SE540347C2 - Method of changing the size of a helical rotor - Google Patents

Abstract

The present invention relates to a method of controlling during operation the size of a rotor of a turbine which extracts the energy from the velocity of a flowing fluid such as wind, steam, water currents and water waves. The line of rotation of the turbine is substantially perpendicularly oriented to the fluid direction in question and of a kind comprising a self-supporting rotationally symmetrical blade body integrally constructed of pairwise and crosswise connected rotor blades arranged in space spirals between both ends of the rotor and suspended in the turbine at least one of the turbines. The method means that rod joints arranged to increase or decrease the spiral angle of the blade body are rotated at the same time as support arms arranged to increase or decrease the diameter of the blade body are rotated, so that the relationship between the blade body length and diameter thereby automatically changes. a ground-based or floating power unit which converts the extracted energy into electrical or mechanical or visual power, or into a combination of these effects.

Description

TECHNICAL FIELD The present invention relates to a method of controlling the size of a rotor to a turbine arranged to recover energy from a flowing fluid by rotating the rotor about a line of rotation of substantially perpendicular orientation thereof. against the fluid direction in question, ie a transverse turbine, the rotor being provided with rotor blades arranged in space spirals between the two ends of the rotor and suspended in the turbine at at least one of said ends.

The invention also relates to the performance of the control method in a ground-based or floating power unit which converts the recovered energy into electrical or mechanical or visual effect, or into a combination of two or three of said effects.

BACKGROUND OF THE INVENTION Turbines arranged to recover energy from a flowing fluid - such as air currents, steam currents, water currents or water waves - are usually designed to extract maximum energy from the flow at a certain fluid velocity, i.e. have a construction operating point. Fundamental to the efficient operation of the turbine is the existence of a fluid velocity which provides sufficient lifting force on the rotor blades to overcome the total resistance of the rotor blades and turbine. The turbine shaft is thus caused to rotate by the lifting force, which arises as a result of pressure differences when the fluid passes through the wing profile of the rotor blades, has a force component directed in the direction of rotation which - when multiplied by the distance to the line of rotation - gives rise to a force. The above applies to both conventional so-called quick runners (wind turbines), steam turbines and water turbines where the turbine shaft is directed substantially parallel to the fluid direction; as for more unconventional transverse turbines where the turbine shaft is directed vertically and perpendicular to the fluid direction, e.g. wind turbines of the type s.k. H-rotors (SE564997C2), or where the turbine shaft is directed perpendicularly but horizontally to the fluid direction in question, e.g. US2011 / 110779A1.

Transverse turbines have a known axis of rotation with a rotor rotating about said axis of rotation, and four significant passages of the fluid through the rotor: upstream, cocurrent, downstream and countercurrent; thereby obtaining a pulsating lifting force on the rotor blades during the rotational revolution which is cosine distributed to the amount and to the magnitude maximum upstream and downstream, and minimal downstream and countercurrent. It is known in the art that the rotation of the rotor is transmitted to the turbine in one or more connections, each of which has a suspension point to a rotor blade. Thus, the rotor and the rotor blades can be connected to the turbine at a plurality of suspension points. Suspension at two symmetrically located points in or around the central normal plane of the rotor, so-called center-mounted rotor, is available from e.g. a. the aforementioned H-rotors. Suspension at both ends of the rotor blades is made of e.g. a. Darrieus wind turbine (NL19181). Also suspension at one end of the rotor blades, so-called end-suspended rotor, is known and made of a wind turbine with straight blades connected in a central turbine hub located at ground level and spreading obliquely upwards. It is further known that center-suspended turbines are provided with a support structure comprising support arms, turbine hub and turbine shaft which disturb the flow of fluid through the blade body, so that the lifting force on the rotor blade decreases, especially in the downstream passage and the turbine efficiency is thereby reduced. This disadvantage i.a. a. means that transverse turbines have a lower efficiency than conventional fast runners at the same solidity, i.e. that the ratio between the tip speed of the rotor blades and the actual fluid speed is lower. When investing in wind turbines, fast runners are therefore often preferred. As may be appreciated from the foregoing, there is a need to avoid a rotor that is center-suspended in order to achieve a higher efficiency of the turbine.

As is known, transverse turbines preferably have three straight rotor blades, i.e. with the nose (leading edge) parallel to the line of rotation, as for example in H-rotors. It is further known that a centrifugal force arises as a result of the rotation of the turbine about the line of rotation and acting on the mass of the turbine, directed perpendicularly and outwards from the line of rotation. The centrifugal force is thus added vectorially to the lifting force on the rotor blades, so that the resulting force on the rotor blade increases at the passage downstream, downstream and countercurrent; while it instead decreases upstream. The resulting pulsating force on the rotor blades thus has its maximum downstream and minimum upstream, an oblique distribution which gives risk of material fatigue, unwanted vibrations, natural oscillations and noise of the turbine. Rotors provided with straight rotor blades present the above challenges in the construction of the rotor blades and attachments thereof. It is known in the art that transverse turbines having three straight rotor blades do not self-start the rotor at low fluid velocities, but the turbine must be started with the generator; on the other hand, helical rotor blades have the property of being able to start the rotor more easily. Spiral rotor blades are known technology from, inter alia, CA 2674997 which describes a wind turbine arranged with helical vertical rotor blades, which in most places are directly and fixedly connected to the turbine hub on the turbine shaft; and in WO2120153813 (A1) which describes a water turbine arranged analogously to a multi-bladed so-called Darrieus wind turbine (NL19181); and in WO2120152869 (A1) which describes a water turbine with collapsible helical blades. As may be appreciated from the above, a rotor with helical blades has advantages which can be further developed and emphasized.

As is known, transverse turbines preferably have rotor blades in the wind version provided at a wing profile with a constant angle of attack against the direction of rotation, which do not have the property of being able to brake the turbine aerodynamically at wind speeds exceeding the design operating point as above. In the case of fast runners, for example, the turbine blade can be rotated mechanically about its own longitudinal axis in order to - at a sufficiently high wind speed - adjust the angle of attack of the turbine blades (?) And thus obtain a constant speed, so that - if the wind speed exceeds a certain value - the turbine blades turned off. No power is generated then, but when the wind decreases, the blades turn back and the turbine delivers power again. In H-rotors as well, the speed increases with the wind speed up to a certain upper limit where the turbine shaft must be equipped with a device or method for braking or controlling the turbine speed, otherwise the turbine fails due to excessive load or overheating of the generator. In the absence of, or in combination with, methods for controlling the speed - such as a speed gearbox - the turbine can be equipped with two generators intended for different speed ranges, which require a larger control system with accompanying control equipment. Instead, a single generator can be used - which simplifies electricity production - by the turbine being electrically braked by a permanently magnetized synchronous generator, which is described in WO2010 / 039075 and is said to require a strong mains connection with a mains voltage exceeding 10 kV to be efficient. However, for turbines which are not connected to a strong mains with a mains voltage exceeding 10 kV, the above-mentioned solution is not possible to implement, instead an aerodynamic braking is preferable for such autonomous free turbines. However, since the rotor blades have a constant angle of attack (?) As above, they can not be turned out of wind so that the lifting force ceases and the rotor stops, as is possible for the rotor blades of fast runners as above. As may be appreciated from the above, there is a need to be able to aerodynamically brake transverse turbines with a constant angle of attack (?) Against the direction of rotation in order to reduce the speed at wind speeds greater than the nominal rated power, instead of stopping the turbine completely.

