Patent Application
20170237369
This application claims the benefit of the German patent application No. 102016202066.8 filed on Feb. 11, 2016, and of the German patent application No. 102016222265.1 filed on Nov. 14, 2016, the entire disclosures of which are incorporated herein by way of reference.
The invention relates to an electric power-generating system for a rotor blade, to a lighting system for a rotor blade, to a rotor blade and to a rotor system.
Modern helicopters comprise a plurality of electrically operated components, such as lighting devices, sensors, control devices or the like. Usually, electric components are also required in regions which are difficult to reach with electric power lines. In particular, rotating components are also required, such as the rotor or rotor blades. As there are considerable risks associated with using rotating rotor blades, devices are known from the prior art by means of which the external outline of rotating rotor blades can be displayed visually and thus made recognizable.
For example from WO 2008/111932 A1, an autonomous blade tip light is known for rotor blades, in which the lighting is provided by means of light-emitting diodes and in which the electric power required for powering the light-emitting diode is provided piezoelectrically. The movement of the rotor blades is used for the piezoelectric power supply in that the vibrations of the rotor blades are converted piezoelectrically into current.
Also from DE 20 2008 008 517 U1, an energy self-sufficient lighting system for rotor blade tips is known, in which the electric power required for powering the light source is provided by an energy supply unit arranged in the rotor blade, which, during the operation of the rotor blade, produces electric current from the vibrations thereof.
One of the ideas of the present invention is to provide an electric power-generating system for a rotor blade which ensures a reliable and effective power supply to electrically powered functional components.
According to a first aspect of the present invention, an electric power-generating system for a rotor blade is provided. The system comprises at least one electromechanical power-converting device and at least one power-guide line, which is connected mechanically to the electromechanical power-converting device. The electromechanical power-converting device is designed in such a way that, during a movement of the power-guide line, the device converts into electric power the forces introduced by the movement of the power-guide line into the electromechanical power-converting device.
The electric power-generating system thus comprises one or more devices for providing electric power in the form of electromechanical power-converting devices. One or more power-guide lines are assigned respectively to a power-converting device. The power-guide lines or movement bands are coupled kinematically to the power-converting device. When charging the at least one power-guide line with force, for example caused by the movement of the rotor blade, the force is introduced by means of the power-guide line or power-guiding band into the power-converting device. The mechanical power supplied in this way to the power-converting device is converted by the power-converting device into electric power.
By means of the movement of the power-guide line, in particular, tensile forces are exerted on the electric power-converting device, wherein also transverse forces from the movement of the power-guide line can be transmitted to the electric power-converting device. The movement of the power-guide line can be caused, on the one hand, by the forces exerted by the rotor blade on the power-guide line, for example due to the inertia of the power-guide line and due to rotations of the rotor blade, or in particular by aerodynamic forces acting on the power-guide line, wherein as a rule, various forces act on the power-guide line. In this case, the power-guide line has the advantage that the line can absorb strong tensile forces and thereby ensures an efficient power conversion.
In the solution according to the invention, greater forces can be exerted on the electromechanical power-converting device by the power-guide line excited by means of the rotor-blade movement than by the vibrations of the rotor blade alone, so that more power can be converted. In this way, either the number of electromechanical power-converting devices per rotor blade can be reduced, or additional or more light-intense electric functional components can be used.
According to some embodiments, the at least one power-guide line can be connected, in particular, directly to the electromechanical power-converting device. For this purpose, it can be provided, for example, that the power-guide line runs in an uninterrupted manner between a first end facing away from the electromechanical power-converting device and a second end mechanically connected to the electric power-converting device. In this way, a simpler structure of the power-converting system is ensured.
Alternatively to this, it is possible to arrange an electric functional component mechanically between two line portions, e.g., between the first and the second end of the power-guide line or between one of the ends of the power-guide line and the electromechanical power-converting device, so that the electric functional component can be arranged in the force flow itself. In this way, it is ensured that only a small amount of installation space is required. In particular, it is possible to omit electrical supply lines, which also reduces the weight advantageously.
