Method of manufacturing rotor blade for wind turbine
By combining high-pressure resin transfer molding and sheet molding molding process, the half-shell and leading edge closure of the rotor blade are manufactured, which solves the problem of high manufacturing cost of rotor blades and realizes a low-cost and efficient production method.
Patent Information
- Application Number
- CN202380088925.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-11-10
- Filing Date
- 2023-10-30
- Publication Date
- 2025-08-08
AI Technical Summary
The prior art is difficult to optimize large-scale production and procurement costs while reducing the manufacturing costs of rotor blades.
The high-pressure resin transfer molding process is used to combine the sheet molding material molding process to manufacture the first half-rotor blade shell and the second half-rotor blade shell, and the leading edge closure of the rotor blade is formed through the spacer, eliminating additional fixing steps and fixing using a bushing and a gasket.
Low-cost manufacturing of rotor blades is achieved, suitable for small- and large-scale production, reducing additional steps and material waste in the manufacturing process, and improving production efficiency and cost-effectiveness.
Smart Images
Figure CN120457019A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for manufacturing a rotor blade for a wind turbine, more particularly to a method for manufacturing a first rotor blade shell half, a second rotor blade shell half and a spacer, the spacer forming a leading edge closure of the rotor blade and being designed to receive the leading edge of the first rotor blade shell half on one side and the leading edge of the second rotor blade shell half on the opposite side in the assembled state. Background Art
[0002] To achieve cost reduction in rotor blade manufacturing, mass production is the primary solution to limit downtime and simultaneously reduce procurement costs. Different manufacturing processes can be used for the mass production of rotor blades.
[0003] Resin transfer molding (RTM) is a well-known production process in which a reactive resin in the form of a resin-hardener mixture is injected into a closed mold, typically a two-piece mold, into which a dry fiber layup has been previously placed. In this process, the fiber layup is placed in the mold. The mold is then closed, and the reactive resin is continuously injected through the gate at an injection pressure of 0.5 to 8 bar. The components of the resin system are pre-mixed in the pressure head. As a result, the fiber layup is impregnated with resin. Excess resin escapes through vents. The resin cures while holding pressure and with the vents closed. Once the reactive resin has cured, the mold is opened and the finished part is removed from the mold. This process produces high-performance structural components by directly combining the reinforcement material in the form of the fiber layup with the matrix in the form of the reactive resin.
[0004] In high-pressure resin transfer molding (HP-RTM), injection pressure can be increased to up to 200 bar. Depending on the selected chemicals and process parameters, fully cured composite parts can be obtained in less than 10 minutes. High-pressure processes allow for high production volumes, thereby reducing manufacturing costs.
[0005] Compression molding using sheet molding compound (SMC) is another well-known production process that allows for high-volume production and cost-effective manufacturing, typically with less scrap. Weight reduction of manufactured parts can also be achieved due to reduced dimensional requirements. Summary of the Invention
[0006] The object of the present invention is to provide a method for manufacturing a rotor blade for a wind turbine, which method allows combining different production processes which are selected to optimize the manufacturing of each component of the rotor blade, thereby reducing the manufacturing costs at the level of the components of the rotor blade.
[0007] According to the invention, this object is achieved by a method for producing a rotor blade for a wind turbine according to claim 1. Further preferred embodiments of the invention are subject matter of the dependent claims.
[0008] A method for manufacturing a rotor blade for a wind turbine is disclosed, comprising the steps of providing a layup of fiber material and stacking the layups in a first mold for a first rotor blade shell half and in a second mold for a second rotor blade shell half, the first mold and the second mold being designed for a high-pressure resin transfer molding process. The first rotor blade shell half and the second rotor blade shell half each include a plurality of circular channels arranged on an inner side and designed to cooperate with a plurality of bushings for securing the rotor blade to a hub of the wind turbine. Preferably, the layup is made of dry fiber material to produce a uniform laminate with minimal defects. Typically, triaxial, non-crimped fabric layups made of carbon fiber can be used. Recycled carbon fiber can also be used as an ecological alternative. Preferably, two circular channels are provided, each for receiving a bushing.
