EP0082956B1 - Device for a contactless out-of-balance measurement - Google Patents

Device for a contactless out-of-balance measurement Download PDF

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Publication number
EP0082956B1
EP0082956B1 EP82110802A EP82110802A EP0082956B1 EP 0082956 B1 EP0082956 B1 EP 0082956B1 EP 82110802 A EP82110802 A EP 82110802A EP 82110802 A EP82110802 A EP 82110802A EP 0082956 B1 EP0082956 B1 EP 0082956B1
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EP
European Patent Office
Prior art keywords
sensor
rotor
magnetic field
gap
centrifuge
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EP82110802A
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German (de)
French (fr)
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EP0082956A1 (en
Inventor
Gerhard Wicki
Rolf Näff
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Cessione kontron Instruments Holding Nv
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Kontron Holding AG
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Priority to AT82110802T priority Critical patent/ATE17928T1/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
    • B04B—CENTRIFUGES
    • B04B9/00—Drives specially designed for centrifuges; Arrangement or disposition of transmission gearing; Suspending or balancing rotary bowls
    • B04B9/14—Balancing rotary bowls ; Schrappers
    • B04B9/146—Unbalance detection devices

Definitions

  • the invention relates to a device for non-contact unbalance measurement on centrifuges and the like, in particular on ultracentrifuges, with a magnetic field sensor arranged on the fixed part of the centrifuge in the vicinity of an annular part rotating with the rotor for detecting the changes in the geometry of the gap resulting from deflection movements of the rotor shaft between the ring-shaped part and the sensor.
  • a permanent magnet is attached to the centrifuge rotor, the magnetic field of which is detected by a coil arranged on the fixed housing. Deflection of the rotor during centrifugation results in a corresponding change in the detected field, which can thus be used for monitoring.
  • the arrangement of a permanent magnet on the upper part of the rotor is hardly possible in this or a similar form in a modern ultracentrifuge.
  • the arrangement is relatively complex if high precision is required.
  • GB-A641 732 shows a device for measuring the eccentricity of rotating shafts.
  • the field change of a permanent magnet with a coil caused by a change in an air gap is measured.
  • the monitored gap should be on the largest possible circumference of the rotating part.
  • the arrangement of the monitoring device on a circumference of the rotor is in terms of structural complexity, precision and handling of the device, for. B. unfavorable when replacing the rotors.
  • the object of the invention was therefore to provide a contactless unbalance measurement on centrifuges, which requires relatively little material and labor in the manufacture, detects an unbalance with high precision and does not interfere with the handling of the device.
  • this is achieved by a device of the type mentioned at the outset, in which the annular part rotating with the rotor has an annular flat end face which lies in a plane perpendicular to the centrifuge axis and which is opposite the magnetic field sensor in order to provide for the between the end face and the sensor Define the measured gap.
  • the rotor has a coaxially arranged flange-shaped part, opposite the end of which the sensor is arranged.
  • a magnetic field-dependent resistor or a Hall generator is preferably used as the sensor.
  • the flange-shaped part is preferably made of soft iron.
  • the sensor is a differential sensor.
  • the single figure shows a schematic representation of the essential parts of the rotor and the fixed part of an ultracentrifuge with a device for measuring unbalance according to the invention.
  • a receiving head for the centrifuge rotor is attached to the rotor shaft 1.
  • a ring-shaped or flange-shaped part 3 made of soft iron is formed on this adapter 2, which is referred to below as the measuring flange.
  • the measuring flange can also be arranged on the rotor 5 (not shown).
  • the measuring flange 3 has an annular end face 4 which defines a plane perpendicular to the rotor axis.
  • a magnetic field sensor 6 is arranged on the fixed part of the centrifuge at a short distance from the flat end face of the measuring flange 3.
  • the sensor is a differential sensor, consisting of two magnetic field-dependent resistors 7, 8, which are attached to a common permanent magnet 9.
  • Such differential sensors are commercially available components and are available, for example, from Siemens under the type designation FP 210 L 100.
  • other differential sensors made of magnetic field-dependent resistors, as well as individual field plates or arrangements made of Hall generators, can also be used.
  • the measuring flange 3 from permanent magnetic material.
  • the permanent magnet 9 on which the both field plates are mounted are eliminated or replaced by a soft iron plate.
  • the distance referred to as a gap for the purpose of this description between the end face 4 of the measuring flange 3 and the differential sensor 6 is preferably between 0.2 and 0.7 mm.
  • these values are not absolute limit values for the function of the invention.
  • the sensor Since the displacement of the measuring flange 3 relative to the differential sensor 6 takes place in the direction perpendicular to the axis, the sensor is arranged such that the two field plates 7, 8 lie one behind the other in the radial direction to the axis.
  • the axis is at an angle, during centrifugation there is a precession movement of the axis in addition to the deflection or due to the deflection, which leads to a temporal change in the deflection at the location of the sensor 6 and thus to a temporal change in the resistance values.
  • An inclined rotor axis can result from the fact that the device is not absolutely horizontal or also because the rotor is filled unevenly.
  • the two magnetic field-dependent resistors are arranged in a bridge circuit 10, from which an output signal is generated in a known manner with the aid of a suitable amplifier 11.
  • the output signal consists of a voltage that is proportional to the deflection in the radial direction of the rotor axis. It is therefore an analog signal, which constitutes a considerable advantage of the device according to the invention.
  • the conventional devices for determining the unbalance in a centrifuge which are based on the principle of contact of a ball-bearing ring through the axis, are digital sensors: a signal is emitted at a certain critical deflection. Due to the mechanical construction, the sensitivity, i.e. H. to vary the response threshold of the deflection, especially not during operation.
  • the system according to the invention in which an analog signal is generated, makes it possible to change the sensitivity without any problems, even during operation. This is a considerable advantage, because it enables the sensitivity to be selected lower at lower speeds, at which experience has shown greater deflections, but which do not endanger the rotor at these speeds, and at higher speeds when the rotor is self-stabilizing is done to shift up. This ensures that in all cases in which a centrifuge previously switched off, because at relatively low speeds due to critical vibrations deflections that would endanger the rotor at higher speeds, the centrifuge can continue to run if the rotor is above the critical speed stabilized again.
  • the following measures are provided in the circuit to switch over the response sensitivity of the unbalance measurement:
  • the amplifier 11 is followed by a comparator 12, to which the output signal of the amplifier is fed and whose reference input can be changed as a function of the speed.
  • a warning signal is emitted at the signal output 13.
  • the signal available at the output of the amplifier 11 can also be processed further via a microprocessor.