SUMMARY OF THE INVENTION A first object of the present invention is to provide a method of controlling the size of a rotor of a turbine for recovering energy from flowing fluids at substantially perpendicular orientation of the line of rotation towards the fluid direction, the invention introducing a new type of rotor for the purpose of achieve higher efficiency of the turbine in comparison with corresponding transverse turbines with vertical-axis or horizontal-axis rotors.

A second object of the present invention is to overcome or improve at least one of the disadvantages of the prior art or to provide a useful alternative. At least one of the above objects is achieved with a method according to claims 1-3.

As used herein, the term "axial" refers to a direction parallel to the line of rotation and "radial" perpendicular to the line of rotation; - the term "cross-sectional section" means the planar figure arising from the cross-section of a structural element at right angles to its longitudinal axis; The term "center line" is used even if the longitudinal axis of the structural element is not straight, ie the "center line" has the property of being curved. The term "skeletal line" (Q) refers to the line connecting the midpoints of the circles which can be inscribed in a wing profile, i.e. the skeletal line lies midway between the upper and lower wing surfaces of a wing profile; - the term refers to being "connected to", "in connection with" or "enclosed by" another part, that the part may either be directly connected to or directly enclosed by the other part or intermediate parts may also be present.

On the other hand, when one part is referred to as being "directly connected" with or "directly enclosed" by another part, then no intermediate part is present; - the term "fixed connection" or "fixed connection" refers to rotation and translation between components of the joint are not possible, while the term "bearing" indicates that rotation and translation between components are both possible; wherein "plain bearing" indicates that axial translation but not rotation is possible, and "roller bearing" that rotation but not axial translation is possible; - the terms "first", "second" and "third" refer to the need to distinguish singularity of a plurality of completely permutable elements, but not to number physically, that is, any of the elements can be referred to as the "first". "," Second "or" third ".

Thus, the present invention relates to a method of using a displacing means to control the size of a blade body of a turbine arranged to produce useful energy from the motion of a flowing fluid while substantially perpendicularly orienting the line of rotation of the turbine towards the fluid direction (W), comprising a turbine roller bearing provided with a rotatable bearing housing and a non-rotatable bearing housing, and having a center point and a center line passing through said center point, and at least one support hub arranged in fixed connection with the rotatable bearing housing and a support structure arranged in fixed connection with the non-rotatable bearing housing , and a blade body wholly or partly located in the fluid and arranged in communication with the rotatable bearing housing, the movement of the fluid allowing rotation of the blade body about the line of rotation which coincides with the center line at a point identical to the center point, and comprising a plurality of rotor blades each t is continuously extending axially and radially in a space spiral curve with a helical axis in the line of rotation and having a helical direction about the line of rotation and in the normal plane of the space helix curve provided with a cross section having a center line and having a wing profile with two end portions. N) directed in the direction of rotation of the blade body (V) and the other end portion has a tip (S) in the opposite direction, the turbine having an intersection point (PN) between the line of rotation and a normal line to the line of rotation, and a plurality of blade joints each having a intersection point (PB1) between the center line of a first rotor blade and said normal line and an intersection point (PB2) between the center line of a second rotor blade and said normal line, the intersection points (PN, PB1, PB2) being connected by a common normal line (14) to the rotation line and (14) is provided with an endpoint in (PN), wherein of the position PN-PB1 is not equal to the distance PN-PB2, said first and second rotor blades having different torsional directions about the line of rotation and being connected to each other in at least one of said blade joints (13), and the blade body having a length (L) and a diameter (D) and a spiral angle (?) Between the center line (11) of the rotor blade and the line of rotation when projected on the line of rotation, and a midpoint (PM) at the point of intersection between the line of rotation and the center normal plane (M).

The invention is characterized in particular by the fact that the blade connections are connected to each other by intermediate parts consisting of said rotor blades.

As may be appreciated from the above (see claim 1): - it is the movement of a flowing fluid which gives rise to the rotation of the leaf body, i.e. that the leaf body may be located either entirely in the flowing fluid or partially in a portion of the fluid which is not flowing. Thus, the blade body cannot rotate if it is completely in the portion of the fluid that is not flowing, i.e. where the fluid is stationary; - the fluid can in principle consist of any matter in a liquid or gaseous aggregation state. For example, the fluid may consist of one or more elements in gaseous form, such as air; or in liquid form, such as water; or a mixture of gas and liquid forms, such as in condensing steam. Thus, the fluid may be composed of two or more different substances, for example air and water, whereby the flow of these fluids may have different strength and direction; - the term "twist direction" indicates whether the space spiral curve is right-turned or left-handed. A rotor blade can thus have one of two twist directions, i.e. right-turned or left-handed; Thus, according to the present invention, a first right-hand rotor blade is connected to all left-hand rotor blades, a second right-hand rotor blade is connected to all left-hand rotor blades, etc. until all right-hand rotor blades are connected to it. In the present invention it can be noted that it is not a necessary condition that the biadbody is rotationally symmetrical, i.e. that rotor blades having different twist directions are equal in number, or that rotor blades having equal twist directions also have equal spiral angle or are istanta, or are separate and unconnected; there is a blade joint at each intersection between a right-handed and left / ridden rotor blade, the blade joint connecting the two intersecting rotor blades.

