High-strength bolt for connecting wind turbine generator variable pitch bearing and installation method

Abstract

The application discloses a high-strength bolt for connecting a variable-pitch bearing of a wind turbine generator and a mounting method, which comprises a bolt body, a placing hole is arranged at the top of the bolt body, two clamping grooves are arranged at the top end of the placing hole, a plurality of through holes one are equidistantly arranged on the outer wall of the placing hole, a hollow cylinder is slidably connected to the inner wall of the placing hole, two protrusions are symmetrically and fixedly connected to the top end of the hollow cylinder and are in clearance fit with the clamping grooves, a plurality of impact balls are arranged in the hollow cylinder, an elastic rope is fixedly connected between every two adjacent impact balls, the uppermost impact ball is fixedly connected with a fixing column through the elastic rope, and the fixing column is fixedly connected to the inner wall of the hollow cylinder. The anticorrosive agent can be applied on the inner wall of the bolt hole of the variable-pitch bearing through the through hole one on the bolt body to form an anticorrosion layer, so that the pitting corrosion is prevented, the cracks caused by the pitting corrosion are avoided, and the fatigue fracture of the variable-pitch bearing is prevented.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and in particular to a high-strength bolt for connecting the pitch bearing of a wind turbine and its installation method. Background Technology

[0002] In wind turbines, the pitch bearing, also known as the blade bearing, is a crucial component. It connects the rotor hub and rotor blades. The bearing allows for the necessary oscillations to control the wind turbine's load and power. The pitch system adjusts the aerodynamic angle of attack to bring the blades to the desired position. The pitch system is also used for emergency shutdowns of the turbine system.

[0003] Chinese patent application number CN202122592310.5 discloses a pitch bearing bolt connection system for a wind turbine generator set, including a hub, blades, a pitch bearing, a stud, a sleeve, and a custom nut. The hub is connected to the inner ring of the pitch bearing via a flange, and the blade root is connected to the outer ring of the pitch bearing. The hub has a first threaded hole, and the pitch bearing has a second mounting hole. One end of the stud is screwed into the first threaded hole, and the other end of the stud passes through the second mounting hole and the sleeve and is secured by the custom nut. The sleeve is fitted onto the stud, and the outer diameter of the sleeve is larger than the diameter of the second mounting hole. This invention can improve the fatigue characteristics of the pitch bearing bolt connection system and has a thread anti-loosening function, achieving the goal of less maintenance or even no maintenance, improving the reliability of the pitch bearing bolt connection system, and ensuring the safe operation of the unit. When the pitch bearing is fixed and running, the bolts are easily affected by external impact, vibration, high temperature, and various complex stresses. The bolt connection may loosen or separate, which will allow various corrosive media in the external environment to easily enter the bolt hole, causing pitting corrosion, easily initiating fatigue cracks, and crack propagation leading to fatigue fracture.

[0004] In view of this, the present invention proposes a high-strength bolt for connecting the pitch bearing of a wind turbine and an installation method thereof, in order to solve the problems existing in the prior art. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-strength bolt for connecting the pitch bearing of a wind turbine and its installation method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A high-strength bolt for connecting the pitch bearing of a wind turbine includes a bolt body, a placement hole at the top of the bolt body, two locking grooves at the top of the placement hole, multiple through holes equidistantly arranged on the outer wall of the placement hole, and a hollow cylinder slidably connected to the inner wall of the placement hole. Two protrusions are symmetrically fixedly connected to the top of the hollow cylinder, and the protrusions are clearance-fitted with the locking grooves. Multiple impact balls are arranged inside the hollow cylinder, and an elastic rope is fixedly connected between adjacent impact balls. The uppermost impact ball is fixedly connected to a fixing post by the elastic rope, and the fixing post is fixedly connected to the inner wall of the hollow cylinder. The lowermost impact ball is connected to the bottom inner wall of the hollow cylinder by the elastic rope. Multiple sliding grooves are equidistantly arranged on the outside of each impact ball, and a through hole 2 is arranged on one side of each sliding groove. An anti-corrosion agent spraying mechanism is arranged inside each sliding groove. When the bottom end of the hollow cylinder is close to the bottom inner wall of the placement hole, the axis of the through hole 2 coincides with the axis of the corresponding through hole 1, and the through hole 1 is funnel-shaped, with the narrow opening of the funnel-shaped through hole 1 close to the through hole 2.

