DE102010019738A1 - Passive element for generating flow in mechanically deformable environments - Google Patents

Abstract

Arrangement for converting mechanical energy into electrical energy, the arrangement comprising: a passive element for generating a fluid flow, wherein the passive element is attached to a mechanically deformable environment such that upon mechanical deformation of the environment a mechanical energy is generated which is imparted to the device acting mechanical element and thereby generates a fluid flow at an opening of the passive element; and a piezoelectric energy converter having at least one piezoelectric element, in which a mechanical force caused by the fluid flow can be coupled in such a way that the piezoelectric element is excited to mechanical vibrations and electricity is generated by the piezoelectric effect, which is used for a self-sufficient supply, in particular for decentralized local systems (eg actuators or sensors) can be used. This indirect way of coupling energy from the mechanical ambient energy into the piezoelectric element has the advantage that the fluid flow can be generated in a highly defined manner and does not directly couple a potential mechanical overload in the environment with a suitable design of the passive element to the piezoelectric element. Thus, a defect or destruction is avoided.

Description

The invention relates to an arrangement for converting mechanical energy into electrical energy. Furthermore, the invention relates to a method for converting mechanical energy into electrical energy using a piezoelectric element.

Many new applications require sophisticated sensors and / or actuators. Often this is distributed locally or decentralized, which means that an electrical energy supply is complex and expensive (eg., By laying electrical supplies). In some applications, a physical connection of such decentralized actuator or sensor nodes is completely impossible, so they must be operated completely self-sufficient. Such systems have to provide themselves with electrical energy.

It is known to equip such decentralized sensor or actuator systems with batteries for power supply. However, the battery limits the service life of the system. Such battery operated distributed systems still require a considerable amount of maintenance, as the batteries need to be changed from time to time. If no battery change is possible, such systems will fail.

Furthermore, systems are known which are powered by a solar cell with energy. However, the use of these systems is limited in the field of industrial automation and the associated significantly reduced light budgets.

The object of the present invention is to provide an arrangement and a method for a self-sufficient energy supply for decentralized systems, in particular in an industrial environment.

• – ein passives Element zur Erzeugung eines Fluidstroms, wobei das passive Element dergestalt an einer mechanisch verformbaren Umgebung angebracht ist, dass bei mechanischer Verformung der Umgebung eine mechanische Energie erzeugt wird, die auf passive Element einwirkt und dabei einen Fluidstrom an einer Öffnung des passiven Elements erzeugt; und
• – einen piezoelektrischen Energiewandler mit mindestens einem piezoelektrischen Element, in das eine durch den Fluidstrom hervorgerufene mechanische Kraft derart eingekoppelt werden kann, dass das piezoelektrische Element zu mechanischen Schwingungen angeregt wird. Die beschriebene Art der Umwandlung von mechanischer Energie in elektrische Energie kann überall dort eingesetzt werden, wo ein Fluidstrom auftritt bzw. erzeugt werden kann, beispielsweise in einem Reifen eines Kraftfahrzeugs. Der Fluidstrom wird dabei derart an einem geeignet ausgestalteten piezoelektrischen Element vorbeigeleitet, dass dieses zu mechanischen Schwingungen angeregt wird. Diese mechanischen Schwingungen werden dazu benutzt, elektrische Energie zu gewinnen. Die gewonnene Energie wird einem Verbraucher (z. B. dezentrale Aktoren oder Sensoren) zur Verfügung gestellt. Dies ermöglicht den autarken Betrieb dieser dezentralen Systeme, d. h. ohne Verkabelung oder Batteriebetrieb. Diese Systeme können somit prinzipiell wartungsfrei betrieben werden.

The object is achieved by an arrangement for converting mechanical energy into electrical energy, comprising the arrangement:

• - A passive element for generating a fluid flow, wherein the passive element is attached to a mechanically deformable environment such that upon mechanical deformation of the environment, a mechanical energy is generated, which acts on passive element and thereby generates a fluid flow at an opening of the passive element ; and
• - A piezoelectric energy converter with at least one piezoelectric element, in which a caused by the fluid flow mechanical force can be coupled in such a way that the piezoelectric element is excited to mechanical vibrations. The described type of conversion of mechanical energy into electrical energy can be used wherever a fluid flow occurs or can be generated, for example in a tire of a motor vehicle. The fluid flow is guided past a suitably designed piezoelectric element in such a way that it is excited to mechanical oscillations. These mechanical vibrations are used to generate electrical energy. The energy gained is made available to a consumer (eg decentralized actuators or sensors). This enables the self-sufficient operation of these decentralized systems, ie without cabling or battery operation. These systems can thus be operated in principle maintenance-free.