Thus, each right-hand rotor blade is connected to all left-hand rotor blades in one or more blade joints, and likewise, each left-hand rotor blade is connected to all right-hand rotor blades in the same blade joints. The number of blade connections depends on the number of rotor blades and spiral angles (?). For example, 21 blade joints are required to connect a blade body consisting of 3 right-handed and 3 left-handed rotor blades which rotate 1 spiral turn (i.e. have the pitch 1) on the length of the blade body (L), which is denoted (3 + 3) x1. The spiral angle (?) Of the rotor blade is the angle between the center line of the rotor blade and the projection of the rotation line on the rotor blade. - the term "blade body" refers to the rotationally symmetrical spatial area bounded in part by the two end normal planes (M1, M2), which constitute the normal plane of the line of rotation and each contains at least one point tangential to the rotor blades axially; and partly by the inner and outer concentric rotating surfaces which are generated radially by the envelope of the rotor blades as the helical rotor rotates, the radius from the rotation line to the inner rotating surface being smaller than the radius from the rotating line to the outer rotating surface in each normal plane located between the two said end planes. The center normal plane (M) of the leaf body refers to the plane of symmetry of the two end normal planes (M1, M2) and the length (L) of the leaf body refers to the distance between the two end normal planes (M1, M2); - the blade body is part of the turbine but does not constitute a solid body but an inhomogeneous space provided with openings in both the end normal plane and the surfaces of rotation. The blade body thus extends continuously and circumferentially the line of rotation in an integrated grid of intersecting rotor blades, where the blade joints form the knots and the meshes are bounded by the rotor blades, the rotor blades being connected to each other only in the blade joints. Since each blade joint connects two blades with opposite twist direction, it means that each right-handed rotor blade is connected to a left-handed rotor blade. The return torque of a right-hand and left-hand rotor blade, respectively, are opposite and thus take each other out of the blade joint if the helical angles are equal, which in practice gives a torque-free blade body in the unloaded state; i.e. without significant built-in natural voltages such as a. may result in the disadvantage of unwanted deformations; - the blade body constitutes a self-rigid and thus self-supporting structure, since the rotor blades support each other in the blade joints; wherein the bending and torsional rigidity of the blade body depends on e.g. the number of rotor blades, the number of blade joints, the length and diameter of the blade body. The blade body can thus be bent out in the fluid direction in question due to the load from the fluid on the blade body, which has the consequence that the line of rotation can deviate markedly from the center line of the blade body. The blade body can thus rotate about a curved line of rotation so that certain parts of the blade body during the rotation are not perpendicular to the fluid direction; - the rotor blades can be constructed with shorter span lengths and thus smaller dimensions than is usual with other turbine types with independent rotor blades - such as in quick runners and H-rotors - as the number of storage points increases when the rotor blades support each other. In addition, the rotor blades can be constructed with a rounder cross-section, i.e. with a thicker wing profile than is otherwise usual with the above-mentioned turbine types with independent rotor blades; and thereby obtain increased bending and torsional resistance with concomitant reduction of the stresses in and between the bearing points, as well as a stiffer blade body. Thus, it may be appreciated that since the rotor blades are helical, the angle between the center lines of the rotor blades and the line of rotation coincides with the helical angle (y); and since the fluid direction in question is substantially perpendicular to the line of rotation, the angle of impact (?) between the center line of the rotor blade and a normal to the projection of the line of rotation on the rotor blade thus becomes equal to 90 minus (?) degrees. From this it may also be understood that the effective chord of the wing profile in the fluid direction is extended by a factor equal to the inverse of the sine of (y), compared with the actual width of the rotor blade; and since the ratio of the blade profile between thickness to chord can be assumed to be determined at the given turbine size, the rotor blade must therefore be constructed with an actual height which is correspondingly greater whereby it obtains a rounder cross-section; the said shorter span lengths of the rotor blades can allow a considerably higher aspect ratio calculated on the free arc length between two blade joints than is usual with other turbine types with independent rotor blades.

The aspect ratio of rotor blades according to the present invention is typically a number between 100 and 150, which gives rise to a low induced resistance which i.a. a. makes the present invention a suitable candidate for turbine parks in a limited area. The high aspect ratio also allows the fluid flow to appear fully or partially laminar over the wing profile, i.e. exhibit a low Reynolds number at high fluid velocities which reduces the resistance of the rotor blade to the fluid and thereby increases the efficiency of the turbine; - the continuous helical rotor blade of the blade body has the advantageous property of being positioned somewhere on the angle of rotation for an optimal angle of attack against the fluid flow, so that the blade body can thereby be able to start the rotation. The angle of rotation of the blade body (?) Refers to the angle in the normal plane of the line of rotation with the point in the line of rotation. The angle of attack (?) Of the rotor blade refers to the angle between the cord of the rotor blade and the apparent wind direction in question; the continuous and integrated helical rotor blade of the blade body has the advantageous property of receiving and distributing the fluid load more evenly than straight rotor blades can do, by spreading the moment of force of the rotation over at least parts of the angle of rotation. This reduces the risk of material fatigue, unwanted vibrations and natural oscillations of the leaf body; as well as that the noise from the turbine in wind design can be avoided, compared to fast runners with straight turbine blades that generate a pulsating and whistling noise every time they pass the wind power mast.

As may also be appreciated from the foregoing, the present invention allows: - two rotor blades to be connected to each other at different radial distances to the line of rotation, i.e. they are plane separated. This reduces the risk of fluid flow from the front rotor blade interfering with the rear during rotation; different cross-sectional sections can be used for rotor blades with different radial distances to the line of rotation in order to best utilize the energy of the higher blade speed at the larger radial distance, and the lower blade speed at the less radial distance to the line of rotation; unnecessary distortion and skew of the cross-section of the blades and the associated secondary torque in the blade overhang and loss of power of the turbine, can be avoided by the resultant of the lifting force on the wing profiles of the two rotor blades attacking in a common normal line to the line of rotation; which can be allowed, since the aerodynamic center of the wing profiles in a blade joint can both be assumed to have the same distance to the nose (N) relative to the length of the respective chord; - the spiral curves of the rotor blades can be generated so that the inner and outer surfaces of rotation of the blade body separately describe a cylindrical, straight conical, double-conical (hourglass conical) or biconically truncated space area; wherein the volume of the blade body is limited by the space area between the outer and inner surface of rotation, which means that the blade body can assume the most appropriate shape for the turbine in question among 16 (4x4) different and possible formations.

In accordance with the present invention, a first blade joint has the distance PN-PB1 which is greater than the distance PN-PB2 and a second blade joint the distance PN-PB1 which is smaller than the distance PN-PB2, no blade joint being located between the first and second the leaf bandage.

