KR20150022980A - Improved hinge for wind turbine blades - Google Patents

Abstract

The present invention provides a hinge for a wind turbine comprising a body capable of hinging with respect to at least one hinge axis. The body is formed from a flexible and resilient material in which the reinforcing particulate material is distributed.

Description

[0001] IMPROVED HINGE FOR WIND TURBINE BLADES FOR WIND TURBINE BLADES [0002]

The present invention relates to a hinge for a wind turbine, in particular a wind turbine blade.

International PCT Patent Application WO 91/12429 discloses a wind turbine in which each blade is connected to the hub assembly by a flexible and resilient hinge. The hinge defines two non-parallel hinge shafts and is made of a sheet of plastic material such as PVC or polyurethane. In this example, although other similar known hinges are formed separately from the blades and the hub, the hinges are formed integrally with the blades.

Such hinges work well with relatively small wind turbines, for example with 3 kW or 6 kW wind turbines. However, when used with larger blades, for example, when used with a 15 kW wind turbine, the force experienced by the hinge in use can cause hinge failure. In particular, the fatigue can cause cracks to appear at any sharp corners caused by hinges, particularly inserts, holes, or other possible inclusions. It is also believed that the relatively large flexural strain experienced by the hinge is too large for conventional plastic materials used to make the hinge.

It would be desirable to provide a hinge that alleviates this problem.

A first aspect of the present invention provides a hinge for a wind turbine, comprising a body capable of hinging with respect to at least one hinge axis, the body being formed from a flexible and resilient material in which the reinforcing particulate material is distributed .

Preferably, the reinforcing particulate material comprises synthetic fibers, preferably polymer fibers, more preferably aramid fibers.

Preferably, the particulate material has a size (length or diameter, if applicable) of from about 0.1 mm to about 2.5 mm.

In a preferred embodiment, the reinforcing particulate material is present in an amount of from about 0.5% to about 10% by weight of the material forming the hinge.

Generally, the flexible and resilient material comprises an elastomer, such as a polyurethane elastomer.

In a preferred embodiment, the hinge comprises at least one reinforcing mesh incorporated in the body. The preferred mesh comprises a plurality of mutually spaced reinforcing strands extending in a first direction and preferably parallel and spaced apart from each other that extend in a second direction that is not parallel to the first direction and is preferably perpendicular to the first direction Preferably a plurality of substantially parallel connecting strands.

The reinforcing strands are preferably formed from synthetic fibers, in particular polymer fibers, such as aramid fibers formed generally of yarns. The connecting strands are formed from synthetic fibers, such as glass fibers, and the reinforcing strands are configured to maintain a desired arrangement. In a preferred embodiment, the connecting strands do not provide significant support or reinforcement to the hinges, and the materials and / or thickness to be made and / or the spacing between them are selected accordingly. Thus, in general, the connecting strand is relatively light and the reinforcing strand is relatively heavy.

The at least one mesh extends across an area of the body corresponding to at least one of the at least one hinge axis. [0254] Optionally the at least one mesh is shaped and dimensioned to substantially cover the entire major cross-sectional area of the body.

Advantageously, said at least one mesh is arranged such that said first strand direction is substantially perpendicular or at least parallel to at least one of said at least one hinge axis.

In a preferred embodiment, the at least one mesh is embedded in the body and does not break the front or back of the body, but generally lies between the front and back of the body, preferably substantially the front and back of the body. It is parallel to the back side. Advantageously, said at least one mesh is located substantially in a plane in which the neutral axis of said hinge lies. In a preferred embodiment, the at least one mesh lies substantially midway between the front and back surfaces of the body and substantially in a plane substantially parallel to the front and back surfaces of the body.

Optionally, a flexible line comprising a rope is conveniently embedded in the flexible and resilient material. Advantageously, the line is not stretched. Preferably, the lines are arranged generally sinusoidally, and are preferably arranged to traverse the at least one hinge axis, preferably several times. A position member may be provided on the body on which the line is wound.

Advantageously, the line is formed from a material suitable for bonding with the flexible and resilient material. For example, the line may comprise a Kevlar or aramid fiber rope. Alternatively or additionally, the line may be treated with a suitable polymer, such as a polyurethane dispersion. Advantageously, the line is pre-dried prior to use.

