THE DESCRIPTION

Technical Field

The described invention presents improvements in drum and S- wind rotors, as well as in their assembly to the electromagnetic generators of electric energy.

Background Art

Machinery for transformation of the wind energy into electric one aggregate wind motor(s), electric generators) and ancillary devises.

A grate diversity of wind motors exists around the world, called aero, or air, or wind wheels, rotors, mills, turbines, machines, engines, drives.

The first type of wind motor considered here is known under different names: wind-wheel, fan-wheel, cylindrical rotor, drum rotor, impulse-turbine water wheel, and runner. We have found the earliest examples in [1.1] - [1.9]. We use the name 'drum rotor'.

The second type of wind motor is named 'S-rotor' because of the shape of cross section (profile) of its wings. We have found the earliest implementations in [1.10] - [1.14]. The conventional S-rotor is popular also as "Savonius rotor".

The wing of rotors is named differently: plate, airfoil, vane, blade, scoop, paddle, bucket, and cup. We use the name 'blade'.

In 1915, John C. Bunnell splits both semi-cylindrical blades f om the shaft, and overlaps them [1.15]. By doing this, he provides communicating passage {CP), later on named Opening' or Offset' (o). This passage is the essence of the overlapped S-rotors because the fluid passes through it and acts upon the concave surfaces of the returning blade.

From 1922 to 1931 Savonius S. Johannes advances, patents and propagates the utilization of S-rotors [1.16], [1.17], [II.l]. Many of his investigations examine rotors with a single module, named floor (story, stage, stack, tier, level), which presents a set of blades, fixed between two horizontal circular disks (endplates).

After the thirties of the past century, the interest to S-rotors decreases and then revives about 50 years later pi.2] and pi.3J.

The S-rotors have many benefits [ΪΙ.4], [II.5]; nevertheless, they are still the less disseminated motors in the real operated installations. The reasons are the fluctuating torque, the lower speed of rotation, the lower coefficient of power C _p , and the lower harvested energy in comparison to the modern horizontal axis wind turbines [II.6], [II.7]. After the energy crisis of the seventies, many inventors suggest improvements in order to overcome these weaknesses, but the performance is still far from the desired.

With regard to vertical axis wind motors consistin of two coaxial wind rotors, we have found an early source for coaxial rotation of water wheels [1.18] and four subsequent sources: p.8], [1.19], [1.20] and [1.21].

The review of prior art in electricity generators indicates a big diversity.

Classic alternators consist of stator and cylindrical rotor, but variety with disk rotors also exists [1.22]. Generators with two contrary rotating rotors are known too p.23]-[1.25], as well as a direct fixing of the electric rotor to the wind one [1.26].

The target of our improvements is to increase the operational performance of the machines with S-rotors to the levels prescribed in [II.8] and in [II.9]. Disclosure of the Invention

The disclosed machine disposes on a stationary base but has no stator, neither of the wind motor nor of the electricity generator.

In one embodiment, the wind motor of the disclosed machine transforms wind energy solely by an improved S-rotor. In another embodiment, such a rotor is implemented as an inner rotor, concentric to an outer rotor. Each rotor consists of two or more floors. The blades and disks of the floors form a central hollow shaft. They bear alone all loads and transmit them to the bottom and to the upper bearing supports by means of flange connectors.

The electricity generator of the disclosed machine transforms the kinetic energy of rotation into electric one by means of two rotors of the generator, which are in the form of laminar disks or concentric drums as the case is.

Each floor of the improved S-rotor consists of four or six blades and three passages unlike the existing one with only two overlapped blades and one passage.

The number of blades, as well as their size, disposition and form are determined according to the intended function and capacity of the machine. Bach of the four or six blades, as the case is, redirects wind flow through individual passage. The height of each passage is only a part of the total floor height.