[0009] Furthermore, the method comprises the step of injecting resin in the first and second molds to bond the plies and manufacture the first and second rotor blade shell halves by a high pressure resin transfer molding process.
[0010] The method further comprises the step of providing a plurality of bushings, each of which is formed as a solid cylindrical sleeve having a wall protrusion extending radially outward from the outer surface of the sleeve. The presence of the radially extending wall protrusions facilitates increasing the circumferential contact surface with the material surrounding each bushing and improves the axial fixation of the bushing. Preferably, the bushings are made of steel to provide the required mechanical resistance, and the bushings may be electrostatically coated to limit the risk of corrosion.
[0011] Furthermore, the method includes the steps of manufacturing and providing a spacer. The spacer comprises a preferably solid rotor blade root defining a reference plane and comprising a plurality of bushings arranged with their axial direction perpendicular to the reference plane. The wall projections of the bushings are each embedded in the rotor blade root during the manufacturing process to ensure their anchoring in the rotor blade root. Advantageously, the method eliminates the step of securing the bushings after manufacturing the rotor blade root, for example using an adhesive.
[0012] As is known, a rotor blade includes a rotor blade root for securing the rotor blade to a rotor shaft or a hub of a wind turbine. The hub is typically attached to the rotor shaft. During operation, the rotor shaft or its axis of rotation is at least approximately aligned with the direction of the incoming wind.
[0013] Furthermore, the spacer comprises a leading edge closure and a rotor blade tip, the leading edge closure extending from the outside of the rotor blade root into the rotor blade tip facing away from the rotor blade root.
[0014] The rotor blade root and leading edge closure have a receiving area designed to receive the leading edge of a first rotor blade shell half on one side and the leading edge of a second rotor blade shell half on the opposite side to form the leading edge of the rotor blade. The spacer forms a support structure for the first and second rotor blade shell halves and, together with the first and second rotor blade shell halves, defines the hollow body of the rotor blade. The spacer is designed to hold the trailing edges of the first and second rotor blade shell halves at a distance to form the trailing edge of the rotor blade.
[0015] Preferably, the receiving area has a contour complementary to the leading edge of the first rotor blade shell half on one side and to the leading edge of the second rotor blade shell half on the opposite side. This arrangement creates a seamless transition from the leading edge closure to the first and second rotor blade shell halves.
[0016] After preferably cleaning the contact surfaces of the first and second rotor blade shell halves, the method comprises positioning the first and second rotor blade shell halves in a receiving area by installing a plurality of circular channels around a plurality of bushings. Furthermore, the steps of bonding the first and second rotor blade shell halves and the spacer to form the leading edge of the rotor blade and bonding the first and second rotor blade shell halves to form the trailing edge of the rotor blade are performed.
[0017] As a further step, a plurality of washers having an inner diameter corresponding to the outer diameter of the plurality of bushings are provided for mounting a washer at each end of the bushings. To mount the washers, they are inserted into each end of the bushings, and a pair of washers can be retained at each end of the bushings by bolts used to secure the rotor blades to the rotor shaft or the hub of the wind turbine.
[0018] Advantageously, the method allows for the use of a high-pressure resin transfer molding process for the manufacture of the first and second rotor blade shell halves, a process that is particularly suitable in terms of cost. Furthermore, the leading edge closure of the rotor blade can be manufactured using a different method that is more suitable for this type of part. Thus, the method optimizes costs by allowing the use of different manufacturing processes for the adapter and the first and second rotor blade shell halves, each of which can be optimized independently. Furthermore, the method enables scalability of manufacturing by using a production process suitable for both small and large batches. Furthermore, the bushing is integrated into the rotor blade during the manufacture of the rotor blade itself, so that no additional step is required to secure the bushing after the rotor blade has been molded.