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  • Centrifugal Separators (AREA)
  • Testing Of Balance (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
  • Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
  • Coupling Device And Connection With Printed Circuit (AREA)
  • Automatic Cycles, And Cycles In General (AREA)
  • Processing Of Solid Wastes (AREA)
  • Level Indicators Using A Float (AREA)
  • Optical Measuring Cells (AREA)
  • Spectrometry And Color Measurement (AREA)
  • Automatic Analysis And Handling Materials Therefor (AREA)

Abstract

In accordance with the invention, a magnetic field sensor is disposed on a stationary part of a centrifuge near an annular member of a rotor and is adapted to detect those variations in a gap which exists between the annular member and the sensor. The variations in the gap arising from deflection and/or precession of the rotor axis.

Description

Die Erfindung betrifft eine Einrichtung zur berührungslosen Unwuchtmessung an Zentrifungen und dergleichen, insbesondere an Ultrazentrifugen, mit einem am feststehenden Teil der Zentrifuge in der Nähe eines sich mit dem Rotor drehenden ringförmigen Teils angeordneten Magnetfeldfühler zur Erfassung der durch Auslenkungsbewegungen der Rotorwelle entstehenden Veränderungen der Geometrie des Spalts zwischen dem ringförmigen Teil und dem Fühler.The invention relates to a device for non-contact unbalance measurement on centrifuges and the like, in particular on ultracentrifuges, with a magnetic field sensor arranged on the fixed part of the centrifuge in the vicinity of an annular part rotating with the rotor for detecting the changes in the geometry of the gap resulting from deflection movements of the rotor shaft between the ring-shaped part and the sensor.

