Rotor for vertical axis turbine and vertical axis turbine

Abstract

The present invention relates to a rotor for a vertical axis turbine comprising a blade support structure extending from a center of the rotor, blades pivotally connected to the blade support structure at a distance from the center of the rotor, and a pitch adjustment mechanism arranged between the blade support structure and the blades for adjusting the pitch of the blades in response to hydrodynamic forces acting on the blades, wherein the pitch adjustment mechanism comprises a damper system having a first damping coefficient in a first rotational direction of the blades relative to the blade support structure and a second damping coefficient in a second rotational direction of the blades relative to the blade support structure.

Description

[Technical field]

[0001] The present invention relates to a rotor for a vertical axis turbine, such as a wind turbine or an underwater turbine, and to a vertical axis turbine including such a rotor. [Background technology]

[0002] Turbines in the context of this application are used to extract energy from wind or water currents by converting the kinetic energy from the wind or water into kinetic energy of a rotor and then possibly into other forms of energy, for example electrical energy, although this is not necessarily the primary purpose and turbines may also be used for recreational or promotional purposes.Turbines, for example wind turbines, are of two types: the well-known horizontal axis turbines, which have a main rotor shaft extending horizontally, and the vertical axis turbines, which have a main rotor shaft extending vertically.

[0003] Furthermore, vertical axis turbines can also be generally divided into two types: those with Savonius rotors and those with Darrieus rotors. The Savonius type operates mainly on the basis of drag differences, which limits its maximum efficiency. However, the advantage of this type of turbine is its simplicity of design and the fact that it starts working automatically when it captures enough wind or water. The Darrieus type, on the other hand, operates on the basis of lift generated on the wings, allowing higher relative speeds and higher efficiency.

[0004] It is well recognized that the rotor of a Darrieus type vertical axis turbine is subjected to higher forces and torques due to the higher relative speed. The blades are subjected to lift and drag forces caused by the relative motion of the blades through the medium, i.e. air or water. Turbulence, for example the passage of strong wind gusts in the case of wind turbines, can introduce extreme and potentially destructive forces on the blades and rotor. In addition, the blades are subjected to centrifugal forces that increase as the relative speed increases.

[0005] Other disadvantages of vertical axis turbines may include difficult / impossible automatic starting, lower power output due to operation closer to the ground, and, at least in the "small" region, high levels of vibration caused by inherent torque ripple and dynamic stall in the blades. Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above, it is an object of the present invention to provide an improved vertical axis turbine. [Means for solving the problem]

[0007] According to one embodiment of the present invention, a blade support structure extending from the center of the rotor; a wing pivotally connected to a wing support structure at a distance from the center of the rotor; a pitch adjustment mechanism disposed between the wing support structure and the wing for adjusting the pitch of the wing in response to hydrodynamic forces acting on the wing; A rotor for a vertical axis turbine, comprising: A rotor is provided in which the pitch adjustment mechanism includes a damper system having a first damping coefficient in a first rotational direction of the blade relative to the wing support structure and a second damping coefficient in a second rotational direction of the blade relative to the wing support structure.

[0008] In one embodiment, the wing is oriented substantially parallel to the rotor's vertical axis of rotation or is configured with at least a portion substantially parallel to the rotor's vertical axis of rotation. The wing may be oriented in a substantially helical shape or may be part of the contour of a balloon or sphere centered on the rotor's vertical axis of rotation. In some embodiments, the wing support is a preferably integral extension of the wing that extends from the center of the rotor to the substantially vertically oriented wing. Such extensions may be provided at both ends of the wing.

[0009] The rotor may define a forward rotational direction in which the rotor rotates during operation. A first rotational direction of the blades relative to the blade support may be in the same direction as the forward rotational direction, in which case a second rotational direction of the blades relative to the blade support is opposite to the forward rotational direction.

[0010] The damping coefficient is defined as the ratio between the force generated by a damper system as a result of the relative velocity between its two components: the higher the relative velocity, the greater the force generated.

