DE102007035760B4 - Flapping wing arrangement - Google Patents

Abstract

A flapping wing assembly, in particular for use in an aircraft or for moving a fluid, formed from a number of 2 ⁿ (n ≥ 2) similar flapping wings, the movement areas of which are clover-shaped juxtaposed, wherein a driving device is configured for the flapping wings, which each of the flapping wings to his both adjacent flapping wings can oscillate in opposite directions, and each flapping wing in both reverse regions approaches its respective oncoming neighbors in the same operation.

Description

The The invention relates to a flapping wing arrangement to promote of fluids, which in particular as a drive unit for flying or floating apparatus can be used.

Background of the invention

oscillating wing (Flapping wing) or paddles as driving members in fluids have long been known. In practice, however, this drive concept has not been able to date prevail against the propeller. These are the most common mentioned reasons against the use of flapping wings or paddling the discontinuous Thrust generation, the sometimes complex mechanics and the oscillating forces which act on the driven structure and this itself to vibrate.

Yet are flapping wings and paddles used successfully for propulsion of ships and aircraft Service. An example for, that high efficiencies in flapping wings not only achieved in nature is one built by Adalbert Schmidt in 1942, about 70 kg manned glider, which in addition to the wings with a flapping wing pair equipped which produced the propulsion. This aircraft could start automatically and land and reached with a drive power of 2.1 KW (!) a top speed from 60 km / h.

Height Efficiencies are also for the 1960 developed by Wilhelm Schmidt Wellpropellerantrieb also been based on principles of flapping wings based.

The flow conditions around a propeller wing around are at constant speed and constant speed the driven apparatus by the surrounding fluid at any time the same and can calculated relatively easily become. One speaks of the propeller of stationary fluid power generation, since the forces generating flow around around the propeller with respect to the propeller blade is stationary. The Fluid power generation in the flow around an oscillating flapping wing can to a big one Part only by transient Explained effects be, d. H. those arising from the change in the flow around the aerofoil result.

scientific Investigations on insects and birds suggest that with skillful technical design of a flapping wing apparatus this across from a propeller incorporating transient fluid power components comparable dimensions and same average angular velocity of the grand piano a much higher one Can develop thrust at comparable efficiencies. An excellent overview of the State of knowledge to the transient Fluid power generation in insects and birds and their technical Applicability is given by Werner Nachtigall in his book "Insect Flight Construction Morphology - Biomechanics Flight Behavior", published 2003 in the Springer publishing house. Here is in particular referred to the Chapter 5.3 "Instationary Air Forces and their effects "(pages 171 ff.).

For the here illustrated invention is mainly the so-called clap-and-fling effect of importance, the approach two beating in opposite directions flapping wings takes effect.

Effects of fluid power generation are known in the art, which arise from the approach of a flapping wing to a solid wall or an anti-phase swinging flapping wing (eg. DD 47871 A ). The flapping wing presses on approaching the wall or the anti-phase oscillating flapping wing supported by increasing the angle of attack a volume of fluid under it (Clap) and pulls when folding the wing at the beginning of the follower - as when pulling apart two pages - the fluid from the front after (Fling). From this approach can be achieved with appropriate design of the wing a very strong momentary thrust. For example, budgerigars and pigeons take advantage of this effect observed by biologists at take-off and during steep ascent. Technically, "clap-and-fling" is already used in some experimental aircraft. (eg Yusuke Takahashi's model "Luna" published in English http://www.ornithopter.org, or the Delfly model developed in the Netherlands by the Delft University of Technology, see also http: //www.delfly .nl). Both aircraft use two anti-phase swinging flapping wing pairs. This offers the advantage that the torques of the beating wings cancel each other, so that the drive unit introduces only small vibrations in the supporting structure.

Summary of the invention

The The object of the invention is based on an oscillating Verdrängerflächen (wings) Turbomachine to promote specify of fluids which as a drive unit for flying and floating apparatus can be used.