[0019] In a preferred embodiment, the thickness of the spacer is designed to allow the bushing to protrude on each side of the spacer by at least a height corresponding to the thickness of the second rotor blade shell half and the first rotor blade shell half, respectively, and a height corresponding to less than the combined thickness of the second rotor blade shell half and the washer, and the combined thickness of the first rotor blade shell half and the washer, respectively. This arrangement creates a seamless transition from the bushing to the first rotor blade shell half and the second rotor blade shell half.
[0020] In a preferred embodiment, the spacers are manufactured by compression molding using sheet molding compound, preferably glass-fiber-reinforced polyester. This process allows for cost-optimized spacer manufacturing. Furthermore, without the need for an impregnation step, a wide range of dry fiber materials, such as recycled fiber materials or fiber materials from renewable sources, can be used, which is not possible with resin transfer molding.
[0021] In a preferred embodiment, the spacer is manufactured by injection molding, preferably using thermoplastic foam. This process also allows to optimize the costs of the spacer manufacturing, while the thermoplastic foam allows to reduce the weight of the spacer.
[0022] In a preferred embodiment, the step of forming the spacer comprises forming the spacer into a plurality of spacer segments, and assembling the plurality of spacer segments to form the spacer. Preferably, the spacer is formed into two to six spacer segments. Most preferably, four to six spacer segments are provided. Advantageously, this step allows for a reduction in tool size.
[0023] In a preferred embodiment, the spacer segments are assembled by a form-fit connection. Such a connection allows the spacer segments to be assembled to form a spacer without the use of mechanical elements or adhesives, which limits the manufacturing costs.
[0024] In a preferred embodiment, the trailing edge of the first rotor blade shell half and the trailing edge of the second rotor blade shell half are directly assembled to each other to form the trailing edge of the blade. This embodiment allows for further weight reduction since the trailing edge has no spacers.
[0025] In a preferred embodiment, the trailing edges of the first rotor blade shell half and the second rotor blade shell half are milled to size before assembly. The wall thickness of the trailing edges of the first rotor blade shell half and the second rotor blade half is thinner than the wall thickness of the remaining parts of the first rotor blade shell half and the second rotor blade half, and are designed so that in the assembled state, the two trailing edges, when directly assembled together, form the trailing edge of the rotor blade, without requiring any spacer portion at the trailing edge. Milling the trailing edges of the first rotor blade shell half and the second rotor blade half to size, even when they have their final shape for assembly into the rotor blade, allows for the removal of irregularities at their edges before bonding the first rotor blade shell half and the second rotor blade half.
[0026] In a preferred embodiment, the rotor blade tip forms a tip closure of the rotor blade, which is arranged at the outboard end of the second rotor blade shell half and the outboard end of the first rotor blade shell half. Outboard defines a position or direction further from the center, and inboard defines the opposite direction.
[0027] Preferably, the rotor blade tip has a tip receiving area designed to receive a tip edge of a first rotor blade shell half on one side and a tip edge of a second rotor blade shell half on an opposite side to form the tip edge of the rotor blade.
[0028] Preferably, the rotor blade tip has a profile in the form of a wedge, tapering in the direction from the leading edge to the trailing edge to follow the shape of the outboard end of the second rotor blade shell half and at the outboard end of the first rotor blade shell half.
[0029] Preferably, the tip receiving area is formed with a profile complementary to the tip edge of the first rotor blade shell half on one side and with a profile complementary to the tip edge of the second rotor blade shell half on the opposite side. This arrangement forms a seamless transition from the tip closure to the first and second rotor blade shell halves.
[0030] In a preferred embodiment, the rotor blade root forms a trailing edge closure which is arranged at the inner end of the second rotor blade shell half and at the inner end of the first rotor blade shell half.
[0031] In a preferred embodiment, the plurality of liner wall projections are in the form of at least one rib, which is arranged at mid-height of the liner.This embodiment provides a strong anchoring of the liner in the rotor blade root.