In a preferred embodiment, the hinge includes first and second hinge axes that are typically spaced apart and generally not parallel.

A support member may be provided on one or both of the front and back sides of the body, for example including a plate, and advantageously the support member does not extend across the hinge axis.

In a preferred embodiment, the thickness of the material forming the hinge is from about 25 mm to about 45 mm.

A second aspect of the present invention provides a blade assembly for a wind turbine comprising a plurality of blades connected to a hub by respective hinges according to the first aspect of the present invention.

A third aspect of the present invention provides a wind turbine comprising an electric generator connected to a blade assembly according to the second aspect of the present invention.

A fourth aspect of the present invention provides a method of manufacturing a hinge for a wind turbine, the method comprising: forming a body from a flexible and resilient material, the hinge being capable of hinging against at least one hinge axis; And distributing the reinforcing particulate material to the flexible and resilient material.

Generally, the method includes forming the body in a mold. The forming step includes casting, e.g., hot casting, the flexible and resilient material to the mold. In a preferred embodiment, the material comprises an elastomer, which comprises the steps of adding a curing agent, generally liquid, to the prepolymer (generally in liquid form), and introducing the mixed curing agent and prepolymer into the mold . Advantageously, the method comprises adding the reinforcing particulate material to the curing agent prior to mixing the flip-polymer. Preferably, the method comprises drying the enhanced particulate material before adding the enhanced particulate material to the curing agent.

In a preferred embodiment, the method includes positioning the flexible line in the mold prior to placing the mixed curing agent and prepolymer into the mold. The flexible line includes a rope.

In a preferred embodiment, the method includes providing at least one support to the mold to maintain the line away from the main mold surface. The support includes a tensioned line traversing the mold. The at least one support is preferably provided in at least one of the at least one hinge axis.

In a preferred embodiment, the method further comprises providing at least one mesh to the mold before the mixed curing agent and the prepolymer are introduced into the mold.

In a preferred embodiment, the method comprises providing at least one support, for example at least one tensioned line, traversing the mold to maintain the at least one mesh at a desired location. In embodiments where the at least one mesh and the flexible line are present, the support may be arranged to hold the at least one mesh with respect to the flexible line.

A fifth aspect of the present invention provides a mold for forming a hinge according to the first aspect of the present invention.

Further advantageous aspects of the invention will be apparent to those of ordinary skill in the art in light of the following description of the preferred embodiments with reference to the accompanying drawings.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.

Figure 1 shows a wind turbine suitable for use with hinges embodying the present invention.
Figure 2 shows a hinge embodying an aspect of the present invention.
Figure 3 is a table providing data on the physical properties of the Hyperlast 100/90 PU.
Figure 4 is a table providing data showing the effect of adding fibers to the Hyperlast PU.
Figure 5 illustrates a preferred mesh reinforcing structure incorporated into the hinges embodying the present invention.
Figure 6 shows a mold for use in the manufacture of a preferred hinge.
Figure 7 shows a preferred hinge.
Figure 8 shows a comparative graph of strain versus fatigue failure of one embodiment of a hinge of the present invention including Hyperlast 100/90 PU.
FIG. 9 is a table providing exemplary data of a statement of material for manufacturing an embodiment of a hinge of the present invention. FIG.

Referring now to FIG. 1, there is shown a wind turbine 10 for generating electricity installed in a post 12. An electric generator (not shown) is provided in the housing 14 and is driven in use by a plurality of blades 16 extending from the rotatable hub 18. The hub 18 is connected to the generator by a rotatable shaft (not shown). In use, the wind drives the blades 16 to rotate the hub 18 and the shaft. Rotation of the shaft causes the rotor of the generator to rotate, allowing electricity to be produced.

Each blade 16 is connected to a hub 18 by an individual hinge 20. The hinge 20 is configured to have first and second hinge axes 22 and 24 and the blades 16 are rotatable relative to the hub 18 about the first and second hinge axes. The hinge 20 includes a body 26 hingedly connected to the hub 18 along the first hinge axis 22 and hingedly connected to the blade 16 along the second hinge axis 24 do. The hinge shafts 22, 24 are not parallel, but preferably substantially coplanar. The body 26 may be substantially planar, but in the preferred embodiment has a generally angled distal end 28 (not shown) (see FIG. 2) that is not coplanar with respect to the remainder of the body 26, 24 are located between the distal end 28 and the rest of the body 26. In general, the body 26 is generally triangular.

