ABSTRACT

A wind energy-harvesting device receiving wind energy and converting the wind energy into rotational energy is disclosed. The energy-harvesting device includes a base capable of orienting the energy harvesting device toward a wind direction, and frame assemblies having flaps configurable to be closed or opened. The closed configuration is adapted to receive wind loading, while the open configuration is adapted to let pass wind flow therethrough. The frame assemblies are movable in a swinging manner such that windward and leeward frame assemblies are in closed and open configurations, respectively, when said assemblies are in converging phase and said windward and leeward assemblies are in open and closed configurations, respectively, when said assemblies are in diverging phase. A converter of synchronized swinging movement into rotational movement is also included. The energy harvesting electrical generator engine includes a leverage interconnecting the assemblies and base.

FIELD OF THE INVENTION

The present invention relates to a wind energy harvesting and, more specifically, to a wind energy-harvesting device provided with synchronized swinging receiving areas.

BACKGROUND OF THE INVENTION

Wind has been used as a source of power since earliest times. Whether to move sailing ships or to turn windmills, wind has supplied energy for man to adapt to his use. Probably the best-known wind-powered device is the windmill, which has found usage in generating electricity, in pumping water and in many other applications. The conventional windmill uses a plurality of vanes or blades which extend radially outwardly from a central hub. A shaft is driven by this central hub and the shaft's output is then used as desired. The windmill must be quite large to be effective and requires a large space for the blades to turn in. The essential operational characteristics of the windmill are quite well known and this device has had a lengthy existence.

Classic windmills and turbines employ vanes or propeller blade surfaces to engage a wind stream and convert the energy in the wind stream into angular force which rotates a horizontal shaft. These devices, with their exposed rotating blades, have posed technical as well as safety, environmental, and aesthetic concerns which have limited their use in today's world.

US Patent 4238171 discloses a reciprocating wind engine utilizing plural, movably mounted sets of panels to form pistons. The pistons are slidably movable along guides disposed on the engine base. Mechanical linkage between guideline and shows is characterized by the high level of friction losses because of large contact area. There is a long-felt and unmet need to provide a wind engine with decreased losses to raise efficiency of the wind engine.

SUMMARY OF THE INVENTION

In an example wind-harvesting device, cooperating first and second pistons may be spaced from each other on either side of a central crankshaft. As the wind strikes the surface of a first set of panels, the first piston is moved toward the crankshaft and the second piston is pulled toward the crankshaft from the opposite side. When both pistons are adjacent the crankshaft, the panels on the first or windward piston open to allow the wind to pass therethrough into contact with the panels of the second piston which are closed to present a uniform surface to the wind. The pistons are forced away from the crankshaft to complete one cycle of operation. The output from the crankshaft may be utilized to generate electricity, or for any other suitable purpose. Plural engine segments may be cooperatively joined together to form a bank of such units.

A wind-harvesting device may comprise (a) a base capable of orienting an energy harvesting device toward a wind direction; (b) two frame assemblies having flaps configurable to be closed or opened; the closed configuration is adapted to receive wind loading; the open configuration is adapted to let pass wind flow therethrough; the frame assemblies are movable in a swinging manner such that windward and leeward frame assemblies are in closed and open configurations, respectively, when the assemblies are in converging phase and the windward and leeward assemblies are in open and close configurations, respectively, when the assemblies are in diverging phase; (c) a converter configured to convert synchronized swinging movement into rotational movement. The wind-harvesting device further comprises a leverage interconnecting the assemblies and the base. The leverage is provided with balance weights compensating assembly weights.

The wind-harvesting device may further comprise a leverage interconnecting the assemblies and the base. The leverage may include counter balance weights compensating assembly weights, to to reduce an influence from gravitation.

The leverage may comprise two pairs of parallel levers fulcrumed to the base. Each pair of the levers may interconnect the base and corresponding assembly so that swinging movement of corresponding assembly is kept at a constant direction to a wind.