The object is achieved by an arrangement in which four similarly shaped flapping wings are arranged concentrically around an axis. There are those of the four Flapping wings swept through, in normal operation the same size areas cloverleaf-like set together. Each flapping wing oscillates to each of its two neighbors 180 ° out of phase and the amplitude of the wing vibration is chosen so that a wing in the reversal regions alternately closely approaches or even touches its left and right neighbors in the same way and the opposing employees, successive wing profiles before swinging a fluid volume press away from itself and the subsequent opening the fluid from above retighten (clap-and-Fling). In contrast to known models, the "clap-and-fling" effect can be used in an inventive aggregate with four cloverleaf arranged impact areas in both reversal regions, resulting in the same average thrust to smaller spans and a more uniform thrust generation. In addition, a drive unit according to the invention benefits from the comparatively large amplitudes of up to 90 ° compared to known models. This large amplitude allows the flapping wing to accumulate a high kinetic energy during the acceleration phase, which can then be converted into thrust during the "clap-and-fling".

at known models with two anti-phase swinging flapping pairs sit the flapping wings on a common swing axis. The two are each diagonally opposite flapping wings through a central node piece with each other connected, which is rotatably mounted on the swing axle. The for four Flapping wings required two knot pieces sit one behind the other on a common swing axle. The drive is a crank drive which acts on the node pieces and this in a torsional vibration with an amplitude of about ± 22.5 ° offset. The synchronization of the wing movement is achieved by the common crankshaft. A disadvantage of this Arrangement is that the wing surfaces of a Flapping wings couple never be able to stand parallel to each other, as they are in this case interpenetrate each other. Due to the arrangement of the crank drive, it is in this arrangement about that beyond impossible, the flapping wings too with the other flapping wing neighbors in a high approximation to bring, since the driving crank then approximately parallel to the driven Lever would stand and thus could not initiate sufficient torque.

The present invention solves this problem by giving each flapping wing its own swing axis or assigns its own wing suspension, which are concentric and evenly distributed around a common Space axis are arranged. This allows a flapping wing with both his left as well as his right neighbor in a parallel Position are brought. The drive can turn through take a crank drive with a centrally performed crankshaft. An alternative drive for an inventive arrangement on the basis of oscillating electric motors is shown below.

critical for the Thrust generation in a flapping wing apparatus is the dynamic change the wing rotation, or the effective sash profile. Many of the known solutions rely on a positively controlled mechanics, in which every stroke phase of the flapping wing a certain wing rotation or wing profiling is permanently assigned.

A advantageous embodiment the invention forms the flapping wing in contrast so that this is elastically suspended and the wing angle or its Profiling in the alternating field between the fluid forces occurring and inertia on the one hand and the effective restoring forces of the resiliently effective components on the other hand in predetermined Limits automatically established. Thus, an inventive drive unit reacts flexibly to changing Environmental conditions z. Due to speed changes of the incoming Fluid.

A preferred development of the invention provides that the effective Restoring forces of on the wing rotation or -profilierung resiliently acting components at least partially variable are formed, so that thereby at constant amplitude and beat frequency the thrust changed can be.

A other expedient embodiment of Invention allows it that the effective restoring forces of the elastically effective components for each wing independently adjusted from each other can be causing a change the direction of the resulting thrust vector is achieved. hereby For example, a helicopter-like aircraft, which uses a drive unit according to the invention instead of the rotor, being able to control laterally in any direction. With regard to such an application, a drive unit according to the invention also offers the advantage that no tail rotor required for torque compensation is.

When Drive for an inventive drive unit come hydraulic, pneumatic and electromagnetic sources and explosion piston into consideration.

An expedient embodiment of the Er tion provides for each wing its own electric motor as a drive source. This sits directly on the swing axis of the wing or is coupled with this via an intermediate gearbox. As a result, the motors do not rotate continuously, but change the direction of rotation at the moment the blade also changes its direction of impact. The motor initiates a force in the wing as a function of the respective impact phase or angular position. This usually accelerates on the wing, but it can also have a deceleration effect. The required in this case 4 motors of a drive unit thus formed are electronically synchronized according to an appropriate development. This would offer the advantage that with constant beat frequency, the amplitude of individual flapping wings could be selectively changed with a correspondingly extended electronics so as to effect a change in direction of the resulting thrust vector with respect to the overall apparatus.