[0032] Bolts made of glass-fiber-reinforced or carbon-fiber-reinforced thermoplastic materials can be inserted into washers and bushings to secure the rotor blades to the rotor shaft. Using these materials can reduce weight and cost while avoiding corrosion problems. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The present invention will now be described by way of example with reference to the accompanying drawings, in which:
[0034] Figure 1 shows a perspective view of a rotor blade assembly before assembly;
[0035] Figure 2 shows a top view of the rotor blade in an assembled state;
[0036] Figure 3 Shows the rotor blades along Figure 2 The cross section of section AA is shown;
[0037] Figure 4 Shows the rotor blades along Figure 2 The cross section of the CC section is shown;
[0038] Figure 5 Shows the rotor blades along Figure 2 Cross section of DD section shown;
[0039] Figure 6 A portion of a rotor blade root is shown in a cross-sectional view after a step of manufacturing the rotor blade root with an embedded bushing;
[0040] Figure 7 The cross-sectional view shows the next step after Figure 6 an identical portion, wherein the first rotor blade shell half and the second rotor blade shell half are accommodated around the bushing; and
[0041] Figure 8 The cross-sectional view shows the next step after Figure 6 Same part where the washer is arranged around the bushing. DETAILED DESCRIPTION
[0042] Figure 1 A first rotor blade shell half 10 and a second rotor blade shell half 20 of a rotor blade 30 for a wind turbine manufactured according to the invention are shown.
[0043] The method for manufacturing a rotor blade includes providing a fiber material layup in the form of a carbon fiber triaxial non-crimp fabric and stacking the layup in a first mold for a first rotor blade shell half and a second mold for a second rotor blade shell half, the first mold and the second mold being designed for a high-pressure resin transfer molding process. Furthermore, the method includes injecting resin into the first mold and the second mold using the high-pressure resin transfer molding process to bond the layups and manufacture the first rotor blade shell half 10 and the second rotor blade shell half 20.
[0044] The first and second rotor blade shell halves 10, 20 each comprise a plurality of circular channels 40, here two each, arranged on the inside for cooperating with a plurality of bushings 50 to secure the rotor blade to the hub of the wind turbine.
[0045] The rotor blade includes a rotor blade root 42 for securing the rotor blade 10 to a rotor shaft (not shown) or a wind turbine hub. The hub is typically attached to the rotor shaft. During operation, the rotor shaft, or its axis of rotation, is at least approximately aligned with the direction of the incoming wind. The rotor blade has a leading edge 44 and a trailing edge 46 extending from an inboard end 45 to an outboard end 47.
[0046] The method further comprises the step of providing a plurality of bushings 50 made of steel, such as Figure 6 As shown, each bushing is formed as a solid cylindrical bushing having a wall protrusion 52 extending radially outward from the outer surface of the bushing. The wall protrusion 52 is in the form of at least one rib disposed at mid-height of the bushing. The rib provides a strong anchoring of the bushing in the rotor blade root 42.
[0047] Furthermore, the method includes the steps of manufacturing and providing a spacer 60. The spacer 60 includes a rotor blade root 42 defining a reference plane and includes a plurality of bushings 50 arranged with the axial direction perpendicular to the reference plane. The rotor blade root 42 is formed as a solid inner end portion of the rotor blade extending from a leading edge 44 to a trailing edge 46.
[0048] The wall projections 52 of a plurality of bushings are each embedded in the rotor blade root during the manufacturing process in order to ensure their anchoring in the rotor blade root 42 .
[0049] Furthermore, the spacer comprises a rotor blade leading edge closure 64 extending from the outside of the rotor blade root 42 into a rotor blade tip 68 facing away from the rotor blade root.
[0050] like Figure 3 、 Figure 4 and Figure 5 As shown, the spacer 60 has a receiving area 70 designed to receive the first rotor blade shell half 10 on one side and the second rotor blade shell half 20 on the opposite side to form a rotor blade. The receiving area extends across the rotor blade root 42, the leading edge closure 64, and the rotor blade tip 68. The receiving area is formed with a profile that is complementary to the leading edge of the first rotor blade shell half on one side and to the leading edge of the second rotor blade shell half on the opposite side. This arrangement creates a seamless transition from the spacer to the first and second rotor blade shell halves.