Bisher übliche Einrichtungen zur Unwuchtmessung an Ultrazentrifugen beruhen beispielsweise auf dem Prinzip, dass die Rotorwelle der Zentrifuge bei Auslenkung durch Unwucht einen sie in einem bestimmten Abstand umgebenden Ring berührt, der drehbar gelagert ist und durch die Berührung mitgenommen wird und dessen Bewegung überwacht wird. Dieses System ist jedoch mechanisch verhältnismässig aufwendig, so dass schon seit geraumer Zeit das Bedürfnis nach einer nicht-mechanischen Lösung bestand.Hitherto conventional devices for measuring unbalance on ultracentrifuges are based, for example, on the principle that the rotor shaft of the centrifuge, when deflected by unbalance, touches a ring surrounding it at a certain distance, which is rotatably mounted and is carried by the contact and the movement of which is monitored. However, this system is mechanically relatively complex, so that there has been a need for a non-mechanical solution for some time.

Es wurden auch bereits Versuche durchgeführt, die Unwucht optisch zu messen. Dies hat sich jedoch kaum bewährt, da die Sensoren im Umfeld von Ultrazentrifugen sehr störanfällig sind.Attempts have already been made to optically measure the unbalance. However, this has hardly proven itself since the sensors in the vicinity of ultracentrifuges are very susceptible to faults.

Eine andere Form der berührungslosen Unwuchtüberwachung ist in der FR-A-1.298.343 beschrieben. Am Zentrifugenrotor ist ein Permanentmagnet angebracht, dessen Magnetfeld von einer am feststehenden Gehäuse angeordneten Spule erfasst wird. Eine Auslenkung des Rotors bei der Zentrifugation resultiert in einer entsprechenden Aenderung des erfassten Feldes, das somit zur Ueberwachung herangezogen werden kann.Another form of contactless unbalance monitoring is described in FR-A-1.298.343. A permanent magnet is attached to the centrifuge rotor, the magnetic field of which is detected by a coil arranged on the fixed housing. Deflection of the rotor during centrifugation results in a corresponding change in the detected field, which can thus be used for monitoring.

Die Anordnung eines Permanentmagneten am oberen Teil des Rotors ist bei einer modernen Ultrazentrifuge kaum in dieser oder ähnlicher Form möglich. Ausserdem ist die Anordnung verhältnismässig aufwendig falls hohe Präzision verlangt wird.The arrangement of a permanent magnet on the upper part of the rotor is hardly possible in this or a similar form in a modern ultracentrifuge. In addition, the arrangement is relatively complex if high precision is required.

Aenliche Anordnungen wie bei Zentrifugen sind auch bei anderen Vorrichtungen bekannt. So zeigt die GB-A641 732 eine Einrichtung zur Messung der Exzentrizität von drehenden Wellen. Auch hier wird die durch eine Aenderung eines Luftspalts hervorgerufene Feldänderung eines Permanentmagneten mit einer Spule gemessen. Wie die Ausführungsbeispiele in dieser Patentschrift zeigen, soll sich der überwachte Spalt an einem möglichst grossen Umfang des drehenden Teils befinden.Similar arrangements as for centrifuges are also known for other devices. GB-A641 732 shows a device for measuring the eccentricity of rotating shafts. Here too, the field change of a permanent magnet with a coil caused by a change in an air gap is measured. As the exemplary embodiments in this patent show, the monitored gap should be on the largest possible circumference of the rotating part.

Die Anordnung der Ueberwachungseinrichtung an einem Umfang des Rotors ist hinsichtlich des baulichen Aufwands, der Präzision und der Handhabung des Geräts, z. B. beim Auswechseln der Rotoren ungünstig.The arrangement of the monitoring device on a circumference of the rotor is in terms of structural complexity, precision and handling of the device, for. B. unfavorable when replacing the rotors.