As may be appreciated from the foregoing (see claim 1), this means that the rotor blade having the smallest radius of the line of rotation in a blade joint will have the largest radius in an immediately adjacent blade joint. This exchange of the position of the rotor blade in two adjacent blade joints, means that the rotor blade alternately belongs to the outer and inner rotation surface, respectively, in the blade body; which means that the space spiral curve of the rotor blade has the property of undulating as a sine curve with the largest amplitude in the blade joints and zero amplitude between two blade joints. The sine curve of an undulating rotor blade which has a right-handed twisting direction is shifted by a factor (?) Relative to the left-handed rotor blade, i.e. with 180 degrees; but exhibits the same amplitude, i.e. is opposite. The blade body thus gives the impression - for a viewer - that all rotor blades are "braided" around each other. Thus, the space spiral curve of the rotor blade around the line of rotation is superimposed in the axial and radial direction of a sine curve as above. It should be noted that the definition of a (non-superimposed) cylindrical or conical space spiral curve requires that the amplitude must be equal to zero for the tangent angle of the rotor blades to the line of rotation to be constant, thus not being met for said superimposed space spiral curve. An advantage of the above undulated blade body is that the risk is reduced that the rotor blades interfere with each other during the rotation, and that all blade joints are exposed to compressive forces which strive to hold each individual blade joint together.

According to the present invention, a first blade joint has a first sum of said distances PN-PB1 and PN-PB2, while a second blade joint has a second sum of said distances PN-PB1 and PN-PB2, the first sum being equal with the second sum.

As may be appreciated from the above (see claim 1), this means that the diameter (D) of the leaf body is by definition set equal to its average diameter, i.e. that (D) is counted in the middle of the "wall thickness" and that the leaf body thus has a common diameter (D) along its entire length (L). A significant advantage of the above is that all rotor blades have the same arc length, so that two rotor blades can thus be mutually distorted without having to be displaced in the blade joint, which is a prerequisite for the control method according to claim 1.

In accordance with the present invention, the blade joint comprises two blade enclosures each of which is provided with a cross-sectional section having a center line parallel to the center line of the rotor blade, the cross-sectional section completely or partially enclosing the wing profile of the rotor blade.

As may be appreciated from the above (see claim 1), the advantage of enclosing blade covers is that the rotor blades are reinforced on the outside where the highest bending stresses of the cross section occur, and that they can be placed continuously without splicing in the blade joints (except at non-planar junctions blade attacks, which reduces the risk of fatigue of the rotor blades. Furthermore, the blade shells can advantageously be provided with a cross-sectional section at the wing profile with a nose (N) in the direction of rotation of the blade body (V) and comprise a slot in the rear edge (S) of the blade profile, the blade shear elastic structure through a friction joint or bolt joint (not shown). This device allows the rotor blades to adjust freely one after the other and thereby avoids unnecessary intrinsic stresses in the blade body when mounting the blade body.

In accordance with the present invention, the blade joint comprises a rod joint which connects the two blade sheaths to each other and is provided with a rod having a cross-sectional section with a center line, the center line coinciding with the common normal line of the blade joint.

As may be appreciated from the above (see claim 1), the rod joint serves the primary purpose of connecting two intersecting rotor blades to each other which lie at different radii and is particularly well suited to absorb compressive forces occurring in undulated blade bodies.

In accordance with the present invention, the rod joint comprises at least one rod roller bearing provided with a center line coinciding with the center line of the strut, the roller bearing allowing mutual rotation of the center lines of the rotor blades about the common normal line of the blade joint.

As may be appreciated from the above (see claim 1), the roller bearing allows the helical angle (y) to be changed by the rotor blades in the blade joint; and, since the blade body is integrated, the change becomes equal in all rotor blades in the blade body; i.e. that the length (L) and diameter (D) of the leaf body can be changed simultaneously. For example, in leisure use, the spiral angle can be reduced to close to zero or increased to close to 90 degrees, and the blade joints are thus transported flat with the blade body in a rolled-up condition.

According to the present invention, the connection of the blade body to the support hub comprises at least one support arm which comprises a blade cover connected to the support arm and fixedly connected to an end portion of said rotor blade, and is rotatable about a straight center line passing through at least two arm roller bearings connected to the support hub, each blade cover being fixedly connected to an end portion of a rotor blade.

As may be appreciated from the above (see claim 1), a helical rotor suspended in one of the two end normal planes (M1, M2) of the blade body is described, a support arm being required for attachment to a blade overhang of an end portion of a rotor blade. It should be obvious to a person skilled in the art that a blade body according to the invention can also be suspended in both end normal planes simultaneously and thus constitute a double-suspended rotor, for example several water turbines made with a common horizontal line of rotation placed in a row across a river. In the practice of the present invention, it can be noted that it is not a necessary condition that the center line of the turbine bearing is vertical, but that it may have an arbitrary angle in a plane perpendicular to the fluid direction in question; i.e. the center line can also be horizontal or skewed. An essential advantage of an end-suspended or double-suspended spiral rotor is that a central turbine shaft can be avoided in the fluid so that the fluid flow through the turbine is not disturbed, whereby several advantageous properties can be achieved: the turbine efficiency increases produced power unit can be reduced; disturbing noise can be avoided because there is no non-rotating body upstream which creates a stationary pressure change downstream, for example as in fast runners where a hissing noise is heard every time a turbine blade passes the wind power mast. This advantage makes it possible to place the invented turbine in an urban environment.

From a second aspect of the present invention there is provided a method of controlling the size of a blade body to the above turbine by means of a displacement means comprising a rod joint arranged to rotate the center lines of the rotor blades about a common normal line of rotation and a support arm arranged to rotate about a center line passing by at least two arm roller bearings connected to a support hub, the turbine having an angular velocity and said displacing means being arranged to simultaneously increase the length (L) and decrease the diameter (D) of the blade body, or vice versa, said method comprising the steps of: causing said support arm to be arranged in a first position, said first position corresponding to a first helical angle (? 1) of the blade body; causing said support arm to be arranged in a second position, said second position corresponding to a second helical angle (y2) of the blade body, wherein (? 2) is not equal to (? 1).

As may be appreciated from the above (see claim 1), the size of the blade body can be changed by allowing the rotor blades to rotate relative to each other in the blade joints so that the angle to the line of rotation, i.e. the helical angle, changes. This is made possible by all blade attacks rotating at the same angle around their respective normal lines to the line of rotation in said rod bearing. According to the embodiment with undulated rotor blades and common diameter (D), a changed helical angle means that the rotor blades only rotate towards each other in the blade joints, while other embodiments mean that the two rotor blades in a blade joint also receive different mutual displacement in the direction of rotation line (Z). The change in the size of the leaf body takes place by means of the displacing means which acts on the leaf body with a force resultant, which component attacks in the attachment of the leaf cover to the support arm and is directed in the circumferential joint of the leaf body. The magnitude of the power resultant is determined by the equilibrium between the turbine and the surrounding system, which equilibrium occurs at both stationary and rotating turbines.

