DE102017118301A1 - DEVICE AND METHOD FOR WIRELESS POWER SUPPLY - Google Patents

Abstract

The invention relates to a device (100) and a method (200) for the wireless power supply of at least one sensor unit (107), wherein the sensor unit (107) is fixedly connected to a mobile unit of a machine. The device (100) has at least one primary unit (101), wherein the primary unit (101) is arranged at a distance from the movable unit. The device also has at least two secondary units (102), wherein the at least two secondary units (102) are fixedly connected to the movable unit and wherein the secondary units (102) are connected in parallel, wherein an electrical energy for powering the at least one sensor unit (107 ) and the secondary units (102) are wirelessly transferable from the primary unit (101) and wherein the amount of electrical energy due to the arrangement of the secondary units (102) is constant.

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to an apparatus and method for wirelessly powering a sensor unit. The sensor unit is firmly connected to a movable unit of a machine. The machine is used in particular for producing and / or processing a material web, in particular a paper, board or tissue web, and for this purpose has at least one rotating roller as a movable unit.

BACKGROUND OF THE INVENTION

Movable units, for example a rotating roller or a conveyor belt, of a machine have, for example, units, in particular sensor units, in order to be able to monitor the condition of the machine and / or its surroundings. Upon receipt of sufficient energy, this sensor unit communicates its sensed sensor values to a signal processing device in which these sensor values can be further processed and evaluated.

The sensor unit must be powered to acquire and provide sensor data. Due to the movement of the movable unit of the machine, a wired power supply of this sensor unit is often not possible. For example, a roller in a machine may rotate about its longitudinal axis, so that it is difficult to connect sensor units in and / or on the roller to power supply devices located outside the roller.

In the DE 20 2012 012 490 U1 a wireless communication between a sensor unit and an evaluation unit is described. In this case, a signal processing device has a not attached to the roller primary signal processing unit and a non-rotatably mounted on the roller, wirelessly communicating with the primary signal processing unit secondary signal processing unit. The supply of energy takes place together with the communication link. For this purpose, an antenna on the primary signal processing unit is set up to transmit both data and energy to the sensor unit. The energy and data transmission takes place only when the primary signal processing unit is in sufficient communication range with the secondary signal processing unit, which can be done only a small fraction when considering a rotation of the roller about its longitudinal axis, especially if primary and secondary signal processing unit arranged directly opposite one another are and an inductive coupling is maximum. Thus, the power supply of the sensor unit is not permanent, but occurs only in a small fraction of the operation of the mobile unit of the machine. Since this is insufficient to operate the sensor unit reliably, the sensor is an energy storage, for example in the form of an accumulator. With the help of this energy storage, the sensor unit is supplied with energy. Such energy storage must be recharged in a complex manner and replaced from time to time. In addition, they increase the space requirement of the sensor unit.

In the EP 1 653 207 A2 a sensor unit is described, which is attached to a rotating roller. The sensor unit can be supplied with power wirelessly, with each revolution a primary unit transfers energy to a secondary unit. This arrangement of primary unit and secondary unit prevents a continuous reading of the sensor unit and a continuous monitoring of the sensor values. In addition, this type of energy transfer depends on the rotational speed. If the rotational speed is too high, the time window for transmitting the sensor values to a length of time which is insufficient to completely transmit the sensor values is reduced. If the rotational speed is too low, the time between two energy supply periods is too long to make a reliable statement about the condition of the machine.

All conventional wireless power supplies prevent a constant and permanent power supply of the sensor unit, so that no constant monitoring of a parameter in the machine is possible. In addition, these power supplies are limited in time, either because the energy storage is discharged or because the rotational speed does not allow power.

The object of the present invention is to provide a wireless power supply for sensor units in a machine with moving units, with which the sensor unit can be permanently supplied with power from outside a mobile unit of the machine to the evaluation of the sensor values detected in the sensor unit improve.

SUMMARY OF THE INVENTION

This object is achieved with the technical measures described in the independent claims. Advantageous embodiments are described in the respective dependent claims.

In particular, the object is achieved by a device for wireless energy supply solved at least one sensor unit. The sensor unit is firmly connected to a movable unit of a machine. The device has at least one primary unit, wherein the primary unit is arranged at a distance from the movable unit. The device also has at least two secondary units, wherein the at least two secondary units are fixedly connected to the movable unit and wherein the secondary units are electrically connected in parallel, wherein an electrical energy for powering the at least one sensor unit and the secondary units is wirelessly transmitted from the primary unit and wherein the power supply due to the arrangement of the secondary units when moving the movable unit can be done permanently.

