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1. WO2019046877 - TURBINES

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[ EN ]

TURBINES

TECHNICAL FIELD

[0001] The present invention relates to turbines for conversion of kinetic energy into work or other forms of energy such as electric energy.

[0002] The invention has been devised particularly, although not necessarily solely, in relation to turbines driven by wind for generating electricity.

BACKGROUND ART

[0003] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0004] Use of fluids in movement, such as wind or water currents, for generating electricity has increased dramatically; one of the main reason for this is that, generation of the electricity using for example wind or water currents does not require fuel because the kinetic energy used for driving the electric generators is obtained by simply locating turbines in the path of wind or water currents.

[0005] Another advantage of this type of electricity generation is that no emissions are generated during the process of generating the electricity. However, other type of pollution is generated; for example, wind turbines generate noise. Thus, for example, wind farms including a multitude of wind turbines typically disturb farm land and populations located adjacent the wind farms. The presence of wind farms at particular landscapes may also not be esthetically pleasing, in particular, if a relative large amount of wind turbines populate landscapes adjacent attractive coastal or rural scenery.

[0006] Broadly speaking, wind turbines include one or more blade assemblies and one or more electric generators operatively connected to the blade assemblies. The blade assemblies are adapted to rotate for driving of the electric generator as wind impinges on the blades.

[0007] Particular examples of wind turbines are: horizontal win c! tu i"b ¾nrl

wind turbines.

[0008] Horizontal wind turbines typically comprise a relative high tower onto which the blade assembly and electric generator are installed. The blade assembly must be pointed towards the wind direction for proper wind collection such that the rotation axis of the blade assembly be oriented parallel to the wind direction. One particular disadvantage of horizontal wind turbines is that the process for transporting them to site and their assembly at the site is particularly cumbersome. This is particularly true due to the relative high tower that the wind turbines require and the relative long blades required for capturing the wind. Another disadvantage of this type of wind turbines is the noise that is emitted during operation of the blade assemblies.

[0009] Vertical wind turbines include a vertical shaft around which a blade assembly is attached for rotation of the shaft when wind impinges on the blade assembly. An advantage of these types of wind turbines is that the blade assembly does not need to be aligned with wind direction as is the case with horizontal wind turbines. This makes the horizontal wind turbines particular advantageous in areas where the direction of the wind is highly variable.

[0010] Also, the fact that the blade assembly of vertical wind turbines do not need to be aligned with the wind direction makes vertical wind turbines particularly useful for installation in build areas; one of the reasons of this is that, the electric generator may be placed near the ground due to the fact that the vertical wind turbines do not have relative large outreaching blade assemblies as is the case in horizontal wind turbines. Vertical wind turbines are ideal for installation on rooftops of buildings because the building structure re-direct the wind to the top of the building where it can be received by the vertical wind turbine.

[0011] These advantages makes vertical wind turbines ideal for operation in build areas for commercial and residential use. However, a mayor disadvantage of the conventional vertical wind turbines is that the blade assembly is typically bulky and relative heavy making them difficult to transport and to install in, for example, roof tops of buildings. [0012] Another disadvantage of conventional vertical wind turbines is there relative low rotational speed producing much less electrical energy averaged over a particular period of time when compared to horizontal wind turbines.

[0013] It is against this background that the present invention has been developed.

SUMMARY OF INVENTION

[0014] According to a first aspect of the invention there is provided a blade assembly for a turbine comprising a shaft defining the rotation axis of the blade assembly and the shaft being operatively connected to means for converting energy, wherein the blade assembly comprises at least one blade wound at least partially around the rotation axis, the blade comprising inner and outer side edges adapted to be attached to the shaft, the inner side edge being adapted to be located at a proximal location from the shaft and the outer side edge being adapted to be located at a distal location from the shaft, wherein the blade comprises a plurality of blade sections adapted to be attached to each other for defining the blade.

[0015] Preferably, the blade assembly is adapted to be selectively displaced between a disassembled condition and an assembled condition.

[0016] Preferably, the blade sections are adapted to be releasably attached to each other.