The levers may belong to different pairs including cogwheels coaxially fulcrumed with the levers and and may be engaged therebetween. The cogwheels may synchronize the relative motion and position of the frame assemblies in a way that when one frame is pushed by the wind flow to its end position, the other frame assembly is moved to its starting position in order to get ready for its turn to take over and control the other frame assembly, and so on.

The frame assemblies may open and close their panels according to a set of configurable stoppers. These stoppers may be located at the end of the path of motion, such that the panels may change their state from opened to closed and vice-versa, according to the location and position of the configurable stoppers. The stoppers may be configured in a way which would prevent both panel assemblies from having their panels open at the same time. A short delay between the closing of the shutters of one panel and the opening of the shutters of another panel may be implemented to prevent such a situation, although the system is expected to preserve its motion due to its inertia.

Each of the frame assemblies may further comprise panels rotatable through generally 90°. The panels may rotate from a position perpendicular to the direction of wind flow when the assembly moves with the wind to a position generally parallel to the direction of wind flow when the assembly moves in opposition to the wind flow.

The orientable base may also include a directing empennage.

The frame assembly may comprise a plurality of sections further comprising said rotatable panels; a rotating direction of said panels in said sections may be set so that a wind force applied to the frame may be symmetrically balanced relative to a direction of frame assembly movement.

The method of rotating the panels may include rotating each panel to a different direction to avoid a situation that during its position change, all panels may rotate to the same direction, and by that, a wind flow may create a force to swivel the structure away from the wind's direction. By rotating each set of two panels to the opposite direction, such forces may be eliminated and the system may stay oriented to the wind direction. Other rotating panels systems do not take care of this problem and therefore may rotate away from wind direction during the rotation process of their panels.

The converter of swinging movement into rotational movement may further comprise (a) swinging cogwheels engaged to the lever cogwheels; (b) sectorial elements mechanically connected to the corresponding swinging cogwheels; and (c) a receiving shaft positioned such that the shaft is in alternate mechanical contact with a cam element.

The wind-harvesting device may comprise (a) a base orientable according to a wind direction; (b) two frame assemblies having a closed and an opened configuration; the closed configuration adapted to receive wind loading; the opened configuration adapted to let pass wind flow therethrough; the assemblies oppositely movable in a reciprocal manner along the base such that windward and leeward assemblies are in close and open configurations, respectively, when the assemblies are in converging phase and the windward and leeward assemblies are in open and close configurations, respectively, when the assemblies are in diverging phase; (c) a converter configured to convert reciprocal movement into rotational movement.

The converter may further comprise a driving chain strained between two cogwheels and a pair of gripping devices individually attached to the frame assemblies; the gripping device may be configured to grip the driving chain in an alternating manner during the converging and diverging phases such that the chain moves in one direction.

The wind-harvesting device may furthercomprise a tail fin adapted for wind orientation of the base.

The assemblies may be slidably connected to the base.

The assemblies may be hingedly connected to the base by means of an accordion-like leverage.

A method of converting wind energy into electric energy may comprise: (a) providing a wind harvesting device for converting the wind energy into rotational energy; the wind harvesting device comprising (i) a base capable of orienting the wind harvesting device toward a wind direction; (ii) two frame assemblies having flaps configurable to be closed or opened; the closed configuration may be adapted to receive wind loading; the open configuration may be adapted to let pass wind flow therethrough; the frame assemblies may be movable in a swinging manner such that windward and leeward frame assemblies may be in closed and opened configurations, respectively, when the assemblies are in converging phase and the windward and leeward assemblies may be in opened and closed configurations, respectively, when the assemblies are in diverging phase; (iii) a converter configured to convert synchronized swinging movement into clockwise controlled rotational movement. The wind harvesting device may further comprise a leverage interconnecting the assemblies and the base. The leverage is provided with balance weights compensating assembly weights; (b) base orient the wind harvesting device according to the wind direction; (c) oppositely moving the frame assemblies in a synchronized way; (d) closing and opening windward and leeward assemblies panels, respectively, when the assemblies are in converging phase and opening and closing the windward and leeward assemblies, respectively, when the assemblies are in diverging phase.