In the first hinge axis 22, which may be referred to as a coning hinge axis, the hinge 20 allows the blade 16 to rotate relative to the hinge body 26. This is known as Corning. Generally, Corning occurs as a result of transient environmental conditions, particularly wind speed and / or wind strength.

In the second hinge axis 24, which may be referred to as the base hinge axis, the hinge 20 is configured such that the blade 16 adopts the base pitch for the hub 18 under the centrifugal force generated by the rotation of the hub 18 during use It will. Thus, the base pitch can be said to be centrifugally regulated.

The biaxial hinge configuration allows the wind turbine to adjust the rotational speed to maximize output. In use, as the wind becomes stronger and stronger, the blade 16 pitches and corners to protect the turbine 10 and to enable continuous operation even in the event of a severe storm.

More specifically, as the wind turbine 10 increases the rotational speed RPM, the centrifugal force produced by each blade 16 stretches each hinge 20. The hinge position can be adjusted by a damper spring (not shown). The more the blade 16 pulls the hinge 20, the more it is pushed toward the stall. At a certain point, the turbine 10 reaches equilibrium, stalling so that the hinge rotates fast enough to be pulled into the stall, but no longer raises the speed. Blade coring reduces stress on the rotor (blades 16 are self-regulated) and smooth turbine response to gust conditions. It also reduces the size of the rotor disk in high-speed winds and reduces the load on the turbine. This is just a peak power adjustment, and whenever the turbine is connected to the grid, the RPM is also regulated by the amount of load applied by the inverter (the power taken from the generator). This configuration enables continuous power generation at all wind speeds, unlike other wind turbines that must be braked in high wind conditions.

Figure 2 shows a specific embodiment of the hinge 20. The hinge 20 can be secured to the blade 16 and the hub 18 by any convenient method, such as by screws, bolts, rivets, adhesives, adhesives, welding or other fixing methods, . In the illustrated embodiment, the distal end 28 is provided with a socket 30 for receiving a suitable mechanical fastener (not shown), and the socket 30 is preferably elongated substantially parallel to the hinge axis 24 Lt; / RTI > Similarly, the body 26 has an opposite distal end 32, the first hinge axis 22 extends between the distal end 32 and the remainder of the body 26 and receives an appropriate mechanical fastener (not shown) And the socket 34 is disposed along a hypothetical line which preferably extends substantially parallel to the hinge axis 22. [

In the preferred embodiment, a support member, generally comprising a plate (not shown in FIG. 1 but not shown in FIG. 2), is secured to one or both sides of the body 26 such that a region substantially between the axes 22, And has a covering dimension. Thus, this plate helps define the axes 22, 24. The support member may be formed from, for example, metal or carbon fiber. The support member may be secured to the body 26 by any suitable fastening means such as screws, bolts, rivets, adhesives, adhesives, welding, or other fastening means, or a combination thereof. In the embodiment shown in FIG. 2, the body 26 is provided with a socket between the axes 22, 24 for receiving a suitable mechanical fastener for this purpose.

The body 26 comprising the distal ends 28, 32 is an elastomer and is generally formed from a flexible and resilient plastic such as polyurethane or synthetic rubber. The material for making the body preferably comprises at least one elastomer, for example a polyurethane elastomer. In a preferred embodiment, the material comprises a cast elastomer, preferably a cast polyurethane elastomer. The cast elastomer can be formed by adding a suitable hardener or chain extender (generally in liquid form) to a suitable prepolymer (generally in liquid form), for example by adding a polyether-based curing agent to the polyurethane or urethane prepolymer . The mixed prepolymer and curing agent are added to a mold of a suitable shape (generally open), where the prepolymer and curing agent react to form an elastomer. The casting process is generally a hot casting (or hot curing) process. The body 26 may alternatively be formed by other casting or molding techniques.