In contrast, is another embodiment the invention equipped with a mechanical synchronization via gears. This offers the advantage of requiring only one motor to drive is, as expected, a better power-to-weight ratio entails. By using only one motor which constantly its Direction of rotation changes, However, the problem arises that the apparatus due to unbalanced Torques begin to swing around its vertical axis. For this Reason has another advantageous embodiment, two smaller, opposite directions rotating drive motors, which together the required To generate motive power.

Becomes in the wing initiated kinetic energy not completely during a half blow in flow energy converted, would the wing collide with his neighbor in the reverse region. Therefore provides a further advantageous embodiment of the invention resilient energy storage which are arranged to absorb the excess kinetic energy of a shock record and this to speed up the wing in the opposite Use direction. Such an arrangement allows very high impact frequencies and thus a high power density.

One Invention drive unit is suitable due to its torque-free thrust generation in particular Way as the main drive for vertical launching helicopter-like Aircraft. Here, the total thrust of the drive unit via a change the amplitude, the beat frequency, the flapping profile or the flapping wing angle of attack adapted to the current requirements. With help The mechanisms described above will be a change of direction of the resulting thrust vector, allowing a fast reaction lateral maneuverability is reachable. By at least one additional control flap, which in the thrust jet below the drive unit is arranged beyond a rotation about the vertical axis of the aircraft are initiated.

at another aircraft, where the payload is hanging below the drive unit according to the invention may be arranged alternatively to the mechanisms already described for lateral maneuverability at the transition be arranged between the drive unit and payload a joint, around which the drive unit in the desired direction of flight relative can be tipped to payload.

A Reversal of the conveying direction can in a drive unit according to the invention an execution achieved with a rigid flapping wing surface be, at the z. B. by pivoting the wing of the focus on the Acting wing surface Wind pressure with respect to the wing axis can be adjusted over which adjusts the angle of elasticity. switches the wind pressure center of gravity from one side to the other The axis of rotation becomes the conveying direction reversed.

Simple flapping wings have a rigid wing surface, which sets its angle of attack more or less flexible depending on the flapping phase. A rigid wing surface but would be in terms of an inventive drive unit with larger Reynolds numbers a fluidic compromise, ideal would be a wing profile, the profiling and profile rotation (small angle of attack near the joint, large angle of attack at the wing tip) in response to the flapping phase and the current flow conditions self-adjusting. This requirement is met in another expedient embodiment of the invention, in which the flapping wing surface is designed to be flexible and is clamped in a triangle, which spans between wing axis and swing axis. The section of the flexible flapping wing surface can be carried out in the manner of a ship's sail so that the desired profiling automatically sets under load. When reversing the impact direction, the side of the wing surface bulge also changes. According to an advantageous development, the flexible wing surface is biased by spring force so that it develops its bulge only by the pressure of the acting fluid. This spring force can act both on the swing axis or the wing axis facing part of the wing surface. A spring-loaded wing surface offers additional to the load-dependent wing profiling the particular advantage of a leveling of the thrust profile, ie that a part of the energy of the thrust peaks, which is created by the clap-and-fling effect in the reversal regions in the springs, which span the wing surface is cached. This energy is then released again in the further course of the shock and thus leads to a more uniform thrust development and a lower operating noise.

Description of preferred embodiments the invention

detailed Representations of preferred embodiments of the invention can be found in the following figure descriptions:

1 : Power unit with four separate drive motors, torsion springs for wing rotation and energy storage

2 : Movement study

3 : Alternative drive unit with gear synchronization and central engine.