Furthermore, it is possible for the first and the second end of the power-guide line to each be connected directly to the electromechanical power-converting device. In this way, the power-guide line forms a loop. In cases where the power-guide line runs outside of the rotor blade, the loop causes a relatively high degree of air resistance and thus a high tractive force on the power-guide line. In this way, the performance of the power-generating system is improved.
The power-guide line or the power-guiding band can be made, in particular, from a plastics material, for example a polymer material. Plastics materials, in particular polymers, are available in numerous different variations and have a high degree of mechanical strength. A further advantage of plastics materials, in particular polymers, is that the materials can be produced with various different refractive indices. In this way, the power-guide line can be designed advantageously and in a simple manner as an optical fiber. Furthermore, nanotubes embedded in a plastics matrix can also be used advantageously as a material for the power-guiding band. Weaves of metal material can also be used as power-guide lines. The weaves can be produced particularly inexpensively and have a high degree of mechanical stability.
In some embodiments, it is possible for the electromechanical power-converting device to comprise at least one piezo element connected mechanically to the power-guide line for converting mechanical power from the movement of the power-guide line into electric power. The electromechanical power-converting device thus converts the mechanical power from the movement of the power-guide line through the effect of one or more piezo elements into electric power. The piezo elements convert the mechanical alternating forces exerted by the power-guide line on the power-converting device into electric power. The electric power can be used advantageously for powering the electrically powered functional components, for example in the form of light sources. For example, one piezo element can be provided for each power-guide line. However, it is also conceivable to provide only one piezo element for a plurality of power-guide lines.
In this case, the power-guide line can be secured directly or via further connecting elements to the respective piezo element.
According to some embodiments, it is possible for the power-guide line to be surrounded, at least in some portions, by a piezo electric material of the piezo element. In this way, a particularly high degree of conversion efficiency of the mechanical movement of the power-guide line into electric power is achieved.
According to some embodiments, the piezo elements can be configured, in particular, in such a way that the elements surround the power-guide line with regard to the longitudinal extension thereof at least in some portions. The forces from the movement of the power-guide line are then introduced to the surrounding piezo element, for example in a planar manner, where the power-guide line is connected to the surrounding piezo element. For this, for example PVDF-nanocomposites, i.e., polyvinylidene fluoride nanocompo sites, are used. Furthermore, also at least one end portion of the power-guide line can be embedded into the piezoelectric material or received thereby.
For all the embodiments, in particular what are known as “conformable piezoelectric polymers” can be used as the piezoelectric material, such as polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) or materials based on what are known as carbon nanotubes (CNT base).
According to some embodiments, the electric power-generating system comprises at least one energy store connected electrically to the electromechanical power-converting device for storing electric power. In this way, the power converted during the movement of the rotor blade can be stored temporarily in order to supply an electrically operating functional component with electric power even when the rotor blades are rotating at a relatively low speed, or to supply the component with electric power temporarily even when the rotor has stopped.
The energy store can be designed, in particular, as a capacitor, as an accumulator or as a similar storage device for electric power.
According to some embodiments, the electric power-generating system also comprises an electronic control device, by means of which the provision of electric voltage produced by means of the electromechanical power-converting device can be switched on or off at electric connection points of the power-generating system provided for connecting electric functional components. The electric power-generating system thus comprises an electronic system, by means of which electric functional components which are connectable to the system can be switched on or off. In this way, the possible applications of the functional components are improved.
In some embodiments, the control device can be controlled wirelessly. For example, the control device can be designed to be controlled by radio signals. However, other control options are also possible, for example optical signals or acoustic signals. Furthermore, the control device can comprise brightness sensors or the like, which at a specific brightness switch on or off the supply of electric voltage. By means of the wireless control, the electric power-generating system can be controlled and operated advantageously without control lines.