[0011] In one embodiment, the first damping coefficient is greater than the second damping coefficient.

[0012] In one embodiment, the second damping coefficient is substantially zero.

[0013] In one embodiment, the blades and pitch adjustment mechanisms form a blade combination and the rotor comprises two or more such blade combinations distributed, preferably evenly distributed, around the center of the rotor, In one embodiment, the pitch adjustment mechanisms of two or more blade combinations are integrated with each other and / or are part of a common pitch adjustment system.

[0014] In one embodiment, the damper system has a third damping coefficient over a first distance in a first rotation direction of the blade, and the first damping coefficient is applied for a second distance in the first rotation direction of the blade, said second distance being adjacent to the first distance. The third damping coefficient may be substantially equal to the second damping coefficient and / or the third damping coefficient may be substantially zero. Preferably, when reversing direction from the second rotation direction to the first rotation direction, the blade first rotates in the first rotation direction over the first distance and then over the second distance. Thus, preferably, the third damping coefficient is applied first before the first damping coefficient is applied when rotating in the first rotation direction.

[0015] In one embodiment, the rotor further comprises a lower support to be attached to a shaft, pole, or spar, and a lower bearing disposed between the lower support and the wing support, allowing the wing support to rotate relative to the lower support.

[0016] In one embodiment, the rotor further comprises an upper support to be attached to a shaft, pole, or spar, and an upper bearing disposed between the upper support and the wing support, allowing the wing support to rotate relative to the upper support.

[0017] To be attached to the shaft, pole or spar means that the lower support and / or the upper support are attachable to the shaft, pole or spar for transferring at least horizontal loads to the shaft, pole or spar. Preferably, the lower support and / or the upper support are also attachable to the shaft, pole or spar for transferring vertical loads to the shaft, pole or spar.

[0018] In one embodiment, a (separate) bearing, preferably a plain bearing, is provided between the wing support and the shaft, pole or spar to transfer horizontal loads to the shaft, pole or spar. The bearing may be provided anywhere, but is preferably combined with said lower support (including a lower bearing) where the bearing is provided above the lower support at a distance from the lower support, or with said upper support (including an upper bearing) where the bearing is provided below the upper support at a distance from the upper support.

[0019] In one embodiment, the rotor is configured such that the orientation of the blades relative to the blade support is determined primarily by hydrodynamic forces, damping forces applied by the damper system, and / or friction forces. Any elastic, resilient or spring forces present on the rotor during operation are then significantly smaller, e.g. non-existent, preferably significantly smaller than the combination of other forces, e.g. at most 50% of the combination of other forces, preferably at most 30% of the combination of other forces, more preferably at most 20% of the combination of other forces, most preferably at most 10% of the combination of other forces. Smaller elastic, resilient or spring forces may additionally or alternatively mean that their maximum value is less than 50% of the maximum value of the damping force applied by the damper system, preferably less than 30%, more preferably less than 20%, most preferably less than 10% of the maximum value of the damping force applied by the damper system. For example, it is envisaged that springs are used to prevent damage to the blades. The wing may have a central position defined, for example, by the position where the wing or a portion of the wing is tangent to a circle centered on the rotor center and two extreme rotational positions, and a spring is provided to urge the wing towards its central position when one of the extreme rotational positions is reached to prevent a sudden stop and therefore damage to the wing or wing support.

[0020] In one embodiment, the pitch adjustment mechanism lacks a spring and an element that provides a spring force. Thus, the spring or the element that provides a spring force may not be present.

[0021] In one embodiment, the wing has a leading edge and a trailing edge, the wing has a center of gravity, and a pivot axis defined by the wing support structure is located between the center of gravity and the leading edge of the wing.