[0051] After cleaning the contact surfaces of the first half rotor blade shell and the second half rotor blade shell, Figure 4 and Figure 7 As shown, the method comprises the steps of positioning the first half rotor blade shell 10 and the second half rotor blade shell 20 in a receiving area 70 with a plurality of circular channels 40 mounted around a plurality of bushings 50. Then, the step of bonding the first half rotor blade shell, the second half rotor blade shell and the spacer 60 is performed to form the leading edge 44 and the trailing edge 46 and the inboard end 45 and the outboard end 47 of the rotor blade.
[0052] In a previous step, the trailing edge of the first half rotor blade shell and the trailing edge of the second half rotor blade shell have been milled to size before being directly bonded to each other to form the trailing edge, e.g. Figure 4 shown.
[0053] Figure 4 A receiving area 70 of the leading edge closure 64 is shown, in which the leading edge of the first rotor blade shell half 10 is received on one side and the leading edge of the second rotor blade shell half 20 is received on the opposite side to form the leading edge 44 of the rotor blade.
[0054] Figure 5 A receiving area 70 of the rotor blade tip 68 is shown, in which the outboard end of a first rotor blade shell half 10 is received and, on the opposite side, the outboard end of a second rotor blade shell half 20 is received to form the outboard end of the rotor blade.
[0055] As a further step, Figure 8 As shown, a plurality of washers 80 are provided, the inner diameter of which corresponds to the outer diameter of the plurality of bushings 50 at a time, and a washer is installed at each end of the bushing. Figure 6 、 Figure 7 and Figure 8 As shown, the thickness of the spacer 60 is designed to allow the bushing 50 to protrude on each side of the spacer by at least a height corresponding to the thickness of the second half rotor blade shell 10 and the first half rotor blade shell 20, respectively, and corresponding to a height smaller than the combined thickness of the second half rotor blade shell and the gasket and the combined thickness of the first half rotor blade shell and the gasket, respectively.
[0056] The spacer 60 is manufactured by compression molding using a sheet molding compound of glass fiber reinforced polyester, wherein the spacer 60 is manufactured into a plurality of (here, four) spacer segments 60a, 60b, 60c, and 60d, as shown in FIG. Figure 2As shown, a plurality of spacer segments are assembled into a spacer 60 by a form-fit connection. A first spacer segment 60a comprises the rotor blade root 42 and the adjacent portion of the leading edge closure 64. A second spacer segment 60b, which is adjacent to the first spacer segment, and a third spacer segment 60c, which is adjacent to the second spacer segment, each form a section of the leading edge closure 64. A fourth spacer segment 60d, which is adjacent to the third spacer segment, comprises an outer section of the leading edge closure 64 and the rotor blade tip 68.
[0057] The rotor blade tip 68 has a wedge-shaped profile which tapers in the direction from the leading edge to the trailing edge in order to follow the shape of the outer ends of the second half rotor blade shell and the outer ends of the first half rotor blade shell.
