EP0286095A1 - Inductive energy supply device for electric circuit mounted on a rotative shaft - Google Patents
Inductive energy supply device for electric circuit mounted on a rotative shaft Download PDFInfo
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- EP0286095A1 EP0286095A1 EP88105559A EP88105559A EP0286095A1 EP 0286095 A1 EP0286095 A1 EP 0286095A1 EP 88105559 A EP88105559 A EP 88105559A EP 88105559 A EP88105559 A EP 88105559A EP 0286095 A1 EP0286095 A1 EP 0286095A1
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- 230000001939 inductive effect Effects 0.000 title claims abstract description 6
- 230000005294 ferromagnetic effect Effects 0.000 claims abstract description 7
- 230000010355 oscillation Effects 0.000 claims description 10
- 239000003990 capacitor Substances 0.000 claims description 7
- 238000005259 measurement Methods 0.000 abstract description 6
- 238000004804 winding Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 3
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- 238000011161 development Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 230000005291 magnetic effect Effects 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011089 mechanical engineering Methods 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F38/00—Adaptations of transformers or inductances for specific applications or functions
- H01F38/18—Rotary transformers
Definitions
- the invention relates to a device for inductive energy supply to an electrical circuit arranged on a rotating shaft, in particular a transmitter and an associated measuring point, with a primary coil arranged stationary near the shaft and a secondary coil rotating with the shaft.
- the measured values recorded by the measuring point can be transmitted wirelessly to the stationary display device with the aid of a transmitter arranged on the rotating shaft and a receiver galvanically connected to the stationary display device.
- the transmitter With this type of measured value transmission, the transmitter must also be supplied with energy in addition to the measuring point. This can be done with the help of an accumulator arranged on the shaft.
- an accumulator has the disadvantage that the transmitter and the measuring point can only be supplied with energy for a limited time, depending on the storage capacity of the accumulator, without the interposition of a charging process. This time is very short when using a small and light accumulator.
- the additional large weight of the accumulator has such a negative influence on the mechanical properties of the shaft that the maximum permissible shaft speed must be reduced from a desired value to a significantly lower value .
- measuring systems have also been developed in which the energy for supplying the transmitter and the measuring point on the rotating Shaft is transmitted inductively.
- a torque measuring shaft is known in which the energy supply to the torque measuring point arranged on the rotating part of the measuring shaft takes place with the aid of an electromagnetic transmitter, the annular primary coil of which surrounds the rotating part of the measuring shaft.
- the coil carrier can be rotated thereon stored.
- the disadvantage of measuring on a rotating shaft with the aid of a separate measuring shaft is that the shaft on which measurements are to be carried out must be separated in order to be able to use the separate measuring shaft. This requires a lot of work and costs. Furthermore, the mechanical behavior of the shaft to be checked is changed by inserting the separate measuring shaft. In addition, this known measuring shaft requires a lot of space, which is not available, for example, for measurements on a propeller shaft arranged in the vehicle tunnel.
- the coil carrier of the primary coil is rotatably mounted on the rotating part of the measuring shaft, the rotating part of the measuring shaft and thus also the shaft connected to it, on which the measurements are to be carried out, has no freedom of movement in the axial direction when the primary coil is arranged in a stationary manner and radial direction.
- the secondary coil which rotates with the shaft during operation, consists of two half-shells which each encompass half of the shaft and which, when assembled, have an inside diameter which is slightly smaller than the outside diameter the wave.
- This constructive design means that the two half-shells can be clamped onto the shaft by simply screwing them together.
- the two half-shells have on their outer circumference a radially protruding edge which in operation runs freely in a groove which is formed on the end of a stationary rod-shaped primary coil facing the shaft.
- a U-shaped ferromagnetic coil core is provided for the primary coil, the legs of which are arranged one behind the other in the axial direction of the shaft and aligned with their free ends towards the shaft that the primary coil consists of two on the two legs of the Parts arranged coil core and that the secondary coil is arranged approximately in the middle between the two legs of the coil core on the shaft.
- the arrangement of the two parts of the primary coil in the axial direction of the shaft one behind the other ensures that the magnetic flux generated by the two parts of the primary coil flows through a region that is widely extended in the axial direction of the shaft.
- the arrangement of the secondary coil on the shaft approximately in the middle between the two parts of the primary coil ensures that the secondary coil wound, for example, on the shaft is still flooded by the magnetic flux of the primary coil when the shaft is shifted in the axial direction by an amount which corresponds to approximately half the distance between the two parts of the primary coil. This ensures a large scope for movement of the shaft in the axial direction. In the radial direction, too, there is a large freedom of movement of the shaft compared to the prior art given.
- the primary coil can be arranged anywhere near the circumference of the shaft.
- the secondary coil can be easily attached to the shaft by winding it up. Due to the low weight of the winding of the secondary coil arranged on the shaft, the mechanical properties of the shaft also remain almost unaffected.