[0022] In one embodiment, the damper system comprises a damper in which the fluid is forced through a fluid resistance, the fluid resistance being variable. Providing a variable fluid resistance can be done in various ways. A passive method is to provide a one-way valve with a small opening, such that when the one-way valve is closed, the fluid is forced through the small opening, resulting in a high fluid resistance and therefore a high damping coefficient, and when the one-way valve is open (corresponding to the opposite fluid flow direction), the fluid is forced through a relatively large opening, resulting in a low fluid resistance and therefore a high damping coefficient. The fluid may be a liquid or a gas, for example a working fluid.

[0023] Alternatively, active control can be used to vary the fluid resistance, for example by actively controlling a valve, e.g. a pneumatic valve, or by adjusting the resistance of an electric actuator to adjust the amount of energy dissipation of the electric actuator.

[0024] In one embodiment, the damper extends between the wing support and the leading edge of the wing.

[0025] In one embodiment, the wing includes a damper support extending from a leading edge of the wing, the damper extending between the wing support and the damper support on the wing.

[0026] According to a further embodiment of the invention there is provided a vertical axis turbine comprising a rotor according to the invention, which may be mounted to a pole, shaft, spar or other structural member for rotation about an axis of rotation defined by the pole, shaft, spar or other structural member.

[0027] In one embodiment, the turbine is a wind turbine, which extracts energy from wind, hi another embodiment, the turbine is a water turbine, which extracts energy from flowing water.

[0028] In one embodiment, the turbine further comprises a rotational speed limiting device for limiting the maximum rotational speed of the rotor. The rotational speed limiting device may be passive and may, for example, comprise a control element subjected to centrifugal force against a spring and configured to reduce or limit the net torque to the rotor once a predetermined rotational speed is achieved.

[0029] In one embodiment, the rotational speed limiting device is active and includes a sensor for measuring the rotational speed of the rotor and an actuator for actively reducing or limiting the speed by dissipating excess energy, for example by using mechanical braking or electrical braking using a generator connected to the rotor.

[0030] In one embodiment, the rotational speed limiting device is connected to or integrated with the pitch adjuster to regulate operation of the pitch adjuster to reduce or limit the rotational speed of the rotor once a predetermined rotational speed is achieved.

[0031] It is expressly noted here that the inventors, like all those skilled in the art of engineering, recognize that ideal springs and dampers do not exist in practice. Thus, springs do in practice dissipate some energy and therefore have a non-zero damping coefficient, and dampers or other components of the rotor do not in practice have infinite stiffness and therefore have a non-zero spring constant. Thus, statements about zero damping coefficients or lack of springs must be interpreted within this practical context to mean, respectively, that energy dissipation is minimal as can be reasonably expected, and that no elements are used that provide significant elastic behavior of the blade pitch.

[0032] The present invention will now be described in a non-limiting manner with reference to the accompanying drawings, in which like parts are indicated with like reference symbols, and in which: [Brief description of the drawings]

[0033] [Figure 1]1 illustrates diagrammatically a perspective view of a turbine according to an embodiment of the present invention; [Figure 2A] 2 shows a schematic top view of a rotor according to an embodiment of the invention in a first rotational position; [Figure 2B] 2B shows a schematic top view of the rotor of FIG. 2A in a second rotational position; [Figure 2C] 2B shows a schematic top view of the rotor of FIG. 2A in a third rotational position; [Figure 2D] 2B shows a schematic top view of the rotor of FIG. 2A in a fourth rotational position; [Figure 2E] 2B shows a schematic top view of the rotor of FIG. 2A in a fifth rotational position; [Figure 2F] 2B shows a schematic top view of the rotor of FIG. 2A in a sixth rotational position; [Figure 2G] 2B shows a schematic top view of the rotor of FIG. 2A in a seventh rotational position; [Figure 2H] 2B shows a schematic top view of the rotor of FIG. 2A in an eighth rotational position; [Figure 2I] 2B shows a schematic top view of the rotor of FIG. 2A in a ninth rotational position; [Diagram 3] 2B shows a schematic diagram of the torque generated by the blades of the rotor of FIG. 2A as a function of rotational position; [Figure 4] 2 shows a schematic cross-sectional view of the upper and lower parts of the rotor of the wind turbine of FIG. 1 on a pole; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Figure 1 shows a schematic perspective view of a wind turbine 1 according to an embodiment of the invention. The wind turbine 1 is of the vertical axis type and comprises a pole 2 having a longitudinal axis 3 running substantially parallel to the vertical. The pole 2 may be designed as part of the wind turbine 1, but it is also possible that the pole 2 is an already existing element originally used for other purposes, such as a flagpole, and the wind turbine 1 is formed by attaching a rotor 5 to the pole 2. In this example, the longitudinal axis 3 of the pole 2 coincides with the vertical axis of rotation of the rotor.