[0058] Reference Signs List
[0059] First rotor blade shell half 10
[0060] Second rotor blade shell half 20
[0061] Rotor blade 30
[0062] Circular channel 40
[0063] Rotor blade root 42
[0064] Leading Edge 44
[0065] Inner end 45
[0066] Trailing Edge 46
[0067] Outer end 47
[0068] Bushing 50
[0069] Wall protrusion 52
[0070] Spacer 60
[0071] Spacer segments 60a, 60b, 60c, and 60d
[0072] Leading edge closure 64
[0073] Rotor blade tip 68
[0074] Receiving area 70
[0075] Washer 80
Claims
1. A method of manufacturing a rotor blade (30) for a wind turbine, comprising the following steps: a) providing a layup of fiber material and stacking the layups in a first mold for a first rotor blade shell half (10) and in a second mold for a second rotor blade shell half (20), the first mold and the second mold being designed for a high-pressure resin transfer molding process, the first rotor blade shell half (10) and the second rotor blade shell half (20) each comprising a plurality of circular channels (40) arranged on an inner side and designed to cooperate with a plurality of bushings (50) for fixing the rotor blade to a hub of the wind turbine; b) injecting resin into the first mold and the second mold by a high pressure resin transfer molding process to bond the plies and manufacture the first half rotor blade shell and the second half rotor blade shell; c) providing a plurality of bushings (50), each bushing being formed as a solid cylindrical sleeve having a wall protrusion (52) extending radially outwardly from an outer surface of the sleeve; d) manufacturing a spacer (60), the spacer comprising a rotor blade root (42), the rotor blade root defining a reference plane and comprising a plurality of bushings (50) arranged perpendicular to the reference plane, the spacer (60) further comprising a leading edge closure (64) and a rotor blade tip (68), the leading edge closure extending from outside the rotor blade root to the rotor blade tip facing away from the rotor blade root, the rotor blade tip (68) and the leading edge closure (64) having a receiving area (70) designed to receive a leading edge of the first rotor blade shell half on one side and a leading edge of the second rotor blade shell half on an opposite side to form the leading edge (44) of the rotor blade; and e) positioning the first half rotor blade shell (10) and the second half rotor blade shell (20) in the receiving area (70) by mounting the plurality of circular channels (40) around the plurality of bushings (50), bonding the first half rotor blade shell, the second half rotor blade shell and the spacer (60) to form a leading edge (44) of the rotor blade (30), and bonding the first half rotor blade shell and the second half rotor blade shell to form a trailing edge (46) of the rotor blade; f) providing a plurality of washers (80) having an inner diameter corresponding to the outer diameter of the plurality of bushings (50) to mount a washer at each end of the bushings.
2. The method according to claim 1, characterized in that The thickness of the spacer (60) is designed to allow the bushing (50) to protrude on each side of the spacer at least by a height corresponding to the thickness of the second half rotor blade shell (20) and the first half rotor blade shell (10), respectively, and corresponding to a height smaller than the combined thickness of the second half rotor blade shell and the washer, and the combined thickness of the first half rotor blade shell and the washer, respectively.
3. The method according to claim 1 or 2, characterized in that The spacer (60) is manufactured by compression molding using sheet molding compound, preferably glass fiber reinforced polyester.
4. The method according to claim 1 or 2, characterized in that The spacer (60) is manufactured by injection molding, preferably injection molding of thermoplastic foam.
5. The method according to any one of claims 1 to 4, characterized in that The step of manufacturing the spacer (60) by molding includes the steps of manufacturing the spacer into a plurality of spacer segments (60a, 60b, 60c, 60d), and assembling the plurality of spacer segments to form the spacer.
6. The method according to claim 5, characterized in that The spacer segments (60a, 60b, 60c, 60d) are assembled by a form-fitting connection.
7. The method according to any one of claims 1 to 6, characterized in that The trailing edge of the first half rotor blade shell (10) and the trailing edge of the second half rotor blade shell (20) are directly assembled with each other to form the trailing edge (46) of the blade.
8. The method according to claim 7, characterized in that The trailing edge of the first rotor blade shell half and the trailing edge of the second rotor blade shell half are milled to size before assembly.
9. The method according to any one of claims 1 to 8, characterized in that The rotor blade tip (68) forms a tip closure of the rotor blade, which is arranged at the outer end of the second half rotor blade shell (20) and the outer end of the first half rotor blade shell (10).
10. The method according to any one of claims 1 to 9, characterized in that The rotor blade root (42) forms a trailing edge closure which is arranged at the inner end of the second half rotor blade shell and the inner end of the first half rotor blade shell.
11. The method according to any one of claims 1 to 10, characterized in that The wall protrusion (52) of the plurality of bushings (50) is in the form of at least one rib arranged at a mid-height of the bushings.