The sensor unit is fixedly connected to the movable unit, whereby the above-described problems in the power supply are present. In this case, the sensor unit can be arranged on or in the movable unit of the machine.

In this case, sensor unit, also referred to as detector, sensor or sensor, is understood to be any unit suitable for detecting a physical or chemical quantity. This physical or chemical quantity is for example a quantity of heat, a temperature, a humidity, a pressure or a train, a sound, a brightness, a speed and / or an acceleration. For example, pressure and / or temperature-sensitive sensor units are used to monitor the pressure and / or temperature of a moving part in a machine. Also, moisture sensors, speed or acceleration sensors, etc. may be disposed in / on the moving part of the machine.

These quantities are detected by physical or chemical effects of the sensor unit and converted into a further processable electrical signal to provide this as a sensor signal. The electrical energy required for this purpose is provided by the device according to the invention. The sensor signal can now be continuous, i. be monitored without interruption and without interruption and thus the corresponding parameters are evaluated much more accurate.

For processing and forwarding of electrical signals, such as may originate from the sensors described above, usually transmission device, signal generator or computer units (computer) are used. The computer units may in particular also comprise data memories for storing the measured data. These can be permanently connected to the mobile unit. Such devices should also be understood as part of a broadly understood sensor unit and can be supplied with energy by means of the device according to the invention. In the context of this application, such transmission devices, signal transmitters, computer units or data storage are also to be understood by the term "sensor unit" even if they do not serve or not only the processing of a detected physical or chemical quantity.

The device has at least one primary unit, wherein the primary unit is arranged at a distance from the movable unit. This is understood to mean that the primary unit is not part of the mobile unit of the machine in particular.

The device also has at least two secondary units, wherein the at least two secondary units are fixedly connected to the movable unit and wherein the secondary units are connected in parallel (electrically). An electrical energy is then transmitted wirelessly from the primary unit to the at least two secondary units, wherein the power supply can be permanent due to the arrangement of the secondary units when moving the movable unit.

The electrical energy is thus transmitted by an alternating magnetic field from the primary unit to at least one of the at least two secondary units. In this case, primary and secondary coils may be formed. The alternating magnetic field generated by the primary magnetic coil induces an electric current in the secondary coil.

The primary unit and the at least two secondary units form a transmission of energy according to the transformer principle, wherein the primary unit has a primary coil and each secondary unit has a secondary coil. The energy transfer thus takes place by inductive coupling of primary unit and secondary units. In this way, a power supply for a sensor unit is provided in a machine having a movable unit, which is transmitted to the sensor unit independently of the moving of the movable unit from the primary unit due to the arrangement of the secondary units.

According to the invention it is provided that regardless of a position of the movable unit is always at least one secondary unit to the primary unit electrically, in particular inductively coupled to transmit energy to the sensor unit. In this way, the energy transfer is permanent and independent of a rotational speed from outside the movable unit, so that sensor values of the sensor unit can be permanently provided and continuously evaluated.

In a preferred embodiment is always between a constant number of secondary units, preferably more than two secondary units, and the primary unit electrical energy to power the at least one sensor unit wirelessly transferable. The principle of a series resonance converter is used, which operates in a fully resonant mode. The primary unit is designed to always be coupled to a constant number of secondary units to transfer energy. If this number is greater than 1, a transient of secondary units added by the movement of the movable unit for power transmission and / or swinging action of secondary units omitted by the movement of the movable unit for power transmission can be easily compensated.

In a preferred embodiment, all secondary units are arranged equidistantly and / or axially symmetrically. An equidistant arrangement here means a constant or, within a tolerance range, the same average distance between two adjacent secondary units. Alternatively or additionally, the distance between the secondary units can be selected so that at least one secondary unit is always coupled to the primary unit in the entire path of movement of the movable unit and energy is transferable. The arrangement can also be symmetrical, for example, axisymmetric or mirror-symmetrical. The arrangement of the secondary units takes place in a movement path, for example a movement radius or a movement distance, the movable unit. By such equidistant and / or axisymmetric, so at the same distance aligned arrangement of the secondary units, it can be ensured that always at least one secondary unit is aligned for energy transmission at a minimum distance from the primary unit. This allows a constant flow of energy and thus leads to a constant energy supply.

In a preferred embodiment, there is a greater distance between two of the secondary units than between the remaining secondary units. Within this distance, another component, such as a position detection can be placed.

In a preferred embodiment, the length of the primary unit corresponds to a multiple of the length of a secondary unit. Thus, the length of the secondary unit is only a fraction of the length of the primary unit. The length of the primary unit preferably corresponds to three and a half lengths of a secondary unit. By length is meant, for example, the structural dimension of the energy-effecting elements of the respective unit. Alternatively, the length can also be understood as the distance of the respective unit which is effective for transmitting energy.