[0035] In other embodiments, the pole 2 may alternatively be a spar, a mast, a shaft or any other element making it possible to mount the rotor and provide it with a vertical axis of rotation.

[0036] The rotor 5 comprises three blades 6a, 6b, 6c and a blade support structure for supporting the three blades 6a, 6b, 6c. The blade support structure in this example includes a lower member 7, an upper member 8 and a respective frame 9 for each of the three blades 6a, 6b, 6c. Each frame 9 is connected to the lower member 7 and the upper member 8, and each blade 6a, 6b, 6c is pivotally connected to its respective frame 9, allowing the corresponding blade 6a, 6b, 6c to pivot about a pivot axis 10 that extends substantially parallel to the longitudinal axis 3 and thus substantially parallel to the vertical axis of rotation of the rotor 1.

[0037] In the embodiment of FIG. 1 , the upper member 8 is connected to a bearing 11, in this embodiment a plain bearing 11, and engages the pole 2. The bearing 11 is configured to transmit horizontal forces between the rotor 5 and the pole 2 to guide the rotation of the rotor about the pole 2. In this embodiment, the bearing 11 is not configured to transmit vertical forces between the rotor 5 and the pole 2. Vertical and horizontal forces are transmitted between the rotor 5 and the pole 2 using a structure in the lower member 7, which will be described in more detail below with reference to FIG. 4 .

[0038] Between the blade support structure and the blades 6a, 6b, 6c, a pitch adjustment mechanism 15 is arranged, which is only visible for the blade 6a in FIG. 1. The pitch adjustment mechanism 15 is configured to adjust the pitch of each blade depending on the hydrodynamic forces acting on the blade. The pitch adjustment mechanism comprises a damper system, which has a first damping coefficient for a first rotation direction and a second damping coefficient for a second rotation direction. The advantage of different damping coefficients for different rotation directions is that the pitch behavior of the blades during a full 360° rotation of the rotor can be optimized to address different drawbacks and operating conditions of this type of vertical axis wind turbine. For example, as will be explained in more detail below with reference to other embodiments, the first damping coefficient may be optimized to address the passage of strong wind gusts and / or centrifugal forces, and the second damping coefficient may be optimized to address easy self-starting and torque generation.

[0039] Although the pitch adjustment mechanism is shown as an externally visible component between the frame 9 and the blades 6a, the pitch adjustment mechanism may be at least partially hidden, for example integrated into the blades 6a and / or frame 9, which has the advantage that the pitch adjustment mechanism does not interfere, or only minimally interferes, with the hydrodynamic forces acting on the rotor 5.

[0040] Each of the blades 6a, 6b, 6c and their corresponding pitch adjustment mechanisms form a blade combination. The rotor 5, in this embodiment, includes three blade combinations evenly distributed around the center of the rotor 5. However, other numbers of blade combinations are also envisioned.

[0041] Figures 2A-2I show diagrammatically top views of a simplified representation of a rotor R according to an embodiment of the invention, each showing the rotor R in a different rotational position. The rotor R comprises a support S at the centre of the rotor R defining a vertical axis of rotation RA, a wing support structure BS extending from the support S of the rotor R, and a wing B pivotally coupled to the wing support structure BS at a distance from the centre of the rotor R for pivoting about a pivot axis PA, the wing B being configured to be oriented substantially parallel to the vertical axis of rotation RA of the rotor R. A damper system DS is arranged between the wing B and the wing support structure BS as part of a pitch adjustment mechanism.