The panel assemblies may be moved in a swinging manner, wherein the leverage interconnects the assemblies and the base. Balance weights may compensate assembly weights to eliminate gravity-derived influence. The panel assemblies may lock their panels in any position to allow maximum efficiency of wind pressure capturing and may open panels at a configurable angle in order to avoid excessively high pressure on panels.

A method of converting of swinging movement into controlled rotational movement may include alternately contacting cam elements being in swinging rotation with a receiving shaft. Each of one or more cogwheels may be connected to the front and back frame assemblies may rotate in an opposite direction during movement of the frame assemblies. As such, a set of two opposite single-side-motion-lock bearings may be installed to connect an electrical energy generator to a desired cogwheel when the cogwheel is rotating in the desired direction. One of the single-side=motion=lock bearings may be installed to collect the motion of the front cogwheel when it is moving in the desired direction and the other single-side-motion-lock bearings is installed to collect the motion of the rear cogwheel when it is moving in the desired direction. As such, the system assures that at any time during its movement, the electrical energy generator may be rotated in one direction.

A wind engine may include a track; a first frame assembly and a second frame assembly, comprising rotatable flaps; and a converter configured to convert reciprocal movement into rotational movement. The frame assemblies are orientable relative to a wind direction. Positions of the flaps are switchable such that wind pressure force applied to said assemblies has an oppositely switchable component parallel to said track and said assemblies reciprocate along said track.

A method of converting wind energy into electric energy comprises providing a wind engine for converting the wind energy into rotational energy and oppositely moving said frame assemblies.

The method comprises steps of orienting said frame assemblies relative to a wind direction and positioning of the flaps are switchable such that wind pressure force applied to the assemblies has an oppositely switchable component parallel to the track and the assemblies reciprocate along the track. BRIEF DESCRIPTION OF THE DRAWINGS

Figs 1 and 2 are schematic views of a wind engine;

Figs 3a and 3b are schematic views of closed and opened frame assemblies;

Figs 4 and 5 are schematic views of a swinging-to-rotational motion converter including sectorial cams;

Fig. 6 is a schematic view of a swinging-to-rotational motion converter including one- directional couplers; and

Fig. 7 is a schematic view of a smoothing mechanism;

Fig. 8 is a schematic view of a wind engine including a driving chain;

Figs 9a and 9b are schematic views of an accordion-like leverage;

Fig. 10 is a graph of an output turning torque vs. time;

Fig. 1 1 is a schematic view of a wind engine including a directing empennage;

Fig. 12 is a schematic view of a wind engine including balanced frame assemblies;

Figs 13a and 13b are schematic views of a wind engine including tiltable frame assemblies; and

Fig. 14 is a schematic view of a multi-row wind engine.

DETAILED DESCRIPTION

The following description is provided, wherein like reference numerals refer to similar components across the several views..

Power P in watts of free wind flow applied to a wind turbine rotor can be calculated from the following equation

? = *° ^{' A ' V} (1)

2 where rho is air density (about 1.225 kg/m at sea level, less higher up), A is swept area, exposed to the wind (m ² ), is wind speed in meters/sec.

Taking into account some theoretical and practical limitations we estimate output power of the wind turbine in accordance with the following expression:

_{p ^} rho - A - Cp - V ³ - Ng - Nb ₍₂₎ where Cp is a coefficient of performance limited by the maximal theoretical value 0.59 known as the Betz limit. A practically achievable value of Cp is 0.35. Vis wind speed in meters/sec, Ng is generator efficiency. A car alternator has a typical generator efficiency of 50% and 80% or more may be possible for a permanent magnet generator or a grid- connected induction generator. Nb is a gearbox/bearings efficiency which depends on used components. A 95% gearbox/bearings efficiency is achievable.

