles. Magnetic circuitry may be designed so that the total bias flux is independent or substantially independent of a position of the target with respect to the poles or the control flux. The electromagnetic actuator also includes flux sensors introduced into each gap between the poles and the target. The electromagnetic actuator further includes an actuator control circuit to command the current in the control coil to bring a difference between the readings of the two flux sensors to a targeted level. In some aspects, the force exerted on the actuator target in this arrangement may be proportional to the command signal regardless of the position of the actuator target, MMF drop in the soft-magnetic parts of the magnetic circuit, or the frequency.
摘要:
A method for avoiding an unstable working condition in centrifugal compressors (1), which unstable working condition is better known under the term "surge" or "surging" condition, characterised in that it consists in measuring and/or calculating the forces on the bearings (10,11) of the rotor; in detecting timely an exceptional imbalance of radial forces on the bearings (10,11), which occurs before the centrifugal compressor (1) ends up in an unstable condition; and, when the above-mentioned exceptional radial imbalance has been detected, in changing the operational parameters of the centrifugal compressor (1) so as to avoid "surge".
摘要:
A apparatus processes an object (19), such as a semi-conductor wafer at accurately controlled positions. The object (19) is supported by a working platform (12) that is moveable along a path. A suspension actuator part (14) attached to the working platform (12), contains a soft magnetic core (24) with poles facing the surface of a soft magnetic element (34) on the support structure along the path and a winding (20) for application of a current to generate a magnetic field that runs through the core (24) via the poles and returns via the soft magnetic element (34). A sensor (17) senses a measured position of the suspension actuator part (14) relative to the position reference element (16). A control circuit comprises an outer control circuit (40) and an inner control circuit (42). The outer control circuit (40) receives a sensing result and determines force set point information to regulate the measured position of the actuator part (14) to a required value. The inner control circuit (42) receives the force set point information and controls the current to realize a force between the actuator part (14) and the support structure (10) according to the force set point information.
摘要:
A microwheel having stators constructed on a wafer material forming an evacuated cavity in which a rotor is levitating to lessen friction losses. A plurality of microwheels can be integrated to serve as energy storage and/or momentum control devices.
摘要:
A magnetic bearing for suspending a rotatable shaft comprises a backiron (1), and a plurality of poles (2) fixedly coupled to the backiron and extending radially inward toward the rotatable shaft (6). The magnetic bearing also comprises a plurality of electromagnetic coils (4) each being circumferentially disposed around the backiron or the poles, and a magnetic target ring (5) fixedly coupled to the rotor shaft. Each of the poles is separated from the magnetic target ring by an airgap (3). The magnetic bearing further comprises one or more electrical circuits electrically coupled to the plurality of electromagnetic coils and being adapted to energize the plurality of electromagnetic coils so that magnetic flux is induced in the airgaps. The magnetic bearing includes features providing relating to fault detection and fault-tolerant operation. The magnetic bearing also includes mechanical and control-system features that reduce the power consumption of the magnetic bearing.