4a . 4b . 4c : Elastomer pads for energy storage, servos with tension springs for wing rotation, multi-part flapping wing surface

5a . 5b : Lever system for controlling the angle of attack

6a . 6b : Twisted lever system for control around the vertical axis

7 : Suspension wing suspension

8th : Thrust diagram

9 : Pendulum suspended wing axis

10a . 10b : Fully flexible flapping wing surface with springy wing leading edge

11 : Airplane with control surfaces in the thrust jet

12 : Regarding the conveying direction reversible drive unit

13 : Drive unit for miniaturized embodiment

1 shows an inventive drive unit with four flapping wings 2 , which at four evenly around a central spatial axis 1 distributed vibration axes 4 are hung up. The impact areas of the flapping wings are clover-leaf-like. The flapping wings 2 are on the wing hanger 36 along the wing axis 3 rotatably suspended, whereby the angle of attack is variable. A torsion spring located inside the flapping wing 12 (not shown) gives the angle of attack of the flapping wing 2 a middle position (zero position) before. In this middle position the motionless flapping wing has 2 the least resistance to the fluid flowing in the conveying direction. Begins the flapping wing 2 around his swinging axis 4 to turn, act on the flapping wing 2 lateral fluid forces, which is a change in the angle of attack of the flapping wing 2 cause. Depending on the speed of the rotation about the swing axle 4 and the spring force of the torsion spring 12 creates a thrust force opposite to the conveying direction. 1 shows a snapshot of the drive unit by the flapping wings A and B and the flapping wings C and D move towards each other. The two pairs of flapping wings include a fluid volume between them, which they push away as they approach each other. The generated thrust force is greatest shortly before the end of a stroke, when the wings experience the greatest approximation and at the same time due to the negative acceleration at the end of the swing of the flapping wings around the wing axis back to the center position swings. Between the complementary flapping wing pairs A and D as well as B and C there is a suction between the flapping wing surfaces moving away from each other. This is greatest at the beginning of a strike, when the abutting flapping wing surfaces begin to open and thereby move the fluid between them as when pulling two pages apart. In the illustrated embodiment, each of the four flapping wings 2 from its own electric motor 5 powered, which directly with the wing suspension 36 is coupled. A mounted on the electric motor encoder 6 Determines the current angular position of the wing around the swing axis 4 and forwards them to control electronics (not shown). Depending on the currently effective setpoint parameters (amplitude, frequency, possibly angular acceleration) for this flapping wing 2 The control electronics regulates the power flow to the electric motor 5 , At the end of a wing stroke, the electric motor returns 5 its direction of rotation and accelerates the flapping wing 2 in the opposite direction. With the help of the rotary encoder 6 and the control electronics are also the vibrations of the individual flapping wings 2 so synchronized to each other that every flapping wing 2 oscillates to its two neighbors 180 ° out of phase.

To be able to use the kinetic energy accumulated during a wing stroke is the wing suspension 36 every flapping wing 2 along the swing axis 4 with a torsion spring 7 verkop pelt, which is relaxed in the middle position of the impact area and develops an increasing restoring force in a deflection of the flapping wing in the direction of one of the reversal regions. This restoring force slows down the movement of the beating wing when approaching the reverse region and prevents the electric motor 5 must apply a braking torque. At the same time it is in the torsion spring 7 accumulated energy again to accelerate the flapping wing 2 available in the opposite direction.

To adapt the spring rate to the respective performance requirements of the drive unit shown, the fixed counter bearing 8th the torsion springs in the direction of the spatial axis slidably executed. With the help of the adjusting spindle 9 So the desired spring rate can be specified.

2 represents in a circuit ten positions of a beating cycle of a drive unit according to the invention.

position 1: In the state shown here are two wings in the Reversal regions in the position of their closest approach. The flapping wings are nearly parallel, the angle of attack is zero.

position 2: The flapping wings are still moving together path. The angle of attack increases while against the direction of movement of the flapping wings. The surrounding fluid is drawn between the diverging wing surfaces.

position 3: The angular velocity of the flapping wings now increases steadily and due to inertia of the flapping wing and the growing fluid pressure also increases the angle of attack further. In this impact phase, especially stationary fluid force effects, which also from the flow around of wings are known.

position 4: The flapping wings be at the approach slowed down to the other reverse regions. angular velocity and angle of attack decrease.

position 5: As the rapprochement approaches, they close flapping wings a volume of fluid under it, which is pushed away towards the bottom. For additional Thrust generation ensures that by spring force and inertia steadily decreasing angle of attack. In this beat phase develops a Drive unit according to the invention the biggest pushing forces. It is doing a lot the energy accumulated in the acceleration phase into thrust.

position 6: The end of the stroke is reached, the direction of movement of the Flapping wing returns around.

positions 7 to 10: The ones described in the position descriptions 2 to 5 procedures repeat themselves.