[0008] Furthermore, the corrosion inhibitor spraying mechanism includes a slide plate, which is slidably connected to the inner wall of the sliding groove, and two spring plates are provided between the slide plate and the inner wall of the sliding groove. A storage air bladder is provided on the outer wall of the slide plate near the impact ball, and the storage air bladder contains corrosion inhibitor.

[0009] Furthermore, a discharge pipe is provided on one side of the storage airbag, and the discharge pipe is connected to the discharge end of the storage airbag. One end of the discharge pipe extends into the through hole two, and the one end of the discharge pipe is close to the outlet end of the through hole two.

[0010] Furthermore, a sealing plug is provided at the top of the hollow cylinder, and an installation plate is fixedly connected to the outer wall of the top of the sealing plug, and L-shaped plates are fixedly connected to the outer walls on both sides of the installation plate.

[0011] Furthermore, the bolt body has fixing grooves on both sides of the top end, and fixing holes are provided on the inner walls of both ends of the fixing grooves. The fixing grooves are clearance-fitted with the lower end of the L-shaped plate.

[0012] Furthermore, each of the L-shaped plates has a receiving groove at its lower end, and a locking block is slidably connected to both sides of the receiving groove. The two locking blocks are fitted with the fixing holes with a clearance, and two connecting springs are fixedly connected between the outer walls of the two locking blocks on opposite sides.

[0013] Furthermore, a threaded rod is fixedly connected to the outer wall of the top of the mounting plate, and a threaded cylinder is screwed onto the outer wall of the threaded rod. A sealing cover is fixedly connected to the top of the threaded cylinder, and a sliding cavity is provided at the bottom of the sealing cover.

[0014] Furthermore, a telescopic cover is slidably connected to the bottom of the sliding cavity, and a lifting disc is fixedly connected to the top of the telescopic cover. The lifting disc is slidably connected to the inner wall of the sliding cavity, and multiple connecting springs are fixedly connected between the lifting disc and the sliding cavity.

[0015] Furthermore, a rotating shaft is rotatably connected to the middle of the receiving groove, and one end of the rotating shaft extends out of the receiving groove to the outside of the L-shaped plate. Two traction ropes are fixedly connected between the locking block and the rotating shaft. A turntable is fixedly connected to one end of the rotating shaft outside the L-shaped plate, and multiple rotating plates are fixedly connected at equal intervals on the outer wall of the turntable.

[0016] An installation method for high-strength bolts used to connect the pitch bearings of wind turbine generators includes the following steps:

[0017] S1: First, insert each hollow cylinder into the placement hole of the bolt body, then insert the sealing plug into the hollow cylinder, and at the same time, insert the L-shaped plate into the fixing groove at the top of the bolt body to fix the hollow cylinder.

[0018] S2: Insert multiple bolt bodies into the bolt holes of each pitch bearing in sequence, then tighten the four bolt bodies located at 0°, 180°, 90°, and 270° on the pitch bearing in sequence, and then tighten the four bolt bodies located at 45°, 225°, 135°, and 315° in sequence. Repeat this process, tightening the bolt bodies located in the middle between the bolt bodies adjacent to the bolt bodies at 0°, 180°, 90°, and 270° on the pitch bearing in sequence.