Unlike the known floors, in addition to horizontally, the disclosed floor redirects wind flow vertically towards the relevant passage. The vertical redirection effects by concave redirectors (guiding surfaces, redirecting lamellas) installed between each pair of adjacent blades. Due to the compressive effect of advancing blades and redirectors, the wind flow accelerates through the passage and then expands between the respective pair of returning blades. The magnitude of torque and the harvested power from every single floor increase, and the fluctuations reduce. Additional positive effect is that the redirectors enhance the solidity of blades, which is an important benefit especially for blades of thin sheet material.

The disclosed outer rotor presents an improved drum rotor, which embraces the inner one. Its first function is to capture the energy of entering and exiting wind, and to transmit this same energy to one of the electric generator rotors. The second function is to guide the wind flow into the inner wind rotor.

The inner wind rotor captures another part of the total energy of the entering and exiting wind, and transmits this part of energy to the second electric generator rotor. In one embodiment, the two concentric wind rotors rotate in opposite directions while in another - in the same direction. In the second case, one of the wind rotors transmits the rotation to the relevant generator rotor in reverse direction.

Depending on the size and uie shape of blades, as well as on the wind velocity, each of the wind rotors can outrun or can lag behind with respect to the other. Optimal sizing provides optimal relative rotation and maximum total power from both rotors in conditions of prevailing wind velocity for the site emplacement.

Brief Description of Drawings

For simplicity, the figures illustrate parts of a relatively small machine. The wind rotors of such machines are manufactured by sheet materials (metal or plastic or composite), the thickness of which is illustrated with a single line.

Fig.l depicts vertical plane section of an embodiment of the disclosed wind electric machine, cut through the line 1-1 in Fig.lA.

Fig.l A depicts horizontal cross section through the line 1A-1A in Fig.l across the upper division of the second floor of the embodiment.

Fig.2 illustrates dimensioning, drawing, cutting off, bending and assembling of the blades on a floor of the improved S-rotor.

Fig.2A illustrates the geometric characters of the blades and the determination of the length of the slot by extension of the tail surface of the blades.

Fig.2B illustrates the determination of the length of the slot by partial twisting of each blade.

Fig.3 depicts perspective view on a floor of the disclosed improved S-rotor before the installation of the redirectors on it.

Fig.3A depicts horizontal cross section through the line 3A-3A in Fig.3, and the momentary wind flow through the passage in the upper division.

Fig.3B depicts horizontal cross section through the line 3B-3B in Fig.3, and the momentary wind flow through the passage in the mid division. Fig.4 depicts horizontal cross section through a floor comprising six blades in their initial state (before modification).

FigAA depicts horizontal cross sections taken through the upper division of a floor with six blades, dimensioned according to the first designs.

Fig.4B depicts horizontal cross sections taken through the upper division of a floor with six blades, dimensioned according to the second designs.

Fig.5 depicts other perspective view on the floor in Fig.3, after the installation of the redirectors on it, and view on the prepared redirectors, which are oriented towards corresponding places between blades, where they are installed.

Fig.5 A depicts horizontal cross section through the line 5A-5A in Fig.5.

Fig.6 depicts vertical plane section through the line 6-6 in Fig.6A.

Fig.6A depicts a view on the floor shown in Fig.5, turned to 45°.

Fig.6B depicts horizontal cross section through the line 6B-6B in Fig.6A.

Fig.7 depicts vertical plane section through the line 7-7 in Fig.7A.

Fig.7A depicts a view on the floor shown in Fig.5, turned opposite t 45°.

Fig.7B depicts horizontal cross section through the line 7B-7B in Fig. 7A.

Fig.8 depicts a side view on a floor of drum wind rotor with four vertical blades. Fig.SA depicts a vertical plane section through the line 8A-8A of the floor of drum wind rotor at Fig.8.

Fig.8B depicts a horizontal cross section through the line 8B-8B of the floor of drum wind rotor at Fig.8.

Fig.8C depicts a momentary wind flow through the cross section of outer and inner rotors presented at Fig.lA.

Fig.8D depicts a momentary wind flow through the same cross section as in Fig.8C but the outer rotor is turned to 45°.