3 represents an alternative embodiment of a drive unit according to the invention with only one electric motor 5 as a drive. About a pinion on the output shaft (hidden by the engine body) he drives two drive wheels 10 to which with the wing suspensions 36 two diagonally opposite flapping wings are coupled.

The synchronization of the remaining two flapping wings 2 with the two directly driven flapping wings 2 takes place via a further gear arrangement in which on each swing axis a synchronizing gear 11 sits, which with the synchronizing gear 11 his right and left neighbor combs (ring coupling of all four wing suspensions 36 ). As in 1 are also in this embodiment four with the wing suspensions 36 coupled torsion springs installed, which the braking energy at the approach of the flapping wings 2 pick up on the reverse region and release it again while accelerating in the opposite direction. Alternatively, in such an arrangement, a single spring can be used for energy storage, the z. B. directly to the motor shaft of the electric motor 5 can be coupled. In this illustration is in the cut forward flapping wing 2 the torsion spring 12 visible, which the restoring force for the angle of attack of the flapping wing 2 generated.

The 4a to 4c show 3 views of a flapping wing configuration for a drive unit according to the invention. The wing surface is in this embodiment of several surface segments 13 to 17 composed by means of freely movable joints 18 are juxtaposed. The top surface segment 13 is doing along the wing axis 3 freely rotatable in a pivot bearing 19 fixed, the axis of rotation at right angles to the swing axis 4 located. The pivot bearing 19 itself is part of the wing suspension 36 , The axes of the joints 18 cross the wing axis 3 in a region near the imaginary crossing point of wing axis 3 and swing axle 4 , At the lower surface segment 17 grips a tension spring 20 on, by which the wing surface is pulled flat in the unmoved state, so that they are in a plane with the swing axis 4 and the wing axis 3 located. Begins the flapping wing 2 around the swing axle 4 To turn, the wing surface bulges due to the inertia of the surface segments 13 to 17 and the effects of the displaced fluid and generated by the resulting wing profiling a force component in the direction of the swing axis 4 , Would you profile sections of the bulging flapping wing 2 at different distances from the swing axle 4 create, one would notice an increase in the average angle of attack of the wing profile from the wing root towards the wing tip, which can expect a higher aerodynamic efficiency over a rigid wing profile due to the outwardly higher flow velocities. The spring tension of the tension spring 20 is in the embodiment shown by means of a servo control element 21 influenceable, whereby the bulge of the airfoil can be influenced. This embodiment of a flapping wing 2 follows the principles for the construction of the mainsail of a recreational sailboat, in which the flow behavior is controlled in a similar manner by the mainsheet. If in a drive unit according to the invention each flapping wing 2 an independently controllable servo actuator 21 receives to influence the airfoil, can be changed in its direction with such an arrangement, the resulting total thrust vector. Thus, a lateral thrust component pointing in any direction is perpendicular to the axis of space 1 producible, whereby such a drive unit is particularly suitable for the main drive of a vertical-type aircraft, which relies on a good lateral maneuverability.

The illustrated embodiment of a flapping wing has an electric motor 5 as drive, which directly with the wing suspension 36 is coupled. At the pivot bearing 19 is a hammerhead 37 as part of the wing suspension 36 recognizable, which in the left and right inversion region in an elastomeric pad 22 suggests. It takes the elastomer pad 22 The excess kinetic energy at the end of a wing beat and accelerates the flapping wing 2 then in the opposite direction. The advantage of such an arrangement over one on a torsion spring 7 based energy storage (as in the 1 and 3 it is shown that a torsion spring 7 the flapping wing 2 decelerates long before reaching the reversal region, while the arrangement shown in this figure allows acceleration of the flapping wing close to the reversal point, which allows higher impact frequencies and thus a higher thrust force with the same driving force and size. To achieve this effect may alternatively to the illustrated arrangement for energy storage also on the wing suspension 36 directly acting spring mechanism can be selected, which has a strong progressive spring characteristic.

