Main shaft structure and method for prolonging service life of key area of rotor main shaft of wind turbine generator

Abstract

The invention relates to the technical field of wind power generation, in particular to a main shaft structure and method for prolonging the service life of a key area of a rotor main shaft of a wind turbine generator system, and the main shaft structure comprises a shaft body, and a fixed flange structure used for being connected with a mounting structure is formed at one end of the shaft body. The inner side flange wall extends from the shaft body to the inner side, and the outer side flange wall and the inner side flange wall are both provided with a plurality of connecting fasteners and connect the main shaft to a mounting structure. The structure of the shaft body is improved, a single-side stress structure is adjusted into a double-side stress structure, stress concentration at the flange structure on the shaft body is avoided, the stability and reliability of the structure of the shaft body are guaranteed, and the effective life of the shaft body can be prolonged in the actual use process.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and in particular to a spindle structure and method for improving the lifespan of key areas of the rotor spindle of a wind turbine. Background Technology

[0002] As wind turbine generators become larger, the load-bearing capacity of large-diameter rotors is increasing, including bending and torque. The rotor load is transferred to the rotor shaft through the hub at the center of the rotor. Currently, the shaft is connected and fixed via a flange structure, with fasteners only on the outer side of the flange. This single-sided fixing structure results in high stress in the bending area at the shaft connection, making it susceptible to damage. This shortens the shaft's lifespan, poses safety hazards to the unit's safe operation, and fails to meet design requirements.

[0003] It is evident that the current rotor spindle structure still has room for improvement and should be optimized to reduce the structural stress in the bending area at the external connection of the rotor spindle, thereby reducing the overall structural stress without compromising the structural strength of the rotor spindle and enabling it to operate stably and reliably for a long time after being put into practical use.

[0004] Therefore, it is necessary to propose more reasonable technical solutions to address the technical problems existing in the current technology. Summary of the Invention

[0005] The main objective of this invention is to provide a spindle structure and method for improving the lifespan of critical areas of the rotor spindle of a wind turbine. By improving the connection and fixing method of the rotor spindle, the structural stress it experiences is reduced, which can prevent the structure of the rotor spindle from being damaged under stress conditions, thereby improving the effective lifespan of the rotor spindle.

[0006] To achieve the above objectives, the spindle structure adopted in this invention is as follows: A main shaft structure for improving the lifespan of critical areas of the wind turbine rotor main shaft includes a shaft body. One end of the shaft body forms a fixed flange structure for connecting to the mounting structure. The fixed flange structure includes an outer flange wall extending outward from the moving shaft body and an inner flange wall extending inward from the shaft body. Both the outer flange wall and the inner flange wall are provided with several connecting fasteners to connect the main shaft to the mounting structure.

[0007] The aforementioned main shaft structure changes the stress structure of the shaft from unilateral to bilateral by altering the outer and inner flange walls at the fixed flange structure. This optimizes and improves the stress structure of the shaft, facilitating a longer service life and ensuring stable and reliable operation of the wind turbine.

[0008] Furthermore, the structures of the outer and inner flange walls can be constructed in various similar forms, and are not limited to a single one. Here, we optimize and propose one feasible option: both the outer and inner flange walls are continuously arranged annular rings, and the outer and inner flange walls are integrally formed with the shaft body. When the above scheme is adopted, the thickness of the outer and inner flange walls is the same.

[0009] Furthermore, various solutions can be adopted for external connection and fixation. Here, we optimize and propose one feasible option: several connection holes are formed on the outer flange wall and the inner flange wall, and the connecting fasteners are disposed at the connection holes. When adopting the above solution, the connection holes are evenly spaced circumferentially, and the diameter and number of the connection holes on the outer flange wall and the inner flange wall are the same.

[0010] Furthermore, in some designs, the connection holes on the outer flange wall and the inner flange wall are correspondingly arranged. Specifically, the connection holes on the outer flange wall and the inner flange wall are arranged in a one-to-one correspondence along the circumference of a circle. When the above design is adopted, the corresponding connection holes on the outer flange wall and the inner flange wall are located on the same circular radius.