The arrangement according to the invention can be used in any dynamically deformable environments. For example, in conveyor belts, at the reversal points of the elastic conveyor belt is deformed or in industrial automation (eg robots), where there are many moving parts, the z. B. are protected by mechanically deformable rubber sleeves. But even a tire gossip is usable as a mechanically deformable environment.

These mechanical movements, which are already present in an industrial environment anyway - ie present kinetic energies which are also present in defined and known directions of movement, can be "harvested" by the arrangement according to the invention. The energy converter in the array is thus supplied with kinetic mechanical energy that provides an already existing infrastructure.

The piezoelectric element consists of at least one piezoelectric layer and electrode layers. The electrode layers may consist of a wide variety of metals or metal alloys. Examples of the electrode material are platinum, titanium and a platinum / titanium alloy. Also conceivable are non-metallic, electrically conductive materials. The piezoelectric layer may also consist of different materials. Examples include piezoelectric ceramic materials such as lead zirconate titanate (PZT), zinc oxide (ZnO) and aluminum nitride (AlN). Piezoelectric organic materials such as polyvinylidene difluoride (PVDF) or polytetrafluoroethylene (PTFE) are also conceivable. The piezoelectric layer and the electrode layers may be applied to an optional carrier layer. This increases the stability of the piezoelectric element. Due to the fluid flow, the piezoelectric element is excited to mechanical vibrations. In the case of fluidic shock excitation, the piezoelectric element, for example a piezoelectric flag, experiences a decaying oscillation. On the piezoelectric effect generates a periodic charge separation between the electrodes. The resulting charge flow is then available externally as electrical energy. An electrical connection to the electrodes and a corresponding wiring provide the electrical current for consumers. In order to ensure that the force of the fluid flow can be efficiently coupled into the piezoelectric element, the piezoelectric element is curved, for example, or suitable flow geometries are located on its surface or the flow is as perpendicular as possible to the piezoelectric flag.

The fluid is preferably a gas or gas mixture. Also conceivable is a fluid in the form of a liquid. The liquid is preferably electrically insulating.

A first advantageous embodiment of the invention is that the passive element is formed as a membrane of elastic material which is tightly connected in its entire edge region with the deformable environment. As an elastic material can, for. As rubber can be used. The membrane can, for. B. be tightly connected by gluing or vulcanization with the environment. Such embodiments are easy to produce.

A further advantageous embodiment of the invention is that the membrane is substantially circular. Due to the circular shape, efficiently defined fluid flows can be generated.

A further advantageous embodiment of the invention is that the passive element comprises means for ensuring that the passive element forms a sufficient cavity. This ensures that sufficient fluid flow is generated.

A further advantageous embodiment of the invention is that as a means for securing the cavity of the passive element, a spring connection between the passive element and the mechanically deformable environment is attached, wherein the first end of the spring is mounted substantially centrally on the passive element and starting therefrom in the vertical direction, the second end of the spring is attached to the mechanically deformable environment. This arrangement is easy to produce. Furthermore, it makes sense to design the arrangement so that the spring stiffness of the spring is minimized, followed by the spring stiffness of the membrane. However, both spring stiffnesses should be significantly lower than the spring stiffness of the mechanically deformable environment itself.

A further advantageous embodiment of the invention is that the piezoelectric element has a piezo-flag. The piezoelectric element is designed as a bending element, preferably as a piezo-flag. For this purpose, the bending element is for example a piezoelectric bending transducer. To produce the bending transducer, for example, ceramic green sheets printed with a metallization for the electrode layers are stacked on top of one another and sintered. The result is a monolithic bending transducer. In this case, the bending transducer can be configured arbitrarily, for example bimorph.