A solution based upon a wind-wall sail like structure may collect wind energy with performance efficiency Cp = 1 because the whole area of wind-exerted sail may be for harvesting wind energy. Each sail may be built up of a plurality of small parallel rotatable panels such that they can form a closed or an opened Venetian-curtain-like structure.

Figures 1 and 2 depict an example wind-harvesting device 5 comprising frame assemblies 20a and 20b which may include rotatable flaps 30a and 30b, respectively. The frame assemblies 20a and 20b may be swingingly movable by means of levers 50a to 50d between stoppers 40a, 40b and 40c. The frame assemblies 20a and 20b may move in opposite directions. The frame assemblies may be mounted on a bar 10, which enables the automatic orientation of the system around the base pole 15, according to wind flow direction.

Referring to Figure 1, wind flow may cause movement of the closed frame assembly 20b rightwards. The frame assembly 20b may be mechanically connected with cogwheel 60b by means of a lever 50d. Movement of the frame 30b rightward may cause rotation of the cogwheel 60b clockwise. The cogwheel 60a may be in engagement with the cogwheel 60b. Counterclockwise rotation of the cogwheel 60a may result in leftward motion of the frame 20a. An opened position of the flaps 30a may allow the wind flow to freely pass through the frame 20a with negligible opposing impact. Thus, the wind flow may the closed frame assembly 30b and opened frame assembly 30a to be drawn towards each other.

End switches 40a, 40b and 40c may be designed for switching configurations of the frame assemblies 20a and 20b, from the closed configuration to the opened configuration and vice versa.

The frame assemblies 20a and 20b may be switched by the end switch 40b into the closed and opened configurations, respectively. Referring to Figure 2, the wind flow may freely pass through the frame assembly 20b and exert pressure on the frame assembly 20a, thus causing the frame assemblies 20a and 20b to move apart. Similar to the switch 40b, the switches 40a and 40c may switch configurations of the frame assemblies 20a and 20b into opened and closed configurations, respectively.

The cogwheels 60a and 60b may include balance-weights 70a and 70b which may be designed for balancing the frame assemblies 20a and 20b, respectively. The balance between assembly 20a/20b and weight 70a/70b may decrease mechanical losses associated with friction.

Figures 3a and 3b depict example opened and closed configurations of the frame assembly 20a/20b which may comprise a frame 21 and flaps 22. As seen in Figures 3a and 3b, the flaps may be rotatable in opposite directions.

Figures 4 and 5 depict an example kinematic scheme of a swinging-to-rotational-motion converter 120. Fig. 4 corresponds to the convergent motion of the frame assemblies 20a and 20b depicted in Fig 1. Fig. 5 corresponds to the divergent motion of the assemblies 20a and 20b depicted in Fig. 2.

The term "sectorial member" hereinafter refers to a part of a circle fulcrumed in the centre of the circle.

Rotational torque from levers 50a/50b is transferred to the cogwheels 60a/60b. Further, cogwheels 80a/80b are in engagement with the cogwheels 60a/60b provided with sectorial members 90a/90b connected to the cogwells 80a/80b by shafts 85a/85b. The sectorial members 90a/90b are centered so that cylindrical surfaces 92a/92b may alternately come into engagement with a wheel 100. The proposed arrangement provides uniform engagement over surfaces 92a/92b. An output rotational torque is received from an output shaft 110.

When the frame assemblies 20a and 20b convergently move as depicted in Figure 1, the sectorial member 90b may be in engagement with the wheel 100 which rotates clockwise as depicted in Figure 4. Referring to Figure 5, when the frame assemblies 20a and 20b divergently move as depicted in Figure 2, the sectorial member 90a may be in engagement with the wheel 100 which rotates clockwise, as well. Thus, conversion from swinging movement into rotation is performed.