Fig.8E depicts a momentary wind flow through the same cross section as in Fig.8C but the inner rotor is turned to 90°.

Fig.9 depicts the momentary wind flow through the cross section of outer floor with five blades and inner floor as in Fig.10. Fig.10 depicts the widening of the blades presented at Fig.3A by means of additional front surfaces.

Fig.l 1 depicts side view on a floor of outer wind rotor with inclined blades.

Fig.12 depicts side view on a floor of outer wind rotor comprising eight vertical blades, which is designed for opposite rotation with respect to the inner rotor.

Fig.l2A depicts a momentary wind flow through floors of an outer and of an inner wind rotor, which rotate in opposite directions.

Fig.l2B depicts a horizontal cross section through the line 12B-12B in Fig.12. Best Mode for Carrying Out the Invention

The main components of the disclosed machine are illustrated and explained in details while the auxiliary ones are depicted, but not clarified.

The most general presentation is provided in the Fig.l and in the Fig.1 A.

The whole machine is placed on a horizontal base 1, which could be located on a land or a rocks surface, roof of a building, pillar, tower or another proper carrying construction. On the base 1, the bearings 2 and 3 are installed.

To the upper disk of bearing 2 the outer wind rotor is fixed, which comprise two floors, each of them with four blades 4, accordingly 5, symmetrically and balanced fixed between three horizontal flat ring disks 6, 7 and 8. For reduction of the fluctuations of the torque or for improvement of the solidity and of the capacity of the machine, this number of blades can be increased to five, six and more.

Around the mid disk of the bearing 3, the bottom disk rotor 9 of the electricity generator is fixed. Around the upper disk of the same bearing 3 the upper disk rotor 10 of the generator is fixed. Above them, the inner wind rotor is placed, which propels the rotor 10 by means of the reinforcing flange 11.

The inner wind rotor also comprises two floors. Each floor consists of four blades 12, accordingly 13, symmetrically fixed between the three horizontal flat circular disks 14, 15 and 16. The both floors of the inner rotor are identical, as well as the both floors of the outer one. The only distinction between related pairs of floors is that the blades of the first floor are fixed by 45° in advance with respect to the blades of the second floor. In effect, the fluctuations of torque are reduced and the solidity of rotors is enhanced.

The height of each inner rotor's floor is divided into three divisions: 17, 18, 19 for the first and 20, 21, and 22 for the second floor accordingly. The concave surfaces 23, 24, 25, 26, 27 for wind redirection, named redirectors, partially seen at Fig.l and Fig.lA, are explained below. The space between each pair of adjacent blades at each individual division comprises a wind passage or a redirector respectively.

The flange 28 that is pressed to the axis 29 reinforces the upper disk 14 of the inner rotor. By means of the bearing 30, the rotor turns in the cross support 31, which is guyed by steel cables 32 and 33 to the footings 34 and 35.

The outer rotor turns in the upper support by means of the bearing 36. This outer rotor transfers its rotation to the bottom disk rotor 9 of the electricity generator by means of the transmission gear 37, supported to the base 1 by the axle 38. At the illustrated embodiment, the outer and the inner rotors rotate in the same direction and the gear 37 inverts the rotation direction for the bottom generator rotor 9. According to the size and the design of the machine, the transmission gear 37 is a belted one or chained or classic gear wheels train, etc.

Setting the generator's rotors 9 and 10 under the wind rotors in the form of horizontal ring disks provide compact construction of the machine. In one of the disks, e.g. 9, the windings are installed, where the electromotive force is induced. Next to it, the current collector apparatus 39 and the power conducting cable 40 are also illustrated. In the second disk 10 the exciter of the magnetic field is installed, which can consist of permanent magnets or of conventional DC assembly. In other embodiments, generators with two concentric drum rotors can be implemented. For small size machines most likely the available at the market, ready-made generators would be used.