[0017] Preferably, the plurality of blade sections comprises a first blade section, a second blade section and a third blade section, each blade section comprising an upper edge and a lower edge, the lower edges of the blade sections and the upper edge of the second blade sections being adapted to be joined together to define the blade.

[0018] In a particular arrangement, (1 ) the lower edge of the first blade section and the upper edge of the second blade section overlap each other and (2) the lower edge of the second blade section and the upper edge of the third blade section overlap each other for defining the blade.

[0019] Preferably, the first to third blade sections comprise inner and outer edge sections, the inner edge sections define the inner side edge of the blade and the outer edge sections define the outer side edge of the blade when the first to third blade sections are joined together.

[0020] Preferably, the outer edge section of each blade section is configured as a step for defining the outer edge of the blade as having a step-like configuration when the first to third blade sections are joined together.

[0021] Preferably, the outer edge section of each blade section comprises an arched section.

[0022] Preferably, the arched section defines an outwardly extending curved protrusion substantially centered at the outer edge section including the arched section.

[0023] Preferably, the height of the outer side edge of each blade progressively reduces as the outer side edge extends from (1 ) a location where the outer side edge is at substantially at the same level than an upper end of the shaft to (2) the location where the outer side edge at substantially at the same level than a lower end of the shaft.

[0024] Preferably, the blade assembly comprises a plurality of blades, each blade being configured to wind at least partially around the rotation axis of the blade assembly.

[0025] In one arrangement, each blade winds a single turn around the rotation axis.

[0026] In alternative arrangements, each blade winds two or more turns around the rotation axis.

[0027] Preferably, each blade is configured to take the shape of a helix.

[0028] Preferably, the plurality of blades comprises first and second blades, the first blade being configured to wind around the rotation axis in a first direction and the second blade being configured to wind around the rotation axis in a second direction opposite to the first direction.

[0029] Preferably, the blade sections, that define the blades, are adapted to be selectively displaced between a flat condition (for storage purposes) and a curved condition (for operation purposes).

[0030] Preferably, the blade sections, that define the blades, comprise flexible materia! selectively to permit displacement of the blade sections between a flat condition and a curved condition.

[0031] Preferably, the outer side edges blades are adapted to be distally attached to the shaft via spokes traversing the shaft defining spokes sections extending outwardly from the shaft, each spoke section having an outer end for attachment to the blade sections for attachment of the blade sections distally from the shaft.

[0032] Preferably, the step defined by each blade section extends between the outer ends of adjacent spoke sections attaching each blade section distally from the shaft to the shaft.

[0033] Preferably, the arched section of each blade section is located between the adjacent spoke sections.

[0034] Preferably, the inner edge of each blade section is adapted to be attached to the shaft.

[0035] According to a second aspect of the invention there is provided a hub assembly for attachment to a shaft of a turbine comprising at least one blade having one inner edge attached proximal to the shaft and one outer edge attached distal to the shaft, the hub assembly comprising an outer ring and an inner ring assembly, wherein the outer ring comprises an outer face for attachment of the inner edge of the blade of the turbine, and the outer ring further comprises openings traversing the outer face of the outer ring and located opposite with respect to each other for the spokes of the turbine to traverse the outer ring as well as the shaft for attachment of the outer side edge of the blade distal to the shaft, and wherein the inner ring assembly comprises a pair of plates attached to upper and lower faces of the ring in opposite relationship with respect to each other, the plates comprising apertures located opposite to each other permitting the shaft to traverse the hub assembly.

[0036] Preferably, each hub assembly is adapted to secure the spoke to the hub assembly.

[0037] Preferably, the hub assembly comprises a pair of bolts that extend between the plate sections and traverse the spokes for securing the spokes to the shaft.

[0038] According to a third aspect of the invention there is provided a turbine, the turbine comprising a blade assembly in accordance with the first aspect of the invention and a shaft defining the rotation axis of the turbine, the shaft being adapted to be operatively connected to means for converting energy, wherein the shaft is adapted to receive the inner edges of the blades of the blade assembly, and a plurality of spokes traversing the shaft and oriented at different azimuthal angles around the shaft with respect to each other, wherein the spokes define spoke sections extending outwardly from the shaft for attachment of the outer side edges of the blades distally from the shaft.