The dynamic equilibrium includes the effect of the fluid flow on the turbine, which mainly results in a lifting force and a resistance on the rotor blades but also gives rise to a centrifugal force and a moment of movement of the turbine. An increasing centrifugal force tends to displace the mass of both the leaf body and the support arms perpendicularly outwards from the line of rotation. The blade joints allow, as above, the rotor blades to be rotated and the diameter of the blade body to be increased, which is made possible by the support arms being suspended in the support hub for rotation outwards from the line of rotation; thereby separating - circumferentially - the attachment points of the rotor blades to the blade surfaces; whereby the spiral angle increases and the length of the leaf body decreases. This increases the cord length of the wing profile (see requirement 1) and the profile risks being exceeded to the extent that the ratio of the lifting force divided by the resistance decreases. With an increasing spiral angle exceeding 45 degrees, the turbine's solidity also increases. At very high fluid velocities, in combination with the overshoot above, this means that the fluid resistance eventually becomes so great that the angular velocity of the turbine decreases; to in the extreme case further decrease as the lifting force disappears as the diameter increases to the point that the blade body almost appears as an obstacle for the fluid to pass. A decreasing centrifugal force has an opposite effect on the blade body and the support arms, so that a "closed" blade body with high solidity automatically "opens" as the high fluid velocity decreases; thus allowing the turbine to return to the design operating point. As may also be appreciated, dynamic equilibrium at an accelerating or decelerating fluid velocity requires that the momentum of the turbine be conserved, i.e. that the product of the turbine's moment of inertia and angular velocity momentarily remains unchanged. In the present invention, this means that the diameter and angular velocity of the blade body can both change, simultaneously and momentarily, before a new equilibrium enters at the new fluid velocity. Only at the new equilibrium is the new momentum obtained. Thus, the displacement means allows the angular velocity of the turbine to be changed automatically according to the fluid velocity without forced displacement, so that e.g. the turbine speed can be regulated and the turbine brakes aerodynamically at high fluid velocities.

In accordance with a preferred embodiment of the present invention, the center line (25) of the arm roller bearings has an intersection point with the center line (6) of the turbine bearing.

As may be appreciated from the foregoing (see claim 2), in the particular case the centerline of the turbine bearing is vertical, the centerline of the arm roller bearings forming an angle with the vertical line. In the case that the point of intersection between the center lines is located vertically above the center point (6), said angle becomes pointed upwards, which means that the blade cover connection to the support arm will pivot upwards as it is moved in radial direction out of the line of rotation. This upward displacement of the support arm strives to lift the attachment of the rotor blades to said blade cover and thereby increase the positional energy of the blade body, i.e. consume energy from any centrifugal force and an ever-present gravitational force on the turbine. These forces both strive to increase the helical angle of the rotor blades with the result that the blade body collapses into a stable equilibrium position, i.e. the length (L) decreases and the diameter (D) increases; which the leaf body consumes at a decreasing or completely absent centrifugal force. One effect of the vertical and horizontal movement of the support arm is that the blade cover must be connected at a pivot point to the support arm to accommodate the change of the helix angle with the diameter of the blade body.

In a third aspect, the present invention relates to the use of the turbine and performing the control in a power unit arranged in solid ground or floating in a body of water for generating electrical or mechanical or visual power or a combination of two or more of said effects, said support structure is arranged in fixed connection to said foundation.

As can be seen from the above (see requirement 3), the turbine is used in a power unit which converts the energy of the turbine into power. Ground-based power plant units also refer to bottom-fixed ditto placed at sea. Furthermore, it may be appreciated that - the power unit may be arranged vertically, horizontally or inclined and at different distances in relation to the center of mass of the power unit. Thus, the length of the power unit may exceed the length of the blade body, for example, said power unit may constitute a wind power mast to said turbine; the power supply can be arranged in different media - such as air or water.

Thus, the flowing fluid may comprise wind in one part and water currents or water waves, individually or in combination with each other, in the other part; wherein the fluid direction may be unidirectional in different media (see claim 1); the electrical power can be transported in a cable (K) from said power supply to consumers on land and / or at sea, which is a known technique and not further explained; the mechanical power can be, for example, a turbine shaft for direct mechanical operation of a propeller or pump, which completely eliminates the need to generate electrical power for the operation of the pump; the visual effect can be achieved by illumination of the rotor blades. These can be made, for example, in milk-white high-density polyethylene (HDPE), which makes them permeable to light from a light source placed inside the rotor blades, or clear polymethyl methacrylate (PMMA), which makes them fully or partially transparent to light even from a light source placed outside the rotor blades. . Transparent rotor blades can also be made tight and filled with gas, for example neon gas, whereby the rotor blades can obtain a colored glow according to known technology. The gas can be ignited by means of the electric current produced by the power supply and distributed in the power cables located in the section holes in the rotor blades. The turbine can thus be a rotating illumination for use as an advertising space, lighthouse, floating beacon, flare for night fishing or other vantage point.

As may also be appreciated (see claim 3), the invention is adapted for use for mobile leisure use in that the rotor blades can advantageously be carried in a rolled-up condition and the blade joints and any power units can be packed in a portable package. Assembly of the blade body takes place on site by inserting the rotor blades into the blade joints, which are twisted up and fastened; whereupon the rotor blades are snapped into the blade struts on the support hub, after which the turbine shaft is stored in the power unit which is proposed to be fastened with ropes to the ground or the float. The turbine shaft can be placed in a portable generator and the power unit thus generates electric current and is just as easily disassembled after use.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described below more fully with reference to figures of non-limiting examples of various embodiments. It is to be understood, however, that the embodiments have been introduced to explain the principles of the invention and not to limit the scope of the invention, as determined by the appended claims. It should be noted that the figures have not been drawn up to scale and that the dimensions of certain features have been exaggerated for the sake of clarity. In particular, the leaf body has a three-dimensional design which in reality may deviate from the sketchy models presented according to the figures.

Figure 1. is a perspective view of the rotor blades of the blade body according to the first aspect of the present invention.

Figure 2. is a schematic side view of the turbine mounted on the sea or lake bottom in accordance with the third aspect of the present invention.

Figure 3. is a view showing the distribution of a cylindrical blade body with 3 left-handed and 3 right-handed undulated rotor blades with the pitch 1 revolution per length L of the blade body.

Figure 4 is a view showing the distribution of a cylindrical blade body with 4 left-handed and 4 right-handed non-undulated rotor blades with the pitch 0.5 turns per blade length L.

Figure 5 is a view showing different cross-sections of the leaf body in Fig. 3.

Figure 6 is a perspective view of a blade joint with a normal line to the line of rotation.

Figure 7 is a schematic view of the blade body with undulated rotor blades.

Figure 8 is a schematic view of the blade body with non-undulated rotor blades.

Figure 9 is a view showing two blade attachments to the blade joint of Fig. 6.

Figure 10 is a view showing blade joints in two sections of the undulated blade body of Figure 3.