Fig.2 illustrates dimensioning, drawing, cutting, bending and assembling of the blades 12 or 13 on a floor of the improved S-rotor, which can be used solely as a simple motor or as an inner rotor in the disclosed machine. The example presents classic semi-circle profile with diameter d so mat the blade is semi-cylinder. In other embodiments, diverse profiles can be implemented. The elaboration of such blades is analogical.

Unlike the existing ones, the disclosed semi-cylinders are not equally wide throughout their whole height. The outer (advancing) edge 41 is a permanent vertical line, but the inner (tail, returning) edge 42 presents a step line in three divisions e.g. 20, 21, 22. Here is the method for elaboration of the blades.

The original whole tail edge of the primordial semi-cylindrical sheet is cut across by two cuts 43 perpendicular to the edge, each of length /, which divide the height H in three divisions: upper 44, mid 45 and bottom one 46. The height of the upper division h _u is equal to the height of the bottom division ¾, and both are equal to one quarter of H h _u = h _u =l/4H). The height of the mid division h _m is 1/2H.

For floors with six blades, tile heights of all three divisions are equal in length to one third of the total height H i.e. h _u = h _u = h _m -1/3Ή.

For floors with four blades, the heights of all three divisions can also be equal in length (1/3H), or the only one horizontal cut 43 could be made by which the total height H be divided to only two equal divisions. However, the last two options are less efficient.

The length / of the cutting 43 depends on the blade diameter d and the overlapping o of both the opposite blades, forming the wing. This length / could be determined by two approaches.

According to the first approach, the tail surface/line of the original blade is extended in the same circular profile as it is illustrated with the dashed arches 47 at Fig.2A. The blade transforms from semi-cylinder to segment of cylinder with bigger length of the arc. The chord of this arc forms an acute angle with respect to the diameter of the initial blade.

According to the second approach, illustrated for a single blade at Fig.2B, the original semi-cylindrical blade is turned around its own center to the angle β with reference to the initial position of the chord. Same turning can be determined by the angle γ between the final position of the chord and the diameter drafted through the final position of the advancing edges of the both opposite blades.

The extension of the tail surfaces according to the first approach, and respectively the turning of the blades according to the second approach, ends when the tail edge 42 of the blade touches the concave surface of the preceding blade.

At the end of cutting /, vertical line is drafted in parallel to the tail edge of the blade, which forms vertical strips with width / and height h _u , and h _m accordingly. The resulting strips are bent along the vertical lines as it is illustrated at Fig.2. For floors with four blades, the strips of each two opposite blades 12a and 12c are bent along the upper division 44 and along the bottom division 46, while the strips of the other two opposite blades 12b and 12d are bent along the mid division 45.

Depending of sheet material used for the blades, after bending the strips 44, 45 and 46 are glued or welded or riveted etc. to the corresponding strips of the adjacent blades as it is illustrated in Fig.2 b the two directional arrows, drafted with dashed lines.

The upper and the bottom edges of the already prepared blades are fixed to its appropriate position at the disks, which is illustrated in Fig.2 with the dotted at the beginning arrows.

A floor elaborated according to the above explanations is depicted in Fig.3. The advancing edges 41 of the blades lay on a circle smaller than the peripheral disk circles for the wind motors without outer rotor (Fig.3 A). For motors with two concentric floors/rotors, the advancing edges 41 lay on the peripheral circle of the disks (Fig.lA and Fig.3B).

As a result of the drafting, cutting, bending and fixing of the strips 44, 45 and 46 of blades 12a, 12b, 12c H 12d bilayer walls are formed on the opposite positions along the three divisions 20, 21 and 22 of the tubular central hollow. By this, the strength of the floors is preserved and the hollow can perform the function of a central shaft.

Simultaneously the other two opposite walls in the same divisions 20, 21 and 22 are exempted. By this three communicating passages CP20, CPU H CP22 are formed between the pairs of opposite blades and the wind flow is redirected towards concave surfaces of the returning blades .