- the device according to the invention can be manufactured at only a low cost.
- the primary coil forms a primary-side electrical resonant circuit together with a first capacitor.
- the secondary coil is arranged on a ferromagnetic region of the shaft and forms, with a second capacitor, a secondary-side electrical resonant circuit whose natural vibration frequency corresponds to the natural vibration frequency of the primary-side resonant circuit at a predetermined maximum permissible distance between the leg ends of the U-shaped coil core and the shaft.
- the energy transmitted via the air gap between the U-shaped coil core of the primary coil and the shaft is minimal.
- the natural oscillation frequency of the secondary electrical Resonant circuit with the natural oscillation frequency of the primary-side resonant circuit that is, the secondary-side electrical resonant circuit is excited with the resonance frequency, the absorption of the energy transmitted via the air gap between the primary coil and the shaft is maximum. If the shaft is now deflected radially in the direction of the primary coil, the distance between the leg ends of the U-shaped coil core and the shaft decreases. On the one hand, this increases the energy transmitted through the air gap between the primary coil and the shaft.
- the reduction in the distance between the primary coil and the shaft reduces the energy absorbed by the secondary coil.
- This increase in the inductance of the primary coil of the primary-side electrical oscillating circuit causes its natural oscillation frequency to decrease.
- the secondary-side electrical resonant circuit is now no longer excited with its natural oscillation frequency, but rather with the lower natural oscillation frequency of the primary-side electrical resonant circuit.
- the energy absorbed by the secondary-side electrical oscillating circuit becomes smaller as the natural oscillation frequency of the primary-side electrical oscillating circuit deviates from the natural oscillation frequency of the secondary-side electrical oscillating circuit, the proportion of the energy transmitted via the air gap absorbed by the secondary-side electrical oscillating circuit decreases. Due to the fact that these two opposing effects almost completely compensate each other, the amplitude of the voltage induced in the secondary coil remains largely constant with a radial deflection of the shaft within the predetermined limits. By supplying the rotating shaft Arranged electrical circuit with a voltage with an almost constant voltage amplitude ensures reliable operation of the electrical circuit.
- the device shown in FIG. 1 essentially consists of a primary-side electrical oscillating circuit 12 arranged stationary near the shaft 10 and a secondary-side electrical oscillating circuit 14 arranged on the shaft.
- the primary-side electrical oscillating circuit 12 comprises a primary coil consisting of the two parts 16 and 18 20 and a first capacitor 22, the electrodes of which are connected to the winding ends 24 and 26 of the primary coil 20.
- the two parts 16 and 18 of the primary coil 20 are arranged on the two legs 28 and 30 of a U-shaped ferromagnetic coil core 32. This is assigned to the shaft 10 such that its legs 28 and 30 lie one behind the other in the axial direction of the shaft 10 and that the free ends 34 and 36 of the legs 28 and 30 are aligned with the shaft 10.
- FIG. 2 is only intended to illustrate the geometric relationships between the coil core 32 of the primary coil 20 (FIG. 1) and the shaft 10. It can be seen that the device according to the invention, the most space-intensive part of which is the U-shaped coil core 32, requires very little space compared to the shaft. Another advantage of the device according to the invention is that the primary coil can be arranged at any point around the circumference of the shaft 10. The device according to the invention is therefore particularly suitable for inductive energy supply to an electrical circuit arranged on a cardan shaft rotating in the narrow vehicle tunnel, for example a transmitter and an associated torque measuring bridge.
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Abstract
Description
Die Erfindung betrifft eine Einrichtung zur induktiven Energieversorgung einer auf einer rotierenden Welle angeordneten elektrischen Schaltung, insbesondere eines Senders und einer dazugehörigen Meßstelle, mit einer nahe der Welle stationär angeordneten Primärspule und einer mit der Welle rotierenden Sekundärspule.The invention relates to a device for inductive energy supply to an electrical circuit arranged on a rotating shaft, in particular a transmitter and an associated measuring point, with a primary coil arranged stationary near the shaft and a secondary coil rotating with the shaft.