Figure 11 is a view showing the wing profile of the rotor blade at different helix angles.

Figure 12 is a view of the turbine according to the second aspect of the invention at no or low angular velocity where the support frames are positioned in the retracted position.

Figure 13 is a view of the turbine of Figure 4 fixed at a higher angular velocity where the support arms are positioned in the extended position.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Fig. 1 shows a perspective view of a blade body (9) according to the invention and a line of rotation (3) around which the blade body is intended to rotate. The leaf body is placed in a flowing fluid (2) with the velocity vector (W) directed perpendicular to the line of rotation and attacks the leaf body in the fluid eye at the angle of rotation (?) Equal to 0. The extent of the leaf body in the direction of the line of rotation, i.e. in the axial direction, is bounded by the two end normal planes (M1) and (M2) which are perpendicular to the line of rotation; and in the radial direction, of the outer and inner concentric mantle surface generated by the envelope of the outer and inner rotor blades, respectively, as the blade body rotates with the radius (r). The leaf body according to Fig. 1 thus has a double-conical (hourglass conical) inner and a cylindrical outer mantle surface which are both truncated in the end normal plane, so that the largest body of the leaf body between the mantle surfaces is shown in the central normal plane (M). It should be noted that Fig. 1 is primarily intended to illustrate the geometric construction of the blade body of rotor blades and not how these are attached to each other or to the turbine (1). Thus, Fig.1. only one blade joint (13), although the present invention is characterized in that each pair of intersecting rotor blades is connected by a blade joint between them.

Fig. 1 shows the blade body made up of 6 rotor blades in space spiral curve, of which three are twisted with right rotation (10-H1, 10-H2, 10-H3) and three pieces are twisted with left rotation (10-V1, 10-V2, 10 -V3). The rotor blades are made of injection molded plastic profiles that allow them to rotate to a suitable radius (s). In Fig. 1 the rotor blades are shown rotated one revolution per length of the blade body, i.e. the pitch is equal to 1. Each right-hand rotor blade is thus connected to a left-hand ditto at the ends: thus 10-H1 is connected to 10-V1 in a blade joint (13) in (M2) and a blade joint (not shown) in (M1) , 10-H2 connected to 10-V2 in a blade joint (not shown) in both (M1) and (M2), and 10-H3 connected to 10-V3 in a blade joint (not shown) in both (M1) and (M2 ); i.e. 6 blade joints. In addition, each right-handed rotor blade is connected in a bath joint (not shown) in (M), i.e. 3 blade joints. Since no right-handed rotor blade intersects another right-handed rotator and no left-handed one crosses any other left-handed rotor blade, each right-handed rotor blade in Fig. 1 intersects the other two left-hand rotor blades in an area between (M1) and (M), i.e. 6 blade joints; and in a range between (M2) and (M), i.e. another 6 blade joints. This gives a total of 21 blade joints for the blade body in Fig. 1.

Fig. 1. indicates that all rotor blades are provided with a wing profile with a round nose in the direction of rotation (V) of the blade body and a pointed trailing edge (S) in the opposite direction. All rotor blades thus have a wing profile against the direction of rotation which makes them suitable for generating the lifting force required to rotate the turbine.

From the above, it will be apparent to one skilled in the art that Fig. 1 shows only one of a myriad of embodiments of the present invention. Thus, the pitch, number, arc length and undulation ("braid") of the rotor blades can be varied by one and the same combination of blade length and diameter, in addition the blade joints can be varied so that the blade body can assume one of 16 different combinations of outer and inner shell surfaces: cylindrical , conical, double conical (hourglass conical) and biconical Finally, the combination of the length and diameter of the leaf body can be varied according to an embodiment of the invention.

Fig. 2 shows a turbine (1) arranged to recover energy from a flowing fluid (2) of a body of water (F2) with a seabed (F1). For simplicity, the term "seabed" is used whether the body of water is an area of an ocean, a sea, a lake or a river. bearing housing (4) in a turbine roller bearing, wherein a non-rotating bearing housing (5) of said turbine roller bearing is fixedly connected to a support structure (8) fixedly connected to a power unit (28) Fig. 2 shows the turbine completely immersed in the water mass, but alternatively, the turbine may be partially submerged, such as in shallow tidal bays. Fig. 2 further shows the power unit equipped with a power cable (K) located on the seabed. liquid, gas or information and regardless of the direction in which the medium is transported. As may be appreciated, the power cable can be used to transmit energy to consumers, for example located on land; but alternatively be non-existent when all the energy produced by the turbine is consumed for operation in equipment located on the power unit, for example pumps for circulation of oxygen-rich seawater. In addition to the leaf body, the above can be considered as prior art.

The turbine (1) in Fig. 2 is oriented with a vertical center line (6) through the rotating bearing housing (4) of the turbine roller bearing, the blade line (3) of rotation of the blade body coinciding with said center line at a center point of the turbine roller bearing. As shown in Fig. 2, the line of rotation bends the distance (Uh) in the direction of fluid velocity (W), which means that the turbine rotates about a curved line of rotation. A further feature of the present invention is that the line of rotation will also bend out to the side a distance (not shown), alternately to the right and to the left and thus describing a oscillating movement perpendicular to (W). The aforementioned turbine roller bearing is intended to absorb the bending moment corresponding to the above-mentioned deflections of the turbine and at the same time allow the purposeful rotation of the turbine.

Fig. 3 is intended to illustrate a blade body (9) of length L and diameter D which is cut longitudinally with a section parallel to the line of rotation (3) through the blade joints (13 ', 13 ", 13"', 13 "") and viewed in Fig. 3 shows the cut-out blade body spread out in a plane, the width thus being equal to? multiplied by D; having 21 blade joints (13) connecting 3 right-hand turns (10-H1, 10-H2 , 10-H3) and 3 left / ride (10-V1, 10-V2, 10-V3) undulated rotor blades, which have the pitch 1 revolution on the length L and the spiral angle (?).

The present invention neither limits the arc length of the rotor blades (10) nor requires blade joints (13) located in the end normal plane (M1, M2). This is shown in Fig. 1 as the length (L) of the blade body comprises a part length (dL), the part length corresponding to a distance between one of the end normal planes (M1, M2) and a blade joint (13); i.e. that the rotor blade is provided with an end portion which is not laid in a blade joint and can thus obtain a free displacement. As may be appreciated, such a free end portion of a rotor blade offers the possibility of providing a lifting force on said free end portion which counteracts and partially reduces the bending moment in the rotor blade caused by the lifting force on the non-free portion of the rotor blade between two blade joints.