In Fig.3A, momentary wind flow is illustrated through the passage CP20 across the horizontal section trough the line 3A-3A in the upper division 20 of the floor in Fig.3. The wind that enters between the blades 12c and 12d passes through the passage CP20 acting on the blades 12d and 12b as well. This process is identical with the process in the bottom division 22 through the passage CP22.

It is not the same case between the blades 12d and 12a. Here lacks neither upper nor bottom passage. The divisions are closed blocked. The wind that enters swirls and congests. "Looking" for the exit the wind finds the mid passage CP21 and exits between the blades 12b and 12c, that is not visible on the illustration.

In Fig.3B, a momentary wind flow is illustrated through the passage CP21 across the horizontal section trough the line 3B-3B in the mid division 21 of the floor in Fig.3. The wind that enters between the blades 12a and 12d passes through the passage CP21 acting on the blades 12a and 12c as well.

It is not the same case between the blades 12d and 12c: a passage in the mid lacks here. The division is closed/blocked. The wind that enters swirls and congests. "Looking" for the exit, the wind finds one of the two passages-the upper one CP20 or the bottom one CP22, and exits between the blades 12a and 12b. The form and the dimensions of the passages for floors with six blades can be defined by two designs. They are illustrated in figures Fig.4, Fig.4A and Fig.4B.

Fig.4 depicts horizontal cross section across a floor with six blades in their initial state (before modification). Fig.4A depicts the profile of the passage CP _up for the upper division in the floor according to the first (simple) design. The shape of the passage is not a smooth line but twice broken line and the canal is narrower than that in Fig.4B is where the second design is illustrated. It is more complex because in addition to the cutting and the bending of the adjacent blades, each pair of advancing and returning blades also has to be extended, but the passage is more broad, smooth and flowing in comparison to the previous one. The wind flow swirls less and the energy losses reduce.

In order to avoid the mentioned congestions and swirls of the wind a set of concave redirectors are installed in the divisions without passages. At the first floor in Fig.l, the mid redirectors 23 and 24 are partially seen, while at the second floor parts from the three redirectors 25, 26 and 27 are seen. These identical in form and dimensions concave surfaces are illustrated in more details in Fig.5, Fig.6 and Fig.7. Their role is to redirect the gripped by the blades wind in vertical direction towards corresponding passage(s).

The bottom redirectors 25 present two identical surfaces with concave shape, which are installed diametrically, but the only one of them is seen in Fig.5. They are situated above the bottom disk 15 between blades 12a and 12d, as it is illustrated with bidirectional dashed arrows, as well as between blades 12b and 12c. The concave surfaces of the redirectors begin tangentially to the disk 15 and in a spiral or circle shape rise up to the bottom cutting 43 of the mid passage CP21. The edges of the redirectors follow the blades' surfaces. Both redirectors deflect the wind entering between the corresponding blades from the blocked bottom division 22 towards the mid division 21 with the passage CP21.

The upper redirectors 27 are also two identical surfaces with concave shape, which are installed diametrically, but the only one of them is seen in Fig.5. They are situated below the upper disk 14 between the same blades as the bottom redirectors. Their concave surfaces begin tangentially to disk 14 and descend to the upper cutting 43 of the mid passage CP21 in shape of circle or spiral. The edges of the redirectors follow the blades' surfaces. Both redirectors deflect the wind entering between the corresponding blades from the blocked upper division 20 towards the mid division 21 with the passage CP21.

The mid redirectors 26 are identical to the upper and the bottom ones, but are installed diametrically in the middle of division 21 between the blades 12a and 12b, as well as between the blades 12c and 12d. Their horizontal edges merge in a common mid edge at which the concave surfaces begin tangentially each with respect to the other and then unfold in two directions: i) upward towards the upper cutting 43 and ii) downward towards the bottom cutting 43. Both the redirectors deflect the wind entering between the corresponding blades from the blocked mid division 21 towards the upper passage CP20 and the bottom passage CP22 accordingly.