A further advantageous embodiment of the invention is that the piezo-flag has a substantially triangular base. This causes a high efficiency in energy conversion.

A further advantageous embodiment of the invention is that the piezoelectric element is formed as a membrane and the fluid flow impinges substantially perpendicular to the membrane and wherein the membrane has at least two intersecting membrane slots. A lateral membrane diameter (diameter of a membrane opening of the membrane slot) is z. B. a few microns. The membrane diameter is selected, for example, from the range of 100 .mu.m to 10 mm. The slots reduce the stiffness of the membrane. The piezoelectric membrane is mounted in the energy converter so that the fluid flow is substantially perpendicular to it and causes it to vibrate. Advantageously, the membrane slots substantially intersect at the center of the membrane and form triangles in the membrane structure. The force of the fluid flow is used by the triangle arrangement in this way for efficient energy conversion.

A further advantageous embodiment of the invention is that the piezoelectric energy converter has piezoelectric elements with a substantially triangular base surface, which are arranged so that a substantially square base area results and wherein the fluid flow impinges substantially perpendicular to the total base area. The piezoelectric elements are connected via their respective side edges with the inside of the energy converter or with a fluid flow guide of the energy converter. The arrangement ensures efficient energy conversion.

A further advantageous embodiment of the invention is that a plurality of piezoelectric energy converters are connected in series. This increases the amount of energy generated. It can thus be supplied to systems that require larger amounts of energy. Furthermore, this allows the power generation system to be scaled with respect to the required energy.

A further advantageous embodiment of the invention is that the passive element is designed as a deformable bag, in particular as a rubber bag, and the outer surface of the bag is substantially completely connected to inner surfaces of the mechanically deformable environment, wherein the bag is mounted within the mechanically deformable environment and the fluid flow is generated by expansion or reduction of the bag volume. The rubber bag is integrated or embedded in a substantially completely mechanically deformable environment. Mechanical changes of the environment act directly on the rubber bag and cause an expansion or reduction of the bag volume. Due to the resulting pressure or suction effect, the fluid flow is generated.

The object is further achieved by a method for converting mechanical energy into electrical energy, by generating a fluid flow by mechanical action of energy on a passive element and by coupling a force caused by the fluid flow in a piezoelectric element, so that the piezoelectric element to mechanical vibrations is stimulated. This indirect way of coupling energy from the mechanical ambient energy into the piezoelectric element has the advantage that the fluid flow can be generated in a highly defined manner and does not directly couple a potential mechanical overload in the environment with a suitable design of the passive element to the piezoelectric element. Thus, a defect or destruction is avoided.

Reference to several embodiments and the associated figures, the invention will be explained in more detail below. The figures are schematic and do not represent true to scale figures.

Showing:

1 an example of the basic concept of the arrangement according to the invention,

2 a first example of a passive element for flow generation,

3 a second example of a passive element for flow generation,

4 an exemplary piezoelectric energy converter,

5 a piezoelectric membrane in plan view, for use in a piezoelectric energy converter,

6 an exemplary piezoelectric lance (or a piezoelectric bending beam) having a substantially triangular base, and

7 an exemplary arrangement of piezoelectric elements.

Many new applications require sophisticated sensors and / or actuators. Often this is distributed locally, which means that an electrical energy supply is complex and therefore expensive (eg laying of electrical feeders). In some applications, a physical connection of such decentralized local systems is completely impossible, so they must be operated completely independently. This means that these sensors or actuators must provide themselves with energy and the measured quantities obtained must be transmitted wirelessly. In our industrialized world, there are many dynamically deformable environments that seem suitable for harvesting energy. An example are conveyor belts at the reversal points of the elastic band is significantly deformed. In industrial automation (eg robots) there are a lot of moving parts, eg. B. are protected by deformable rubber sleeves. Another example can be found in the automotive industry. The tread of a car tire (tire lash) is continuously mechanically deformed during operation. These existing mechanically deformable environments can be used to power self-sufficient systems.