Fig. 4 is intended to illustrate a blade body (9) of length L and diameter D which is cut longitudinally with a section parallel to the line of rotation (3) through the blade joints (13 ', 13 ", 13'") and viewed in the direction of the line of rotation from a place outside the leaf body. Fig. 4 shows the cut leaf body spread out in a plane, the width thus being equal to? multiplied by D; having 20 blade joints (13) connecting 4 right-handed and 4 left-handed non-undulated rotor blades (10), which have the pitch 0.5 turns on the length L and the helical angle (?).

As mentioned above, the embodiments shown in Figs. 3 and 4 are two examples among a myriad of other examples of a possible configuration of a leaf body.

Fig. 5 shows cross-sections of the blade body at the direction of rotation (V) according to Fig. 3, i.e. to the left of the viewer. View a - a shows a section in the middle normal plane (M) of the leaf body, which is parallel to (V); through 3 blade joints (13) and 6 rotor blades (10), the nose (N) of the wing profile of all rotor blades being directed in the direction of rotation (V). The distance between the center lines of the rotor blades in the center normal plane (M) is indicated by the distance with the length (h0). In section a - a, all left / rotated rotor blades (10-V1, 10-V2, 10-V3) thus have a common radius (r) of the line of rotation (3) which exceeds the common radius of all right-rotated rotor blades (10-H1, 10-H2, 10-H3).

As shown in Fig. 3, views b - b show a section in the direction of rotation (V) of the blade body located midway between two blade joints (13), where all rotor blades have a common radius (r) to the line of rotation due to the undulation. As may be appreciated from Fig. 5, this is due to the fact that the distances are equal between the center lines of the rotor blades in the central normal plane (h0) and in the blade joint closest to the respective end normal plane (h1, h2). In another example (not shown), views b - b are not located midway between two blade joints, but only somewhere between two blade joints; all leaf joints having a common radius (r) to the line of rotation, but different distances (h0) and (h1) and (h2).

Fig. 5 shows in views c - c a section in the longitudinal direction of the blade body through 4 blade joints and 8 rotor blades, the nose of the wing profile to one half of the rotor blades being directed in the direction of rotation (V) and to the other half being directed, which is a consequence of the section is taken perpendicular to the direction of rotation (V). In the section, there are no rotor blades located in the central normal plane (M) and the distance (h0) can thus not be specified. The distances (h1) and (h2) are equal in this example, but may be different in other examples described above.

As shown in Fig. 3, views d - d show a section of a rotor blade (10-V3), i.e. in the approach angle (?) of the rotor blade to the fluid direction (W) in question.

Since the helix angle (γ) is shown to be about 45 degrees in Fig. 3, the center lines of all right-hand rotor blades become almost perpendicular to the center line of the rotor blade (10-V3) in the section; i.e. the cross-sectional sections of all wing profiles are almost maximally round, which corresponds to the width (x0) in Fig. 11.

The undulation shown is intended to illustrate a sinusoidal shape. As shown in Fig. 3, (13 ') and (13 "") denote different blade joints; and (10i) and (10ii) different part lengths of the rotor blade (10-V3), which may thus have different lengths. The distances (h1) and (h2) are equal in this example, but may be different in other examples described above.

Fig. 6 shows a perspective view of a blade joint (13) comprising two rotor blades (10) each provided with a center line (11) and wing profile (12). A normal line (14) of the line of rotation (3) has a point of intersection (PN) with the line of rotation, said normal line also having a point of intersection (PB1) with the center line of the rotor blade having the smaller distance, i.e. radius, to (PN); and an intersection point (PB2) with the center line having the greater distance to (PN). As shown in Fig. 5, PB1 and PB2 are connected by a structure further described in Fig. 7.

Fig. 7 is intended to locate a first (15) and second biad joints (16) and shows a view of an undulated leaf body which is viewed in the direction of the line of rotation from a place outside the leaf body. As shown in Fig. 7, no blade joint is located between said first (15) and second blade joints (16); i.e. the leaf joints are the nearest neighbors.

Fig. 8 has the same purpose as Fig. 7, but for a non-undulated leaf body. Fig. 8 shows that no blade joint is located between said first (15) and second blade joints (16); i.e. the leaf joints are the nearest neighbors.

Fig. 9 shows the blade joint (13) and the rotor blades (10) in Fig. 6 (dotted line) comprising two blade enclosures (17, solid line) which partially enclose the respective wing profile (12) and leave an opening in the trailing edge. When mounting a blade cover (17) with a rotor blade (10), the rotor blade can be allowed to be pressed into the blade cover with the nose first through said opening by means of an applied external force and utilizing the blade cover flexibility in construction and material. As may be appreciated from Fig. 9, the blade cover is connected in contact with the wing profile except in said opening; which is an advantage in the uptake and distribution of the forces on the rotor blades to the blade joint.

In another embodiment of a blade cover (not shown), the blade cover for a rotor blade comprises two parts, for example shaped after the upper and lower side of the wing profile, which are connected by screw, bolt or glue joints. The blade sheaths (17) are connected by a rod joint (18) shown in Fig. 9, the center line (19) of the rod joint coinciding with the normal line (14) of the blade joint.

Fig. 10 shows a view of a blade joint (13) in section e - e according to Fig. 3 comprising two blade covers (17) connected by a rod joint (18) provided with a rod roller bearing (T). The rotor blades (10) can be allowed to rotate around the center line (19) of the rod joint so that the spiral angle (?) Changes. Fig. 10 shows the rotor blades with the cross-sectional section drawn for the purpose of clarifying the appearance and orientation of the wing profile, i.e. that the direction of rotation points perpendicular to the viewer. Section f - f in Fig. 10 shows the blade joint at the direction of rotation pointing to the left.

Fig. 11 shows in section g - g a view of a rotor blade (10i) seen perpendicular to the plane containing the cord of the wing profile, showing the spiral angle (? 1) and the angle of impact (? 1), where (y1) plus (? 1) is equal to 90 degrees; and the cord length (x1) in the flow direction (? 1). After a rotation of the rotor blade (101) about the center line (19) of the rod joint (18), until a new approach angle (? 2) occurs, the rotor blade (102) obtains a new cord length (x2), whereby (? 2) is less than ( ? 1) and (x2) are greater than (x1). The physical cord length of the rotor blade is equal to (x0), which is less than both (x1) and (x2) as shown in Fig.11. It also shows that the thickness (y) of the wing profile is unchanged, and since the chord lengths (x0, x1, x2) change with the spiral angles (y1, y2), this means that the angles of attack (? 1,? 2) also change. Thus, a larger helix angle (y2) also means a larger chord length (x2) and a smaller angle of attack (? 2), i.e. when the leaf body collapses due to a higher rotational speed, the angle of attack becomes smaller and the risk of exceeding the wing profile decreases.