[0011] Furthermore, the outer flange wall and the inner flange wall form the external connection structure of the shaft. To avoid stress concentration leading to damage at the connection between the shaft and the outer and inner flange structures, an optimization is proposed, and one feasible option is suggested: several structural stress holes are formed on the outer flange wall and the inner flange wall. When adopting the above scheme, the structural stress holes are evenly spaced along the circumference.

[0012] Furthermore, when setting up the fixed flange structure, considering the tightening effect during connection, the structure of the outer flange wall and the inner flange wall can be optimized. One feasible option is proposed here: the outer flange wall, the inner flange wall, and the main shaft form a Y-shaped or T-shaped structure. When a Y-shaped structure is formed, a recessed cavity is created between the outer flange wall and the inner flange wall. When the outer flange wall and the inner flange wall are fixed to the mounting structure by fasteners, the outer flange wall and the inner flange wall are abutted against the bolts. Using the above scheme, the T-shaped structure ensures better fit, and the Y-shaped structure ensures better tightening effect.

[0013] Furthermore, to enhance the fastening effect at the fixed flange structure, an optimization is proposed, and one feasible option is suggested: a hollow cavity is formed inside the shaft, with the wall thickness gradually increasing from the hollow cavity to the fixed flange structure. When this scheme is adopted, a thickened area is formed at the junction of the hollow cavity with the outer flange wall and the inner flange wall.

[0014] The above content discloses a spindle structure that improves service life, and the present invention also discloses a corresponding method.

[0015] A method for improving the lifespan of critical areas of the rotor main shaft of a wind turbine adopts the main shaft structure described above, characterized by: The shaft is positioned at the mounting structure and secured with fasteners. Install the rotor onto the shaft.

[0016] Furthermore, in order to maintain the standardization and consistency of the connection fastening, the tightening force of the fasteners on the outer and inner flange walls is limited when installing the shaft, and the fasteners are installed by a set torque during the installation process.

[0017] Compared with the prior art, some of the beneficial effects of the technical solution disclosed in this invention include: This invention improves the shaft structure, changing the single-sided stress structure to a double-sided stress structure, avoiding stress concentration at the flange structure of the shaft, ensuring the structural stability and reliability of the shaft, and improving the effective service life of the shaft in actual use. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the main shaft.

[0020] Figure 2 This is a cross-sectional view of the main shaft structure.

[0021] Figure 3 This is a schematic diagram showing the load-bearing arrangement of bolts on both sides.

[0022] The meanings of each component in the diagram are as follows: 1. Shaft; 2. Outer flange wall; 3. Structural stress hole; 4. Outer connecting hole; 5. Hollow cavity; 6. Thickened area; 7. Inner flange wall; 8. Inner connecting hole. Detailed Implementation

[0023] The following description, in conjunction with the accompanying drawings and specific embodiments, further illustrates this embodiment.

[0024] To address the issue of stress concentration in the existing shaft-flange connection structure leading to reduced spindle lifespan, the following embodiments are optimized to overcome the defects present in the prior art.

[0025] Example 1 like Figure 1 , Figure 2 and Figure 3 As shown, this embodiment discloses a spindle structure for improving the lifespan of critical areas of the wind turbine rotor spindle, including a shaft body 1. One end of the shaft body 1 forms a fixed flange structure for connecting to the mounting structure. The fixed flange structure includes an outer flange wall 2 extending outward from the shaft body 1 and an inner flange wall 7 extending inward from the shaft body 1. Both the outer flange wall 2 and the inner flange wall 7 are provided with several connecting fasteners to connect the spindle to the mounting structure.

[0026] The main shaft structure disclosed in this embodiment changes the stress structure of the shaft body 1 from unilateral stress to bilateral stress by using the outer flange wall 2 and the inner flange wall 7 at the fixed flange structure. This optimizes and improves the stress structure of the shaft body 1, which facilitates the improvement of the actual service life of the shaft body 1 and can maintain stability and reliability during the operation of the wind turbine.