Figure 6 depicts an example kinematic scheme of a swinging-to-rotational-motion converter 120a. Rotational torque from levers 50a/50b may be transferred to the cogwheels 60a/60b. Cogwheel 80a/80b may be in engagement with cogwheels 60a/60b. Cogwheels 140a/140b may be connected to cogweels 80a/80b by one-directional couplers 130a/130b. The couplers 130a/130b are designed to transfer the rotational torque in a predetermined direction and provide free rotation in the opposite direction. The cogwheels 140a/140b may be in engagement with a wheel 150. An output rotational torque is received from an output shaft 160. As can be seen in Figure 6, one-directional coupler 130a may allow cogwheel 140a to rotate freely in a direction opposite of cogwheel 80a.

Figure 7 depicts an example mechanism for smoothing the output rotational torque. A cogwheel 210 may receive the rotational torque from the shaft 1 10 or 160 (not shown). A smoothed rotational torque may be received from the cogwheel 220. The cogwheels 210 and 220 may be kinematically interconnected by means of a chain passed through two cogwheels 230 and two cogwheels 240. Positions of the cogwheels 230 are securely fixed. The cogwheels 240 may be coupled by springs 250 or other elastic devices to pins 260. The oscillations in the rotational torque at the cogwheel 210 may be damped by means of changes in positions of the cogwheels 240. The aforesaid position changes may result in changes in the chain tension. Additional smoothing may be provided by an inertial wheel 270. Figure 8 depicts an example embodiment 5a of a wind engine. The assemblies 20a and 20b may reciprocally move along the base 10 which may be oriented according to a wind direction by means of a rib tile 175. The assemblies 20a and 20b may be slidably connected to the base 10. The wind engine 5a may include a driving chain 160 strained between two cogwheels 170a and 170b. Linear motion from the assemblies 20a and 20b to the chain 160 may be transferred by means of gripping devices 190a and 190b. These gripping devices 190a and 190b may be preprogrammed for alternatively gripping the driving chain 160. The gripping device 190a may grip the driving chain 160 at the converging phase of reciprocal motion while the gripping device 190b may grip the driving chain 160 at the diverging phase or vice versa. Linear motion of the driving chain 160 may be converted into rotational motion by means of the cogwheel 170c and may be transferred onto a shaft of electric generator 180.

Figures 9a and 9b depict schematic views of an accordion-like leverage 300 adapted for low-frictional reciprocal movement. The assemblies 20a and 20b may be interconnected by levers 330, 340a and 340b hinged by hinges 310 and 320. The central hinge 320 may be mechanically fixed to the base 10 (not shown). At the convergent phase of reciprocal movement of the assemblies 20a and 20b (Fig. 9a), angles between the levers 330 and 340a/340b interconnected by the hinges 310 may decrease. At the convergent phase of reciprocal movement of the assemblies 20a and 20b (Fig. 9b), angles between the levers 330 and 340a/340b interconnected by the hinges 310 may increase.

Figure 10 depicts a graph of the variation of the output rotational torque with time. The rotational torque graph A received from the output shaft 1 10 of Figures 3 or 4 or output shaft 160 of Figure 5 is substantially pulsative. Curve B represents the rotational torque represented by a smoothed by the mechanism depicted in Figure 6.

Figure 11 depicts an example wind engine including a directing empennage 12. The frame assemblies 20a and 20b may swingingly move along the base 10. The wind engine may be rotatable around the axis 15. The empennage 12 may hold the wind engine in an optimal position.

Figure 12 depicts example frame assemblies 22a and 22b which may comprise a plurality of sections 22a/32a and 22b/32b, respectively. The panels in the sections 22a/22b and 32a/32b may be rotatable contrariwise so that a wind force applied to the frame may be symmetrically balanced relative to a direction of frame assembly movement.

Although features and elements are described above in particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements.