[0042] The rotor R shows similarities with the rotor 5 of FIG. 1. Thus, the support S may correspond to or comprise similar components to the structure of the pole 2 and bearing 11 and / or the lower member 7. The wing support structure BS may correspond to or comprise similar components to the lower member 7, the upper member 8 and the frame 9. The wing B may correspond to one of the wings 6a, 6b, 6c, and the pivot axis PA may correspond to the pivot axis 10. The pitch adjustment mechanism 15 of FIG. 1 may be or comprise the damper system DS of FIGS. 2A-2I.

[0043] Using a combination of different rotational positions of rotor R as shown in Figures 2A-2I and a constant wind direction W of constant magnitude, the behavior of rotor R, in particular the behavior of blade B, and more particularly the pitching behavior of blade B, which can also be applied to each blade of rotor 5 in Figure 1, is described below.

[0044] In the following, reference is made to the pitch angle α of the wing, which is defined with reference to a top view such as in Figures 2A-2I as the angle between a line connecting the vertical axis of rotation RA of the rotor R, which in this embodiment coincides with the wing support structure BS, and the pivot axis PA of the wing B, and the trailing edge TE side of a line connecting the leading edge LE and the trailing edge TE of the wing B, also known as the chord BC.

[0045] When discussing the behavior of rotor R for different rotational positions of rotor R shown in Figures 2A-2I, reference is also made to Figure 3, which shows the generated torque T as a function of rotational position, with reference symbols A-I corresponding to the rotational positions in Figures 2A-2I.

[0046] Furthermore, for simplicity, the rotation axis RA and the damper system DS are shown only in FIG. 2A and are omitted in the other FIGS. 2B to 2I.

[0047] In Figure 2A, the rotor R is in a first rotational position where the pitch angle α of the blades B is substantially 90 degrees and the blade chord BC is parallel to the wind direction W. This first rotational position may alternatively be referred to as the 0 degree rotational position. The rotor R defines a forward rotational direction, in this case indicated by the arrow RD, in which the blades B move in a direction parallel to the direction from the trailing edge TE to the leading edge LE.

[0048] The wing B can pivot about a pivot axis PA relative to the wing support structure BS in two rotational directions: the rotational direction corresponding to the forward rotational direction RD is called the first rotational direction FRD and the rotational direction opposite to the forward rotational direction is called the second rotational direction SRD.

[0049] In the first rotational position of FIG. 2A, the torque T generated by the blade B is zero or at least minimal, as shown in FIG.

[0050] In Figure 2B, the rotor R has rotated in a forward rotational direction RD to a second rotational position. The wind W rotates the blade in a second rotational direction SRD relative to the blade support structure BS, which results in a smaller pitch angle α and keeps the orientation of the blade B substantially aligned with the wind W. As a result, the torque T generated in the second rotational position B is minimized.

[0051] In Figure 2C, rotor R has rotated in a forward rotational direction RD to a third rotational position. Blade B has a minimum pitch angle α but begins to rotate against wind W. The rotational speed of rotor R combines with wind W to produce lift and drag forces on blade B, resulting in a net torque T about the rotational axis RA of rotor R.

[0052] This torque T increases to a maximum when the rotor R rotates in the forward rotation direction RD to the fourth rotation position shown in FIG. 2D, and then decreases when the rotor R rotates in the forward rotation direction RD to the fifth rotation position shown in FIG. 2E and to the sixth rotation position shown in FIG. 2F.