An example is the Hyperlast 100/90 (trade name) ( http://www.dow.com/hyperlast/ ) provided by Hyper Limited of Staines, England. Hyperlast 100/90 contains a polyether-based curing agent that reacts with the Hyperlast 100 (TM) prepolymer to produce a high performance polyurethane elastomer. Figure 3 provides data describing the physical properties of the Hyperlast 100/90. It will be appreciated by those of ordinary skill in the art that other materials having the same or similar characteristics may alternatively be used.

Thus, in the preferred embodiment, the hinge 20, particularly the body 26, is made by a cast molding process. Generally, this entails mixing a polyether (or other) curing agent with a Hyperlast (or other) prepolymer through a dynamic mixer that allows mixed chemicals to be poured into a mold (not shown). Once in the mold, the mixture reacts through an exothermic reaction and forms an elastomer, in this example a polyurethane elastomer, in particular a hot-cast polyurethane elastomer.

Surveys and analyzes performed in the course of reaching the present invention show that the Hyperlast 100/90 does not have sufficient strength properties to withstand the forces experienced by the hinges 20 when used, for example, in a 15 kW wind turbine beyond the standard operating temperature range Respectively. The fatigue performance of the material is a major characteristic that is not sufficiently high for applications. In addition, in operation, the blade 16 may experience a significant amount of bending that conveys the bending moment along the length of the blade, and the resultant force is damped by the hinge 20. Since such a force generates stress on the hinge, it is desirable to improve the damping characteristic of the hinge. The problem with modifying the hinges for this purpose is that the hinges must maintain sufficient flexibility and elasticity to perform the pitching and coring described above.

By dispersing the fibers into the material during the vulcanization or injection molding step, the fibers can be used to strengthen the elastomeric material. This allows the orientation of the fibers to be controlled and allows the material to be well dispersed. The problem with integrating fibers with Hyperlast 100/90 or similar materials is a two-part process in which the polyether-based curing agent and the Hyperlast 100 material are all in liquid form until the reaction takes place in the cast mold.

In a preferred embodiment of the present invention, the reinforcing particulate material, preferably comprising fibers, is introduced into the elastomer during casting or other manufacturing processes. Generally, synthetic fibers, preferably polymer fibers, are used. In particular, aromatic polyamides (often known as aramid (including meta-aramid and para-aramid)) fibers are preferred. For example, aramid fibers provided by Teijin Limited of Osaka, Japan (e.g., sold under the trademark Twaron) or Kevlar fibers produced by DuPont of Wilmington, Delaware may be used. Other particulate materials, particularly synthetic particulate materials (e.g., plastics, polymers, glasses, and / or metals) may be used for consolidation.

For example, one or more of the following fibers may be used.

Twaron 1088, aramid fibers with a length of 0.25 mm (Teijin)

- Twaron 1189, aramid fibers with a length of 1.5 mm (Teijin)

- Kevlar Pulp Merge 1F543, Kevlar pulp (DuPont)

Kevlar pulp is a fibrillated pulp that generally includes fibers cut to a length of 0.25 to 1 mm.

More generally, it is desirable to use particles / fibers having a size of from about 0.1 mm to about 2.5 mm (length or diameter, if applicable).

When adding fibers during the casting process, several problems must be considered. Aramid fibers and Kevlar tend to absorb water. Water reacts with the Hyperlast material and can produce carbon dioxide when reacted. Thus, it is advantageous that the fibers are pre-dried for 6 to 8 hours at a temperature higher than 80 degrees, for example, before processing. It is preferred that the fibers are added to the curing agent, since the prepolymer should not be exposed to moisture and therefore should not be exposed to atmospheric conditions. If the fiber / pulp is not added to the curing agent, the viscosity of the curing agent is increased. This can affect the processing characteristics of materials including amenability that can be molded or otherwise processed. For example, the viscosity of the base polyether curing agent is approximately 300 cps and the maximum viscosity capable of reacting with the prepolymer is approximately 1500 cps.

The following results are presented by way of example:

- Including Twaron 1088 at approximately 2% viscosity will be approximately 960 cps

- Including Twaron 1189 approximately 0.75%, viscosity will be approximately 1500 cps

- Including approximately 0.5% Kevlar Pulp 1F543, viscosity will be approximately 1450 cps

Each fiber can be added to a curing agent, such as a polyether curing agent, in an amount up to the indicated percentage level, while allowing the desired reaction with the prepolymer to occur.