This length condition between the primary unit and the secondary unit makes it possible to provide a constant permanent flow of energy even when the movable unit is in motion, regardless of a moving speed. Due to the greater length of the primary unit, the primary unit overlaps with a plurality of secondary units, so that always at least one, preferably three and a half secondary units are inductively coupled to the primary unit.

In a preferred embodiment, the movable unit of the machine exercises a rotation and is in particular a roller or roller unit rotating about a longitudinal axis. The secondary units are arranged radially on one end face of the rotating movable unit. The sensor unit can be arranged at any position inside or outside the movable unit.

In an alternative or additional embodiment, the movable unit of the machine exercises a translation, preferably the movable unit is a conveyor belt and the secondary units are arranged axially along the translational movement direction.

In a preferred embodiment, the primary unit additionally comprises a buck converter and an inverter. In this way, a DC power source can be used as a constant current source, ie as an energy source. The adjustment of the switching frequency of the buck converter can be adapted to load and geometry changes of the transformer consisting of primary unit and secondary units. With geometry change, inter alia, a changed due to the movement of the moving part geometry is taken. Under a load change, for example, the switching on and / or off further sensor units of the mobile unit of the machine to understand.

In a preferred embodiment, each secondary unit is connected to a rectifier and a step-up converter. The step-up converter serves to stabilize the received energy, whereas the rectifier converts the energy transferred as an alternating quantity into a direct variable.

In a preferred embodiment, the at least two secondary units feed the transmitted electrical energy into a common DC link capacitor. This DC link capacitor can thus minimize fluctuations, which arise due to the movement of the mobile unit in the energy transfer due to appropriate buffering (buffers) compensate for the transmitted energy. As a result, the transmitted energy is constant.

In a preferred embodiment, the device has ten or more secondary units. These units are arranged axially or radially, preferably equidistantly and / or axially symmetrically, with a constant fraction of these secondary units being used for permanent energy transfer, irrespective of movement and moving speed of the mobile unit of the machine. Due to the high number of secondary units, the primary unit can be comparatively smaller in size, allowing easy maintenance and installation.

In a preferred embodiment, a power supply is provided to the sensor unit only if this energy provided by the secondary units is within a predefined range of values. This allows, in particular, the swinging in and out of the machine when starting and stopping in order to provide a stable power supply (power supply).

In a preferred embodiment, a distance to be bridged between the primary unit and the secondary units for wireless energy transmission is less than 30 millimeters, preferably less than 15 millimeters. In a basic state of the machine, for example in the cold state before operation of the machine, the distance is for example 12 millimeters.

The object is also achieved by a method for wireless power supply at least one sensor unit. At least the sensor unit and at least two secondary units are fixedly connected to a movable unit of a machine. In addition, a primary unit is arranged at a distance from the movable unit. The method comprises the method steps: inverting a direct current; Applying the alternating direct current to the primary unit; and wirelessly transmitting electrical energy for powering the at least one sensor unit and the secondary units by means of the primary unit, wherein the amount of electrical energy due to the arrangement of the secondary units is constant, for example the power supply due to the arrangement of the secondary units when moving the movable unit can be permanent.

In a preferred embodiment of the method, a constant current source provides the direct current, which is applied by means of a buck converter and an inverter deformed applied to the primary unit and wherein the secondary units rectify the electrical energy and feed it in a common intermediate circuit capacitor.

BRIEF SUMMARY OF THE FIGURES

The invention or further embodiments and advantages of the invention will be explained in more detail with reference to figures, the figures only describe embodiments of the invention. Identical components in the figures are given the same reference numerals. The figures are not to be considered as true to scale, it can be exaggerated large or exaggerated simplified individual elements of the figures.

• 1 ein Ausführungsbeispiel eines Blockschaltbilds einer erfindungsgemäßen Vorrichtung;
• 2 eine Weiterbildung des in 1 gezeigten Blockschaltbilds;
• 3 ein detailliertes Ausführungsbeispiel einer erfindungsgemäßen Vorrichtung;
• 4a ein Ausführungsbeispiel einer Prinzipdarstellung zur Verwendung der erfindungsgemäßen Vorrichtung;
• 4b ein Ausführungsbeispiel zur Verwendung der erfindungsgemäßen Vorrichtung gemäß 4a in einer Maschine mit einer beweglichen Einheit;
• 4c ein alternatives Ausführungsbeispiel zur Verwendung der erfindungsgemäßen Vorrichtung gemäß 4a in einer Maschine mit einer beweglichen Einheit;
• 5a ein Ausführungsbeispiel einer erfindungsgemäßen Anordnung von Sekundäreinheiten;
• 5b ein zu 5a alternatives Ausführungsbeispiel zum erfindungsgemäßen Anordnen von Sekundäreinheiten;
• 6 eine erfindungsgemäße Sekundäreinheit;
• 7 ein Ausführungsbeispiel einer erfindungsgemäßen Primäreinheit;
• 8 ein Ausführungsbeispiel eines Verfahrensablaufdiagramms eines erfindungsgemäßen Verfahrens.