[0039] Preferably, the turbine further comprises a plurality of hub assemblies in accordance with the second aspect of the invention attached to the shaft and arranged in a spaced apart relationship with respect to each other along the rotation axis for attachment of the inner side edges of the blades.

[0040] Preferably, the outer edges of each blade section defining the blades are attached distally from the shaft by a pair of adjacent spoke sections.

[0041] Preferably, the wind turbine further comprises plates extending from spoke sections to inner surfaces of the blades.

[0042] Preferably, each plate is oriented at a particular angle with respect to the plane in which each spoke section lies.

[0043] Preferably, each plate comprises at least one solar panel.

[0044] Preferably, the turbine comprises means for connecting the solar panels to a storage means of electric energy or to other means for utilising the electric energy generated by the solar panels.

[0045] Preferably, each blade of the blade assembly comprises outer side edges extending from a location where the blade is distally attached to the upper end of the shaft (point A or A') to the location where the blade section is dista!!y attached to the lower end of the shaft (point D or D').

[0046] Preferably, each blade of the blade assembly comprises an upper edge extending from (1 ) the location where the inner side edges of the blades are attached to the shaft (point B or B') to (2) the location where the outer side edge of the blade is attached to the outer end of the spoke section located at the upper end of the shaft (point A or A').

[0047] Preferably, each blade of the blade assembly comprises lower edges extending from (1 ) the location where the inner side edges of the blades are attached to the shaft (point B or B') to (2) the location where the outer side edge of the blade is attached to the outer end of the spoke section located at the lower end of the shaft (point D or D').

[0048] Preferably, each blade of the blade assembly comprises upper and lower edges wound an angle β greater than zero around the shaft.

[0049] Preferably, the angle β is about 180° .

[0050] Preferably, the outer side edge of each blade wound an angle a greater than zero around the shaft.

[0051] Preferably, the angle a is about 90°.

[0052] Preferably, the turbine comprises a wind turbine for converting wind energy into other forms of kinetic energy or electric energy.

[0053] According to a fourth aspect of the invention there is provided a blade assembly for a turbine comprising a shaft defining the rotation axis of the blade assembly and the shaft being operatively connected to means for converting energy, wherein the blade assembly comprises at least one blade wound at least partially around the rotation axis, the blade comprising inner and outer side edges adapted to be attached to the shaft, the inner side edge being adapted to be located at a proximal location from the shaft and the outer side edge being adapted to be located at a distal location from the shaft, wherein the outer side edge of blade comprises a step-like configuration having a plurality of steps.

[0054] Preferably, each step comprises an arched section.

[0055] According to a fifth aspect of the invention there is provided turbine comprising a blade assembly in accordance with claims 40 or 42 and a shaft defining the rotation axis of the turbine, the shaft being adapted to be operatively connected to means for converting energy, wherein the shaft is adapted to receive the inner edges of the blades of the blade assembly, and a plurality of spokes traversing the shaft and oriented at different azimuthal angles around the shaft with respect to each other, the spokes define spoke sections extending outwardly from the shaft for attachment of the outer side edges of the blades distally from the shaft, wherein the turbine further comprises plates extending from spoke sections to inner surfaces of the blades.

[0056] Preferably, each plate is oriented at a particular angle with respect to the plane in which each spoke section lies.

[0057] Preferably, each plate comprises at least one solar panel.

[0058] A wind turbine substantially as herein described in the specification with reference to figures 1 to 3 of the accompanying drawings.

[0059] A wind turbine substantially as herein described in the specification with reference to figures 8 and 9 of the accompanying drawings.

[0060] A wind turbine substantially as herein described in the specification with reference to figures 10 to 12 of the accompanying drawings.

[0061] A blade assembly substantially as herein described in the specification with reference to figures 4 to 7 of the accompanying drawings.

[0062] A blade assembly substantially as herein described in the specification with reference to figures 8 and 9 of the accompanying drawings.