[0019] S3: Next, align the threaded cylinder inside the sealing cover with the threaded rod on the mounting plate, and then screw the threaded cylinder into the threaded rod until the telescopic cover at the bottom of the sealing cover is tightly against the outer wall of the pitch bearing.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. By setting up impact balls and corrosion inhibitor spraying mechanism, the impact balls inside the hollow cylinder inside the bolt body will shake when the pitch bearing is working. When the impact balls vibrate, they can hit the corrosion inhibitor spraying mechanism, causing the corrosion inhibitor contained therein to be sprayed out. Thus, the corrosion inhibitor is applied to the inner wall of the bolt hole of the pitch bearing through the through hole on the bolt body to form an anti-corrosion layer, preventing pitting corrosion and avoiding cracks caused by pitting corrosion, thereby preventing fatigue fracture of the pitch bearing.

[0022] 2. By setting up a sealing cover and a telescopic cover, after the bolt body fixes the pitch bearing, the sealing cover and telescopic cover are fixed to the top of the bolt body, thereby sealing and protecting the top of the bolt body. This can prevent corrosive media such as oxygen, sulfur, and chlorine in the environment from corroding the bolt body, and at the same time prevent corrosive media from entering the bolt hole and causing pitting corrosion.

[0023] 3. By setting a rotating shaft, the traction rope can be wound around its outer wall, thereby allowing the locking blocks on both sides of the receiving groove to enter the receiving groove, enabling quick removal of the sealing plug, thus allowing the hollow cylinder to be taken out for easy replacement of the anti-corrosion agent during maintenance. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a high-strength bolt for connecting the pitch bearing of a wind turbine, as proposed in Example 1.

[0025] Figure 2 This is a schematic diagram of the bolt body structure of a high-strength bolt for connecting the pitch bearing of a wind turbine, as proposed in Example 1.

[0026] Figure 3 This is a schematic diagram of a sealing plug structure for connecting a high-strength bolt to a wind turbine pitch bearing, as proposed in Example 1.

[0027] Figure 4 This is a schematic diagram of the cross-sectional structure of an L-shaped plate for connecting a high-strength bolt to a wind turbine pitch bearing, as proposed in Example 1.

[0028] Figure 5 This is a schematic diagram of the cross-sectional structure of a high-strength bolt for connecting the pitch bearing of a wind turbine, as proposed in Example 1.

[0029] Figure 6 This refers to a high-strength bolt for connecting the pitch bearing of a wind turbine, as proposed in Example 1. Figure 5 Enlarged schematic diagram of the structure at point A in the middle;

[0030] Figure 7 This is a schematic diagram of the external structure of a mounting plate for connecting the pitch bearing of a wind turbine, as proposed in Example 2.

[0031] Figure 8 This is a schematic diagram of the cross-sectional structure of a receiving groove for a high-strength bolt used to connect the pitch bearing of a wind turbine, as proposed in Example 3.

[0032] In the diagram: 1. Bolt body; 2. Through hole one; 3. Protrusion; 4. Mounting plate; 5. Locking groove; 6. Placement hole; 7. Fixing hole; 8. Fixing groove; 9. Sealing plug; 10. L-shaped plate; 11. Receiving groove; 12. Locking block; 13. Connecting spring one; 14. Hollow cylinder; 15. Fixing column; 16. Elastic rope; 17. Impact ball; 18. Spring plate; 19. Discharge pipe; 20. Through hole two; 21. Sliding groove; 22. Slide plate; 23. Storage airbag; 24. Telescopic cover; 25. Lifting disc; 26. Sliding cavity; 27. Connecting spring two; 28. Sealing cover; 29. ​​Threaded cylinder; 30. Threaded rod; 31. Rotating plate; 32. Traction rope; 33. Rotating shaft; 34. Turntable. Detailed Implementation

[0033] The technical solution of this patent will be further described in detail below with reference to specific embodiments.