Show it:

• 1 an embodiment of a block diagram of a device according to the invention;
• 2 a further education of in 1 shown block diagram;
• 3 a detailed embodiment of a device according to the invention;
• 4a an embodiment of a schematic diagram of the use of the device according to the invention;
• 4b an embodiment of the use of the device according to the invention according to 4a in a machine with a mobile unit;
• 4c an alternative embodiment of the use of the device according to the invention according to 4a in a machine with a mobile unit;
• 5a an embodiment of an inventive arrangement of secondary units;
• 5b one too 5a alternative embodiment for arranging secondary units according to the invention;
• 6 a secondary unit according to the invention;
• 7 an embodiment of a primary unit according to the invention;
• 8th an embodiment of a process flow diagram of a method according to the invention.

DESCRIPTION OF THE FIGURES

In 1 is an embodiment of a schematic diagram of a device according to the invention 100 to the wireless power supply shown. The device 100 has a primary unit 101 which is set up to wirelessly power at least two secondary units 102 . 102b transferred to. The primary unit 101 is spaced from the secondary units 102 . 102b arranged. The distance d1 For example, is less than 30 millimeters, preferably, the distance is less than 15 millimeters. This distance d1 allows a good inductive coupling between the primary unit 101 and at least one of the two secondary units 102 . 102b and thus represents a secure energy supply.

The device 100 according to 1 works by means of a transformer 104 , which is a primary coil in the primary unit 101 and per secondary unit 102 . 102b has at least one secondary coil.

This device 100 is used to supply a sensor unit (not shown here) in a mobile unit of a machine by means of contactless energy transfer. This device allows 100 an adaptation of the system power to the power actually required, wherein the speed and also the load of the energy transfer is adaptively adaptable. The contactless energy transfer takes place on a comparatively large geometry range. For example, at a front side of a rotating roller as a movable unit, the secondary units 102 . 102b arranged, see also comments on 5a and 5b , The outer diameter of this face is between 500 and 1400 millimeters and is used to transmit the energy permanently to the sensor unit. The mean distance d1 between the primary unit 101 and the secondary units 102 . 102b should be between 5 and 20 mm. In the ground state of the machine, for example, in the cold state, the distance is d1 preferably 12 mm.

2 shows a further education in 1 shown device 100 , This is a buck converter 103 used, which can adjust the energy to be carried on the basis of its switching frequency to a load and / or geometry change to the secondary unit (not shown). The buck converter 103 , also referred to as down-converter or buck converter, operates in lopsided or non-latching operation. On a detailed functional description of a buck converter 103 is omitted here. The output voltage of the buck converter 103 For example, it is supplied to an inverter (not shown). The switching frequency of the inverter can be quickly adjusted depending on load and / or geometry changes. Thus, the desired operating point of the device 100 be set. The AC voltage processed by the inverter is transmitted by the transformer 104 , consisting of primary unit 101 and secondary unit 102 transfer. At the output of each secondary unit 102 is a rectifier (not shown) arranged to convert the transmitted energy in the form of an alternating variable in a DC size. For voltage stabilization is a boost converter 105 the transformer 104 downstream, which stabilizes the energy already received.

In 3 is a detailed embodiment of a device 100 according to the in 1 and 2 shown. Here is the primary unit 101 and a secondary unit 102 shown. Core of the device 100 is the transformer 104 that's from a primary coil L2 and a secondary coil L3 is formed in the middle distance d1 are spaced. The transformer 104 serves the contactless transfer of energy between the primary unit 101 and the secondary units 102 ,

The primary unit 101 has the buck converter 103 and an inverter. The buck converter 103 has a capacitor on the input side C1 on, the two input terminals of the device 100 bridged. To these input terminals, a constant current source (not shown) is connected. A first input terminal is connected to a drain terminal of a switch S1 , here a self-locking n-channel field effect transistor (FET), connected. The type of switch is not limited, in particular other FET types, other channels, other topologies (bipolar) may be used. The Sorucean connection of the switch S1 is with the cathode of a diode D1 connected. The anode of the diode D1 is connected to the second input terminal of the buck converter 103 connected. The source of the switch S1 is also connected to a first connection of an inductance L1 connected. At a second connection of the inductance L1 is a first connection of a capacitor C2 connected. The second connection of the capacitor C2 is connected to the second input terminal of the buck converter 103 connected. The operation of the buck converter 103 will not be explained in detail.