[0063] A blade assembly substantially as herein described in the specification with reference to figures 1 o to 12 of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Further features of the present invention are more fully described in the following description of several non-limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a particular arrangement of a wind turbine in accordance with an embodiment of the invention;

Figure 2 is top left-side perspective view of the wind turbine shown in figure 1 ;

Figure 3 is a perspective view of the wind turbine shown in figure 1 excluding the blade assembly showing the turbine shaft having a plate arrangement attached thereto;

Figure 4 is a side perspective view of the blade assembly of the wind turbine shown in figure 1 ;

Figure 5 is a top side perspective view of the blade assembly of the wind turbine shown in figure 1 ;

Figure 6 is a top view of the blade assembly of the wind turbine shown in figure 1 excluding the plates;

Figure 7a is a side perspective view of the blade assembly shown in figure 4 rotated a particular angle clockwise around the rotation axis of the blade assembly in comparison with the view of the blade assembly shown in figure 4;

Figure 7b is a side perspective view of the blade assembly of the wind turbine shown in figure 1 ;

Figure 8 is a side perspective view of a second arrangement of the wind turbine in accordance with the present embodiment of the invention;

Figure 9 is a top perspective view of the wind turbine shown in figure 8;

Figure 10 is a side perspective view of a third arrangement of the wind turbine in accordance with the present embodiment of the invention;

Figure 1 1 is a side perspective view of the wind turbine shown in figure 10 rotated a particular angle clockwise around the rotation axis of the blade assembly in comparison with the view of the wind turbine shown in figure 1 1 ;

Figure 12 is a top view of the wind turbine shown in figure 10;

Figure 13 is a top perspective view of a particular arrangement of a hub assembly in accordance with the present embodiment of the invention mounted on the wind turbine shown in, for example, figures 10 and 1 1 ; and

Figures 14 is a top perspective view of the hub assembly shown in figure 13 traversed by a spoke.

[0065] It should be noted that the figures are schematic only and the location and disposition of the components can vary according to the particular arrangements of the embodiments of the present invention as well as of the particular applications of the present invention.

DESCRIPTION OF EMBODIMENT(S)

[0066] Figures 1 to 12 show a particular arrangement of a wind turbine 10 in accordance with a first embodiment of the invention. The wind turbines 10 shown in figures 1 to 8 are vertical wind turbines for, for example, locating in build environments for commercial or residential use.

[0067] The wind turbines 10 are particular useful because they are adapted to be selectively disassembled and assembled; thus, the wind turbines 10 are particularly useful for transportation in a disassembled arrangement within a flat pack for delivery to the consumer.

[0068] Further, the wind turbines 10 shown in the figures are adapted to reduce noise emission during their operation. In the particular arrangements shown in figures, the wind turbines 10 are adapted to circulate the air within an envelope defined by a plurality of blades; the fact that the air is circulated within the envelope avoids that the air fully surrounds the blades and therefore noise emission is reduced.

[0069] Furthermore, the wind turbines 10 are adapted to increase the torque that is applied to the rotation axis of the wind turbine 10 when impinging onto the blade assembly of the wind turbines 10; this increases the rotational speed of the wind turbines 10 in accordance with the present embodiment of the invention. In this manner, the wind turbines 10, in accordance with the present embodiment of the invention, has an increased output of electrical energy averaged over a particular period of time when compared to conventional vertical wind turbines. As will be described with reference to figures 10 and 1 1 , the increased torque is produced due to the presence of arched sections 50 at outer edges 48 of the blade sections 44 of the wind turbine 10.

[0070] Referring now to figures 1 to 7, figures 1 to 7 show a first arrangement of a wind turbine 10 in accordance with the present embodiment of the invention.

[0071] As shown in figure 1 , the wind turbine 10 comprises a shaft 12 (the turbine shaft 12) defining the rotation axis of the wind turbine 10.