According to a further aspect of the invention, a lighting system for a rotor blade is provided. The lighting system comprises an electric power-generating system according to any of the aforementioned embodiments and at least one electric light source, which is connected electrically to the power-converting device of the electric power-generating system. The electric power produced by the power-generating system is then used advantageously for operating an electric light source. Due to the high efficiency of the power conversion of the power-generating system, it is possible to use powerful light sources.
According to a some embodiments of the lighting system, the power-guide line of the power-generating system is in the form of an optical fiber, and the power-guide line is connected mechanically to the light source in such a way that the light source introduces light into the power-guide line, and the light source is connected to the electromechanical power-converting device mechanically in such a way that the forces produced by the movement of the power-guide line are transmitted via the light source to the electromechanical power-converting device. The light produced by the light source is then transmitted through the power-guide line in the form of an optical fiber from a first line end to a second line end which is positioned opposite the first end. In this case, the first line end is the end of the power-guide line placed at the light source, the second line end is the end facing away from the light source or the electromechanical power-converting device. The light source is also connected mechanically to the electromechanical power-converting device. The forces produced by the movement of the power-guide line, which is caused, for example, by the movement of a rotor blade, are thereby transmitted by the light source, which is arranged mechanically in the force flow, to the device for providing electric power, which converts mechanical power into electric power.
In some embodiments, the power-guide line is thus used, on the one hand, for generating forces for the electromechanical power-converting device and, on the other hand, also for transmitting the light produced by the light source. In this way, the light source can also be arranged inside the rotor blade, for example in the immediate vicinity of or directly on the electromechanical power-converting device, and the light is transmitted through the power-guide line in the form of an optical fiber to the outside of the rotor blade. For example, the power-guide line can have such a length that the second line end is positioned outside a rotor blade, so that the power-guide line can move in part outside of the rotor blade. This ensures the easily identifiable lighting of the rotor blade. By using the aforementioned power-converting system, particularly bright light sources can be used.
In some embodiments, the at least one light source comprises respectively at least one light-emitting diode. By means of light-emitting diodes with low power consumption, a high light output can be achieved, and the light can be fed effectively into an optical fiber if necessary. Furthermore, light-emitting diodes are mechanically robust, e.g., with respect to vibrations and accelerations, when arranged on a rotor blade. Also light-emitting diodes are advantageous for the mechanical transmission of forces, for example if they are arranged between a line end of a power-guide line in the form of an optical fiber and the electromechanical power-converting device. However, also other light sources suitable for the purpose can be used.
According to some embodiments of the lighting system, the light source can be arranged on the inside of a rotor blade. The light source is thus provided in particular to be arranged within the cross section of the rotor blade. In this way, the lighting can be achieved without having aerodynamically unfavorable attachments on the outer surface of the rotor blade.
In some embodiments, the light source can be provided to be arranged in a depth-balancing chamber of the rotor blade. This has the advantage that the installation space inside the cross section is used efficiently. In this way, a compact structure of the lighting system is obtained, and a structural reconfiguration of the rotor blade can be largely avoided.
According to a further aspect of the present invention, a rotor blade is provided, in particular for an aircraft. The rotor blade comprises an electric power-generating system according to any of the embodiments described above. The electric power-generating system thus forms an electric power source provided locally on the rotor blade. In this way, vibrations caused by the rotation of the rotor blade due to the power-guide line of the electric power-generating system are converted in a particularly efficient manner into electric power. The power-guide line forms in particular a kind of lever which increases the force acting on the electromechanical power-converting device.
According to some embodiments of the rotor blade, the at least one power-guide line runs at least in portions outside a rotor blade, in particular outside a cross section of the rotor blade. In this case, the power-guide line extends at least in part into a fluid surrounding an outer contour of the rotor blade. In this way, during a movement of the rotor blade, in a particularly efficient manner, a force is exerted onto the power-guide line, in particular a tensile force. The power introduced by the force into the electromechanical power-converting device is then converted by the device into electric power.