In addition to the function of wind deflection, the redirectors strengthen the floor.

For better presentation of the redirectors Fig.5A depicts the horizontal cross section through the line 5A-5A between the mid and the upper divisions of the floor in Fig.5. In addition, the same floor from Fig.5, is turned at 45° and is presented in Fig.6, Fig.6A and Fig.6B as vertical section, side view and cross section accordingly.

The vertical plane section at Fig.6 is taken along the line 6-6 in Fig.6A. The profiles of the bottom 25 and the upper 27 redirectors are presented along the height of the floor. The same plane crosses the mid redirectors 26 transversely and presents their broadways profile.

At Fig.7, Fig.7A and FigJB analogical vertical section, side view and cross section are depicted, but this time the floor is turned 45° in opposite direction with respect to the floor in Fig.5. The vertical plane section at Fig.7 is taken along the line 7-7 in FigJA. The profiles of the mid redirectors 26 are presented along the height of the floor. The same plane crosses transversely the bottom 25 and the upper 27 redirectors, and presents their broadways profiles.

The improvements to the conventional drum rotors are illustrated in the figures from number 8 to number 12 and are explained here.

Fig.8 depicts a side view on a floor of drum wind rotor with four vertical blades by means of which the rotor turns in the same direction like the inner rotor. Fig.8A depicts a vertical plane section along the line 8A-8A of the same floor. Fig.SB depicts a horizontal cross section through the line 8B-8B of the same floor, where the external R and internal r radius of the disk 7 are denoted. Blades' profile is an arch of circle with the same radius R as the one of the outer rotor. The four blades are fixed symmetrically at an angle of 90° between each other. The advancing edge 48 of the blades lies on a smaller circle than the outer circle of the disk 7 and the tail edge 49 is situated on the internal circle. The tail surface of the blades is in parallel to the imaginary tangential plane at the point of contact with the internal circle of the disk. Such arrangement guides the wind tangentially in the air gap between the respective floors of the outer and the inner rotor.

The combined operation of the outer and the inner floors is illustrated in Fig.8C, Fig.8D and Fig.8E by three momentary wind flows through the same cross section but in distinct mutual angular positions of the floors. Despite of their static character these illustrations demonstrate the complexity of the aerodynamic process. The passing of the wind through the transversal (nonvisible) passages is illustrated by dashed lines in order to distinct it from the congested cases presented in fig.3A and Fig.3B.

Even at a minimum air gap between the outer and the inner floor, the guidance of the wind tangentially to the periphery of the inner floor provokes vortical flows, which in turn cause an increase in the losses of kinetic energy. In order to reduce these losses the outer and the inner floors are improved reciprocally, as fallow. According to the illustrations in Fig.9 and Fig.10, the number and the shape of the blades for the outer floor are changed and in the same time, the profiles of the blades for the inner floor are changed by extension of the advancing surfaces with additional foreparts 50a, 50b, 50c H 50d. The last ones translocate the advancing edges 41a, 41b, 41c H 4 Id of the blades to the peripheral circle of the inner floor unlike illustrated in Fig.3A and Fig.3B.

It is appropriate to increase the number of blades to five, six and more, especially in high sized machines. For example in Fig.9, a momentary wind flow is illustrated through the outer floor with five blades, which is operated coaxially to the inner floor from Fig.10. In this embodiment, the profile of all the five blades 9- 4 is a circular arch with radius equal to the internal radius r of the disk 9-7.

Instead of tangential ending, an acute angle δ for the tail surface of the blades is determined. According to the illustration in Fig.9 (for blade 9-4b only) this acute angle δ is formed between an imaginary plane, tangential to the tail surface 51 and another imaginary plane 52 tangential to the internal cylindrical surface of the floor at the point where the tail edge merges the inner circle of the disk.

The size of the angle S ought to be equal to the size of the acute angle, which the additional foreparts 50a, 50b, 50c and 50d form with respect to the imaginary planes, tangential to the floor cylinder and advanced edges, as it is indicated in Fig.10 for the plane 53 and the blade 10-12a only.