[0072] The shaft 12 is adapted for attachment of a blade assembly 14 and the shaft 12 comprises a lower end 16 adapted to be attached to a generator for production of electricity; in this manner, the blade assembly 14 is operatively connected to the generator which produces electricity when the blade assembly 14 rotates due wind impinging onto the blade assembly 14.

[0073] Further, the shaft 12 is adapted for attachment of the blade assembly 14 via a plurality of spokes 24. For this, the blade assembly 14 comprises inner side edges 20 adapted for attachment to the shaft 12 and outer side edges 22. The outer side edges

22 of the blade assembly 14 comprise particular locations adapted for attachment to the end of the spokes 24 extending perpendicularly from the shaft 12.

[0074] Referring now figure 2, figure 2 shows right side view of the wind turbine 10 providing a view of the interior of the envelope defined by the blade assembly 14.

[0075] As shown in figure 2, the wind turbine 9 comprises plates 26 extending from spoke sections 28 of each spokes 24b to 24d to inner surfaces of the blades assembly 14. In the particular arrangement shown in figures 1 to 10, each plate 26 is oriented at a particular angle larger than zero with respect to the plane in which each spoke 24 lie; in this manner, the plates 26 extend diagonally from the spoke sections 28 onto which each plate 26 is attached as illustrated in figure 3a. The plates 26 define plates 26 to 30 for receiving solar panels.

[0076] The turbine comprises means for connecting the solar panels to a storage means of electric energy or to other means for utilising the electric energy generated by the solar panels.

[0077] The first spoke 24a does not include plates 26 due to being the spoke 24a that is located at the upper most part of the wind turbine 10 as illustrated in figures 1 and 2.

[0078] Referring now figures 3, figures 3a and 3b show a particular arrangement of the wind turbine 10 without the blade assembly 12 exposing the interior of the wind turbine 10. As shown in figures 3, the wind turbine 10 comprises four spokes 24a to 24d arranged in a spaced apart arrangement along the length of the shaft 12. The spokes 24 are oriented at different azimuthal angles around the shaft 12 with respect to each other so as to permit attachment of the outer end of the spokes 24 to be attached to the particular locations of the blade assembly 14 - this particular arrangement is best illustrated in figure 3b.

[0079] Further, as shown in figure 3b, each spoke section 28 of each spoke 24 extend from the shaft 12; for this, there are provided hub assemblies 30 arranged in a spaced apart relationship with respect to each other. As will be described with reference to figures 12 and 13, each hub assembly 30 is adapted to be traversed by a spoke 24.

[0080] Referring now to figures 4 to 6, figures 4 to 7 show a particular arrangement of a blade assembly 14 of the wind turbine 10 shown in figure 1.

[0081] The blade assembly 14 comprises two blades 32a and 32b configured to wind around the shaft 12 in such a manner that each of the blades 32a and 32b define, respectively, paths 34a and 34b. The paths 34a and 34b are adapted to allow air to flow partially around the shaft 12. As the air flows through the paths 34, force(s) is(are) applied to the inner surfaces of the blades 32 resulting in the application of a torque to the shaft 12 inducing rotational movement in the shaft 12. As mentioned before rotation of the shaft 12 drives an electric generator operatively attached to the lower portion of the shaft 12 for generation of electricity.

[0082] As mentioned before, each of the blade 32 are configured for defining a path 34 for permitting air flow through the wind turbine 10. As shown in for example figure 5, the paths 34 are defined by curved surfaces 36 of the blades 32. Each blade winds one or more turns around the rotation axis of the blade assembly. In a particular arrangement, each blade is configured to take the shape of a helix.

[0083] In the particular arrangement of the blades 32 shown in figure 4 to 7, the surface 36 of each blade 32a (or 32b) comprises outer side edges 40 - extending from point A (or A') to D (or D') and upper edges 42a and 42b - extending from point B (or B') to A (or A') as well as lower edges 42a and 42b - extending from point B (or B') to D (or D') -however, lower edges 42a and 42b are not shown in the herein attached figures.

[0084] The upper edges 42a and 42b wind an angle β greater than zero around the shaft 12 extending from a point B (or B') to a point A (or A') - see figure 6. And, the lower edges 42a and 42b wind an angle β' around the shaft 12 extending from point B (or B') to D (or D'). In an arrangement the angle β is about 180°.