Im Maschinenbau müssen häufig Messungen an rotierenden Wellen vorgenommen werden. Dazu ist es erforderlich, daß die von einer auf einer rotierenden Welle angeordneten Meßstelle aufgenommenen Meßwerte zu einer stationären Anzeigevorrichtung übertragen werden. Ferner ist bei derartigen Messungen meist erforderlich, die Meßstelle, beispielsweise eine Brückenschaltung mit Dehnungsmeßstreifen zur Drehmomentmessung mit elektrischer Energie zu versorgen. Sowohl zur Übertragung der von der Meßstelle aufgenommenen Meßwerte von der mit der Welle rotierenden Meßstelle zur stationären Anzeigevorrichtung als auch zur Übertragung der elektrischen Energie zur Versorgung der Meßstelle werden häufig Schleifring-Übertrager verwendet. Sie unterliegen jedoch einem hohen Verschleiß, sind empfindlich gegenüber Umwelteinflüssen, benötigen viel Platz, haben ein hohes Gewicht und sind nur mit hohem Arbeits- und Kostenaufwand an der Welle anzubringen.In mechanical engineering, measurements often have to be made on rotating shafts. For this purpose it is necessary that the measured values recorded by a measuring point arranged on a rotating shaft are transmitted to a stationary display device. Furthermore, in such measurements it is usually necessary to supply the measuring point, for example a bridge circuit with strain gauges, for measuring torque with electrical energy. Slip ring transmitters are often used both for transmitting the measured values recorded by the measuring point from the measuring point rotating with the shaft to the stationary display device and for transmitting the electrical energy for supplying the measuring point. However, they are subject to high wear, are sensitive to environmental influences, require a lot of space, are heavy and can only be attached to the shaft with great effort and expense.
Ferner kann die Übertragung der von der Meßstelle aufgenommenen Meßwerte zur stationär angeordneten Anzeigevorrichtung auf drahtlosem Wege mit Hilfe eines auf der rotierenden Welle angeordneten Senders und eines mit der stationären Anzeigevorrichtung galvanisch verbundenen Empfängers erfolgen. Bei dieser Art der Meßwertübertragung muß neben der Meßstelle auch noch der Sender mit Energie versorgt werden. Dies kann mit Hilfe eines auf der Welle angeordneten Akkumulators erfolgen. Die Verwendung eines Akkumulators hat jedoch den Nachteil, daß der Sender und die Meßstelle entsprechend der Speicherkapazität des Akkumulators ohne Zwischenschaltung eines Ladevorgangs nur eine begrenzte Zeit mit Energie versorgt werden können. Bei Verwendung eines kleinen und leichten Akkumulators ist diese Zeit sehr kurz. Verwendet man dagegen einen größeren und damit auch schwereren Akkumulator mit einer größeren Speicherkapazität, so werden durch das zusätzliche große Gewicht des Akkumulators die mechanischen Eigenschaften der Welle derart negativ beeinflußt, daß eine Reduzierung der höchstzulässigen Wellendrehzahl von einem gewünschten Wert auf einen deutlich niedrigeren Wert erfolgen muß.Furthermore, the measured values recorded by the measuring point can be transmitted wirelessly to the stationary display device with the aid of a transmitter arranged on the rotating shaft and a receiver galvanically connected to the stationary display device. With this type of measured value transmission, the transmitter must also be supplied with energy in addition to the measuring point. This can be done with the help of an accumulator arranged on the shaft. However, the use of an accumulator has the disadvantage that the transmitter and the measuring point can only be supplied with energy for a limited time, depending on the storage capacity of the accumulator, without the interposition of a charging process. This time is very short when using a small and light accumulator. If, on the other hand, a larger and thus also heavier accumulator with a larger storage capacity is used, the additional large weight of the accumulator has such a negative influence on the mechanical properties of the shaft that the maximum permissible shaft speed must be reduced from a desired value to a significantly lower value .
Da die Verwendung eines Akkumulators zur Energieversorgung des Senders und der Meßstelle auf der Welle immer einen Kompromiß zwischen Größe und Gewicht des Akkumulators einerseits und seiner Betriebszeit andererseits darstellt, wurden auch Meßsysteme entwickelt, bei denen die Energie zur Versorgung des Senders und der Meßstelle auf der rotierende Welle auf induktivem Wege übertragen wird. So ist beispielsweise eine Drehmoment-Meßwelle bekannt, bei der die Energieversorgung der auf dem rotierenden Teil der Meßwelle angeordneten Drehmoment-Meßstelle mit Hilfe eines elektromagnetischen Übertragers erfolgt, dessen ringförmige Primärspule den rotierenden Teil der Meßwelle umgreift. Zur Zentrierung der ringförmigen Primärspule auf dem rotierenden Teil der Meßwelle ist der Spulenträger auf diesem drehbar gelagert. Der Nachteil der Messung an einer rotierenden Welle mit Hilfe einer separaten Meßwelle liegt darin, daß die Welle, an der Messungen vorgenommen werden sollen, aufgetrennt werden muß, um die separate Meßwelle einsetzen zu können. Dies erfordert nämlich einen hohen Arbeits- und Kostenaufwand. Ferner wird durch das Einfügen der separaten Meßwelle das mechaniche Verhalten der zu überprüfenden Welle verändert. Darüber hinaus benötigt diese bekannte Meßwelle viel Platz, der beispielsweise bei Messungen an einer im Fahrzeugtunnel angeordneten Gelenkwelle nicht vorhanden ist. Da bei der bekannten Einrichtung der Spulenträger der Primärspule auf dem rotierenden Teil der Meßwelle drehbar gelagert ist, hat der rotierende Teil der Meßwelle und somit auch die mit diesem verbundene Welle, an der die Messungen vorgenommen werden