1 shows an example of the basic concept of the inventive arrangement A. The idea is based on converting the mechanical energy of a mechanically deformable environment U by a suitable technical arrangement in a fluidic flow FS. Under fluidic flow or fluid flow are understood here both gaseous and liquid flows. This fluid flow FS can then be used to drive an electromechanical energy converter EW. The arrangement A for converting mechanical energy into electrical energy comprises a passive element PAE for generating the fluid flow FS, wherein the passive element PAE takes the form of a mechanically deformable environment U (eg tire lash, conveyor belt or rubber boot for the protection of joints in industrial robots), that upon mechanical deformation of the environment U a mechanical energy is generated which acts on the passive element PAE and thereby generates a fluid flow FS at an opening O (FIG. 2 and 3 ) of the passive element PAE and a piezoelectric energy converter EW with at least one piezoelectric element PE ( 4 ) is coupled into the one caused by the fluid flow FS mechanical force such can be that the piezoelectric element of the energy converter EW is excited to mechanical vibrations. The generated electrical current for consumers is made available by way of a corresponding electrical contacting on the electrodes of the piezoelement and a corresponding wiring (eg for sensors or actuators). These sensors and actuators can thus be supplied with power autonomously.

This indirect type of energy coupling from the mechanical ambient energy in the energy converter EW has the advantage that a fluid flow FS can be generated very defined and a potential mechanical overload case in the environment U with a suitable design of the passive element PAE for flow generation not directly to the energy converter EW couples over. Thus, a defect or destruction (or at least a lifetime impairment) of the energy converter EW is avoided.

2 shows a first example of a passive element PAE for flow generation FS. In the simplest case, the passive element PAE for generating flow FS can be a circular membrane made of elastic material (eg rubber), which is tightly connected in the complete edge region with the deformable environment U (eg by means of adhesive bonding or by vulcanization). An opening O (inlet or outlet) in the membrane ensures a pressure equalization when changing the enclosed volume. This in turn leads to the formation of a fluidic flow FS. The picture according to 2 shows an undeformed arrangement of the passive element PAE including the mechanically deformable environment U connected to the passive element PAE 2 The existing spring F is optional and additionally supports that the membrane tensions a proper, ie sufficient, cavity to generate a sufficient fluid flow FS. On the spring can z. Example, be waived if the stiffness of the rubber membrane is sufficient to open up a sufficient cavity.

3 shows a second example of a passive element PAE for flow generation FS, in which figure the passive element PAE is deformed. The deformation of the passive element PAE (in this example a membrane) is effected by the mechanical deformation of the environment U and leads to a reduction in volume (reduction) of the cavity formed by the passive element PAE and the mechanical deformable environment U. This reduction in volume leads to a pressure increase in the cavity and causes an outward fluid flow FS at the opening O of the passive element, ie the membrane. It makes sense to design the arrangement so that the spring stiffness of the spring F is as low as possible, followed by the spring stiffness of the membrane. However, both spring stiffnesses should be significantly lower than the spring stiffness of the mechanically deformable environment U itself.

Other embodiments may, for. B. be seen in failed geometries of the passive element PAE with the aim of making the volume change as large as possible or to increase the fluid flow FS. Conceivable z. B. cascaded passive individual elements PAE or even meander arrangements which additively reinforce an existing fluid flow FS.

Another example of an embodiment of the passive element PAE is to form the passive element as a deformable bag, in particular as a rubber bag. The outer surface of the bag is substantially completely connected to the inner surfaces of the mechanically deformable environment U, wherein the bag is mounted (eg integrated or embedded) within the mechanically deformable environment U and the fluid flow FS is generated by expansion or reduction of the bag volume becomes. The bag outer surface may be substantially positively connected to the inner surfaces of the mechanically deformable environment U. Also by series connected energy converter EW the generated electrical energy can be increased. By consecutively connected or cascaded energy converter EW can be done with respect to the required electrical energy Skallierung. In this way, the respectively required electrical energy for a corresponding application or application can be provided adequately and as needed.

• – Erzeugung eines definierten Fluidstromes FS aufgrund einer mechanisch verformbaren Umgebung U.
• – Das passive Element PAE verhindert ein direktes Einkoppeln der mechanischen Umgebungsenergie in den Energiewandler EW (Überlastschutz).
• – Es sind keine klassisch beweglichen Teile zur Fluidstromerzeugung FS notwendig (Robustheit, Lebensdauer, leichte Wartbarkeit).
• – Einfache Indikation bzw. Einbettung in die Umgebung U möglich.