[0085] The side edges 40 of each blade 32 comprise an outer side edge 40a and an inner side edge 40b. The inner edge 40b is configured for attachment to the hub assemblies 30 (that are attached to the shaft 12 as shown in figure 12) for attachment of the blades 32 to the shaft 12.

[0086] The outer side edge 40a extends from point A to D winding an angle OC around the shaft 12 (see figure 6). In the particular arrangement shown in figures 1 to 7, the outer edge 40a is configured to progressively reduce its height as the outer side edge 40a extends from point A (or A') to D (or D') such that: (1 ) at point A (or A'), the height of the outer edge 40a is proximal to the upper end of the shaft 12 and (2) at point D (or D'), the height of the outer edge 40a is proximal to the lower end 16 of the shaft 12. In an arrangement the angle a is about 90°.

[0087] Referring now figure 7a, as shown in figure 7a, the blade assembly 14 of the this particular arrangement of the wind turbine 10 comprises blades 32a and 32b, wherein each blade 32 comprises blade sections 44 configured for defining an outer side edge 40a having a smooth curved configuration along the entire outer side edge 40a.

[0088] In particular, the outer side edge 40a is defined by outer edge sections 48a to 48c, respectively, of each of the blade sections 44a to 44c. For each blade section 44 there is an outer edge section 48 defining particular segments (having a smooth curve) of the outer side edge 40a. The smooth curved outer edge 40a is defined joining the outer side edge 48 together when assembling the wind turbine 10 as is shown in, for example, figure 7a.

[0089] Furthermore, as mentioned before, the wind turbines 10 shown in figures 1 to 9 is adapted to be assembled and disassembled facilitating storing the disassembled wind turbine 10 in, for example, a flat pack for transportation purposes.

[0090] Storage in a flat pack is possible because the blade sections 44 are adapted to be selectively displaced between a flat condition (for storage purposes) and a curved condition (for operation purposes). In a particular arrangement, the blade sections 44 of the third arrangement are made out of flexible material; this is particular advantageous because it permits storing the wind turbine in disassemble condition, for example, a flat pack for transportation purposes.

[0091] In the particular arrangement shown in the figures 1 to 8, each blade 32 of the blade assembly 14 comprises a lower, middle and upper blades sections 44a to 44c (see figure 7).

[0092] The blade sections 44 are adapted to be attached to each other for defining each blade 32. In particular, the middle blade section 44b comprises an upper edge and the upper blade section 44a comprises a lower edge; both upper and lower edges are adapted to be joined together for fastening together the upper and middle blades 44a and 44b defining the joint 46a. Similarly, the middle blade section 44b comprises a lower edge and the lower blade section 44c comprises an upper edge; both upper and lower edges are adapted to be joined together for fastening together the upper and middle blades 44c and 44b defining the joint 46b. In this manner, by joining together the blades sections 44, each blade 32 is assembled.

[0093] In one particular arrangement, each joint 46 may formed by a groove and tongue union defined by an edge of one particular blade section 44 comprising the groove extending along the entire length of the edge of that particular blade section 44; and, another blade section 44 (to be attached to the particular blade section) comprises an edge having the tongue extending along the entire length of the edge of the another blade section 44. The joint 46 is defined when abutting the edge of the particular blade section 44 to the edge of the another blade section 44 permitting the groove to receive the tongue. Appropriate attachment means such as bolts and nuts or welding may be provided for securing the tongue within the groove.

[0094] Referring now to figures 8 and 9. Figures 8 and 9 show a second arrangement of the wind turbine 10 in accordance with the present embodiment of the invention. The wind turbine 10 according to the second arrangement is similar to the wind turbine 10 according to the first arrangement and similar reference numerals are used to identify similar parts.