[0034] Example 1:

[0035] Reference Figures 1-6 A high-strength bolt for connecting the pitch bearing of a wind turbine and its installation method are disclosed. The bolt body 1 has a placement hole 6 at its top, and two locking grooves 5 at the top of the placement hole 6. Multiple through holes 2 are evenly spaced on the outer wall of the placement hole 6. A hollow cylinder 14 is slidably connected to the inner wall of the placement hole 6. Two protrusions 3 are symmetrically fixedly connected to the top of the hollow cylinder 14, and the protrusions 3 are clearance-fitted with the locking grooves 5. Multiple impact balls 17 are disposed inside the hollow cylinder 14, and a spring is fixedly connected between each adjacent impact ball 17. The uppermost impact ball 17 is fixedly connected to a fixed post 15 via an elastic rope 16, and the fixed post 15 is fixedly connected to the inner wall of the hollow cylinder 14. The lowermost impact ball 17 is connected to the bottom inner wall of the hollow cylinder 14 via an elastic rope 16. Multiple sliding grooves 21 are evenly spaced on the outside of each impact ball 17, and each sliding groove 21 has a through hole 20 on one side. An anti-corrosion agent spraying mechanism is installed inside each sliding groove 21. When the bottom end of the hollow cylinder 14 is tightly pressed against the bottom inner wall of the placement hole 6, the through hole 20 and the corresponding... The axes of through holes 1 and 2 coincide, and through holes 1 and 2 are funnel-shaped. The narrow opening of the funnel-shaped through hole 1 and 2 is close to through hole 20. The pitch bearing is fixed by multiple bolt bodies 1. When the pitch bearing is working after fixing, the bolt bodies 1 are subjected to various complex stresses such as tension, compression, torsion and shear. This will cause multiple impact balls 17 in the hollow cylinder 14 inside each bolt body 1 to shake. Each impact ball 17 will hit the corrosion inhibitor spraying mechanism when it shakes. When the impact force is large enough, the corrosion inhibitor spraying mechanism will spray out the corrosion inhibitor. The corrosion inhibitor enters the through hole 2 of the bolt body 1. Because the through hole 2 is funnel-shaped and its narrow opening is close to the through hole 20, part of the sprayed corrosion inhibitor will directly reach the inner wall of the bolt hole, while the other part will flow through the through hole 2 to the outer wall of the bolt body 1. Through the contact between the bolt body 1 and the inner wall of the bolt hole, the corrosion inhibitor can be coated on the inner wall of the bolt hole of the pitch bearing to form an anti-corrosion layer, preventing pitting corrosion and avoiding cracks caused by pitting corrosion, thereby preventing fatigue fracture of the pitch bearing.

[0036] As a further embodiment of the present invention, the corrosion inhibitor spraying mechanism includes a slide plate 22, which is slidably connected to the inner wall of the sliding groove 21. Two spring plates 18 are provided between the slide plate 22 and the inner wall of the sliding groove 21. A storage air bladder 23 is provided on the outer wall of the slide plate 22 near the impact ball 17, and the storage air bladder 23 contains corrosion inhibitor. When the impact ball 17 shakes too much, the impact ball 17 will impact the storage air bladder 23, and at the same time, the slide plate 22 will be subjected to force. When the slide plate 22 is subjected to force, it will compress the spring plates 18 and move them toward the through hole 20.

[0037] As a further embodiment of the present invention, a discharge pipe 19 is provided on one side of the storage airbag 23, and the discharge pipe 19 is connected to the discharge end of the storage airbag 23. One end of the discharge pipe 19 extends into the through hole 20, and one end of the discharge pipe 19 is close to the outlet end of the through hole 20. Thus, when an impact occurs, one end of the discharge pipe 19 will enter the through hole 2 through the through hole 20. When the storage airbag 23 is impacted, the storage airbag 23 is subjected to pressure, and the corrosion inhibitor inside it will be sprayed out through the discharge pipe 19.