The advantages of the arrangement according to the invention and of the method according to the invention are in particular:

• Generation of a defined fluid flow FS due to a mechanically deformable environment U.
• - The passive element PAE prevents a direct coupling of the mechanical ambient energy into the energy converter EW (overload protection).
• - There are no classical moving parts for fluid flow generation FS necessary (robustness, durability, easy maintainability).
• - Simple indication or embedding in the environment U possible.

4 shows an example of a piezoelectric energy converter EW (in a lateral cross-section) for use in the inventive arrangement A. The piezoelectric energy converter EW is used for converting mechanical energy into electrical energy. The energy converter EW has a piezoelectric Element PE on. The piezoelectric element PE has a layer sequence of electrode layer ES, piezoelectric layer and further electrode layer ES. The piezoelectric layer is a piezoceramic layer PKS with zinc oxide. Alternatively, the piezoceramic layer comprises aluminum nitride. Another alternative is lead zirconate titanate. The electrode layers ES are made of platinum. The conclusion forms a carrier layer TS of silicon. Alternatively, the support layer is silicon dioxide or silicon nitride.

The piezoelectric element PE is advantageously arranged in a housing chamber GK of a housing G of the energy converter EW. It is ensured that the fluid flow FS is passed to the piezoelectric element PE over. In this case, an induced by the fluid flow FS mechanical force is coupled into the piezoelectric element PE. The result is the deflection AL of the piezoelectric element PE and, as a consequence thereof, the charge separation, on the basis of which electrical energy can be obtained via the electrodes, which can be made available to consumers (eg sensors, actuators) via suitable contacting and cabling.

In the example according to 4 In the housing G of the energy converter EW, a fluid flow inlet FSE and a fluid flow outlet FSA are integrated and arranged opposite each other. It will be obvious to one of ordinary skill in the art that other arrangements or forms are possible for fluid flow inlet FSE and fluid flow outlet FSA. Fluid flow inlet FSE and fluid flow outlet FSA may also be disposed on the same side of the housing G. Furthermore, it is also possible to use a single (common) opening of the housing G for fluid flow inlet FSE and fluid flow outlet FSA. The fluid flow FS generated by the passive element PAE is conducted via suitable mechanisms from the opening O of the passive element PAE to the fluid flow inlet FSE of the energy converter EW. As mechanisms for fluid flow steering z. B. a pipe or a tunnel guide used. The fluid flow control mechanisms used ensure that as little or as little as possible losses occur in the fluid flow FS. Losses would reduce the energy yield of the energy converter EW.

In the example according to 4 the piezoelectric element PE is a bent piezo-flag. The piezo-flag is designed such that the piezo-flag is excited to vibrate by the passing of the fluid flow FS and thus by the coupling of the mechanical force. The piezoelectric effect generates a periodic charge separation between the electrodes.

A further advantageous embodiment of the invention is that the piezoelectric element PE is formed as a membrane M and has a substantially circular base. The piezoelectric membrane M is mounted in the energy converter EW so that the fluid flow FS is substantially perpendicular to them and makes them vibrate. The circular shape allows generating maximum electrical energy and maximum electrical voltage with minimal mechanical stress on the membrane. The piezoelectric membrane M can be connected by an adhesive bond at its edges with the frame of the energy converter EW. The piezoelectric membrane M has a layer sequence of electrode layer, piezoelectric layer and further electrode layer. In this case, a plurality of such layer sequences can be stacked on top of each other, so that a multi-layer structure with stacked, alternately arranged electrode layers and piezoelectric layers results. A deflection (deformation) of the piezoelectric layer, which is caused by the action of the mechanical force of the fluid flow FS on the piezoelectric layer, leads to the charge transfer or charge separation in the piezoelectric layer (piezoelectric effect). In this case, the two electrode layers and the piezoelectric layer are arranged in such a way that a charge flow caused by the charge separation can be used to obtain electrical energy. As a result, mechanical energy is converted into electrical energy.