Die Aufgabe der Erfindung bestand demnach darin, eine berührungslose Unwuchtmessung an Zentrifugen bereitzustellen, die verhältnismässig geringen Material- und Arbeitsaufwand bei der Herstellung erfordert, mit hoher Präzision eine Unwucht erfasst und bei der Handhabung des Geräts nicht stört.The object of the invention was therefore to provide a contactless unbalance measurement on centrifuges, which requires relatively little material and labor in the manufacture, detects an unbalance with high precision and does not interfere with the handling of the device.

Erfindungsgemäss wird dies erreicht durch eine Einrichtung der eingangs genannten Art, bei der der sich mit dem Rotor drehende ringförmige Teil eine ringförmige ebene Stirnfläche aufweist, die in einer Ebene senkrecht zur Zentrifugenachse liegt und die dem Magnetfeldfühler gegenüberliegt, um zwischen Stirnfläche und Fühler den für die Messung erfassten Spalt zu definieren.According to the invention, this is achieved by a device of the type mentioned at the outset, in which the annular part rotating with the rotor has an annular flat end face which lies in a plane perpendicular to the centrifuge axis and which is opposite the magnetic field sensor in order to provide for the between the end face and the sensor Define the measured gap.

Nach einer besonderen Ausführungsform der Erfindung weist der Rotor einen koaxial angeordneten flanschförmiges Teil auf, gegenüber dessen Stirnseite der Fühler angeordnet ist. Als Fühler kommt vorzugsweise ein magnetfeldabhängiger Widerstand oder ein Hallgenerator in Frage. Der flanschförmige Teil ist vorzugsweise aus Weicheisen. Nach einer weiteren bevorzugten Ausbildung der Erfindung ist der Fühler ein Differentialfühler.According to a special embodiment of the invention, the rotor has a coaxially arranged flange-shaped part, opposite the end of which the sensor is arranged. A magnetic field-dependent resistor or a Hall generator is preferably used as the sensor. The flange-shaped part is preferably made of soft iron. According to a further preferred embodiment of the invention, the sensor is a differential sensor.

Nachfolgend wird anhand der beiliegenden Zeichnung eine bevorzugte Ausführungsform der Erfindung beschrieben.A preferred embodiment of the invention is described below with reference to the accompanying drawing.

Die einzige Figur zeigt eine schematische Darstellung der wesentlichen Teile des Rotors und des feststehenden Teils einer Ultrazentrifuge mit einer Einrichtung zur Unwuchtmessung nach der Erfindung.The single figure shows a schematic representation of the essential parts of the rotor and the fixed part of an ultracentrifuge with a device for measuring unbalance according to the invention.

In der oberen Hälfte der Figur sind die für die erfindungsgemässe Unwuchtmessung wesentlichen Teile einer Ultrazentrifuge schematisch im Schnitt dargestellt. An der Rotorwelle 1 ist ein üblicherweise als Adapter 2 bezeichneter Aufnahmekopf für den Zentrifugenrotor angebracht. An diesem Adapter 2 ist ein ring- oder flanschförmiger Teil 3 aus Weicheisen ausgebildet, der nachfolgend als Messflansch bezeichnet wird. Anstelle der direkten Verbindung mit der Rotorwelle oder dem Adapter kann der Messflansch auch am (nicht gezeigten) Rotor 5 angeordnet sein. Der Messflansch 3 weist eine ringförmige Stirnfläche 4 auf, die eine zur Rotorachse senkrechte Ebene definiert.In the upper half of the figure, the parts of an ultracentrifuge that are essential for the unbalance measurement according to the invention are shown schematically in section. A receiving head for the centrifuge rotor, usually referred to as adapter 2, is attached to the rotor shaft 1. A ring-shaped or flange-shaped part 3 made of soft iron is formed on this adapter 2, which is referred to below as the measuring flange. Instead of the direct connection to the rotor shaft or the adapter, the measuring flange can also be arranged on the rotor 5 (not shown). The measuring flange 3 has an annular end face 4 which defines a plane perpendicular to the rotor axis.