The first connection of the capacitor C2 is also connected to the inverter. The inverter has four switches S2 to S5 , shown here as a normally-off n-channel FET, and a capacitor C3 , The second connection of the capacitor C2 is in each case with the drain connection of the switch S2 and the switch S3 connected. The source of the switch S2 is connected to the drain of the switch S4 connected. The source of the switch S3 is connected to the drain of the switch S5 connected. The source connections of the switches S4 and S5 are connected to the second input terminal of the buck converter 103 connected. The source of the switch S2 is also connected to a first connection of the capacitor C3 connected. A second connection of the capacitor C3 is with a first connection the primary coil L2 of the transformer 104 connected. A second connection of the primary coil L2 of the transformer 104 is in turn connected to the source of the switch S3 connected.

To operate the transformer 104 Accordingly, a power electronic circuit is used. At the primary unit 101 is the buck converter 103 intended. The buck converter on the primary unit 101 is intended to impress a constant current and thus adjust the input voltage of the inverter depending on the load. The switching frequency of this inverter is connected to the respective switching terminals of the switches S2 to S5 created. This switching frequency is adjusted rapidly as a function of load and geometry changes, that is, in particular within a few switching periods. Thus, the operating point of the inverter can be adjusted.

The secondary unit 102 the device 100 is with the distance d1 from the primary unit 101 spaced. Each of the designated secondary units 102 has at least one secondary coil L3 on. A first connection of the secondary coil L3 is with a first connection of a capacitor C4 connected. The second connection of the capacitor C4 and the second terminal of the secondary coil L3 are connected to a rectification circuit. The rectifier circuit can perform a one-way or a two-way rectification to convert the wirelessly transmitted as an exchange size energy in a DC size. According to 3 the rectifier circuit consists of the diodes D2 to D5 which are arranged in a Graetz circuit. An anode of the diode D2 is with the second terminal of the capacitor C4 connected. A cathode of the diode D2 is with a cathode of the diode D3 connected. The anode of the diode D2 is with a cathode of the diode D4 connected. An anode of the diode D4 is with the anode of the diode D5 and with the second terminal of the secondary coil L3 connected. A cathode of the diode D5 is with an anode of the diode D3 connected. The cathode of the diode D3 is with a first connection of a DC link capacitor C5 connected. The anode of the diode D5 is connected to a second connection of the DC link capacitor C5 connected. Thus, at the cathode of the diode D3 and the anode of the diode D5 a constant size. This DC variable is in the DC link capacitor C5 fed. To this DC link capacitor C5 becomes every secondary unit 102 connected. This DC link capacitor C5 is used to get the energy out of each of the secondary units 102 to buffer.

The DC link capacitor C5 is also equipped with a boost converter 105 connected. This is a first connection of the DC link capacitor C5 with a first terminal of an inductance L4 connected. The second connection of the inductance L4 is with an anode of a diode D6 connected. A cathode of the diode D6 is with a first output of the device 100 connected. The second connection of the inductance L4 is also connected to a drain of a switch S6 , shown here as a self-locking n-channel FET connected. The source of the switch S6 is with a second output terminal of the device 100 and the second terminal of the DC link capacitor C5 connected. A capacitor C6 is also connected between the two output terminals of the device.

The device 100 according to 3 prepares the energy to be transmitted in such a way that it has as little loss as possible via the transformer 104 can be transmitted to the sensor unit (not shown). For this purpose, the inverter switching frequency is adapted to the load and geometry conditions and set an ideal operating point for low-loss and permanent energy transfer. The inverter and the buck converter 103 are controlled via a control unit, for example a microcontroller. With the frequency of the inverter whose output current and output voltage is controlled to resonance (phase difference of 0). With the buck converter 103 is the amplitude of the energy to be transmitted (in the form of AC AC voltage) regulated so that the transformer 104 is operated with a constant alternating current. Thus, the output of the primary coil acts L2 as a constant current source. The boost converter 105 on the secondary side is provided to extend the load range.

The several secondary units 102 are connected in parallel behind their rectifiers and all feed the same DC link capacitor C5 , The boost converter 105 then sets the output voltage so that the required output power can be obtained. Dynamically, the load is kept constant, or the output voltage adjusted only slowly, to ensure a stable operating point for the sensor units.