[0027] The outer flange wall 2 and the inner flange wall 7 can be constructed in various similar shapes, and are not limited to a single one. This embodiment optimizes and adopts one feasible option: the outer flange wall 2 and the inner flange wall 7 are both continuously arranged rings, and the outer flange wall 2 and the inner flange wall 7 are integrally formed with the shaft body 1. When the above scheme is adopted, the outer flange wall 2 and the inner flange wall 7 have the same thickness.

[0028] When implementing external connection and fixation, various schemes can be adopted. This embodiment optimizes and adopts one feasible option: a plurality of connection holes are formed on the outer flange wall 2 and the inner flange wall 7, and the connecting fasteners are set at the connection holes. When adopting the above scheme, the connection holes are evenly spaced around the circumference, and the diameter and number of the connection holes on the outer flange wall 2 and the inner flange wall 7 are the same.

[0029] In some embodiments, an outer connecting hole 4 is provided on the outer flange wall 2, and an inner connecting hole 8 is provided on the inner flange wall 7. The diameters of the outer connecting hole 4 and the inner connecting hole 8 may be different.

[0030] In some designs, the connection holes on the outer flange wall 2 and the inner flange wall 7 are correspondingly arranged. Specifically, the connection holes on the outer flange wall 2 and the inner flange wall 7 are arranged in a one-to-one correspondence along the circumference of a circle. When the above design is adopted, the corresponding connection holes on the outer flange wall 2 and the inner flange wall 7 are located on the same circular radius.

[0031] The outer flange wall 2 and the inner flange wall 7 form the external connection structure of the shaft 1. To avoid stress concentration leading to damage at the connection between the shaft 1 and the outer and inner flange structures, this embodiment optimizes the design by employing one feasible option: forming a plurality of structural stress holes 3 on the outer flange wall 2 and the inner flange wall 7. When the above scheme is adopted, the structural stress holes 3 are evenly spaced along the circumference.

[0032] When setting up the fixed flange structure, considering the tightening effect during connection, the structure of the outer flange wall 2 and the inner flange wall 7 can be optimized. This embodiment adopts one feasible option: the outer flange wall 2, the inner flange wall 7, and the main shaft form a Y-shaped or T-shaped structure. When a Y-shaped structure is formed, a recessed cavity is formed between the outer flange wall 2 and the inner flange wall 7. When the outer flange wall 2 and the inner flange wall 7 are fixed to the mounting structure by fasteners, the outer flange wall 2 and the inner flange wall 7 are abutted against the bolts. With the above scheme, the T-shaped structure can ensure better fit, and the Y-shaped structure can ensure better tightening effect.

[0033] To enhance the fastening effect at the fixed flange structure, this embodiment optimizes the process and adopts one feasible option: a hollow cavity 5 is formed inside the shaft 1, and the wall thickness of the hollow cavity 5 gradually increases from the portion to the fixed flange structure. When the above scheme is adopted, a thickened region 6 is formed at the junction of the hollow cavity 5 with the outer flange wall 2 and the inner flange wall 7.

[0034] Example 2 The above embodiment 1 discloses a spindle structure that improves service life, and this embodiment also discloses a corresponding method.

[0035] A method for improving the lifespan of critical areas of the rotor main shaft of a wind turbine adopts the main shaft structure described in Example 1, characterized in that: Shaft 1 is positioned at the mounting structure and secured with fasteners. Install the rotor onto shaft 1.

[0036] To maintain standardization and consistency in connection fastening, the fastening force of the fasteners on the outer flange wall 2 and the inner flange wall 7 is limited when installing shaft 1, and the fasteners are installed using a set torque during the installation process.