More generally, in a preferred embodiment, the reinforcing particulate material is present in an amount of from about 0.5% to about 10% by weight of the elastomeric material used to form the hinge 20.

It is preferred that the fiber or other particulate material is distributed substantially uniformly throughout the body.

It has been found that the inclusion of fibers, such as those described above, leads to a significant improvement in the properties of the elastomer. Figure 4 provides data showing how various amounts and combinations of fibers affect the strength of the Hyperlast PU. In particular, the inclusion of Twaron fibers results in a significant improvement in the strength properties of the material. For example, if it contains 2 wt% Twaron 1088 and 0.5 wt% Twaron 1198, the strength of the material is increased by 75% over the original strength.

The sample tensile properties of FIG. 4 indicate that the characteristics of the PU vary when each fiber reinforcement is included. The tensile strength of PU is improved at a relatively low modulus level, for example at 50% modulus the tensile strength is increased from 4 MPa to 6.5 MPa. This tendency is observed up to about 250% or 300% modulus, where the tensile strength of the PU material has better performance than samples with various fibers. Thus, in this example the tensile strength of the PU material is increased by approximately 40% in the modulus range from approximately 0-250%. Tensile properties are reduced above 250% modulus. In view of the wind turbine blade hinges, the expected maximum strain is generally less than 25% modulus, and thus this result indicates that the addition of fiber reinforcement improves the properties of the PU material for the preferred application.

In view of the wind turbine blade hinge, the tear characteristics of the material used to make the hinge 20 are important. Tear tests, e.g., trouser tests, for each sample of Figure 4 indicate that the tear strength of the PU material is improved by 130% to 18 N / mm at 41 N / mm, including fibers. This is a significant improvement that helps prevent tear propagation, which can cause hinge breakdown.

Optionally, a flexible line of rope 40 (see FIG. 6), such as a simple form of polyester or other synthetic fibers, may be embedded in the hinge 20 material. The rope 40 may be placed in the mold 42 prior to the addition of the curing agent and prepolymer mixture. In general, the rope 40 is generally arranged in a sinusoidal shape, and is preferably arranged to traverse both hinge shafts 22, 24 (preferably several times). A locating member can be provided to the mold 42 and the rope 40 can be wrapped around the mold to help position and shape the rope 40.

Conveniently, the sockets 30, 32 (which may include a sleeve provided in the mold 42) can be used for this purpose.

It is preferred that the rope 40 is embedded in the body 26 and does not break through the front or back of the body 26, for example, preferably substantially centrally between the front and back sides. To this end it is desirable not to hold the rope 40 with a tensile force in the mold since this tends to cause the rope 40 to face the bottom surface of the mold so that the rope faces the corresponding surface of the body 26 It is because it makes it come out through. One or more supports 38 may be provided on the mold 42 to keep the rope 40 away from the mold surface. In Fig. 6, the support 38 includes a tensioned line, e. G., A strand, traversing the mold 42. In Fig. It is preferred that at least one support 38 be provided in the region of the hinge axis 24 because it corresponds at least to the bend of the mold 42 in the illustrated embodiment and where otherwise the rope 40 It is more difficult to keep the mold surface from coming into contact with the mold surface.

It has been confirmed through the finite element analysis that the rope 40 provides support to the elastomeric material of the hinge 20 and increases the damping characteristics of the hinge 20. [ For example, the rope 40 may have a diameter of approximately 5 mm to 15 mm.

If the rope does not provide sufficient bonding force with the Hyperlast PU or other hinge material (which may be the case with a polyester rope), movement of the PU material during operation of the hinge 20 may cause a coupling between the Hyperlast PU and the polyester rope Lt; / RTI > This rupture can propagate to the surface of the hinge 20 and create a vulnerability that can lead to hinge breakdown. Thus, the rope 40 or other reinforcement line is preferably formed from a material suitable for bonding with the hinge material. One such suitable rope is a Kevlar or aramid fiber rope. For example, a 12 strand tenon 240 B (trade name) rope of 10 mm can be used. Alternatively or additionally, the rope may be treated with a suitable polymer, such as a polyurethane dispersion, to improve the adhesion between the rope and the Hyperlast PU material. Advantageously, the rope is pre-dried for at least 8 hours prior to use, e.g.