The 5a and 5b such as 6a and 6b show a flapping wing configuration for a drive unit according to the invention with a rigid wing surface. Drive and energy storage correspond in their execution of the description for the 4a to 4c , The rigid flapping wing 2 is doing along the wing axis 3 freely rotatable in a pivot bearing 19 fixed, the axis of rotation at right angles to the swing axis 4 located. The pivot bearing 19 itself is part of the wing suspension 36 , To the rotatable part of the flapping wing 2 is with a universal joint 24 a lever 23 set over which the angle of attack of the flapping wing 2 can be influenced. This is on its other side again using a universal joint 24 with a movable in the direction of the swing axis 4 mounted support block 25 connected. Will the support block 25 along the swing axis 4 shifted and increases the dimension A, reduces the angle of attack on the flapping wing 2 ( 6a and 6b ). The lever 23 has a spring mechanism in its interior. If a force acts in the direction of the lever axis, the effective lever length shortens or lengthens depending on the direction of the force. The upper spring allows this 26 a dynamic adjustment of the angle of attack on the force acting on the moving flapping wing surface fluid pressure. The lower spring 27 allows the turnover of the flapping wing 2 in the reverse region without the support block 25 on the swing axle 4 would have to be postponed. In the process, part of the kinetic energy accumulated during the acceleration phase becomes impact on the elastomer cushion 22 used for the wing envelope. For this mechanism to work, the center of mass of the flapping wing must be 2 below the wing axis 3 are located. This creates at the end of a strike a very fast rotation of the flapping wing profile about the wing axis. It is known from insect research that the unsteady air force components which are effective in the context of such a forced profile rotation generate an additional thrust point.

In 7 a flapping wing configuration for a drive unit according to the invention is shown, which with the in the 5a to 6b shown configuration is substantially identical. However, the support block is 25 for the lever 23 additionally rotatable about the swing axle, so that the lower bearing point of the lever 23 no longer directly under the pivot bearing 19 the flapping wing is arranged. This has the consequence that the flapping wing has a different angle of attack a when hit than when kickback (angle of attack b, dashed line). As a result, this results in a torque acting on the spatial axis, so that, for example, a helicopter-like aircraft with a drive unit according to the invention as the main drive could execute a rotation about its vertical axis. Is the support block 23 so freely adjustable in its rotational position, could in this way a controllability of such a helicopter-like aircraft can be achieved about the vertical axis. This applies similarly to the in 4 described flapping wing configuration. If at this the suspension point of the tension spring 20 laterally displaced in the direction of one of the reversal regions, acts on the impact wing a different voltage on the flapping wing than the kickback, whereby the same effect is achieved.

8th shows the thrust development of a drive unit according to the invention over a full swing period (back and forth). The dot-dashed graph in the diagram shows the typical course of the thrust development as it would result in a drive unit, which corresponds to the structure of the in 1 described embodiment follows. Here, the effects of the clap-and-fling effect are clearly visible. When pulling apart two adjacent flapping wings at the beginning of the outward and backward blow (Fling) creates the first shear tip. As the wings move farther apart, the effects of the clap-and-fling fade into the background and are superimposed by the increasing thrust forces of stationary air force components as the angular velocity increases. As the approaching clap approaches, fluid masses are now under high acceleration Wing surfaces compressed and in addition by the due to the braking effect of the torsion spring 7 and the mass inertia of the flapping wing accelerates rapidly decreasing angle of attack. This leads to the thrust point at the end of the outward or backward blow. This course of the thrust development results from the in 1 described relatively rigid construction. It is disadvantageous because it introduces vibrations in the structure holding the drive unit. A more flexible design could "dodge" the local thrust force peaks, returning the excess energy to the supporting structure with a time lag. A more advantageous force curve of such an alternative construction is shown by the solid second graph.

