Fan blade connecting bolt cooperative force structure

Abstract

The application provides a fan blade connecting bolt cooperative stress structure, which comprises a plurality of blade mounting bolts arranged circumferentially along a blade butt flange, an inner flange structure is arranged at a head end, the inner flange structure is provided with a plurality of through holes in the circumferential direction, the blade mounting bolt is provided with an extending end, the extending end of the blade mounting bolt comprises a light axis positioning section and a threaded section, the threaded section is inserted into the through hole, a filling sleeve is sleeved outside the light axis positioning section, a clamping cavity is arranged between the filling sleeve and the inner wall of the through hole, an outer flange end is arranged at one end of a ring tooth, a glue filling channel is arranged in the inner flange end and is aligned with the clamping cavity, a filling glue layer is arranged in the clamping cavity, the threaded section passes through the through hole, a locking nut is sleeved on the through hole in a threaded connection mode, and one end of the locking nut is abutted against the outer flange end, so that the problem that a small part of fan blade mounting bolts is subjected to stress and is broken when the blade and the head are dislocated is solved.

Description

Technical Field

[0001] This utility model relates to the field of wind turbine blade and turbine head docking, and in particular to a wind turbine blade connecting bolt cooperative force-bearing structure. Background Technology

[0002] The existing wind turbine blades are mainly connected to the turbine head by a flange-bolt connection structure. This means that a positioning and installation structure and a through hole are reserved at the end of the turbine head drum. Connecting bolts are pre-screwed into the ends of the wind turbine blades. When the turbine is lifted for connection, the connecting bolts pass through the through hole on the inner flange structure at the end of the turbine head drum, and then the bolts are locked with nuts.

[0003] Because the blades are suspended during installation, they sway during docking, making operation difficult. Therefore, the through holes on the inner flange structure typically need to be larger than the diameter of the connecting bolts. Due to machining and installation errors, the distance between each connecting bolt and the inner wall of each through hole is not uniform. When the blades are subjected to wind force, a large torque is generated at the docking point. Furthermore, the mechanical components vibrate during wind turbine power generation. Over prolonged use, the blades and the turbine rotor may slip slightly relative to each other, and a small number of connecting bolts may contact the inner wall of the through holes in the inner flange structure first, experiencing significant shear force and breaking. Utility Model Content

[0004] This invention provides a collaborative force-bearing structure for connecting bolts of wind turbine blades, which solves the problem that when the blades and the turbine head misalign, a small number of wind turbine blade mounting bolts are subjected to force alone, leading to breakage.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a wind turbine blade connecting bolt cooperative force-bearing structure, including multiple blade mounting bolts arranged circumferentially along the blade mating flange, an inner flange structure at the turbine head end, multiple through holes along the circumferential direction of the inner flange structure, a protruding end of the blade mounting bolt, the protruding end of the blade mounting bolt including a shaft positioning section and a threaded section, the threaded section being inserted into the through hole, a filler sleeve being fitted on the outside of the shaft positioning section, a clamping cavity being provided between the filler sleeve and the inner wall of the through hole, an outer flange end being provided at one end of the ring tooth, an adhesive channel being provided inside the outer flange end to align with the clamping cavity, a filling adhesive layer being provided inside the clamping cavity, the threaded section passing through the through hole, a threaded locking nut being fitted on the through hole, one end of the locking nut abutting against the outer flange end.

[0006] In a preferred embodiment, the outer flange end includes an outer end ring and an inner end ring that fit together. The inner end ring has an inner hole near the positioning hole, and the outer end ring has an outer hole near the outer edge of the outer end ring. The outer end ring has a radial transition groove on the side near the inner end ring, and the transition groove connects the inner hole and the outer hole.

[0007] In the preferred embodiment, the inner end ring is provided with a directional groove, and the outer end ring is provided with a directional protrusion, which is engaged in the directional groove.

[0008] In a preferred embodiment, an annular flange is provided on the side of the outer end ring away from the inner end ring, and the outer hole is located outside the annular flange.

[0009] In the preferred embodiment, the inner wall of the through hole is provided with an inner conical surface, and the outer wall of the filling sleeve is provided with a concave-convex structure.

[0010] In a preferred embodiment, the concave-convex structure of the outer wall of the filling sleeve is a spiral protrusion or a spiral groove.