It is desirable to incorporate the mesh 44 into the hinge 20 in order to provide the hinge 20 with improved damping characteristics. In a preferred embodiment, the mesh 44 is provided to the mold 42 prior to adding the curing agent / prepolymer mixture. The mesh 44 includes a plurality of reinforcing strands 46 extending in a first direction (known in the 0-degree direction) and substantially parallel to each other and a second direction 90 (Which may be referred to as < RTI ID = 0.0 > a < / RTI > direction). Each strand 46, 48 can be secured to one another using any suitable means, such as an adhesive or a tackifier, to form the mesh 44. The mesh 44 provides a substantially planar or two dimensional support structure for the body 26.

The mesh 44 is shaped and dimensioned to extend at least across the area of the second hinge axis 24 because this is generally the area that needs to be supported, but alternatively, for example, 22, 24 of the hinges 20, as shown in Fig. The mesh 44 may alternatively be shaped and dimensioned to extend at least across the area of the first hinge axis 22. Individual meshes can be used to traverse each hinge axis, or a single mesh can be shaped and dimensioned to traverse both hinge axes.

It is preferred that the mesh 44 be disposed relative to the hinge 20 such that the first strand direction is substantially perpendicular to, or at least not parallel to, the hinge axis 22, 24 (if applicable). This allows the reinforcing strand 46 to support the hinge 20 and provide damping to the hinge 20 without unduly restricting the flexibility of the hinge 20 in use.

The reinforcing strands 46 are preferably formed from synthetic fibers, such as polymeric fibers, such as aramid fibers, that are conveniently formed as yarns. The thickness of the strands 46 may be selected depending on the material from which the strands 46 are formed and the level of consolidation to be provided, but may generally be from about 0.5 mm to about 3 mm. For example, the spacing between adjacent strands 46 may generally be from about 0.5 mm to about 3 mm. The connecting strands 48 may be formed from any suitable material that serves to hold the strands 46 in the desired direction, conveniently from synthetic fibers, such as glass fibers. In a preferred embodiment, the connecting strand 48 does not provide much support or reinforcement to the hinge 20, and the materials and / or thickness and / or spacing to be made are accordingly selected. Thus, in general, the connecting strand 48 can be described as being relatively light, and the reinforcing strand 46 as being relatively heavy.

For example, mesh 44 may include a Kevlar mesh, such as RUBAN 9081 FK (trade name) Kevlar mesh. These meshes consist of aramid yarn in the 0 degree direction and glass fibers in the 90 degree direction which keep the aramid yarn in the correct direction.

It is preferred that the mesh 44 be embedded in the body 26 and not penetrate the front or back of the body 26 such that it is preferably positioned substantially parallel to the front and back sides of the body 26, Do. Preferably, the mesh 44 is positioned substantially in a plane in which the neutral axis of the hinge 20 lies. In a preferred embodiment, the mesh 44 is substantially centered substantially between the front and back sides of the body 26 and lies substantially in a plane parallel to the front and back sides.

One or more supports, e.g., one or more tensioned lines traversing the mold, may be provided in the mold 42 to hold the mesh 44 at the desired location. Conveniently, supports 38 can be used for this purpose. In embodiments where both the mesh 44 and the rope 40 are present, a support 38 may be positioned to hold the mesh 44 against the rope 40. Figure 7 shows a cut-away view of one embodiment of the structure of a hinge of the present invention cast from such a mold.

In order to further improve the damping characteristics of the hinge 20, it is preferable to make the hinge thicker by 5 mm than the conventional hinge. For example, it has been found that hinges with Teijin 240B ropes and Ruban 9081 mesh exhibit increased strength at these increased thicknesses (approximately 95% increase in strength compared to conventional hinges). This increases the damping characteristics of the hinge 20. [ The analysis of the hinges with this characteristic appeared to have a maximum strain value of 8%, which is well below the typical strain value of 35% for conventional hinges.