The electrode material of the electrode layers can consist of a wide variety of metals or metal alloys. Examples of the electrode material are platinum, titanium and a platinum / titanium alloy. Also conceivable are non-metallic, electrically conductive materials. The piezoelectric layer may also consist of different materials. Examples include piezoelectric ceramic materials such as lead zirconate titanate (PZT), zinc oxide (ZnO) and aluminum nitride (AlN). Piezoelectric organic materials such as polyvinylidene difluoride (PVDF) or polytetrafluoroethylene (PTFE) are also conceivable.

5 shows a piezoelectric element PE formed as a piezoelectric membrane M in plan view, for use in a piezoelectric energy converter EW in the inventive arrangement A. The circular shape of the membrane M allows generating maximum electrical energy and maximum electrical voltage with minimal mechanical stress on the membrane M. Um To further reduce a mechanical load on the membrane M, it is advantageous to equip the housing G with corresponding abutments, so that there is no mechanical overloading of the membrane comes. Such abutments are, for example, an abutment surface integrated in the housing lower part or a corresponding abutment structure in the housing cover. This stop surface or stop structure ensure that the membrane M can not deflect further. They limit the degree of deflection and thus act as overload protection for the membrane M.

It is particularly advantageous to introduce into the membrane at least one membrane slot MS for reducing the rigidity of the membrane. Through the membrane slot MS elasticity of the membrane M is increased. A lateral membrane diameter (diameter of a membrane opening of the membrane slit) is a few μm. The membrane diameter is selected for example from the range of 0.5 microns to 50 microns.

The membrane M is easily elastically deformable. The membrane slot extends partially or completely along a thickness direction of the membrane M through the membrane M. The membrane slot MS be designed in the form of a blind hole or as a through hole.

It has proven to be particularly advantageous if a plurality of such membrane slots MS is present. In the case of a membrane M with a circular base area GF, the membrane slots MS are advantageously oriented radially toward the center of the membrane and arranged around the center (star-shaped). The piezoelectric membrane is mounted in the energy converter so that the fluid flow FS is substantially perpendicular to it and causes it to vibrate. The membrane slots MS advantageously cross substantially in the center of the membrane M and form triangles in the membrane structure. The force action of the fluid flow FS is used by the triangular arrangement in this way for efficient energy conversion.

The piezoelectric element PE can be based on MEMS technology (Micro Electro Mechanical Systems), designed both as a piezo banner or as a piezo membrane. With this technology, a piezoelectric energy converter EW and an arrangement A with very small lateral dimensions are accessible. In addition, very thin layers can be formed. For example, the layer thicknesses of the electrode layers are 0.1 μm to 0.5 μm. The piezoelectric layer is a few microns thick, for example, 1 micron to 10 microns. The piezoelectric element PE is designed as a thin piezoelectric lug or membrane. The piezoelectric element PE has a very low mass. In addition, such a piezoelectric element PE can be easily excited to mechanical vibrations. To complete the piezoelectric element in the form of a piezoelectric membrane or flag, a carrier layer TS may be provided, for example a carrier layer of silicon, polysilicon, silicon dioxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ). A layer thickness of the carrier layer is selected from the range of 1 .mu.m to 100 .mu.m. The carrier layer TS is optional.

6 shows an exemplary piezoelectric lobe (or a piezoelectric bending beam) with a substantially triangular base. The fluid flow ES is substantially perpendicular to an end face of the piezo triangle PE and causes the piezo flag to vibrate. The triangular base creates a high energy conversion efficiency. The piezoelectric flag behind 6 can z. B. in the energy converter according to the invention 4 be used.

7 shows an exemplary arrangement of piezoelectric elements PE, each having a substantially triangular base for use in a piezoelectric energy converter. The piezoelectric elements (PE) are arranged to result in a substantially square overall area and wherein the fluid stream impinges substantially perpendicularly to the total base area. The piezoelectric elements PE are connected via their respective side edges with the inside of the energy converter or with a fluid flow guide of the energy converter. The arrangement ensures efficient energy conversion.