[0038] As a further embodiment of the present invention, a sealing plug 9 is provided at the top of the hollow cylinder 14, and an installation plate 4 is fixedly connected to the top outer wall of the sealing plug 9. L-shaped plates 10 are fixedly connected to the outer walls on both sides of the installation plate 4, and the sealing plug 9 is inserted into the top of the hollow cylinder 14.

[0039] As a further embodiment of the present invention, a fixing groove 8 is provided on both sides of the top end of the bolt body 1, and a fixing hole 7 is provided on the inner wall of both ends of the fixing groove 8. The fixing groove 8 is fitted with the lower end of the L-shaped plate 10 with a clearance, and at the same time, the L-shaped plates 10 on both sides of the mounting plate 4 on the sealing plug 9 are aligned with the two fixing grooves 8 of the bolt body 1.

[0040] As a further embodiment of the present invention, each of the lower ends of the L-shaped plate 10 is provided with a receiving groove 11, and each side of the receiving groove 11 is slidably connected with a locking block 12. The two locking blocks 12 are clearance-fitted with the fixing hole 7, and two connecting springs 13 are fixedly connected between the outer walls of the two locking blocks 12 on opposite sides. Then, the two locking blocks 12 at the lower end of the L-shaped plate 10 are pressed so that the L-shaped plate 10 can be embedded into the fixing groove 8. When the L-shaped plate 10 moves a certain distance in the fixing groove 8, under the elastic force of the connecting springs 13, the locking blocks 12 are embedded into the fixing holes 7 on the inner wall of the fixing groove 8, thereby completing the fixing of the sealing plug 9. At the same time as fixing the sealing plug 9, the hollow cylinder 14 can be fixed so that its bottom is tightly attached to the inner wall of the bolt body 1 placement hole 6.

[0041] Working principle: The pitch bearing is fixed by multiple bolt bodies 1. When the pitch bearing is working after fixing, the bolt bodies 1 are subjected to various complex stresses such as tension, compression, torsion and shear. This causes multiple impact balls 17 in the hollow cylinder 14 inside each bolt body 1 to shake. When the shaking of the impact balls 17 is too large, the impact balls 17 will impact the storage air bladder 23, and at the same time, the slide plate 22 will be subjected to force. When the slide plate 22 is subjected to force, it will compress the spring plate 18 and move it towards the second through hole 20. Because one end of the discharge pipe 19 is close to the outlet end of the second through hole 20, when the impact occurs, one end of the discharge pipe 19 will enter the first through hole 2 through the second through hole 20, and the impact balls 17 will impact the storage air bladder. At 23:00, the storage airbag 23 is pressurized, causing the corrosion inhibitor inside to be sprayed out through the discharge pipe 19. When the impact force is large enough, the corrosion inhibitor spraying mechanism will spray the corrosion inhibitor into the through hole 2 of the bolt body 1. Because the through hole 2 is funnel-shaped and the narrow opening of the funnel-shaped through hole 2 is close to the through hole 20, part of the sprayed corrosion inhibitor will directly reach the inner wall of the bolt hole, and the other part will flow through the through hole 2 to the outer wall of the bolt body 1. Thus, through the contact between the bolt body 1 and the inner wall of the bolt hole, the corrosion inhibitor can be coated on the inner wall of the bolt hole of the pitch bearing to form an anti-corrosion layer, preventing pitting corrosion and avoiding cracks caused by pitting corrosion, thereby preventing fatigue fracture of the pitch bearing.

[0042] Example 2:

[0043] Reference Figures 1-7 A high-strength bolt for connecting the pitch bearing of a wind turbine and its installation method are disclosed. Compared with Embodiment 1, based on Embodiment 1, a threaded rod 30 is fixedly connected to the top outer wall of the mounting plate 4, and a threaded cylinder 29 is screwed onto the outer wall of the threaded rod 30. A sealing cover 28 is fixedly connected to the top of the threaded cylinder 29, and a sliding cavity 26 is provided at the bottom end of the sealing cover 28. Before fixing the sealing plug 9, the threaded cylinder 29 screwed onto the top threaded rod 30 is removed. After the sealing plug 9 is fixed, the threaded cylinder 29 inside the sealing cover 28 is aligned with the threaded rod 30, and then the sealing cover 28 is rotated so that the threaded cylinder 29 can be screwed onto the threaded rod 30.