The optimal size of the angle δ is determined according to the prevailing wind velocity and the designed ratio between the capacities, or accordingly the rotational speed of the inner and the outer rotor.

For further reduction of the torque fluctuations, another embodiment is suggested: outer floor with vertically twisted blades, e.g. at Fig.11 a four bladed floor is illustrated. The advancing edges 11-48 of the blades are tilted forward and in the same time, they lay on the imaginary external cylinder surface. The tail edges 11-49 are tilted also and in the same time, they lay on the imaginary cylindrical surface around the internal circle of the disk. The tail surfaces form an acute angle with respect to the imaginary planes tangential to the same imaginary cylindrical surface around the internal circle of the disk. In addition to the smoothing effect on the torque, such construction provides complementary solidity of the floor .

In addition to the described wind motor with two concentric rotors rotating in same direction, the disclosed improved S-rotor creates a favorable opportunity for accomplishment of a motor with two contrary rotating concentric rotors. Therefore, the conventional drum wind rotor is modified as is illustrated at Fig.12, Fig.12A and Fig.12B.

Fig.12 presents a side view to the floor of vertical drum rotor with eight blades 12-4, symmetrically fixed at 45° with respect one to another between the bottom 12-7 and the upper 12-8 ring disks. The number of blades can vary according to the size and the capacity of the wind motor.

Fig.l2A illustrates momentary wind flow through a cross section of the floors of two concentric rotors: inner as in Fig.10 and outer as in Fig.l2B.

Fig.l2B depicts a horizontal cross section through the line 12B-12B of the floor at Fig.12. The external R and the internal r radiuses of the disks are determined according to the desired capacity and the angular velocity.

The profile of the blades 12-4 consists of two fractions 54 and 55, partially depicted for one of the blades only in order to avoid cluttering. The fraction 54 is a circular arc with radius r _s , which is equal to the half of the disk's width, i.e. r _s =l/2(R-r) for the disclosed embodiment. The second fraction 55 is the intercept part of the radius through the center of the disk, tangential to the arc 54.

When the rotor turns, each subsequent blade escapes out of the wind action at central angel ξ equal to 22,5° with respect to the imaginary radius, perpendicular to the wind direction. Before the reach of this angle, the active blades must direct the wind towards the inner rotor but not outside of its periphery. Such direction is achieved if the angle ψ between the chord of the active blade and the wind direction is obtuse and changes to acute when the central angle ξ reaches the size of 22,5°. This is the condition for dimensioning of the fractions (the radius r _s and the intercept 55).

In other embodiments, the fractions 54 and 55 of blades' profile can form a line that is more complex, e.g. can become an arch of a spiral line.

Industrial Applicability

The disclosed machine transforms the wind energy into electricity without stators, neither wind nor electric one. This peculiarity reduces the torsional loading on the surface of the emplacement, which is of great importance for the roofs, especially of the old existing buildings.

For simplicity, the description and the drawings depict relatively small machine, the wind rotors of which are manufactured from sheet material. This does not reduce the relevance of the disclosure concerning large industrial machines. By increasing the number and the size of the floors, the total capacit could be increased proportionally to the area of the motor's vertical section, i.e. the swept area. This naturally leads to increase of the mechanical loading and the need of strengthening.

The constructive challenges do not present obstacles to the industrial application of the disclosed machine because it produces increased torque with fewer fluctuations in comparison to the known ones, based on the S-rotors. The described machine starts and produces electricity at a lower wind velocity. The gusts of wind provoke relatively small influence on the stability of rotation. The power coefficient Cp, the harvested power and accordingly the quantity of energy are bigger than those of the known machines are with the same swept area.

As any other industrial product, the disclosed machine will pass through the phases of model and experimental investigations, creating prototypes, trials, and upgrades. The specific design of the components will be selected according to technological and economic criteria during the next phases of the elaboration. References Cited

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