In einem geringen Abstand von der ebenen Stirnfläche des Messflansches 3 ist am feststehenden Teil der Zentrifuge ein Magnetfeldfühler 6 angeordnet. Der Fühler ist ein Differentialfühler, bestehend aus zwei magnetfeldabhängigen Widerständen 7, 8, die auf einem gemeinsamen Permanentmagneten 9 befestigt sind. Solche Differentialfühler sind handelsübliche Bauelemente und beispielsweise unter der Typenbezeichnung FP 210 L 100 von der Firma Siemens erhältlich. Selbstverständlich sind auch andere Differentialfühler aus magnetfeldabhängigen Widerständen, sowie auch einzelne Feldplatten oder Anordnungen aus Hallgeneratoren verwendbar.A magnetic field sensor 6 is arranged on the fixed part of the centrifuge at a short distance from the flat end face of the measuring flange 3. The sensor is a differential sensor, consisting of two magnetic field-dependent resistors 7, 8, which are attached to a common permanent magnet 9. Such differential sensors are commercially available components and are available, for example, from Siemens under the type designation FP 210 L 100. Of course, other differential sensors made of magnetic field-dependent resistors, as well as individual field plates or arrangements made of Hall generators, can also be used.

Neben dieser bevorzugten Ausführungsform ist es natürlich auch möglich, den Messflansch 3 aus permanent-magnetischem Material auszubilden. Dafür würde der Permanentmagnet 9, auf dem die beiden Feldplatten montiert sind, wegfallen bzw. durch ein Weicheisenplättchen ersetzt werden.In addition to this preferred embodiment, it is of course also possible to design the measuring flange 3 from permanent magnetic material. For this, the permanent magnet 9 on which the both field plates are mounted, are eliminated or replaced by a soft iron plate.

Der zum Zweck dieser Beschreibung als Spalt bezeichnete Abstand zwischen der Stirnfläche 4 des Messflansches 3 und dem Differentialfühler 6 liegt vorzugsweise zwischen 0,2 und 0,7 mm. Selbstverständlich sind diese Werte für die Funktion der Erfindung keine absoluten Grenzwerte.The distance referred to as a gap for the purpose of this description between the end face 4 of the measuring flange 3 and the differential sensor 6 is preferably between 0.2 and 0.7 mm. Of course, these values are not absolute limit values for the function of the invention.

Bei der vorgegebenen Geometrie des Spalts zwischen dem Messflansch 3 und dem Fühler 6 besteht ein Bestimmtes konstantes Magnetfeld, was einen bestimmten Widerstandswert in den beiden Feldplatten zur Folge hat. Die Geometrie des Spalts, wie sie bei stillstehendem Rotor besteht, ändert sich auch bei laufender Zentrifuge nicht, solange keine Unwucht besteht, so dass die Achse der Welle ruhig steht. Im Fall einer Unwucht jedoch bewegt sich die Achse aus ihrer Ruhelage heraus. Dies führt zu einer Veränderung der Geometrie des Spalts und damit zu einer Aenderung des im Spalt bestehenden Magnetfelds. Diese Feldänderung hat wiederum eine Widerstandsänderung in den Feldplatten zur Folge.Given the geometry of the gap between the measuring flange 3 and the sensor 6, there is a certain constant magnetic field, which results in a certain resistance value in the two field plates. The geometry of the gap, as it exists when the rotor is at a standstill, does not change even when the centrifuge is running, as long as there is no imbalance, so that the axis of the shaft is stationary. In the event of an imbalance, however, the axis moves out of its rest position. This leads to a change in the geometry of the gap and thus to a change in the magnetic field existing in the gap. This field change in turn results in a change in resistance in the field plates.

Da die Verschiebung des Messflansches 3 relativ zum Differentialfühler 6 in der Richtung senkrecht zur Achse erfolgt, ist der Fühler so angeordnet, dass die beiden Feldplatten 7, 8 in zur Achse radialer Richtung hintereinander liegen.Since the displacement of the measuring flange 3 relative to the differential sensor 6 takes place in the direction perpendicular to the axis, the sensor is arranged such that the two field plates 7, 8 lie one behind the other in the radial direction to the axis.