[0037] like Figure 3 The diagram shows the load-bearing capacity of the bolts arranged on both sides, where the corresponding force values ​​satisfy the following relationship:

[0038] Z represents the external tensile force. At the main journal, the same bending moment decomposes into a tensile load of 2Nt. Since both sides of the T-flange bear the load simultaneously, the effect is greater than the sum of its parts (1+1>2). Firstly, without considering prying forces, the load of Nt is evenly distributed between the two flanges. Since the flange thickness can be further reduced, and considering the effect of prying forces, under reasonable conditions… and Under this ratio, the load on both bolts includes a component of the prying force Q, achieving a balance between the flange thickness and the bolts. More importantly, the key factor mentioned in this invention for improving fatigue life is that the deformation bending moment Mpp at the flange neck is reduced on both flanges, thus improving fatigue life.

[0039] in, and As the lever arm, the range of their length ratios is: .

[0040] The above are the embodiments listed in this example; however, this example is not limited to the optional embodiments described above; those skilled in the art can arbitrarily combine the above methods to obtain other various embodiments; anyone can derive other various forms of embodiments under the guidance of this example. The above specific embodiments should not be construed as limiting the scope of protection of this example; the scope of protection of this example should be determined by the claims.

Claims

1. A spindle structure for improving the lifespan of critical areas of a wind turbine rotor spindle, characterized in that: The shaft (1) is included. One end of the shaft (1) forms a fixed flange structure for connecting the mounting structure. The fixed flange structure includes an outer flange wall (2) extending outward from the moving shaft (1) and an inner flange wall (7) extending inward from the shaft (1). Both the outer flange wall (2) and the inner flange wall (7) are provided with several connecting fasteners and connect the main shaft to the mounting structure.

2. The spindle structure for improving the lifespan of critical areas of the wind turbine rotor spindle according to claim 1, characterized in that: The outer flange wall (2) and the inner flange wall (7) are both continuously arranged rings, and the outer flange wall (2) and the inner flange wall (7) are integrally formed with the shaft body (1).

3. The spindle structure for improving the lifespan of critical areas of the wind turbine rotor spindle according to claim 1, characterized in that: A plurality of connection holes are formed on the outer flange wall (2) and the inner flange wall (7), and the connection fasteners are provided at the connection holes.

4. The spindle structure for improving the lifespan of critical areas of the wind turbine rotor spindle according to claim 3, characterized in that: The connecting holes on the outer flange wall (2) and the inner flange wall (7) are arranged in a one-to-one correspondence along the circumference.

5. The spindle structure for improving the lifespan of critical areas of the wind turbine rotor spindle according to claim 1, characterized in that: Several structural stress holes (3) are formed on the outer flange wall (2) and the inner flange wall (7).

6. The spindle structure for improving the lifespan of critical areas of the wind turbine rotor spindle according to claim 1, characterized in that: The outer flange wall (2), the inner flange wall (7) and the main shaft form a Y-shaped or T-shaped structure. When a Y-shaped structure is formed, a recessed cavity is formed between the outer flange wall (2) and the inner flange wall (7). When the outer flange wall (2) and the inner flange wall (7) are fixed to the mounting structure by fasteners, the outer flange wall (2) and the inner flange wall (7) are abutted against the bolts.

7. The spindle structure for improving the lifespan of critical areas of the wind turbine rotor spindle according to claim 1, characterized in that: The shaft (1) forms a hollow cavity (5) inside, and the wall thickness of the part of the hollow cavity (5) to the fixed flange structure gradually increases.

8. A method for improving the lifespan of critical areas of a wind turbine rotor shaft, employing the shaft structure described in any one of claims 1 to 7, characterized in that: The shaft (1) is placed at the mounting structure and fixed by connecting fasteners; Install the rotor onto the shaft (1).

9. The method for improving the lifespan of critical areas of the rotor main shaft of a wind turbine according to claim 8, characterized in that: When installing the shaft (1), the tightening force of the fasteners on the outer flange wall (2) and the inner flange wall (7) is limited, and the fasteners are installed by setting the torque during the installation process.

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