[0011] In the preferred embodiment, the concave-convex structure of the outer wall of the filler sleeve is a ring tooth.

[0012] In the preferred embodiment, the inner edge of the outer end ring away from the inner end ring is provided with a plurality of first friction grooves.

[0013] In the preferred embodiment, the outer edge of the inner end ring away from the outer end ring is provided with multiple second friction grooves.

[0014] The beneficial effects of this utility model are as follows: by reducing the installation gap between the bolt and the through hole of the flange of the machine head by using the filler sleeve, the relative sliding range between the blade and the flange is reduced, avoiding excessive misalignment that could cause one or a few connecting bolts to break due to excessive shear force; by adaptively filling the cavity space after the bolt is inserted with glue, when the blade misaligns after the glue solidifies, all bolts are stressed together, avoiding excessive stress on a single bolt; the through hole of the inner flange structure adopts a conical structure, which facilitates the demolding of the glue layer and makes it convenient for later maintenance and replacement of parts; the flange end of the filler sleeve adopts a spliced ​​structure, which facilitates the processing of each glue-filling hole. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Figure 1 This is a schematic diagram of the blade mating end.

[0017] Figure 2 This is a schematic diagram of the connection between the blade and the turbine head.

[0018] Figure 3 This is a schematic diagram of the through-hole extrusion sidewall bolts in a traditional installation structure.

[0019] Figure 4 This is a schematic diagram of the connection between the optimized blade structure and the turbine head.

[0020] Figure 5 This is a schematic diagram of the adhesive used to fill the cavity.

[0021] Figure 6 This is a structural diagram of the spliced ​​structure at the outer flange end of the filling sleeve.

[0022] Figure 7 It is a filled 3D model.

[0023] Figure 8 It is a decomposition of the filling sleeve. Figure 1 .

[0024] Figure 9 It is a decomposition of the filling sleeve. Figure 2 .

[0025] In the diagram: 1. Wind turbine blade; 101. Blade mating flange; 2. Blade mounting bolt; 201. Optical shaft positioning section; 202. Threaded section; 3. Head end; 301. Inner flange structure; 302. Through hole; 303. Inner conical surface; 4. Locking nut; 5. Filler sleeve; 501. Outer flange end; 502. Glue channel; 503. Positioning hole; 504. Ring tooth; 505. Outer end ring; 506. Inner end ring; 507. Inner side hole; 508. Transition groove; 509. Outer side hole; 510. Orientation groove; 511. Orientation protrusion; 512. Annular flange; 513. First friction groove; 514. Second friction groove; 6. Clamping cavity; 7. Filler adhesive layer. Detailed Implementation

[0026] like Figure 1-9 In a wind turbine blade connecting bolt cooperative force-bearing structure, there are multiple blade mounting bolts 2 arranged circumferentially along the blade mating flange 101. The turbine head end 3 is provided with an inner flange structure 301. The inner flange structure 301 is provided with multiple through holes 302 circumferentially. The blade mounting bolts 2 are provided with protruding ends. The protruding ends of the blade mounting bolts 2 include a shaft positioning section 201 and a threaded section 202. The threaded section 202 is inserted into the through hole 302. A filler sleeve 5 is sleeved on the outside of the shaft positioning section 201. A clamping cavity 6 is provided between the filler sleeve 5 and the inner wall of the through hole 302. One end of the ring tooth 504 is provided with an outer flange end 501. The outer flange end 501 is provided with a glue-filling channel 502 aligned with the clamping cavity 6. The clamping cavity 6 is provided with a filling glue layer 7. The threaded section 202 passes through the through hole 302. A threaded locking nut 4 is sleeved on the through hole 302. One end of the locking nut 4 abuts against the outer flange end 501.

[0027] Through precision machining, the inner hole of the filler sleeve 5 is made to be similar in diameter to the optical axis positioning section 201 of the blade mounting bolt 2, leaving only a small assembly gap.

[0028] Blade mounting bolts 2 are prefabricated on the wind turbine blades 1 or installed on the wind turbine blades 1 by thread.