Wenn die Achse schräg steht, entsteht beim Zentrifugieren zusätzlich zur Auslenkung, bzw. auf Grund der Auslenkung eine Präzessionsbewegung der Achse, was zu einer zeitlichen Aenderung der Auslenkung an der Stelle des Fühlers 6 und damit zu einer zeitlichen Aenderung der Widerstandswerte führt.If the axis is at an angle, during centrifugation there is a precession movement of the axis in addition to the deflection or due to the deflection, which leads to a temporal change in the deflection at the location of the sensor 6 and thus to a temporal change in the resistance values.

Eine schrägstehende Rotorachse kann dadurch entstehen, dass das Gerät nicht absolut waagrecht steht oder auch dadurch, dass der Rotor ungleich gefüllt ist.An inclined rotor axis can result from the fact that the device is not absolutely horizontal or also because the rotor is filled unevenly.

Zur Erfassung der Widerstandswerte der Feldplatten sind die beiden magnetfeldabhängigen Widerstände in eine Brückenschaltung 10 eingeordnet, aus der in bekannter Weise mit Hilfe eines geeigneten Verstärkers 11 ein Ausgangssignal erzeugt wird.To detect the resistance values of the field plates, the two magnetic field-dependent resistors are arranged in a bridge circuit 10, from which an output signal is generated in a known manner with the aid of a suitable amplifier 11.

Das Ausgangssignal besteht in einer Spannung, die zur Auslenkung in radialer Richtung zur Rotorachse proportional ist. Es handelt sich also um ein analoges Signal, was einen erheblichen Vorteil der erfindungsgemässen Einrichtung ausmacht. Die herkömmlichen Einrichtungen zur Bestimmung der Unwucht bei einer Zentrifuge, die auf dem Prinzip der Berührung eines kugelgelagerten Rings durch die Achse beruhten stellen digitale Sensoren dar: Bei einer bestimmten kritischen Auslenkung wird ein Signal abgegeben. Durch die mechanische Konstruktion war es nicht möglich die Empfindlichkeit, d. h. die Ansprechschwelle der Auslenkung zu variieren, insbesondere nicht während des Betriebs.The output signal consists of a voltage that is proportional to the deflection in the radial direction of the rotor axis. It is therefore an analog signal, which constitutes a considerable advantage of the device according to the invention. The conventional devices for determining the unbalance in a centrifuge, which are based on the principle of contact of a ball-bearing ring through the axis, are digital sensors: a signal is emitted at a certain critical deflection. Due to the mechanical construction, the sensitivity, i.e. H. to vary the response threshold of the deflection, especially not during operation.

Durch das erfindungsgemässe System, bei dem ein analoges Signal erzeugt wird, ist nun eine Aenderung der Empfindlichkeit ohne weiteres möglich, auch während des Betriebs. Dies stellt einen erheblichen Vorteil dar, weil dadurch die Möglichkeit besteht, die Empfindlichkeit bei niedrigeren Drehzahlen, bei denen erfahrungsgemäss grössere Auslenkungen vorkommen, die aber bei diesen Drehzahlen den Rotor nicht gefährden, kleiner zu wählen und sie bei höheren Drehzahlen, wenn die Selbststabilisierung des Rotors vollzogen ist, höher zu schalten. Dadurch wird erreicht, dass in all den Fällen, in denen früher eine Zentrifuge abgeschaltet hat, weil bei relativ niedrigen Drehzahlen infolge kritischer Schwingungen Auslenkungen aufgetreten sind, die bei grösseren Drehzahlen den Rotor gefährden würden, die Zentrifuge weiterlaufen kann, sofern sich der Rotor oberhalb der kritischen Drehzahl wieder stabilisiert.The system according to the invention, in which an analog signal is generated, makes it possible to change the sensitivity without any problems, even during operation. This is a considerable advantage, because it enables the sensitivity to be selected lower at lower speeds, at which experience has shown greater deflections, but which do not endanger the rotor at these speeds, and at higher speeds when the rotor is self-stabilizing is done to shift up. This ensures that in all cases in which a centrifuge previously switched off, because at relatively low speeds due to critical vibrations deflections that would endanger the rotor at higher speeds, the centrifuge can continue to run if the rotor is above the critical speed stabilized again.