For example, it is possible for the power-guide line to project with an end portion, for example the second line end facing away from the electromechanical power-converting device, out of the cross section of the rotor blade. It is also possible for a middle portion between the first and second line end to run outside of the rotor blade. In this way, the portion of the line running outside the rotor blade forms a flow resistance and, in addition to the forces of inertia, which also act on the line portion arranged in the rotor blade, aerodynamic forces from the movement of the rotor blade act on the line portion projecting from the rotor blade. In this way, the forces acting on the power-guide line are increased, and a greater amount of mechanical power is introduced into the device for providing electric power and converted into electric power. In this way, the performance of the lighting device is improved.
Furthermore, it is conceivable for the power-generating system to be attached as a whole onto an outer surface of the rotor blade, for example onto the rotor blade tip.
In some embodiments, however, the electromechanical power-converting device is arranged on the inside of the rotor blade, in particular in a depth-balancing chamber of the rotor blade. Thus, the electromechanical power-converting device is arranged on the inside of the cross section of the rotor blade, such as in a depth-balancing chamber of the rotor blade. This has the advantage that the influence of the power-generating system on the aerodynamic properties of the rotor blade is kept to a minimum.
In general, a plurality of electric power-generating systems can be provided, which may be distributed over the longitudinal extension of the rotor blade. For example, the systems can be connected electrically in parallel or in series. In this way, a particularly efficient power supply can be obtained for electrically powered functional components.
A further aspect of the invention relates to a rotor system, in particular for an aircraft, comprising at least one rotor blade according to any of the embodiments described above and comprising at least one electrically powered functional component, which is connected electrically to the power-converting device of the electric power-generating system. By means of the power-converting device, the force produced by the movement of the rotor blade on the power-guide line is converted efficiently into electric power, which is used to supply the electrically powered functional components.
In some embodiments, a light source, a sensor, an actuator device or the like can be provided as an electrically powered functional component. Light sources advantageously allow the lighting of the rotor blade, in particular the blade tip thereof, so that a danger region covered during the movement of the rotor blade is marked clearly visually. Sensors can be used advantageously for detecting aerodynamic or mechanical parameters. By means of actuator devices, for example mechanical systems can be activated on the rotor blades.
The rotor system may comprise a light source as an electrically powered functional component. According to some embodiments of this type of the rotor system, the at least one rotor blade optionally comprises additional rotor components, such as a rotor shaft or the like, as well as an embodiment of the aforementioned lighting system. In this case, for example a plurality of light sources can be provided which are preferably arranged so as to be distributed over the number of rotor blades. For example one or more light sources can be arranged on each rotor blade of a rotor. In this case, the light sources are preferably arranged on the rotor blade tips or in the vicinity thereof. The at least one light source can thus be arranged in general in an end portion of the rotor blade which is axial to the longitudinal extension of the rotor blade. The at least one electric light source is connected electrically to one or more electromechanical power-converting devices of the electric power-generating system.
The invention is explained in the following with reference to the figures of the drawings, in which:
In the figures, the same reference numerals denote identical or functionally similar components, unless otherwise indicated.
The rotor system 100 shown schematically and by way of example in
For example, a light source 41, 42, a sensor 43, an actuator device 44 or the like can be provided as the electrically powered functional component 40.
As shown in
As is also shown in
In the power-generating system 1 shown in
Furthermore,
As is also shown in
For the sake of clarity in
Alternatively to embedding at least one of the end portions 5a, 5b of the power-guide line, as shown in
The electromechanical power-converting device 3 is arranged according to the illustration given by way of example in
The lighting system 150 shown by way of example in
The light sources 41, 42 are each connected electrically to the electromechanical power-converting device 3. Preferably, the electric light sources 41, 42 are arranged respectively within the cross section of the rotor blade 10, as shown by way of example in
In the lighting system shown in
The light source 42 shown in
As also shown in
As already described, it is also possible for the securing line 9 to be connected mechanically to the electromechanical power-converting device 3. In this case, the second optical fiber 8 and the securing line 9 each form a portion of a power-guide line 5.
While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102016202066.8 | Feb 2016 | DE | national |
| 102016222265.1 | Nov 2016 | DE | national |