[0053] In the sixth rotational position of FIG. 2F, both the centrifugal force and the wind W begin to rotate the wing B in a first rotational direction FRD relative to the wing support structure BS. This can happen relatively quickly, so that the pitch angle α increases rapidly to a value greater than 90 degrees as the rotor R rotates in the forward rotational direction RD to the seventh rotational position shown in FIG. 2G. The pitch angle α then remains substantially constant as it moves to the eighth rotational position shown in FIG. 2H and the ninth rotational position shown in FIG. 2I, and then gradually returns to the first rotational position of FIG. 2A to start a new cycle. The increase in the pitch angle α also causes an increase in the torque generated as shown in FIG. 3, but then decreases to a minimum as described in connection with the first rotational position of FIG. 2A.

[0054] The damper system DS is configured to provide different damping behaviors depending on the direction of rotation of the blade B relative to the blade support BS. In a first direction of rotation FRD, i.e. when the pitch angle α increases, the provided damping coefficient (herein referred to as the first damping coefficient) is greater than in a second direction of rotation SRD, i.e. when the pitch angle α decreases (herein referred to as the second damping coefficient). The second damping coefficient is preferably substantially zero. The damper system DS may comprise a damper in which the fluid is forced through a fluid resistance, for example a relatively small opening, the fluid resistance being provided in a one-way valve, such that moving the fluid in one direction corresponds to a closed one-way valve and thus to the application of a fluid resistance, and moving the fluid in the opposite direction corresponds to an open one-way valve and thus to the application of a low, preferably zero, fluid resistance.

[0055] The damper system DS may include a stopper for setting a minimum pitch angle α and / or a stopper for setting a maximum pitch angle α.

[0056] During a cycle starting from the first rotational position shown in FIG. 2A, described in relation to FIG. 2A-FIG. 2I, the pitch angle α is first decreased. Subsequently, the pitch angle α is increased. The damper system DS may be configured to apply a third damping coefficient over a predefined pitch angle change Δα, which may alternatively be called a first distance, when the blade B starts to rotate in the first rotational direction FRD. The third damping coefficient is preferably smaller than the first damping coefficient and may be equal to the second damping coefficient. After rotating over a predefined pitch angle change Δα in the first rotational direction FRD, the first damping coefficient is applied. This subsequent pitch angle range after the predefined pitch angle change may alternatively be called a second distance.

[0057] Providing a smaller third damping coefficient (compared to the first damping coefficient) has the advantage that it first allows a higher acceleration of the wing in the first rotational direction FRD, which helps to overcome static and / or kinetic friction that may be present in the damper system DS. A low, e.g. zero, third damping coefficient can be easily provided by connecting the damper to the wing B and / or the wing support BS with sufficient play, said play setting a predetermined pitch angle change Δα.

[0058] FIG. 4 shows a schematic cross-sectional view of two parts of the pole 2 of the wind turbine 1 of FIG. 1 to show how the rotor of the wind turbine 1 of FIG. 1 is supported by the pole 2 in one embodiment. The upper part of the wind turbine is shown with the top member 8 and the bearing 11. The top member 8 is part of the wing support and is connected to the frame 9. Thus, the wing connected to the frame 9 transmits forces and torques to the wing support, in this case the frame 9, which transmits forces and torques to the top member 8. The bearing 11 is a plain bearing with an opening that matches the diameter of the pole 2 with some manufacturing and / or assembly tolerances. The bearing 11 can transmit horizontal loads to the pole 2.

[0059] Also shown is the lower part of the wind turbine having a lower member 7 connected to a structure including a support 20 attached to a pole 2 using a bolted connection 21 and a bearing assembly having a first bearing part 22 and a second bearing part 23.

[0060] The bearing assembly is disposed between the lower part 7 and the support 20. The support 20 is fixedly attached to the pole 2. The first bearing part 22 is similar to the upper part bearing 11 and includes an opening that matches the diameter of the support 20 with some manufacturing and / or assembly tolerances. The first bearing part 22 is configured to transmit horizontal forces between the rotor and the pole 2 (via the support 20). The first bearing part 22 is a plain bearing.