[0044] As a further embodiment of the present invention, a telescopic cover 24 is slidably connected to the bottom of the sliding cavity 26, and a lifting disc 25 is fixedly connected to the top of the telescopic cover 24. The lifting disc 25 is slidably connected to the inner wall of the sliding cavity 26, and multiple connecting springs 27 are fixedly connected between the lifting disc 25 and the sliding cavity 26. During the engagement process, the threaded cylinder 29 moves downward with the telescopic cover 24. When the bottom end of the telescopic cover 24 contacts the outer wall of the pitch bearing, the threaded cylinder 29 continues to rotate to make it continue to move downward. During this process, the telescopic cover 24 is subjected to pressure, so that more and more of the telescopic cover 24 enters the sliding cavity 26. At the same time, the multiple connecting springs 27 are compressed. When the threaded cylinder 29 is tightly engaged on the threaded rod 30, under the elastic force of the multiple connecting springs 27, the bottom end of the telescopic cover 24 is pressed tightly against the outer wall of the pitch bearing, thereby sealing and protecting the top end of the bolt body 1. This can prevent corrosive media such as oxygen, sulfur, and chlorine in the environment from corroding the bolt body 1, and at the same time prevent corrosive media from entering the bolt hole of the pitch bearing and causing pitting corrosion.

[0045] Working principle: Before fixing the sealing plug 9, remove the threaded cylinder 29 screwed onto the threaded rod 30 at its top. After the sealing plug 9 is fixed, align the threaded cylinder 29 inside the sealing cover 28 with the threaded rod 30, and then rotate the sealing cover 28 to screw the threaded cylinder 29 onto the threaded rod 30. During the screwing process, the threaded cylinder 29 moves downward with the telescopic cover 24. When the bottom end of the telescopic cover 24 contacts the outer wall of the pitch bearing, continue to rotate the threaded cylinder 29 to make it continue to move downward. During this process, the telescopic cover 24 is under pressure, so more and more of the telescopic cover 24 enters the sliding cavity 26. At the same time, multiple connecting springs 27 are compressed. When the threaded cylinder 29 is tightly screwed onto the threaded rod 30, under the elastic force of the multiple connecting springs 27, the bottom end of the telescopic cover 24 is pressed tightly against the outer wall of the pitch bearing, thereby sealing and protecting the top end of the bolt body 1. This can prevent corrosive media such as oxygen, sulfur, and chlorine in the environment from corroding the bolt body 1, and at the same time prevent corrosive media from entering the bolt hole of the pitch bearing and causing pitting corrosion.

[0046] Example 3:

[0047] Reference Figures 1-8 A high-strength bolt for connecting the pitch bearing of a wind turbine and its installation method, compared with Embodiment 2, is provided with a rotating shaft 33 rotatably connected in the middle of the receiving groove 11, and one end of the rotating shaft 33 extends out of the receiving groove 11 to the outside of the L-shaped plate 10. Two traction ropes 32 are fixedly connected between the locking block 12 and the rotating shaft 33. One end of the rotating shaft 33 outside the L-shaped plate 10 is fixedly connected to a turntable 34, and multiple rotating plates 31 are fixedly connected at equal intervals on the outer wall of the turntable 34.

[0048] An installation method for high-strength bolts used to connect the pitch bearings of wind turbine generators includes the following steps:

[0049] S1: First, insert each hollow cylinder 14 into the placement hole 6 of the bolt body 1, then insert the sealing plug 9 into the hollow cylinder 14, and at the same time, insert the L-shaped plate 10 into the fixing groove 8 at the top of the bolt body 1 to fix the hollow cylinder 14.