In 4a is a schematic representation of the supply of energy according to the invention shown. The power supply device 100 according to 3 is input side with a DC power source 106 operated. At the output of the power supply device 100 is at least one sensor unit 107 connected. The embodiment of the sensor unit 107 is not limited according to the invention, besides, various sensor units 107 capture a variety of different physical quantities. Preferably, the pressure and / or the temperature is measured at various points of a movable unit of a machine, in particular at different locations in Circumferential direction of a rotating roller and / or at different locations in the axial direction of the roll cover, and / or a conveyor belt.

The 4b shows an embodiment of the use of the device according to the invention according to 4a in a machine with a moving unit 108 , It is a stationary unit 109 a machine with the DC power source 106 and the primary unit 101 fitted. The stationary unit 109 is not part of the mobile unit 108 , As a mobile unit 108 Here, for example, a roller rotating about a longitudinal axis is shown in a papermaking machine. On or on or within the rotating roller 108 is a sensor unit 107 arranged. This sensor unit 107 For example, it is stuck with the roller 108 connected. To this sensor unit 107 supplying energy is the sensor unit 107 electrically with the secondary unit 102 connected. The according to 4b illustrated secondary unit 102 includes, for example, ten secondary units 102 to 102j , For energy transfer between the primary unit 101 and the secondary units 102 becomes an inductive coupling of the primary coil L1 and the secondary coil L2 every secondary unit 102 used as per 3 is shown.

For rollers 108 , z. As in the press section or in the calender, in web-processing machines, the temperature during operation can change by several 10 degrees Celsius. This can be done with these rollers 108 , which often have a length of 10 meters or more, lead to length changes of 2 centimeters to 5 centimeters or more. This in turn leads to the secondary coil L3 to voltage changes of several volts. These voltage changes can damage and / or affect the operation of the sensor unit 107 and / or the secondary unit 102 to lead. According to the invention, these geometry fluctuations can be compensated by appropriate buck converter and boost converter drives.

The sensor unit 107 For example, a plurality of fiber optic sensors, such as Bragg gratings, may include a light source and a light receiver. These are in operative connection with one another such that the fiber-optic sensors receive a light input signal generated by the light source and the light receiver is acted upon by the fiber-optic sensors in response thereto by a measuring signal. In this case, the measuring signal can be generated, for example, by each of the sensors emitting a light output signal to the light receiver in response to the light input signal acting on and in dependence on pressure and / or temperature in the region of the respective sensor. With this structure, a cost-effective and reliable system can be provided in a particularly simple manner. In this case, the light source and the light receiver preferably form a subassembly housed in a housing, to which the fiber optic sensors are connected.

For example, an optical waveguide is provided which comprises a plurality of the fiber Bragg gratings, wherein the fiber Bragg gratings of the same optical waveguide have mutually different Bragg wavelengths. By using fiber Bragg gratings with different Bragg wavelengths, the operation of the roller is 108 especially easy because the different sensor units 107 by a broadband light signal, eg. In the IR wavelength range, can be excited. The sensor units 107 can then send back a reflection signal for each of the sensor units 107 at one for this sensor unit 107 characteristic wavelength lies. Thus, the respective sensor signal in a simple manner each sensor unit 107 and consequently the respective location at which the pressure and / or temperature effect has taken place can be assigned.

The sensor unit 107 according to 4b For example, it is designed to detect the pressure and / or temperature in the roll cover acting on the outer circumferential surface of the roll cover. The sensor unit 107 is non-rotatable on the roller 108 attached. For processing the measuring signals and for controlling the sensor unit 107 a signal processing unit (not shown) is provided.

4c indicates one 4b alternative embodiment for using the device according to the invention according to 4a in a machine with a moving unit. Succession only applies to differences 4b received to avoid unnecessary repetition. In contrast to 4b exercise the movable unit 108 The machine no rotational movement, but a translational movement. This is done for example on a conveyor or conveyor belt. To acquire the sensor values from on the moving unit 108 arranged sensor unit 107 becomes the device 100 provided, wherein a plurality of secondary units 102 - 102c arranged axially equidistant to ensure a permanent energy transfer.