9 shows a flapping wing configuration for a drive unit according to the invention with a rigid wing surface and a swinging in the wing suspension 36 suspended wing axis 3 , The pendulum path is made by two elastic end stops 28 and 29 limited. A fixedly connected to the drive unit supporting structure associated tension spring 30 pulls the wing axis 3 in the direction of the lower end stop 28 , Will the flapping wing around the swing axle 4 moved around cause the fluid force components against the spring action of the tension spring 30 directed force, the wing axis 3 moves from the lower end stop 28 way up. The greater the upward fluid power component, the farther the wing axis approaches 3 the upper end stop 29 , For temporarily occurring force peaks, the flapping wing gives way 2 so up and out by the energy-storing effect of the spring and the inertia of the flapping so Schubkraft peaks and valleys are "leveled". With optimal design, the results in 8th shown by the solid graph shear curve.

The 10a and 10b show two views of a flapping wing configuration for a drive unit according to the invention with a flexible, foil-like wing surface 31 and a pendulum-hung wing leading edge 33 , When stationary, the tension spring pulls 30 over the swinging jib 32 the flexible wing surface 31 smooth (dashed line in 10a ). Acts on movement of the flapping wing 2 around the swing axle 4 the fluid pressure on the flexible wing surface 31 a, it starts to bulge and the clamped angle between swing axis 4 and wing leading edge 33 decreases (full line representation in 10a and 10b ). This design also works "leveling" on the thrust and also offers as in 4 described embodiment has the advantage of growing towards the wing tip angle of attack of the airfoil. In addition, a flexible flapping wing surface can be 31 optimally adapted to the current flow conditions. The lightweight design also reduces the power to weight ratio.

11 shows a helicopter-like aircraft with a drive unit according to the invention as the main drive. The illustrated embodiment uses the in 10 described flapping wing configuration. The outstanding efficiency of Wilhelm Schmidt's propeller drive, published around 1960, was based on the interaction of a "corrugator", which formed the driven flapping wing, and a "Entweller", a solid surface behind the flapping wing, which had the task of generating the vortex behind the flapping wing reduce and direct the resulting thrust jet. The below the drive unit on the container 37 attached control surfaces 34 take on the same task. If these are used with the help of active control elements as rudder flaps, they can the lateral maneuverability and also the controllability to the space axis 1 enable the drive unit parallel vertical axis of the aircraft.

12 shows a flapping wing configuration for a drive unit according to the invention which allows a reversal of the conveying direction.

The flapping wing 2 is around the wing axis 3 freely rotatable in a pivot bearing 19 attached, whose Rotary axis at right angles to the swing axis 4 located. The pivot bearing 19 itself is part of the wing suspension 36 , By means of acting on the flapping root root 20 becomes the angle of attack of the unmoving flapping wing 2 pulled into the zero position. The flapping wing surface is at a joint 38 suspended, which makes it possible by means of an actuator 35 the distance A between the center of gravity 39 of the fluid on the flapping wing surface and the midline of the wing axis 3 to change. The change of this distance can also serve to influence the flow rate. If the distance is exceeded by exceeding the wing axis 3 Negatively it comes to a reversal of the conveying direction (dashed line).

13 shows a drive unit according to the invention in a configuration which is particularly suitable for highly miniaturized embodiments. The functions of the wing suspension, the oscillatory storage and energy storage in a bending elastic component 40 , which preferably consists of spring steel sheet, summarized. This is firmly bordered to the middle. At the oscillatory end of the flexurally elastic component is the displacement surface, which consists in the example shown of a flexible wing surface, which on a rigid front spar 43 is attached. As drive for such a configuration are in the example shown fixed to the flapping wing connected electromagnets 42 used, which are arranged between the impact areas, permanently installed permanent magnets 41 alternately attract and repel and thus stimulate the flapping wing to vibrate, the control of the magnets is taken over by an electronic control. According to an advantageous development, the electromagnets act 42 even as inductive sensors, that is, they recognize the approach of the flapping wing to the permanently installed permanent magnet and the controller determines based on this information time, direction and strength of the magnetic field to be generated. If the electromagnets can be controlled independently by the control, such a drive unit is suitable as the main drive for a miniaturized aircraft, since thus a maneuverability in all directions is made possible.