[0029] In traditional wind turbine installation, the blades are lifted laterally and aligned with the through holes 302. Because alignment is difficult during lifting, the diameter of the through holes 302 needs to be larger than the outer diameter of the blade mounting bolts 2 to facilitate bolt insertion. After each blade mounting bolt 2 is inserted into its respective through hole 302, the wind turbine blade 1 is locked to the inner flange structure 301 at the turbine head end 3 using lock nuts 4. Due to machining and assembly errors, it is impossible for all blade mounting bolts 2 to be concentric with the through holes 302. After prolonged wind turbine operation, the blades experience slight slippage due to wind force and vibration. Some blade mounting bolts 2 that are significantly eccentric to the through holes 302 first come into contact with the inner wall of the through holes 302. Since most blade mounting bolts 2 do not contact the inner wall of the through holes 302, these few bolts are subjected to significant lateral shear force and break under frequent vibration and wind-induced blade deformation.

[0030] To improve this situation, the blade mounting bolt 2 and its connection structure were optimized. During installation, a filler sleeve 5 with an outer flange end 501 is fitted onto the outer side of the optical axis positioning section 201 of the blade mounting bolt 2 in the through hole 302. The filler sleeve 5 is fitted onto the blade mounting bolt 2 from the inner side of the inner flange structure 301 and inserted into the through hole 302. Since the locking nut 4 can easily block the entrance of the glue channel 502, it is necessary to tighten half of the locking nut 4 at intervals to pre-tighten the fan blade 1, and then fill the remaining cavity 6 without the locking nut 4 with glue. After it solidifies, tighten the locking nut 4 at that location, remove the other half of the locking nut 4, fill the cavity 6 with glue, and finally tighten the remaining locking nut 4.

[0031] Each filler sleeve 5 is provided with two glue-filling channels 502. Before filling the glue, rotate the line connecting the two glue-filling channels 502 to be vertical. Fill the cavity 6 with glue from the lower glue-filling channel 502. After the glue fills the cavity 6, observe that the glue overflows from the upper glue-filling channel 502 and stop filling the glue.

[0032] In a preferred embodiment, the outer flange end 501 includes an outer end ring 505 and an inner end ring 506 that fit together. The inner end ring 506 is provided with an inner hole 507 near the positioning hole 503. The outer end ring 505 is provided with an outer hole 509 near the outer edge of the outer end ring 505. The outer end ring 505 is provided with a radial transition groove 508 on the side near the inner end ring 506. The transition groove 508 connects the inner hole 507 and the outer hole 509.

[0033] The outer hole 509, the transition groove 508 and the inner hole 507 together form the glue-pouring channel 502.

[0034] Since the outer hole 509 is located at the outer edge, the locking nut 4 will not block the outer hole 509 during installation. Therefore, after the fan blade 1 is connected to the blade mounting bolt 2, all locking nuts 4 can be locked directly without having to disassemble and reassemble the locking nuts 4 multiple times to complete the glue injection operation of all clamping cavities 6.

[0035] In a preferred embodiment, the inner end ring 506 is provided with a directional groove 510, and the outer end ring 505 is provided with a directional protrusion 511, which is engaged in the directional groove 510.

[0036] Both the outer end ring 505 and the inner end ring 506 have through holes in the center to form a positioning hole 503. The optical axis positioning section 201 is inserted into the two through holes to make the outer end ring 505 and the inner end ring 506 concentric. The directional groove 510 is inserted into the directional protrusion 511 so that the outer end ring 505 will not rotate relative to the inner end ring 506, so that the inner hole 507 is aligned with the transition groove 508.

[0037] In a preferred embodiment, an annular flange 512 is provided on the side of the outer end ring 505 away from the inner end ring 506, and the outer hole 509 is located outside the annular flange 512.

[0038] The inner area of ​​the annular flange 512 is the installation area of ​​the locking nut 4, which prevents glue from overflowing onto the locking nut 4 when the glue is injected into the outer hole 509, thus preventing the locking nut 4 from sticking.

[0039] In the preferred embodiment, the inner wall of the through hole 302 is provided with an inner conical surface 303, and the outer wall of the filling sleeve 5 is provided with a concave-convex structure.

[0040] In a preferred embodiment, the concave-convex structure of the outer wall of the filling sleeve 5 is a spiral protrusion or a spiral groove.

[0041] In the preferred embodiment, the concave-convex structure of the outer wall of the filling sleeve 5 is a ring tooth 504.