sollen, bei stationär angeordneter Primärspule keinerlei Bewegungsspielraum in axialer und radialer Richtung.Since the use of an accumulator for the energy supply of the transmitter and the measuring point on the shaft always represents a compromise between the size and weight of the accumulator on the one hand and its operating time on the other hand, measuring systems have also been developed in which the energy for supplying the transmitter and the measuring point on the rotating Shaft is transmitted inductively. For example, a torque measuring shaft is known in which the energy supply to the torque measuring point arranged on the rotating part of the measuring shaft takes place with the aid of an electromagnetic transmitter, the annular primary coil of which surrounds the rotating part of the measuring shaft. To center the ring-shaped primary coil on the rotating part of the measuring shaft, the coil carrier can be rotated thereon stored. The disadvantage of measuring on a rotating shaft with the aid of a separate measuring shaft is that the shaft on which measurements are to be carried out must be separated in order to be able to use the separate measuring shaft. This requires a lot of work and costs. Furthermore, the mechanical behavior of the shaft to be checked is changed by inserting the separate measuring shaft. In addition, this known measuring shaft requires a lot of space, which is not available, for example, for measurements on a propeller shaft arranged in the vehicle tunnel. Since in the known device the coil carrier of the primary coil is rotatably mounted on the rotating part of the measuring shaft, the rotating part of the measuring shaft and thus also the shaft connected to it, on which the measurements are to be carried out, has no freedom of movement in the axial direction when the primary coil is arranged in a stationary manner and radial direction.
Bei einer weiteren bekannten Einrichtung zur induktiven Energieversorgung einer auf einer rotierenden Welle angeordneten elektrischen Schaltung besteht die mit der Welle im Betrieb mitrotierende Senkundärspule aus zwei die Welle jeweils zur Hälfte umgreifenden Halbschalen, die im zusammengefügten Zustand einen Innendurchmesser haben, der geringfügig kleiner ist als der Außendurchmesser der Welle. Durch diese kontruktive Gestaltung wird bewirkt, daß die beiden Halbschalen durch einfaches Zusammenschrauben auf der Welle festgeklemmt werden können. Die beiden Halbschalen weisen an ihrem äußeren Umfang einen radial abstehenden Rand auf, der im Betrieb in einer Nut frei läuft, die an dem der Welle zugewandten Ende einer stationär angeordneten stabförmigen Primärspule ausgebildet ist. Dadurch, daß der radial überstehende Rand der mit der Welle rotierenden Sekundärspule nur einen sehr geringen Bewegungsspielraum in der Nut der stationär angeordneten Primärspule hat, ist auch bei dieser Einrichtung die Bewegungsfreiheit der rotierenden Welle sowohl in axialer Richtung als auch in radialer Richtung sehr gering. Darüber hinaus benötigt die in radialer Richtung der Welle ausgerichtete stabförmige Primärspule viel Platz.In a further known device for inductive energy supply of an electrical circuit arranged on a rotating shaft, the secondary coil, which rotates with the shaft during operation, consists of two half-shells which each encompass half of the shaft and which, when assembled, have an inside diameter which is slightly smaller than the outside diameter the wave. This constructive design means that the two half-shells can be clamped onto the shaft by simply screwing them together. The two half-shells have on their outer circumference a radially protruding edge which in operation runs freely in a groove which is formed on the end of a stationary rod-shaped primary coil facing the shaft. The fact that the radially projecting edge of the secondary coil rotating with the shaft has only very little freedom of movement in the groove of the stationary primary coil means that the freedom of movement of the rotating coil is also provided in this device Shaft very low both in the axial direction and in the radial direction. In addition, the rod-shaped primary coil aligned in the radial direction of the shaft requires a lot of space.
Es ist daher Aufgabe der Erfindung, eine Einrichtung der eingangs genannten Art anzugeben, die nur einen geringen Platzbedarf hat und darüber hinaus im Vergleich zu den bekannten Einrichtungen eine deutlich größere Bewegungsfreiheit der Welle sowohl in axialer als auch in radialer Richtung zuläßt.It is therefore an object of the invention to provide a device of the type mentioned at the outset which requires only a small amount of space and moreover allows a significantly greater freedom of movement of the shaft in both the axial and radial directions compared to the known devices.
Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß für die Primärspule ein U-förmiger ferromagnetischer Spulenkern vorgesehen ist, dessen Schenkel in axialer Richtung der Welle hintereinander angeordnet und mit ihren freien Enden zur Welle hin ausgerichtet sind, daß die Primärspule aus zwei auf den beiden Schenkeln des Spulenkerns angeordneten Teilen besteht und daß die Sekundärspule etwa in der Mitte zwischen den beiden Schenkeln des Spulenkerns auf der Welle angeordnet ist.This object is achieved in that a U-shaped ferromagnetic coil core is provided for the primary coil, the legs of which are arranged one behind the other in the axial direction of the shaft and aligned with their free ends towards the shaft that the primary coil consists of two on the two legs of the Parts arranged coil core and that the secondary coil is arranged approximately in the middle between the two legs of the coil core on the shaft.