Figures 13a and 13b depict an alternative embodiment of the current invention. A wind machine 400 may comprise a support 410, a truck 420, tiltable frame assemblies 430 and generator 440 configured to receive kinetic energy of linear motion of the frame assemblies 430. As seen in Figures 13a and 13b, the frame assemblies 430 are at a substantially right angle to wind direction denoted by an array, while a normal to flaps 435 is at an acute angle such that a wind pressure force has a component parallel to the track 420. Positions of the flaps 435 are switched such that the frame assemblies 430 synchronically reciprocate along the track 420 to keep a balance of forces acting on the wind machine.

Figure 14 depict a multi-row embodiment of the wind machine 400.

Embodiments:

1. A wind engine receiving wind energy and converting the wind energy into rotational energy.

2. The engine of embodiment 1, further comprising a base orientable according to a wind direction.

3. An engine as in any preceding embodiment, further comprising a first and second frame assembly, the first and second frame assemblies having a closed and open configuration.

4. An engine as in any preceding embodiment wherein the closed configuration is adapted to receive wind loading; and the open configuration adapted to let pass wind flow therethrough.

5. An engine as in any preceding embodiment wherein the assemblies are oppositely movable in a swinging manner such that windward and leeward assemblies are in close and open configurations, respectively, when the assemblies are in converging phase and the windward and leeward assemblies are in open and close configurations, respectively, when the assemblies are in diverging phase.

6. An engine as in any preceding embodiment, further comprising a converter configured to convert swinging movement into rotational movement.

7. An engine as in any preceding embodiment It further comprising a leverage interconnecting the assemblies and the base.

8. An engine as in any preceding embodiment wherein leverage is provided with balance weights compensating assembly weights.

9. An engine as in any preceding embodiment wherein the assemblies oppositely movable in a reciprocal manner along the base such that windward and leeward assemblies are in closed and open configurations, respectively, when the assemblies are in converging phase and the windward and leeward assemblies are in open and close configurations, respectively, when the assemblies are in diverging phase.

10. An engine as in any preceding embodiment, further comprising a driving chain strained between two cogwheels and a pair of gripping devices individually attached to the frame assemblies.

1 1. An engine as in any preceding embodiment wherein the gripping devices are configured to grip the driving chain in an alternate manner during the converging and diverging phases such that one directional motion of the chain is provided.

12. An engine as in any preceding embodiment, further comprising a tail fin adapted for wind orientation of the base.

13. An engine as in any preceding embodiment wherein the assemblies are slidably connected to the base.

14. An engine as in any preceding embodiment wherein the assemblies are hingedly connected to the base by means of an accordion-like leverage.

15. An engine as in any preceding embodiment wherein the orientable base is provided with a directing empennage. 16. An engine as in any preceding embodiment wherein the frame assembly comprises a plurality of sections further comprising said rotatable panels.

17. An engine as in any preceding embodiment wherein a rotating direction of said panels in said sections is set so that a wind force applied to the frame is symmetrically balanced relative to a direction of frame assembly movement.

18. An engine as in any preceding embodiment wherein the leverage comprising two pairs of parallel levers fulcrumed to the base.

19. An engine as in any preceding embodiment wherein each pair of the levers interconnects the base and corresponding assembly so that swinging movement of corresponding assembly kept at constant to a wind direction is provided.

20. An engine as in any preceding embodiment wherein the levers belonging to different pairs provided with cogwheels coaxially fulcrumed with the levers and being in engagement therebetween.

21. An engine as in any preceding embodiment wherein each frame assemblies further comprises panels rotatable through generally 90° from a position perpendicular to the direction of wind flow when the assembly moves with the wind to a position generally parallel to the direction of wind flow when the assembly moves in opposition to the wind flow.

22. An engine as in any preceding embodiment wherein a converter of swinging movement into rotational movement further comprises any combination of the following: swinging cogwheels engaged to the lever cogwheels; sectorial elements mechanically connected to the corresponding swinging cogwheels; and/or a receiving shaft positioned such that the shaft is in alternate mechanical contact with the cam element.

23. A method of converting wind energy into electric energy in accordance with any previous embodiment.