5a shows an embodiment of an inventive arrangement of secondary units 102 , In 5a is a circuit board 1021 with eight secondary units 102 to 102h shown. The secondary units 102 to 102h are arranged radially and equidistantly. The secondary units 102 to 102h according to 5a are arranged axisymmetrically. The eight secondary units 102 to 102h be upon rotation of a movable unit about its longitudinal axis, for example the roller 108 of the 4b , also rotated (indicated by the arrow). During the movement, all the secondary units will be successively 102 to 102h at the primary unit 101 , in particular the primary coil L2 according to 3 past. According to the invention, it is provided that regardless of the type of rotational movement (uniform, stepwise, accelerating) and the actual rotational speed always a constant number of secondary units 102 to 102h Inductive with the primary unit 101 is coupled. Here is the board 1021 the secondary units 102 on an end face of the rotating roller 108 arranged.

5b shows an alternative embodiment of an inventive arrangement of secondary units 102 , In 5b is also a circuit board 1021 for arranging the secondary units 102 to 102h shown. Between the secondary unit 102g and the secondary unit 102h is a position detection unit 111 arranged. To enable this arrangement, the distance is 111 between the secondary unit 102h and the secondary unit 102g greater than between the remaining secondary units 102 to 102g , This change in the distance 111 between the secondary units 102 generated with a ripple in the received energy on the secondary side of the transformer 104 , by means of the DC link capacitor C5 according to 3 is compensated and also by means of the boost converter 105 can be corrected.

The secondary unit 102 especially without removal of the moving unit 108 For example, be mounted around the respective axis around. In this way, the secondary side of the transfer 104 for example, realized in two parts, in particular half the circumference. Every secondary unit 102 is on the secondary side, so the front side of the rotating roller 108 distributed. For example, 4 or 5 secondary units are on a semicircular board 1022 arranged. This arrangement is equidistant or at a distance 111 between two of the secondary units 102 , All secondary units 102 are connected in parallel and in each case with the DC link capacitor C5 and the boost converter 105 connected.

In 5b is also an axial arrangement of the secondary units 102 shown. The inside of the board 1021 arranged secondary units 102 are not referenced to the legibility of the 5b not to affect further. Practice the roller 108 as a mobile unit, not only a rotation, but also, or thereafter, a translation, the energy transfer can also take place during the translation. Thus, a constant energy between the primary unit permanently 101 and the secondary unit 102 transferred and the sensor unit 107 improved, regardless of the complexity of the movement and moving direction of the moving unit 108 the machine. The arrangement of secondary units 102 takes place in particular axially symmetric or at least almost axisymmetric, to a constant flow of energy during rotation or translation of the movable part 108 to enable.

In 6 is a circuit board 1022 a secondary unit 102 shown. The secondary unit 102 has a secondary coil 1020 on top, that of the coil L3 of the 3 equivalent. So that the secondary units 102 can be connected in parallel, these are by means of two electrical connections 1023 parallel switchable. Not shown are the diodes D2 to D5 of the rectifier and the capacitor C4 according to 3 that still works on the board 1022 are arranged. A length L _secondarily represents a linear dimension of the secondary unit 102 This length L _secondary forms the effective range of the inductive coupling between the primary unit 101 and this secondary unit 102 from. This length L _secondary is smaller than a length L _{primary of} the primary unit 101 , please refer 7 , In a preferred embodiment, the length L is _primarily equal to 3.5 times the length L _secondary . Each of the secondary units 102 consists of the coil 1020 , a ferrite foil, an RF bridge rectifier D2 to D5 and a capacitor C4 ,

7 shows a board 1011 the primary unit 101 and the primary coil 1010 that of the coil L2 according to 3 equivalent. A length L _primarily represents a linear dimension of the primary unit 101 This length L _primarily forms the effective range of the inductive coupling between the primary unit 101 and this secondary unit 102 from. The length L _{secondary to} the secondary unit 102 is smaller than the length L _{primary of} the primary unit 101 , see also 6 ,

The primary coil L2 the in 3 illustrated transformer 104 the device 100 expands according to 7 only over part of the circumference of the rotating roller 108 as a movable part, so that an assembly and disassembly is very easy. The overlap of the secondary units 102 For example, it is 3.5 times, so always at least three secondary units 102 Inductive with the primary unit 101 are coupled. The contribution of a partially overlapping element is very small, whereby the change in the coupling between primary and secondary side during rotation or translation is greatly minimized.

In 8th is a process flow diagram of a method according to the invention 200 shown. In this case, according to the method step 201 a direct current by means of a constant current source 106 provided. The DC current is determined according to step 202 alternately directed. In addition, the operating point according to step 203 through a buck converter 103 set. This DC current is sent to the primary unit 101 in step 204 created. Subsequently, in step 205 the wireless transmission of energy to at least one of the two secondary units 102 , In the respective secondary unit 102 a rectification by means of a rectifier D2 to D5 and turning on this rectified power signal to an intermediate circuit capacitor C5 according to step 206 for energy caching. Subsequently, by means of boost converter 104 a voltage stabilization in step 207 , In the verification step 208 it is checked whether the energy is sufficiently constant to a sensor unit 107 to provide energy. If this is the case (yes case in 8th ), the supply of the sensor unit takes place 107 with the energy in step 209 , If not (NO case in 8th ), stabilization will take place again.