Durch die Anordnung der beiden Teile der Primärspule in axialer Richtung der Welle hintereinander ist gewährleistet, daß der durch die beiden Teile der Primärspule erzeugte Magnetfluß einen in axialer Richtung der Welle weit ausgedehnten Bereich durchflutet. Durch die Anordnung der Sekundärspule auf der Welle etwa in der Mitte zwischen den beiden Teilen der Primärspule wird erreicht, daß die beispielsweise auf der Welle aufgewickelte Sekundärspule auch dann noch vom magnetischen Fluß der Primärspule durchflutet wird, wenn die Welle in axialer Richtung um einen Betrag verschoben wird, der etwa dem halben Abstand der beiden Teile der Primärspule entspricht. Es ist dadurch ein großer Bewegungsspielraum der Welle in axialer Richtung gewährleistet. Auch in radialer Richtung ist ein im Vergleich zum Stand der Technik großer Bewegungsspielraum der Welle gegeben. Er wird lediglich durch den Abstand der Primärspule zur Welle einerseits und durch die gerade noch zulässigen Schwankungen der Amplitude der in der Sekundärwicklung induzierten Spannung andererseits begrenzt. Ein weiterer Vorteil der erfindungsgemäßen Einrichtung liegt darin, daß die Primärspule an beliebiger Stelle in der Nähe des Umfangs der Welle angeordnet werden kann. Ferner ist die Sekundärspule in einfacher Weise durch Aufwickeln auf der Welle anzubringen. Aufgrund des geringen Gewichtes der Wicklung der auf der Welle angeordneten Sekundärspule bleiben ferner die mechanischen Eigenschaften der Welle nahezu unbeeinflußt. Schließlich ist die erfindungsgemäße Einrichtung aufgrund ihres einfachen Aufbaus mit nur geringem Kostenaufwand zu fertigen.The arrangement of the two parts of the primary coil in the axial direction of the shaft one behind the other ensures that the magnetic flux generated by the two parts of the primary coil flows through a region that is widely extended in the axial direction of the shaft. The arrangement of the secondary coil on the shaft approximately in the middle between the two parts of the primary coil ensures that the secondary coil wound, for example, on the shaft is still flooded by the magnetic flux of the primary coil when the shaft is shifted in the axial direction by an amount which corresponds to approximately half the distance between the two parts of the primary coil. This ensures a large scope for movement of the shaft in the axial direction. In the radial direction, too, there is a large freedom of movement of the shaft compared to the prior art given. It is only limited by the distance from the primary coil to the shaft on the one hand and by the just permissible fluctuations in the amplitude of the voltage induced in the secondary winding on the other hand. Another advantage of the device according to the invention is that the primary coil can be arranged anywhere near the circumference of the shaft. Furthermore, the secondary coil can be easily attached to the shaft by winding it up. Due to the low weight of the winding of the secondary coil arranged on the shaft, the mechanical properties of the shaft also remain almost unaffected. Finally, due to its simple construction, the device according to the invention can be manufactured at only a low cost.
Nach einer Weiterbildung der erfindungsgemäßen Einrichtung bildet die Primärspule zusammen mit einem ersten Kondensator einen primärseitigen elektrischen Schwingkreis. Ferner ist die Sekundärspule auf einem ferromagnetischen Bereich der Welle angeordnet und bildet mit einem zweiten Kondensator einen sekundärseitigen elektrischen Schwingkreis, dessen Eigenschwingfrequenz bei einem vorgegebenen maximal zulässigen Abstand zwischen den Schenkelenden des U-förmigen Spulenkerns und der Welle mit der Eigenschwingfrequenz des primärseitigen Schwingkreises übereinstimmt. Durch diese Weiterbildung der Erfindung, wird wie im folgenden näher erläutert wird, erreicht, daß bei einer radialen Auslenkung der Welle in Richtung zur Primärspule hin als auch von dieser weg nahezu keine Änderung der Amplitude der in der Sekundärspule induzierten Spannung auftritt. Beim maximal zulässigen Abstand zwischen der Primärspule und der Welle ist die über den Luftspalt zwischen dem U-förmigen Spulenkern der Primärspule und der Welle übertragene Energie minimal. Da andererseits bei diesem maximal zulässigen Abstand zwischen der Primärspule und der Welle die Eigenschwingfrequenz des sekundärseitigen elektrischen Schwingkreises mit der Eigenschwingfrequenz des primärseitigen Schwingkreises übereinstimmt, der sekundärseitige elektrische Schwingkreis also mit der Resonanzfrequenz angeregt wird, ist die Aufnahme der über den Luftspalt zwischen der Primärspule und der Welle übertragenen Energie maximal. Wird nun die Welle radial in Richtung zur Primärspule hin ausgelenkt, so nimmt der Abstand zwischen den Schenkelenden des U-förmigen Spulenkerns und der Welle ab. Dadurch nimmt einerseits die über den Luftspalt zwischen der