Arrangement for converting mechanical energy into electrical energy, the arrangement comprising: a passive element for generating a fluid flow, wherein the passive element is attached to a mechanically deformable environment such that upon mechanical deformation of the environment a mechanical energy is generated which is imparted to the device acting mechanical element and thereby generates a fluid flow at an opening of the passive element; and a piezoelectric energy converter having at least one piezoelectric element, in which a mechanical force caused by the fluid flow can be coupled in such a way that the piezoelectric element is excited to mechanical vibrations and electricity is generated by the piezoelectric effect, which is used for a self-sufficient supply, in particular for decentralized local systems (eg actuators or sensors) can be used. This indirect way of coupling energy from the mechanical ambient energy into the piezoelectric element has the advantage that the fluid flow can be generated in a highly defined manner and does not directly couple a potential mechanical overload in the environment with a suitable design of the passive element to the piezoelectric element. Thus, a defect or destruction is avoided.

reference numeral

• U

  Mechanically deformable environment

  A

  arrangement

  PAE

  Passive element

  EW

  energy converters

  F

  feather

  O

  opening

  PE

  Piezoelectric element

  IT

  electrode layer

  PKS

  Piezoceramic layer

  TS

  backing

  AL

  deflection

  G

  casing

  GK

  housing chamber

  FS

  fluid flow

  FSE

  Fluid flow inlet

  FSA

  Fluid flow outlet

  M

  Piezoelectric membrane

  GF

  Floor space

  MS

  membrane slot

Claims (12)

Arrangement (A) for converting mechanical energy into electrical energy, the arrangement (A) comprising: a) a passive element (PAE) for generating a fluid flow (FS), wherein the passive element (PAE) is attached to a mechanically deformable environment (U) in such a way that mechanical deformation of the environment (U) generates mechanical energy, acting on the passive element (PAE) creating a fluid flow (FS) at an opening (O) of the passive element (PAE); and b) a piezoelectric energy converter (EW) having at least one piezoelectric element (PE), in which a by the fluid flow (FS) caused mechanical force can be coupled such that the piezoelectric element (PE) is excited to mechanical vibrations. Arrangement (A) according to claim 1, wherein the passive element (PAE) is formed as a membrane made of elastic material, which is sealed in its entire edge region with the deformable environment (U) Arrangement (A) according to claim 1 or 2, wherein the membrane (PAE) is substantially circular. Arrangement (A) according to one of the preceding claims, wherein the passive element (PAE) comprises means for ensuring that the passive element (PAE) forms a sufficient cavity. Arrangement (A) according to one of the preceding claims, wherein as a means for securing the cavity of the passive element (PAE) a spring connection between the passive element (PAE) and the mechanically deformable environment (U) is mounted, wherein the first end of the spring ( F) is mounted substantially in the middle of the passive element (PAE) and starting in the vertical direction, the second end of the spring (F) is attached to the mechanically deformable environment (U). Arrangement (A) according to one of the preceding claims, wherein the piezoelectric element (PE) has a piezo-flag. Arrangement (A) according to claim 6, wherein the piezo-flag has a substantially triangular base. Arrangement (A) according to one of the preceding claims, wherein the piezoelectric element (PE) is formed as a membrane (M) and the fluid flow (FS) impinges substantially perpendicular to the membrane and wherein the membrane (M) at least two intersecting membrane slots ( MS). Arrangement (A) according to one of the preceding claims, wherein the piezoelectric energy converter (EW) piezoelectric elements (PE) having a substantially triangular base, which are arranged so that a substantially square overall area results and wherein the fluid flow (FS) substantially perpendicular to the total base area. Arrangement (A) according to one of the preceding claims, wherein a plurality of piezoelectric energy converters (EW) are connected in series. Arrangement (A) according to one of the preceding claims, wherein the passive element (PAE) as a deformable bag, in particular as a rubber bag, is formed and the outer surface of the bag with inner surfaces of the mechanically deformable environment (U) is substantially completely connected, wherein the bag within the mechanically deformable environment (U) and the fluid flow (FS) is generated by expansion or reduction of the bag volume. Method for converting mechanical energy into electrical energy using an arrangement (A) according to one of claims 1 to 11 by generating a fluid flow (FS) by mechanical action of energy on a passive element (PAE) and by coupling one through the fluid flow (FS) caused force in a piezoelectric element (PE), so that the piezoelectric element (PE) is excited to mechanical vibrations.

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