In the context of the invention, all described and / or drawn and / or claimed elements can be combined with each other as desired.

LIST OF REFERENCE NUMBERS

100

Power supply device

101

primary unit

1010

Coil of the primary unit

1011

Board of the primary unit

102 (a-h)

Secondary unit

1020

Coil of a secondary unit

1021

Carrier of secondary units

1022

Board of a secondary unit

1023

Electrical connection

103

Buck converter

104

exchangers

105

Boost converter

106

DC power source

107

sensor unit

108

Rotating roller unit

109

Stationary part of the machine

110

position sensing

111

Distance between secondary units

201-209

steps

D1-D6

diode

S1-S6

switching element

C1-C6

capacity

L1-L4

inductance

d1

average distance primary unit to at least one secondary unit

l _primary

Length of the primary unit

l _secondary

Length of the secondary unit

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 202012012490 U1 [0004]
• EP 1653207 A2 [0005]

Claims (15)

Device for the wireless power supply of at least one sensor unit (107), wherein the sensor unit (107) is fixedly connected to a mobile unit of a machine, comprising: - At least one primary unit (101), wherein the primary unit (101) spaced from the movable unit is arranged; and - At least two secondary units (102), wherein the at least two secondary units (102) are fixedly connected to the movable unit and wherein the secondary units (102) are electrically connected in parallel; - An electrical energy for powering the at least one sensor unit (107) and the secondary units (102) wirelessly from the primary unit (101) is transferable and - Wherein the power supply due to the arrangement of the secondary units (102) when moving the movable unit can be done permanently. Device after Claim 1 , wherein always between a constant number of secondary units (102), preferably more than two secondary units (102), and the primary unit (101) electrical energy for powering the at least one sensor unit (107) is wirelessly transferable. Device after Claim 1 or 2 , Wherein all secondary units (102) are arranged equidistantly and / or axially symmetrically in the region of the movement path of the movable unit. Device after Claim 1 or 2 , wherein between two of the secondary units (102) is a greater distance than between the other secondary units (102). Device according to one of the preceding claims, wherein the length of the primary unit (101) corresponds to a multiple of the length of a secondary unit (102) and a fraction of the length of a secondary unit (102), preferably three and a half lengths of a secondary unit (102). Apparatus as claimed in any one of the preceding claims, wherein the mobile unit of the machine is rotating, preferably a rotating roller unit (108), and the secondary units (102) are disposed radially on an end face of the rotary mobile unit. Apparatus according to any one of the preceding claims, wherein the movable unit of the machine translates, preferably a conveyor belt, and the secondary units (102) are arranged axially along the translational direction of movement. Device according to one of the preceding claims, wherein the primary unit (101) comprises a buck converter (103) and an inverter. Device according to one of the preceding claims, wherein each secondary unit (102) is connected to a rectifier and a step-up converter (105). Device according to one of the preceding claims, wherein the secondary units (102) feed the transmitted electrical energy into a common link capacitor (C5). Apparatus according to any one of the preceding claims, wherein the apparatus comprises ten or more secondary units (102). Device according to one of the preceding claims, wherein a power supply is provided to the sensor unit (107) only if the energy provided by the secondary units (102) is within a predefined range of values. Device according to one of the preceding claims, wherein a distance to be bridged between the primary unit (101) and the secondary units (102) for wireless energy transmission is less than 30 millimeters, preferably less than 15 millimeters. Method for the wireless energy supply of at least one sensor unit (107), wherein at least two secondary units (102) and the sensor unit (107) are fixedly connected to a mobile unit of a machine and a primary unit (101) is arranged at a distance from the mobile unit, with the steps: - inverting (202) a direct current; - applying (204) the alternating direct current to the primary unit (101); - Wireless transmission (205) of electrical energy for powering the at least one sensor unit (107) and the secondary units (102) of the primary unit (101), wherein the power supply due to the arrangement of the secondary units (102) when moving the movable unit can be done permanently , Method according to Claim 14 wherein a constant current source provides the direct current (201) which is applied to the primary unit (101) by means of a step-down converter (103) and an AC rectifier; and wherein the secondary units (102) rectify the electrical energy and feed it into a common link capacitor (C5) (206).

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