Primärspule und der Welle übertragene Energie zu. Andererseits nimmt durch die Abstandsverringerung zwischen der Primärspule und der Welle die von der Sekundärspule aufgenommene Energie ab. Dies ist darauf zurückzuführen, daß durch die Annäherung des ferromagnetischen Bereichs der Welle an die Schenkelenden des U-förmigen Spulenkerns der Primärspule die Induktivität der Primärspule zunimmt. Diese Zunahme der Induktivität der Primärspule des primärseitigen elektrischen Schwingkreises bewirkt, daß dessen Eigenschwingfrequenz abnimmt. Der sekundärseitige elektrische Schwingkreis wird nun nicht mehr mit seiner Eigenschwingfrequenz angeregt, sondern mit der nun gegenüber dieser kleineren Eigenschwingfrequenz des primärseitigen elektrischen Schwingkreises. Da die vom sekundärseitigen elektrischen Schwingkreis aufgenommene Energie mit zunehmender Abweichung der Eigenschwingfrequenz des primärseitigen elektrischen Schwingkreises von der Eigenschwingfrequenz des sekundärseitigen elektrischen Schwingkreises kleiner wird, nimmt der vom sekundärseitigen elektrischen Schwingkreis aufgenommene Anteil der über den Luftspalt übertragenen Energie ab. Aufgrund der Tatsache, daß sich diese beiden gegensinnig auswirkenden Effekte nahezu vollständig kompensieren, bleibt die Amplitude der in der Sekundärspule induzierten Spannung bei einer radialen Auslenkung der Welle innerhalb der vorgegebenen Grenzen weitgehend konstant. Durch die Versorgung der auf der rotierenden Welle angeordneten elektrischen Schaltung mit einer Spannung mit nahezu gleichbleibender Spannungsamplitude ist ein funktionssicherer Betrieb der elektrischen Schaltung gewährleistet.According to a development of the device according to the invention, the primary coil forms a primary-side electrical resonant circuit together with a first capacitor. Furthermore, the secondary coil is arranged on a ferromagnetic region of the shaft and forms, with a second capacitor, a secondary-side electrical resonant circuit whose natural vibration frequency corresponds to the natural vibration frequency of the primary-side resonant circuit at a predetermined maximum permissible distance between the leg ends of the U-shaped coil core and the shaft. As a result of this development of the invention, as will be explained in more detail below, there is almost no change in the amplitude of the voltage induced in the secondary coil when the shaft is radially deflected towards or away from the primary coil. At the maximum permissible distance between the primary coil and the shaft, the energy transmitted via the air gap between the U-shaped coil core of the primary coil and the shaft is minimal. On the other hand, at this maximum permissible distance between the primary coil and the shaft, the natural oscillation frequency of the secondary electrical Resonant circuit with the natural oscillation frequency of the primary-side resonant circuit, that is, the secondary-side electrical resonant circuit is excited with the resonance frequency, the absorption of the energy transmitted via the air gap between the primary coil and the shaft is maximum. If the shaft is now deflected radially in the direction of the primary coil, the distance between the leg ends of the U-shaped coil core and the shaft decreases. On the one hand, this increases the energy transmitted through the air gap between the primary coil and the shaft. On the other hand, the reduction in the distance between the primary coil and the shaft reduces the energy absorbed by the secondary coil. This is due to the fact that the inductance of the primary coil increases as the ferromagnetic region of the shaft approaches the leg ends of the U-shaped coil core of the primary coil. This increase in the inductance of the primary coil of the primary-side electrical oscillating circuit causes its natural oscillation frequency to decrease. The secondary-side electrical resonant circuit is now no longer excited with its natural oscillation frequency, but rather with the lower natural oscillation frequency of the primary-side electrical resonant circuit. Since the energy absorbed by the secondary-side electrical oscillating circuit becomes smaller as the natural oscillation frequency of the primary-side electrical oscillating circuit deviates from the natural oscillation frequency of the secondary-side electrical oscillating circuit, the proportion of the energy transmitted via the air gap absorbed by the secondary-side electrical oscillating circuit decreases. Due to the fact that these two opposing effects almost completely compensate each other, the amplitude of the voltage induced in the secondary coil remains largely constant with a radial deflection of the shaft within the predetermined limits. By supplying the rotating shaft Arranged electrical circuit with a voltage with an almost constant voltage amplitude ensures reliable operation of the electrical circuit.