[0061] The second bearing part 23 is configured to transmit vertical forces between the rotor and the pole 2 (via the support 20). The second bearing part 23 may be a roller bearing with one part connected to the lower member 7 and another part connected to the support 20 and with balls between the two parts to reduce friction.

[0062] In the embodiment shown, vertical forces are only transmitted to the pole at a single location, but a similar structure could be provided at the location of bearing 11. However, transmitting both vertical and horizontal loads is preferred, at least in the lower part, as this makes it easier to connect the rotor, for example to a generator below the rotor.

[0063] A generator may be connected to the rotor to convert kinetic energy from the spinning rotor into electrical energy. However, the generator may be omitted to allow the rotor to spin freely, for example for commercial or promotional purposes, or the generator may be replaced by another energy conversion device. Other energy conversion devices may provide pressure, thermal energy, chemical energy, kinetic energy, gravitational energy, etc.

[0064] Although the above embodiments have been described in terms of wind turbines, these embodiments also apply to water turbines.

Claims

1. - a blade support structure extending from the center of the rotor; a wing pivotally connected to the wing support structure at a distance from the center of the rotor; a pitch adjustment mechanism arranged between the wing support structure and the wing for adjusting the pitch of the wing in response to hydrodynamic forces acting on the wing; A rotor for a vertical axis turbine comprising: The pitch adjustment mechanism includes a damper system having a first damping coefficient in a first rotational direction of the wing relative to the wing support structure and a second damping coefficient in a second rotational direction of the wing relative to the wing support structure. A rotor characterized by:

2. 2. The rotor of claim 1, wherein the rotor defines a forward rotational direction in which the rotor rotates during operation, the first rotational direction of the blades relative to the blade support being in the same direction as the forward rotational direction, and the second rotational direction of the blades relative to the blade support being in the opposite direction to the forward rotational direction.

3. The rotor of claim 1 , wherein the first damping coefficient is greater than the second damping coefficient.

4. The rotor of claim 1 , wherein the second damping coefficient is substantially zero.

5. The rotor of claim 1 , wherein the blades and the pitch adjustment mechanism form a blade combination, and the rotor comprises two or more of the blade combinations distributed around the center of the rotor.

6. 2. The rotor of claim 1, wherein the damper system has a third damping coefficient over a first distance in the first rotational direction of the blade, the first damping coefficient applied to a second distance in the first rotational direction of the blade, the second distance adjacent the first distance.

7. The rotor of claim 6 , wherein the third damping coefficient is substantially equal to the second damping coefficient and / or the third damping coefficient is substantially zero.

8. The rotor of claim 1 , wherein the pitch adjustment mechanism is devoid of a spring and an element that provides a spring force.

9. 2. The rotor of claim 1, wherein the wing has a leading edge and a trailing edge, the wing has a center of gravity, and the pivot axis defined by the wing support structure is located between the center of gravity and the leading edge of the wing.

10. The rotor of claim 1 , wherein the rotor is configured such that the orientation of the blades relative to the blade support is determined primarily by hydrodynamic forces, damping forces applied by the damper system, and / or friction forces.

11. A vertical axis turbine comprising a pole, a shaft or a spar, and the rotor according to claim 1 attached to said pole, said shaft or said spar.

12. 12. The vertical axis turbine of claim 11, wherein the turbine is a wind turbine.

13. 12. The vertical axis turbine of claim 11, wherein the turbine is a water turbine.

14. The vertical axis turbine of claim 11 , further comprising a rotational speed limiter that limits a maximum speed of the rotor.

15. 15. The vertical axis turbine of claim 14, wherein the rotational speed limiting device is passive.

16. 15. The vertical axis turbine of claim 14, wherein the rotational speed limiting device is active.

17. 15. The vertical axis turbine of claim 14, wherein the rotational speed limiting device is connected to or integral with the pitch adjuster to regulate operation of the pitch adjuster to reduce or limit the rotational speed of the rotor once a predetermined rotational speed is achieved.

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