A comparison between such hinge and fatigue failure data for a conventional hinge is shown in Fig. The line drawn at 35% strain represents a conventional hinge design. These lines intersect with data at approximately 3.4 million cycles. This indicates that the conventional hinge can be expected to last approximately 3.4 million cycles in normal operation. In contrast, the plot of the improved design of the hinge of the present invention (having a maximum maximum strain of 8%) has a very low value below the X axis and does not intersect the fatigue graph. This indicates that the number of cycles to failure is too large to be measured. Improvements in fatigue results are too large to characterize and are in much higher than 10-fold increments.

Thus, through the use of fiber reinforcements in the exemplary amounts listed in FIG. 9, through the inclusion of rope and mesh material, and also through the increase in hinge thickness, the characteristics of the preferred embodiment of the hinge of the present invention are superior to those of conventional hinge designs Lt; RTI ID = 0.0 > no longer occur. ≪ / RTI > Thus, the hinge of the present invention has the strength and rigidity to withstand harsh environments and forces that the hinge can suffer.

It will be clear that the present invention is not limited to being used with a biaxial hinge.

The present invention is not limited to the embodiments described herein, and can be modified or modified without departing from the scope of the present invention.

Claims (64)

A hinge for a wind turbine,
And a body capable of hinging motion with respect to at least one hinge axis,
Wherein the body is formed from a flexible and resilient material in which the reinforcing particulate material is distributed. The method according to claim 1,
Wherein the reinforcing particulate material comprises synthetic fibers. 3. The method of claim 2,
Wherein the synthetic fibers comprise polymer fibers. The method of claim 3,
Wherein the polymer fibers comprise aramid fibers. 5. The method according to any one of claims 1 to 4,
Wherein the particulate material has a size of from about 0.1 mm to about 2.5 mm. 6. The method of claim 5,
Wherein the reinforcing particulate material is present in an amount of from about 0.5% to about 10% by weight of the material forming the hinge. 7. The method according to any one of claims 1 to 6,
Wherein the flexible and resilient material comprises an elastomer. 8. The method of claim 7,
Wherein the elastomer comprises a polyurethane elastomer. 9. The method according to any one of claims 1 to 8,
Wherein the hinge comprises at least one reinforcing mesh incorporated in the body. 10. The method of claim 9,
Wherein the mesh comprises a plurality of spaced reinforcing strands extending in a first direction and a plurality of spaced apart connecting strands extending in a second direction not parallel to the first direction. 11. The method of claim 10,
Wherein the reinforcing strands are substantially parallel to each other and the connecting strands are substantially parallel to each other and the second direction is substantially perpendicular to the first direction. The method according to claim 10 or 11,
Wherein the reinforcing strand is formed from synthetic fibers. 13. The method of claim 12,
Wherein the synthetic fibers comprise polymer fibers. 14. The method of claim 13,
Wherein the polymer fibers comprise aramid fibers. 15. The method according to any one of claims 10 to 14,
Wherein the connecting strand is formed from synthetic fibers. 16. The method of claim 15,
Wherein the synthetic fibers comprise glass fibers. 17. The method according to any one of claims 9 to 16,
Wherein the at least one mesh extends across an area of the body corresponding to at least one of the at least one hinge axis. 18. The method of claim 17,
Wherein the at least one mesh is shaped and dimensioned to cover substantially the entire major cross-sectional area of the body. The method according to claim 17 or 18,
Wherein the at least one mesh is disposed such that the first strand direction is not parallel to at least one of the at least one hinge axis. 20. The method of claim 19,
Wherein the at least one mesh is disposed such that the first strand direction is substantially perpendicular to at least one of the at least one hinge axis. 21. The method according to any one of claims 9 to 20,
Wherein the at least one mesh is embedded in the body and does not break through the front or back of the body. 22. The method of claim 21,
Wherein the at least one mesh is located between the front and back sides of the body. 23. The method of claim 22,
Wherein the at least one mesh is substantially parallel to the front and back sides of the body. 24. The method of claim 23,
Wherein the at least one mesh is located substantially in a plane in which the neutral axis of the hinge lies. 25. The method of claim 24,