Im folgenden wird ein Ausführungsbeispiel der Erfindung anhand der Figuren erläutert.An exemplary embodiment of the invention is explained below with reference to the figures.
Es zeigen:
- Fig. 1 einen Wellenabschnitt, an dem eine Einrichtung nach der Erfindung angeordnet ist und
- Fig. 2 die in Fig. 1 dargestellte Welle zusammen mit dem Spulenkern der in Fig. 1 gezeigten Primärspule aus Blickrichtung A
- Fig. 1 shows a shaft section on which a device according to the invention is arranged and
- Fig. 2 shows the shaft shown in Fig. 1 together with the coil core of the primary coil shown in Fig. 1 from viewing direction A.
Die in Fig. 1 gezeigte Einrichtung besteht im wesentlichen aus einem nahe der Welle 10 stationär angeordneten primärseitigen elektrischen Schwingkreis 12 und einem auf der Welle angeordneten sekundärseitigen elektrischen Schwingkreis 14. Der primärseitige elektrische Schwingkreis 12 umfaßt dabei eine aus den beiden Teilen 16 und 18 bestehende Primärspule 20 und einen ersten Kondensator 22, dessen Elektroden mit den Wicklungsenden 24 und 26 der Primärspule 20 verbunden sind. Die beiden Teile 16 und 18 der Primärspule 20 sind auf den beiden Schenkeln 28 und 30 eines U-förmigen ferromagnetischen Spulenkerns 32 angeordnet. Dieser ist der Welle 10 derart zugeordnet, daß seine Schenkel 28 und 30 in axialer Richtung der Welle 10 hintereinander liegen und daß die freien Enden 34 und 36 der Schenkel 28 und 30 zur Welle 10 hin ausgerichtet sind.The device shown in FIG. 1 essentially consists of a primary-side electrical oscillating
Der sekundärseitige elektrische Schwingkreis 14 umfaßt eine Sekundärspule 38 deren Wicklungsenden 40 und 42 mit den Elektroden 44 und 46 eines zweiten Kondensators 48 verbunden sind. Die Sekundärspule 38 ist etwa in der Mitte zwischen den beiden Schenkeln 28, 30 des Spulenkerns 32 auf die Welle 10 aufgewickelt. Sie wird zur Fixierung lediglich mit einem Gießharz vergossen.The secondary-side
Die beiden elektrischen Schwingkreise 12 und 14 sind durch die Dimensionierung ihrer Kondensatoren 22 und 48 derart aufeinander abgestimmt, daß ihre Eigenschwingfrequenzen bei einem vorgegebenen, maximal zulässigen Abstand zwischen den Schenkelenden 34 und 36 des U-förmigen Spulenkerns 32 und der Welle 10 übereinstimmen. Dadurch wird, wie in der Beschreibungseinleitung bereits ausführlich erläutert ist, erreicht, daß die Amplitude der in der Sekundärspule 38 induzierten Spannung bei radialer Auslenkung der Welle 10 in Richtung zur Primärspule 20 hin bzw. von dieser weg unabhängig vom Abstand der Schenkelenden 34 und 36 des Spulenkerns 32 der Primärspule 20 von der Welle 10 weitgehend konstant bleibt.The dimensions of their
Mit Fig. 2 sollen lediglich die geometrischen Verhältnisse zwischen dem Spulenkern 32 der Primärspule 20 (Fig. 1) und der Welle 10 verdeutlicht werden. Es ist zu erkennen, daß die erfindungsgemäße Einrichtung, deren platzintensivstes Teil der U-förmige Spulenkern 32 ist, im Vergleich zur Welle nur sehr wenig Platz benötigt. Ein weiterer Vorteil der erfindungsgemäßen Einrichtung liegt darin, daß die Primärspule an jeder beliebigen Stelle rund um den Umfang der Welle 10 angeordnet werden kann. Die erfindungsgemäße Einrichtung eignet sich deshalb besonders zur induktiven Energieversorgung einer auf einer im engen Fahrzeugtunnel rotierenden Gelenkwelle angeordneten elektrischen Schaltung, beispielsweise eines Senders und einer dazugehörigen Drehmomentmeßbrücke.2 is only intended to illustrate the geometric relationships between the
Claims (2)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19873711691 DE3711691A1 (en) | 1987-04-07 | 1987-04-07 | DEVICE FOR INDUCTIVE POWER SUPPLY OF AN ELECTRICAL CIRCUIT ARRANGED ON A ROTATING SHAFT |
| DE3711691 | 1987-04-07 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0286095A1 true EP0286095A1 (en) | 1988-10-12 |
| EP0286095B1 EP0286095B1 (en) | 1992-06-10 |
Family
ID=6325042
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP19880105559 Expired - Lifetime EP0286095B1 (en) | 1987-04-07 | 1988-04-07 | Inductive energy supply device for electric circuit mounted on a rotative shaft |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0286095B1 (en) |
| DE (2) | DE3711691A1 (en) |