Fig. 12 shows in section h - h a turbine with (3 3) rotor blades viewed in the direction of the rotation line (3) (Z) and direction of rotation to the right with the blade body (9) in the retracted position (O1). Fig. 12 shows the blade body (9) with a vertical center line (6) and rotor blades (10) connected to the blade shafts (17) in a pivot point (m), the blade shells being articulated to the support arms (24) in a center line (25) through two arm roller bearings (26) on the support hub (7). The blade body has the helical angle (? 1) and the blade connections (13), a filled circle indicating that the blade connection is located in front of the line of rotation (3) and an unfilled circle indicating location behind (3). The figure indicates with the angle (?) The slope of the center line (25) of the suspension towards the center line (6) of the turbine, whereby (?) Is a value between 1 - 15 degrees, typically 5 degrees or large enough to automatically raise the blade body as the fluid velocity decreases. Fig. 12 shows in section h - h the support hub (7) formed as a circular central hub with star-shaped support arms, which constitute a bending and torsionally rigid supporting structure for the support arms with little fluid resistance during rotation. The support arms can advantageously be designed with a wing-profiled cross-section (not shown).

Fig. 13 shows the turbine according to Fig. 12 in the extended position (O2). View k - k shows the position of the blade cover (n) and describes its path from the recessed position shown in view h - h.

Thus, the support arms (24) in the center lines (25) of the arm roller bearings (26) are rotated until they reach the maximum distance from the line of rotation, which is limited by the length of the support arms (24) in the swung-out position. P.g.a. the rigidity of the integrated blade body, see claim 1, the support arms are prevented from displacing each other without also changing the helical angle of the blade body. Fig. 12 shows that the pivot point (m) of the blade cover has been displaced outwards at a changed rotation angle of 60 degrees, the lower end normal plane of the blade body being displaced upwards while the upper end normal plane has been displaced downwards (not shown) so that the blade body length has decreased and diameter increased. that the spiral angle (y2) exceeds (? 1).

Claims (3)

REQUIREMENT A method of controlling by means of a displacing means the size of a blade body (9) of a turbine (1) arranged for the production of usable energy from the motion of a flowing fluid (2) at substantially perpendicular orientation of the line of rotation (3) of the turbine against the fluid direction (W), the turbine comprising: - a turbine roller bearing comprising a rotatable bearing housing (4) and a non-rotatable bearing housing (5), and having a center point and a center line which (6) passes through said center point, and - at least a support hub (7) arranged in fixed connection with the rotatable bearing housing, and a support structure (8) arranged in fixed connection with the non-rotatable bearing housing, and - a blade body (9) wholly or partly located in the fluid and arranged in connection with the support hub, the movement of the fluid allowing rotation of the blade body about the line of rotation which (3) coincides with the center line (6) at a point identical to said center point, comprising - a plurality of rotors blades (10) each of which are continuously extending axially and radially in a space spiral curve with a helical axis in the line of rotation and having a helical direction about the line of rotation and in the normal plane of the space helix curve provided with a cross section with a center line (11) and with two end portions, the first end portion having a rounded nose (N) directed in the direction of rotation (V) of the blade body and the second end portion having a tip (S) in the opposite direction, the turbine (1) having an intersection point (PN) between the line of rotation (3) and a normal line to the line of rotation, and - a plurality of blade joints each (13) having an intersection point (PB1) between the center line (11) of a first rotor blade (10) and said normal line and an intersection point (PB2) between the center line (11) in a second rotor blade (10) and said normal line, the intersection points (PN, PB1, PB2) being connected by a common normal line (14) to The line of rotation and (14) is provided with an end point in (PN), the distance PN-PB1 not being equal to the distance PN-PB2, said first and second rotor blades (10) having different helical directions about the line of rotation (3) and being connected with each other in at least one of said blade joints (13), and the blade body has - a length (L) and a diameter (D) and a helical angle (?) between the center line (11) of the rotor blade and the line of rotation when projected on a plane containing the line of rotation, a plurality of said blade connections (13) are arranged on the same rotor blade (10) and connected to each other by intermediate parts consisting of said rotor blade (10), wherein - a first blade connection (15) has the distance PN-PB1 which is greater than the distance PN PB2 and that a second blade joint (16) has the distance PN-PB1 which is smaller than the distance PN-PB2, no blade joint (13) being located between said first and second blade joints, wherein - said first blade joint (15) is a first sum of the distance PN-PB1 and PN-PB2, and that said second blade joint (16) has a second sum of the distance PN-PB1 and PN-PB2, the first sum being equal to the second sum, wherein - the blade joint (13) comprises two blade shells which (17) are each provided with a cross-sectional section with a center line parallel to the center line (11) of the rotor blade, the cross-section section completely or partially enclosing the wing profile (12) of the rotor blade, the blade joint comprising a rod joint which ( 18) connects two blade joints (17) in a blade joint (13) to each other and is provided with a rod with a cross-sectional section with a center line (19), the center line (19) coinciding with the common normal line (14) of the blade joint (13) , wherein the rod joint (18) comprises at least one rod roller bearing (T) provided with a center line coinciding with the center line (19) of the rod, the rod roller bearing allowing mutual rotation of rotor blades even center lines (11) around the common normal line (14) of the blade joint (13); wherein the connection of the blade body to the support hub (7) comprises at least one support arm which (24) comprises a blade cover (17) connected to the support arm and fixedly connected to an end portion of said rotor blade (10), and is rotatable about a straight center line (25) passing by at least two arm roller bearings (26) each provided with a bearing housing fixedly connected to the support hub (7), said displacing means comprising said rod joint (18) arranged to rotate the center lines (11) of the rotor blades about a common normal line (14) to the line of rotation (3). ) and said support arm (24) arranged for rotation about a center line (25) by at least two said arm roller bearings (26) connected to said support hub (7), said turbine (1) having an angular velocity and said displacing means being arranged for simultaneous increase of the length (L) and reduction of the diameter (D) of the blade body (9), or vice versa, characterized in that said method comprises the steps of: - bringing said the support arm (24) to be arranged in a first position (01), said first position corresponding to a first helical angle (? 1) of the blade body (9); causing said support arm (24) to be arranged in a second position (02), said second position corresponding to a second helical angle (? 2) of the blade body (9), wherein (? 2) is not equal to (? 1). The method according to claim 1, characterized in that the center line (25) of the arm roller bearings has an intersection point with the center line (6) of the turbine bearing. Carrying out the method according to any one of the preceding claims in a power unit which is arranged solidly in the ground or floating in a body of water for generating electrical or mechanical or visual power or a combination of two or more of said effects, characterized in that said support structure (8) is arranged in fixed connection to said power unit.