Wherein the at least one mesh is substantially centered between the front and back surfaces of the body and substantially lying in a plane substantially parallel to the front and back surfaces of the body. 26. The method according to any one of claims 1 to 25,
A hinge for a wind turbine, wherein the flexible lines are embedded in the flexible and resilient material. 27. The method of claim 26,
Wherein the flexible line comprises a rope. 28. The method of claim 26 or 27,
Said line not being tensioned. 29. The method according to any one of claims 26 to 28,
Wherein the lines are generally arranged in a sinusoidal fashion. 30. The method of claim 29,
Wherein the line is arranged to traverse the at least one hinge axis. 31. The method according to any one of claims 26 to 30,
Wherein the position member is provided on the body to which the line is to be wound. 32. The method according to any one of claims 26 to 31,
Wherein the line is formed from a material adapted to be adhered to the flexible and resilient material. 33. The method of claim 32,
Wherein the line comprises a Kevlar rope. 33. The method of claim 32,
Wherein said line comprises an aramid fiber rope. 35. The method according to any one of claims 26 to 34,
Wherein the line is treated with a polymer. 36. The method of claim 35,
Wherein the polymer comprises polyurethane. 37. The method according to any one of claims 26 to 36,
Wherein the line is pre-dried before use. 37. The method according to any one of claims 1 to 37,
Wherein the hinge comprises first and second hinge shafts. 39. The method of claim 38,
Wherein the first hinge axis and the second hinge axis are spaced apart from each other. 40. The method of claim 39,
Wherein the first hinge axis and the second hinge axis are not parallel to each other. 41. The method according to any one of claims 38 to 40,
And a support member provided on one or both of the front and rear surfaces of the body. 42. The method of claim 41,
Wherein the support member does not extend across the hinge axis. 43. The method of claim 41 or 42,
Wherein the support member comprises a plate. 43. The method according to any one of claims 1 to 42,
Wherein the thickness of the material forming the hinge is from about 25 mm to about 45 mm. A blade assembly for a wind turbine,
44. A blade assembly comprising a plurality of blades connected to a hub by a hinge according to any one of claims 1 to 44. A wind turbine comprising an electric generator connected to a blade assembly according to claim 45. A method of manufacturing a hinge for a wind turbine,
A forming step of forming, from a flexible and elastic material, a body capable of hinging motion with respect to at least one hinge axis; And
A distribution step for allowing the reinforcing particulate material to be distributed to the flexible and elastic material
≪ / RTI > 49. The method of claim 47,
Wherein the forming step comprises casting the flexible and resilient material in a mold. 49. The method of claim 48,
Wherein the casting step comprises hot casting. A method according to any one of claims 47 to 49,
Wherein the flexible and resilient material comprises an elastomer. 51. The method according to any one of claims 48 to 50,
Wherein the forming further comprises adding a curing agent to the prepolymer, and introducing the mixed curing agent and the prepolymer into the mold. 52. The method of claim 51,
Wherein the curing agent and the prepolymer are both in liquid form. 54. The method of claim 51 or 52,
Further comprising adding the reinforcing particulate material to the curing agent prior to mixing the flip-polymer. 54. The method of claim 53,
Further comprising drying the reinforcing particulate material prior to adding the reinforcing particulate material to the hardening agent. 55. The method of any one of claims 51-54,
Further comprising positioning the flexible line in the mold prior to placing the mixed curing agent and prepolymer into the mold. 56. The method of claim 55,
Wherein the flexible line comprises a rope. 56. The method of claim 55 or 56,
Further comprising providing at least one support to the mold to maintain the line away from the main mold surface. 58. The method of claim 57,
Wherein the at least one support comprises a tensioned line traversing the mold. 58. The method of claim 57 or 58,
Wherein the at least one support is provided in at least one region of the at least one hinge axis. 60. The method according to any one of claims 51-59,
Further comprising providing at least one mesh to the mold prior to introducing the mixed curing agent and prepolymer into the mold. 64. The method of claim 60,
Further comprising providing at least one support across the mold to hold the at least one mesh at a desired location. 62. The method of claim 61,
Wherein the at least one support comprises at least one tensioned line. 62. The method according to claim 61 or 62,
Wherein the at least one support holds the at least one mesh against the flexible line. 45. A mold for forming a hinge according to any one of claims 1 to 44.

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