Zur Umschaltung der Ansprechempfindlichkeit der Unwuchtmessung sind in der Schaltung folgende Massnahmen vorgesehen : Dem Verstärker 11 ist ein Komparator 12 nachgeschaltet, dem das Ausgangssignal des Verstärkers zugeführt wird und dessen Referenzeingang drehzahlabhängig verändert werden kann. Sobald das Umwuchtmessignal die Referenzspannung VR übersteigt, wird am Signalausgang 13 ein Warnsignal abgegeben.The following measures are provided in the circuit to switch over the response sensitivity of the unbalance measurement: The amplifier 11 is followed by a comparator 12, to which the output signal of the amplifier is fed and whose reference input can be changed as a function of the speed. As soon as the unbalance measurement signal exceeds the reference voltage V R , a warning signal is emitted at the signal output 13.

Alternativ kann das am Ausgang des Verstärkers 11 zur Verfügung stehende Signal auch über einen Mikroprozessor weiterverarbeitet werden.Alternatively, the signal available at the output of the amplifier 11 can also be processed further via a microprocessor.

Claims (6)

1. Apparatus for the contact-less measurement of imbalance in centrifuges and the like, more particularly ultracentrifuges, comprising a magnetic field sensor disposed on the stationary part of the centrifuge near an annular part rotating with the rotor, said sensor being adapted to detect variations in the geometry of the gap between the annular part and the sensor as they occur due to rotor shaft deflection movements, characterised in that the annular part (3) rotating with the rotor (5) has an annular plane end face (4) which is situated in a plane perpendicular to the centrifuge axis and is situated opposite the magnetic field sensor (6) in order to define between the end face (4) and the sensor (6) the gap covered for the measurement.
2. Apparatus according to claim 1, characterised in that the annular part (3) is a soft-iron part in the form of a flange disposed coaxially on the rotor shaft (1).
3. Apparatus according to claim 1, characterised in that the annular part (3) is a soft-iron part in the form of a flange disposed coaxially on the rotor.
4. Apparatus according to claim 1, characterised in that an adapter (2) is connected to the rotor shaft (1) and has a soft-iron part (3) in the form of a flange.
5. Apparatus according to any one of the preceding claims, characterised in that the magnetic field sensor (6) is a magnetic field dependent resistance or a Hall probe.
6. Apparatus according to claim 5, characterised in that the sensor (6) is a differential sensor with two magnetic field dependent resistances (7, 8) disposed on a permanent magnet (9).
EP82110802A 1981-12-24 1982-11-23 Device for a contactless out-of-balance measurement Expired EP0082956B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT82110802T ATE17928T1 (en) 1981-12-24 1982-11-23 DEVICE FOR NON-CONTACT IMBALANCE MEASUREMENT.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH828481 1981-12-24
CH8284/81 1981-12-24

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EP0082956A1 EP0082956A1 (en) 1983-07-06
EP0082956B1 true EP0082956B1 (en) 1986-02-12