| ES (1) | ES2033357T3 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7256505B2 (en) * | 2003-03-05 | 2007-08-14 | Microstrain, Inc. | Shaft mounted energy harvesting for wireless sensor operation and data transmission |
| US7361998B2 (en) * | 2002-03-07 | 2008-04-22 | Microstrain, Inc. | Energy harvesting for wireless sensor operation and data transmission |
| CN107680782A (en) * | 2017-08-16 | 2018-02-09 | 上海交通大学 | Inductive power supply coil device based on metal rotating shaft |
| WO2019040031A3 (en) * | 2017-06-08 | 2019-05-16 | Ti̇rsan Kardan Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇ | A mechanical embodiment providing continuous wireless power transmission on cardan shaft |
| US11431233B2 (en) | 2019-09-27 | 2022-08-30 | Rockwell Automation Technologies, Inc. | System and method for wireless power transfer to a rotating member in a motor |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4019241A1 (en) * | 1990-06-15 | 1991-12-19 | Telefunken Electronic Gmbh | ENERGY AND SIGNAL TRANSMISSION SYSTEM |
| DE4323091A1 (en) * | 1993-07-10 | 1995-01-12 | Heidelberger Druckmasch Ag | Arrangement for monitoring the position of a web edge on a web transporting drum |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1565536A (en) * | 1967-03-09 | 1969-05-02 | ||
| GB1154261A (en) * | 1966-12-01 | 1969-06-04 | Maihak Ag | Apparatus for Inductively Transmitting Electric Power to an Electrical Device secured to a Rotatable or Oscillatable Shaft |
| US4395647A (en) * | 1980-11-03 | 1983-07-26 | Analog Devices, Incorporated | Half-wave signal isolator with means for controlling flux in the coupling transformer |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3387606A (en) * | 1962-03-12 | 1968-06-11 | Robertshaw Controls Co | Inductive signal transfer device, useful for aviators' helmets |
| GB1510126A (en) * | 1974-10-08 | 1978-05-10 | Loughborough Consult Ltd | Measurement of torsional strain in a rotating shaft |
| US4096535A (en) * | 1976-02-25 | 1978-06-20 | International Business Machines Corporation | Rotary transformer with unique physical and electrical characteristics |
| US4232922A (en) * | 1979-07-03 | 1980-11-11 | Teass Jr Horace A | Signal power coupling to rotary shaft |
-
1987
- 1987-04-07 DE DE19873711691 patent/DE3711691A1/en not_active Withdrawn
-
1988
- 1988-04-07 EP EP19880105559 patent/EP0286095B1/en not_active Expired - Lifetime
- 1988-04-07 ES ES198888105559T patent/ES2033357T3/en not_active Expired - Lifetime
- 1988-04-07 DE DE8888105559T patent/DE3871842D1/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1154261A (en) * | 1966-12-01 | 1969-06-04 | Maihak Ag | Apparatus for Inductively Transmitting Electric Power to an Electrical Device secured to a Rotatable or Oscillatable Shaft |
| FR1565536A (en) * | 1967-03-09 | 1969-05-02 | ||
| US4395647A (en) * | 1980-11-03 | 1983-07-26 | Analog Devices, Incorporated | Half-wave signal isolator with means for controlling flux in the coupling transformer |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7361998B2 (en) * | 2002-03-07 | 2008-04-22 | Microstrain, Inc. | Energy harvesting for wireless sensor operation and data transmission |
| US7256505B2 (en) * | 2003-03-05 | 2007-08-14 | Microstrain, Inc. | Shaft mounted energy harvesting for wireless sensor operation and data transmission |
| US8011255B2 (en) | 2003-03-05 | 2011-09-06 | Microstrain, Inc. | Shaft mounted energy harvesting for wireless sensor operation and data transmission |
| WO2019040031A3 (en) * | 2017-06-08 | 2019-05-16 | Ti̇rsan Kardan Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇ | A mechanical embodiment providing continuous wireless power transmission on cardan shaft |
| RU2729412C1 (en) * | 2017-06-08 | 2020-08-06 | Тирсан Кардан Санайи Ве Тикарет Аноним Сиркети | Mechanical device providing continuous wireless transmission of electric power to cardan shaft |
| CN107680782A (en) * | 2017-08-16 | 2018-02-09 | 上海交通大学 | Inductive power supply coil device based on metal rotating shaft |
| US11431233B2 (en) | 2019-09-27 | 2022-08-30 | Rockwell Automation Technologies, Inc. | System and method for wireless power transfer to a rotating member in a motor |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3871842D1 (en) | 1992-07-16 |
| DE3711691A1 (en) | 1988-10-27 |
| EP0286095B1 (en) | 1992-06-10 |
| ES2033357T3 (en) | 1993-03-16 |
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