[0042] Before applying the adhesive, a release agent needs to be applied to the inner conical surface 303. After the adhesive solidifies, it engages with the concave-convex structure on the outer wall of the filler sleeve 5. When it is necessary to replace the blade mounting bolt 2 or the filler sleeve 5, loosen the locking nut 4 and pull out the outer flange end 501 to easily separate the filler adhesive layer 7 from the through hole 302. This avoids the blade mounting bolt 2 becoming connected to the through hole 302 once the adhesive is applied, making maintenance and replacement difficult.

[0043] In a preferred embodiment, the outer end ring 505 has a plurality of first friction grooves 513 on the inner edge of the side away from the inner end ring 506.

[0044] In a preferred embodiment, the inner end ring 506 has a plurality of second friction grooves 514 on the outer edge of the side away from the outer end ring 505.

[0045] When the locking nut 4 is tightened, it squeezes the outer end ring 505 and the inner end ring 506. The locking nut 4 abuts against the first friction groove 513, and the second friction groove 514 contacts the inner flange structure 301, which plays an anti-slip role and improves the anti-loosening ability of the locking nut 4 after it is connected to the blade mounting bolt 2.

[0046] The above embodiments are merely preferred technical solutions of this utility model and should not be considered as limitations on this utility model. The protection scope of this utility model should be the technical solution described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the protection scope of this utility model.

Claims

1. A wind turbine blade connecting bolt cooperative stress-bearing structure, characterized in that: The device includes multiple blade mounting bolts (2) arranged circumferentially along the blade mating flange (101). The head end (3) is provided with an inner flange structure (301). The inner flange structure (301) is provided with multiple through holes (302) circumferentially. The blade mounting bolts (2) are provided with protruding ends. The protruding ends of the blade mounting bolts (2) include an optical axis positioning section (201) and a threaded section (202). The threaded section (202) is inserted into the through hole (302). A filler sleeve is fitted on the outside of the optical axis positioning section (201). (5) A clamping cavity (6) is provided between the filling sleeve (5) and the inner wall of the through hole (302). One end of the ring tooth (504) is provided with an outer flange end (501). The outer flange end (501) is provided with a glue-filling channel (502) aligned with the clamping cavity (6). The clamping cavity (6) is provided with a filling glue layer (7). The threaded section (202) passes through the through hole (302). A threaded locking nut (4) is fitted on the through hole (302). One end of the locking nut (4) abuts against the outer flange end (501).

2. The wind turbine blade connecting bolt cooperative force-bearing structure according to claim 1, characterized in that: The outer flange end (501) includes an outer end ring (505) and an inner end ring (506) that fit together. The inner end ring (506) has an inner hole (507) near the positioning hole (503). The outer end ring (505) has an outer hole (509) near the outer edge of the outer end ring (505). The outer end ring (505) has a radial transition groove (508) on the side near the inner end ring (506). The transition groove (508) connects the inner hole (507) and the outer hole (509).

3. The wind turbine blade connecting bolt cooperative force-bearing structure according to claim 2, characterized in that: The inner end ring (506) is provided with a directional groove (510), and the outer end ring (505) is provided with a directional protrusion (511), which is inserted into the directional groove (510).

4. The wind turbine blade connecting bolt cooperative force-bearing structure according to claim 2, characterized in that: An annular flange (512) is provided on the side of the outer end ring (505) away from the inner end ring (506), and the outer hole (509) is located outside the annular flange (512).

5. The wind turbine blade connecting bolt cooperative force-bearing structure according to claim 1, characterized in that: The inner wall of the through hole (302) is provided with an inner conical surface (303), and the outer wall of the filling sleeve (5) is provided with a concave-convex structure.

6. The wind turbine blade connecting bolt cooperative stress-bearing structure according to claim 5, characterized in that: The outer wall of the filling sleeve (5) has a spiral protrusion or a spiral groove.

7. The wind turbine blade connecting bolt cooperative force-bearing structure according to claim 5, characterized in that: The concave-convex structure of the outer wall of the filler sleeve (5) is a ring tooth (504).

8. The wind turbine blade connecting bolt cooperative force-bearing structure according to claim 2, characterized in that: The outer end ring (505) has multiple first friction grooves (513) on the inner edge of the side away from the inner end ring (506).

9. The wind turbine blade connecting bolt cooperative force-bearing structure according to claim 2, characterized in that: The inner end ring (506) has multiple second friction grooves (514) on the outer edge of the side away from the outer end ring (505).

Images