[0095] As shown in figures 8 and 9, the wind turbine 10 in accordance with the second arrangement is substantially identical to the wind turbine 10 shown in figures 1 to 7; the difference between both arrangements is that the second arrangement of blade assembly 14 comprises blades 32a and 32b that have five blade sections 44a to 44e. instead than the three blade sections 44a to 44c of the first arrangement. Accordingly, the wind turbine 10, in accordance with the second arrangement, comprises six spokes 24 attached to the shaft 12 via the hub assemblies 30.

[0096] Further, due to the increased number of spokes 24 - in comparison with the first arrangement of the wind turbine 10 - the wind turbine 10 in accordance with the second arrangement comprise five pair of plates 26 for receiving solar panels in contrast to the three pair of plates 26 of the first arrangement of wind turbine 10 shown in figures 1 to 7.

[0097] Referring now to figures 10 and 1 1 , figures 10 and 11 show a third arrangement of a wind turbine 10 in accordance with the invention. The wind turbine 10 according to the third arrangement is similar to the wind turbine according to the first arrangement and similar reference numerals are used to identify similar parts.

[0098] As shown in figures 10 and 11 , the wind turbine 10 in accordance with the third arrangement is substantially identical to the wind turbine 10 shown in figures 1 to 7; the difference between both arrangements resides in the particular configuration of blade assembly 14 that each of the wind turbines 10 has. Also, the particular arrangement shown in figure 10 and 1 1 does not include the plates 26 for receiving solar panels; however, the wind turbine 10 in accordance with the third arrangement may include the plates 26 for receiving solar panels.

[0099] As shown in figure 10, the blade assembly 14 of the third arrangement of the wind turbine 10 comprises blade 32a and 32b, wherein each blade 32 comprises blade sections 44 configured for defining an irregular outer side edge 40a having a step-like arrangement defined by a plurality of step-like segments 49a to 49c. This is in contrast with the outer side edge 40a of the blade assembly 14 in accordance with the first and second arrangements shown in figures 1 to 9 where the outer side edge 40a follows a smooth curve.

[00100] In particular, the outer side edge 40a is defined by outer edge sections 48a to 48b, respectively, of each of the blade sections 44a to 44c. For each blade section 44 there is an outer edge section 48 defining one of the steps 49. As shown in figure 10, each step 49 extends between adjacent spokes 24; in particular, each step 49 extends from the location where the outer ends of the spokes 24 are attached to the blade sections 48. The step-like outer edge 40a is defined by joining the outer side edge 48 together when assembling the wind turbine 10 as is shown in figure 10.

[00101] The consequence of the step-like arrangement of the outer side edge 40a is that the height of the outer side edge 40a progressively reduces in a stepped manner as the outer side edge 40a extends from point A to D such that: (1 ) at point A, the outer edge 40a is proximal to the upper end of the shaft 12 and (2) at point D, the outer edge 40a is proximal to the lower end 16 of the shaft 12.

[00102] Furthermore, each blade section 44 is configured such that each of the outer side edge 48 of each blade section 44 comprises an arched section 50. Inclusion of the arched sections 50 in the outer side edges 40a of the blades 32 increases the torque that the wind applies to the axis 12 when the wind enters the wind turbine 10 applying wind pressure to the inner surfaces of the blades 32.

[00103] The presence of the arched section 50 in each of the outer edge section 48 results in that each outer edge section 48 comprises an outwardly extending curved protrusion (the arched section 50) at substantially centered outer edge section 48 as shown in figure 10. This is in contrast with the outer side edge 40a of the first and second arrangement of the wind turbine 10 wherein the outer side edge 40a comprises an even curved line without outwardly extending curved protrusions (the arched section 50) at the outer edge section 48 of each blade section 44 as, for example, shown -respectively - in figures 4 and 5, and figures 8 and 9.

[00104] Each arched section 50 extends between adjacent spokes 24; in particular, each arched section 50 extends from the location where the outer ends of the spokes 24 are attached to the blade sections 48; in particular, as shown in figure 10, the arched section 50a from the upper blade section 48a extends from an outer end of spoke 24a to an outer end of the spoke 24b - similarly, each arched section 50b and 50c of blade sections 44b and 44c extend between the corresponding spokes 24.