[0050] S2: Insert multiple bolt bodies 1 into the bolt holes of each pitch bearing in sequence, then tighten the four bolt bodies 1 located at 0°, 180°, 90°, and 270° on the pitch bearing in sequence, and then tighten the four bolt bodies 1 located at 45°, 225°, 135°, and 315° in sequence. Repeat this process to tighten the bolt bodies 1 located in the middle between the bolt bodies 1 adjacent to the bolt bodies 1 at 0°, 180°, 90°, and 270° on the pitch bearing in sequence.

[0051] S3: Next, align the threaded cylinder 29 inside the sealing cover 28 with the threaded rod 30 on the mounting plate 4, and then screw the threaded cylinder 29 into the threaded rod 30 until the telescopic cover 24 at the bottom of the sealing cover 28 is tightly against the outer wall of the pitch bearing.

[0052] Working principle: When maintaining the bolt body 1, the staff first removes the sealing cover 28 on the bolt body 1 that needs maintenance. Then, the rotating plate 31 on the turntable 34 rotates the shaft 33, which allows the traction rope 32 to be wound around its outer wall, so that the locking blocks 12 on both sides of the receiving groove 11 enter the receiving groove 11, which can quickly remove the sealing plug 9, thereby allowing the hollow cylinder 14 to be taken out, which is convenient for replacing the anti-corrosion agent during maintenance.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-strength bolt for connecting the pitch bearing of a wind turbine, comprising a bolt body (1), characterized in that, The bolt body (1) has a placement hole (6) at the top, and two locking grooves (5) at the top of the placement hole (6). Multiple through holes (2) are provided at equal intervals on the outer wall of the placement hole (6), and a hollow cylinder (14) is slidably connected to the inner wall of the placement hole (6). Two protrusions (3) are symmetrically fixedly connected to the top of the hollow cylinder (14), and the protrusions (3) are clearance-fitted with the locking grooves (5). Multiple impact balls (17) are provided inside the hollow cylinder (14), and an elastic rope (16) is fixedly connected between two adjacent impact balls (17). The uppermost impact ball (17) is fixedly connected to a fixing post (15) by the elastic rope (16), and the fixed post is fixedly connected to the uppermost impact ball (17). The fixed column (15) is fixedly connected to the inner wall of the hollow cylinder (14). The impact ball (17) located at the bottom is connected to the bottom inner wall of the hollow cylinder (14) through the elastic rope (16). Each impact ball (17) has multiple sliding grooves (21) at equal distances on the outside. Each sliding groove (21) has a through hole two (20) on one side. Each sliding groove (21) has a corrosion inhibitor spraying mechanism inside. When the bottom end of the hollow cylinder (14) is close to the bottom inner wall of the placement hole (6), the axis of the through hole two (20) coincides with the axis of the corresponding through hole one (2). The through hole one (2) is trumpet-shaped. The narrow opening of the trumpet-shaped through hole one (2) is close to the through hole two (20).

2. The high-strength bolt for connecting the pitch bearing of a wind turbine as described in claim 1, characterized in that, The corrosion inhibitor spraying mechanism includes a slide plate (22), which is slidably connected to the inner wall of the sliding groove (21). Two spring plates (18) are provided between the slide plate (22) and the inner wall of the sliding groove (21). A storage airbag (23) is provided on the outer wall of the slide plate (22) near the impact ball (17), and the storage airbag (23) contains corrosion inhibitor.

3. A high-strength bolt for connecting the pitch bearing of a wind turbine as described in claim 2, characterized in that, Each of the storage airbags (23) is provided with a discharge pipe (19) on one side, and the discharge pipe (19) is connected to the discharge end of the storage airbag (23). One end of the discharge pipe (19) extends into the through hole two (20), and one end of the discharge pipe (19) is close to the outlet end of the through hole two (20).