1

spatial axis

2

flapping wings

3

wing axis

4

swing axle

5

electric motor

6

encoders

7

torsion spring

8th

Torsion spring abutment

9

adjusting spindle

10

drive wheels

11

Synchronous gears

12

torsion spring (for pitch angle reset)

13

surface segment 1

14

surface segment 2

15

surface segment 3

16

surface segment 4

17

surface segment 5

18

articulation

19

pivot bearing

20

mainspring

21

Servo actuator

22

elastomer cushion

23

lever

24

universal joint

25

support block

26

Upper feather

27

Lower feather

28

end stop below

29

end stop above

30

mainspring (for swinging Wing axis)

31

flexible wing area

32

jib rocker

33

Leading edge

34

control surfaces

35

actuator

36

wing suspension

37

container

38

joint

39

Attack focus

40

Elastic bending module

41

permanent magnet

42

electromagnet

43

Vorderspriet

Claims (14)

A flapping wing assembly, in particular for use in an aircraft or for moving a fluid, formed from a number of 2 ⁿ (n ≥ 2) similar flapping wings, the movement areas of which are clover-shaped juxtaposed, wherein a driving device is configured for the flapping wings, which each of the flapping wings to his both adjacent flapping wings can oscillate in opposite directions, and each flapping wing in both reverse regions approaches its respective oncoming neighbors in the same operation. Flapping wing arrangement according to claim 1, characterized in that the oscillating axes the flapping wing evenly around one Space axis are arranged, which through the center point the clover-like distributed movement areas runs. Flapping wing arrangement according to claim 1 or 2, characterized in that the flapping wings have a rigid displacement surface, which are movably connected to the driven wing suspension and at least one restoring force device is configured, which give the flapping wings at least one starting position, from which they can be moved by the fluid forces arising during operation. Flapping wing arrangement according to claim 3, characterized in that the restoring forces at least a return force device while the operation can be changed by means of an adjusting device. Flapping wing arrangement according to claim 1 or 2, characterized in that the flapping wings a flexible, sail-like Own displacement surface, which are similar to the resulting in the operation fluid forces Sail of a sailboat deformed so that a usable for buoyancy force component is generated. Flapping wing arrangement according to claim 5, characterized in that at least one of the attachment points between which stretched the flexible, sail-like Verdrän gerfläche is designed to be movable with respect to the powered wing suspension, so that the movement by the effective Verdrängerflächenprofil changed. Flapping wing arrangement according to claim 6, characterized in that the movable attachment point an adjusting element is associated, which is a movement of the attachment point while the operation of the flapping wing assembly allows. Flapping wing arrangement according to claim 6, characterized in that the movable attachment point a return force device is assigned, which this attachment point at least one defines definable starting position. Flapping wing arrangement according to claim 8, characterized in that the restoring forces of this Restoring force device while the operation can be changed by means of an adjusting device. Flapping wing arrangement according to one of the preceding claims 1 to 9, characterized that behind the flapping wings in the flow direction at least one area is arranged, which has a directivity to the outgoing thrust jet has. Flapping wing arrangement according to claim 10, characterized in that the position of this surface and Thus, the directivity can be changed by an actuator can. Flapping wing arrangement according to claim 4, 7, 9 or 11, characterized in that the Actuators are electrical actuators, which of a electronic control can be controlled. Flapping wing arrangement according to claim 12, characterized in that the change in length and direction of at least one thrust vector of the flapping wing assembly, which results from the adjustment of the adjusting device (s) by means of at least one sensory device is detected, and the supplied by this sensory device actual value within the controller is compared with a setpoint, and the controller in case of deviation of the actual value of the setpoint, the adjusting devices so on that controls that length and direction of the detected thrust vector approaches the set point. Flapping wing arrangement according to one of the preceding claims, characterized in that single flapping wings or flapping groups independently controllable Own drives and these by an electronic control so can be coordinated that is due to the different control of individual drives a change of direction the total thrust vector or a torque acting on the flapping wing assembly results.