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US (1) US4491019A (en)
EP (1) EP0082956B1 (en)
JP (2) JPS58118938A (en)
AT (1) ATE17928T1 (en)
AU (1) AU542725B2 (en)
CA (1) CA1194709A (en)
DE (1) DE3269101D1 (en)
DK (1) DK571382A (en)
ES (1) ES517774A0 (en)
NO (1) NO156844C (en)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4700117A (en) * 1985-05-31 1987-10-13 Beckman Instruments, Inc. Centrifuge overspeed protection and imbalance detection system
JPH0726669B2 (en) * 1988-09-09 1995-03-29 日立工機株式会社 Rotating body unbalance detection method
DE3935616C3 (en) * 1989-10-26 1998-12-24 Sigma Laborzentrifugen Gmbh Device for monitoring the operation of a centrifuge
JPH0418798U (en) * 1990-06-04 1992-02-17
DE4335119C2 (en) * 1993-10-15 1997-11-20 Eppendorf Geraetebau Gmbh Laboratory centrifuge with unbalance shutdown
US5505684A (en) * 1994-08-10 1996-04-09 Piramoon Technologies, Inc. Centrifuge construction having central stator
JP3710001B2 (en) * 1995-06-16 2005-10-26 日立工機株式会社 centrifuge
DE19701551C1 (en) * 1997-01-17 1998-08-06 Fresenius Ag Centrifuge rotor imbalance detector
DE29712121U1 (en) * 1997-07-10 1997-09-11 Sigma Laborzentrifugen Gmbh Control device for a laboratory centrifuge
US5800331A (en) * 1997-10-01 1998-09-01 Song; Jin Y. Imbalance detection and rotor identification system
JP3968960B2 (en) * 1999-07-15 2007-08-29 日立工機株式会社 Centrifuge
US6350224B1 (en) 2000-07-17 2002-02-26 Westinghouse Savannah River Company, Llc Centrifugal unbalance detection system
US6635007B2 (en) * 2000-07-17 2003-10-21 Thermo Iec, Inc. Method and apparatus for detecting and controlling imbalance conditions in a centrifuge system
EP1455436A1 (en) * 2003-03-05 2004-09-08 Ecole Polytechnique Fédérale de Lausanne (EPFL) Method and apparatus for processing signals for eccentricity detection in a synchronous machine
DE102005018041B3 (en) * 2005-04-19 2007-01-04 Hanning Elektro-Werke Gmbh & Co. Kg Drive device for a laboratory centrifuge
DE102011102606A1 (en) 2011-05-27 2012-11-29 Ika-Werke Gmbh & Co. Kg Stirrer with a stirring tool and with a drive motor
DE102012002891A1 (en) * 2012-02-14 2013-08-14 Hans Heidolph Gmbh & Co. Kg Laboratory apparatus e.g. electrical laboratory apparatus has control device which automatically triggers safety-related reaction when evaluation device detects that predetermined amount of movement is exceeded
GB2523474A (en) * 2014-02-19 2015-08-26 Vibrosystm Inc Real time monitoring of rotor or stator shape change for rotating machines
DE102014116527B4 (en) * 2014-11-12 2020-01-23 Andreas Hettich Gmbh & Co. Kg Centrifuge and method for detecting unbalance in the centrifuge

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB641732A (en) * 1947-09-05 1950-08-16 English Electric Co Ltd Improvements relating to eccentricity measuring instruments
BE571526A (en) * 1957-10-02 1962-02-23 Licentia Gmbh DEVICE FOR MEASURING THE AXIAL MOVEMENTS OF THE SHAFT OF A CENTRIFUGAL MACHINE, INCLUDING A TRANSLATION ORGAN AND A TRANSLATION VALUE EMITTER.
FR1298343A (en) * 1960-03-17 1962-07-13 Reactor Centrum Nederland Device for signaling, indicating, recording and influencing the movements of the axis of rotation and the speed of rotation of the rotor of a centrifuge
CH516885A (en) * 1970-05-20 1971-12-15 Bbc Brown Boveri & Cie Electric machine with a device for monitoring the air gap
US4028524A (en) * 1971-08-06 1977-06-07 The Singer Company Balancing system for a rotating mass
JPS51151568A (en) * 1975-06-20 1976-12-27 Ono Sokki Co Ltd Detector
JPS57192449U (en) * 1981-06-01 1982-12-06

Also Published As

Publication number Publication date
ES8400822A1 (en) 1983-11-16
EP0082956A1 (en) 1983-07-06
JPS6324424Y2 (en) 1988-07-05
JPS6244232U (en) 1987-03-17
NO156844C (en) 1987-12-02
JPS58118938A (en) 1983-07-15
AU542725B2 (en) 1985-03-07
NO824361L (en) 1983-06-27
CA1194709A (en) 1985-10-08
DK571382A (en) 1983-06-25
US4491019A (en) 1985-01-01
DE3269101D1 (en) 1986-03-27
AU9166182A (en) 1983-08-04
NO156844B (en) 1987-08-24
ES517774A0 (en) 1983-11-16
ATE17928T1 (en) 1986-02-15

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