4. A high-strength bolt for connecting the pitch bearing of a wind turbine as described in claim 3, characterized in that, The top of the hollow cylinder (14) is provided with a sealing plug (9), and the outer wall of the top of the sealing plug (9) is fixedly connected with an installation plate (4), and the outer walls on both sides of the installation plate (4) are fixedly connected with L-shaped plates (10).

5. A high-strength bolt for connecting the pitch bearing of a wind turbine as described in claim 4, characterized in that, The bolt body (1) has a fixing groove (8) on both sides of the top end, and a fixing hole (7) is provided on the inner wall of both ends of the fixing groove (8). The fixing groove (8) is clearance-fitted with the lower end of the L-shaped plate (10).

6. A high-strength bolt for connecting the pitch bearing of a wind turbine as described in claim 5, characterized in that, The lower end of the L-shaped plate (10) is provided with a receiving groove (11), and a locking block (12) is slidably connected on both sides of the receiving groove (11). The two locking blocks (12) are fitted with the fixing hole (7) with a clearance, and two connecting springs (13) are fixedly connected between the outer walls of the two locking blocks (12) on opposite sides.

7. A high-strength bolt for connecting the pitch bearing of a wind turbine as described in claim 6, characterized in that, The mounting plate (4) is fixedly connected to the top outer wall of a threaded rod (30), and a threaded cylinder (29) is screwed onto the outer wall of the threaded rod (30). A sealing cover (28) is fixedly connected to the top of the threaded cylinder (29), and a sliding cavity (26) is provided at the bottom of the sealing cover (28).

8. A high-strength bolt for connecting the pitch bearing of a wind turbine as described in claim 7, characterized in that, The bottom of the sliding cavity (26) is slidably connected to a telescopic cover (24), and the top of the telescopic cover (24) is fixedly connected to a lifting disc (25). The lifting disc (25) is slidably connected to the inner wall of the sliding cavity (26), and multiple connecting springs (27) are fixedly connected between the lifting disc (25) and the sliding cavity (26).

9. A high-strength bolt for connecting the pitch bearing of a wind turbine as described in claim 6, characterized in that, A rotating shaft (33) is rotatably connected to the middle of the receiving groove (11), and one end of the rotating shaft (33) extends out of the receiving groove (11) to the outside of the L-shaped plate (10). Two traction ropes (32) are fixedly connected between the locking block (12) and the rotating shaft (33). A turntable (34) is fixedly connected to one end of the rotating shaft (33) outside the L-shaped plate (10), and multiple rotating plates (31) are fixedly connected at equal intervals on the outer wall of the turntable (34).

10. A method for installing high-strength bolts for connecting pitch bearings of wind turbine units according to any one of claims 1-9, characterized in that, Specifically, the following steps are included: S1: First, insert each hollow cylinder (14) into the placement hole (6) of the bolt body (1), then insert the sealing plug (9) into the hollow cylinder (14), and at the same time, insert the L-shaped plate (10) into the fixing groove (8) at the top of the bolt body (1) to fix the hollow cylinder (14); S2: Insert multiple bolt bodies (1) into the bolt holes of each pitch bearing in sequence, and then tighten the four bolt bodies (1) located at 0°, 180°, 90° and 270° on the pitch bearing in sequence. Then tighten the four bolt bodies (1) located at 45°, 225°, 135° and 315° in sequence. Repeat this process to tighten the bolt bodies (1) located in the middle between the bolt bodies (1) adjacent to the bolt bodies (1) at 0°, 180°, 90° and 270° on the pitch bearing in sequence. S3: Next, align the threaded cylinder (29) inside the sealing cover (28) with the threaded rod (30) on the mounting plate (4), and then screw the threaded cylinder (29) into the threaded rod (30) until the telescopic cover (24) at the bottom of the sealing cover (28) is in close contact with the outer wall of the pitch bearing.

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