[00105] Moreover, it was described with reference to the first and second arrangement of the blade assembly that the blade section 44 are adapted to be attached to each other to define a blade 32.

[00106] In accordance with a particular arrangement of the invention, the blade sections 44a to 44c of the third arrangement of the blade 32 are adapted to be attached to each other to define the blade 32.

[00107] In the third arrangement of wind turbine 10 shown in figures 10 and 1 1 , the blade sections 44 are assembled together by overlapping the upper and lower edges of adjacent blade sections 44 defining overlaps 45. The upper and lower edges

of the blade sections 44 are kept in the overlapping condition as the outer edge 40a of each blade assembly 32 is secured to the rotations axis 12 via the spokes 24 as shown in figure 1 1.

[00108] Further, the blade sections 44 are adapted to be selectively displaced between a flat condition (for storage purposes) and a curved condition (for operation purposes). For this, the blade sections 44 of the third arrangement (as well as for the first and second arrangement) are made out of flexible material; this is particular advantageous because it permits storing the wind turbine in disassemble condition, for example, a flat pack for transportation purposes.

[00109] Referring now to figures 13 and 14, figures 13 and 14 show a particular hub assembly 30 in accordance with the invention. In particular, figure 12 shows the upper hub assembly 30a having the inner edges 40 of the blades 32 attached thereto. And, figure 13 shows the hub assembly 30 detached from the shaft 12.

[00110] As is shown in figure 14, the hub assembly 30 comprises an outer ring 52 and inner ring assembly 54. The outer ring 52 comprises an outer face 54 for attachment of the inner edge 40 of each blade 32 as illustrated in figure 12.

[0011 1] Further, the outer ring 52 comprises openings traversing the outer face 54 and located opposite with respect to each other for the spokes 24 to traverse the outer ring 52.

[00112] Further, as mentioned before the hub assemblies 30 are attached to the shaft 12 in a spaced apart relationship with respect to each other as is shown in figure 3b. Attachment of each hub assembly 30 occurs by (1 ) traversing the inner ring assembly 54 the hub assemblies 30 with the shaft 12 and (2) securing each hub assembly 30 at a particular location along the shaft 12. Securing each hub assembly 30 to the shaft 12 is done by traversing the outer ring 52 of each hub assembly 30 and the shaft 12 with a spoke 24. The shaft 12 comprises at each of the particular location along the shaft 12, where the hub assemblies 30 will be attached, a passage to permit the spokes 24 traverse perpendicularly the shaft 12.

[00113] Moreover, the inner ring assembly 54 of each hub assembly 30 is defined by two plates 56a and 56b. Each plate 56 at its centre comprises an aperture 59. The plates 56a and 56b are attached, respectively, to each upper and lower side of the outer ring 52; in this manner, the apertures 59a and 59b are located opposite to each other permitting the shaft 12 to traverse the hub assemblies 30 as was described in the previous paragraph.

[00114] Further, each hub assembly is adapted to secure the spoke 14 (that traverses the hub assembly 30) to the hub assembly 30. In particular, the spokes 24 are secured to the hub assembly 30 via two bolts 58a and 58b that extend between the plate sections 56 and traverse the spokes 24 as is shown in figure 13.

[00115] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.

[00116] Further, it should be appreciated that the scope of the invention is not limited to the scope of the embodiments disclosed. For example, the previously described third arrangement of wind turbine 10 has been described as having blades 32 comprising a plurality of blade sections 44 adapted to be releasably attached to each other. In alternative embodiments of the first to seconed third arrangement of wind turbine 10 has been each blade 32 is made out of a single sheet of material

[00117] In one particular arrangement of these alternative embodiments, the blade 32 made out of a single sheet of material may be configured so as to take the helical shaped including the particular stepped configuration incorporating the arched section 50 as described before with reference to the third arrangement of wind turbine 10 and shown in figures 10 to 12.

[00118] In another particular arrangement of these alternative embodiments where the blades 32 of the wind turbine 10 are made out of a single sheet of material, the wind turbine may incorporate the plates 26 including the solar panels.

[001 19] Throughout this specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.