CN116044653A

CN116044653A - Blade root embedded part and fan blade root connection structure

Info

Publication number: CN116044653A
Application number: CN202310037668.2A
Authority: CN
Inventors: 余岫卷; 陈铁锋; 陶伟; 韩鲁明; 杨春龙; 刘建伟
Original assignee: Envision Energy Co Ltd
Current assignee: Envision Energy Co Ltd
Priority date: 2023-01-09
Filing date: 2023-01-09
Publication date: 2023-05-02

Abstract

The invention relates to a blade root embedded part which is of a cylindrical structure, wherein a plurality of rows of through holes for connecting with shear bolts are formed in the inner wall of the bottom of the embedded part. Compared with the prior art, the blade root embedded part designed by the invention is of a cylindrical structure, the inner cylinder wall at the bottom of the embedded part is provided with a plurality of rows of through holes for connecting with shear bolts, and the blade root connection design of a tensile form is changed into a shear form by utilizing the embedded part. Because the pretightening force of the shear bolt generates pressure between the blade root and the variable-pitch bearing, the friction force between the blade root and the variable-pitch bearing is increased, and the friction force can resist the shearing force of a part of blade bending moment on the joint surface of the blade root and the variable-pitch bearing inner ring, so that the strength of blade root connection can be improved.

Description

Blade root embedded part and fan blade root connection structure

Technical Field

The invention relates to the technical field of wind driven generators, in particular to a blade root embedded part and a fan blade root connecting structure.

Background

A wind power generator is a device that converts wind energy into mechanical energy and then into electrical energy. Which comprises a tower, a nacelle connected to the tower and supporting a hub. The hub is provided with a plurality of fan blades, wherein the fan blades drive a rotor arranged in the hub to rotate around an axis under the action of wind force, and the rotation of the rotor of the generator relative to the stator generates electric energy. There are generally two ways of connecting the wind blade root to the pitch bearing: t-shaped punching and embedded blade root bolt sleeve type. Along with the increase of blade length, the megawatt level of wind generating set improves, and blade load also constantly increases, and more blades transition from traditional T type connection mode that punches to pre-buried blade root bolt cover connected mode to arrange more connecting bolts at the blade root, in order to guarantee that blade root connecting bolt has sufficient ultimate strength and fatigue strength.

The wind-powered electricity generation blade root pre-buried structure of design among the prior art is mostly the blade root connection structure of tensile form, has following shortcoming:

(1) In order to facilitate polishing of a high-speed metal polisher, the embedded bolt sleeve of the blade root generally protrudes out of the end face of the blade root composite material; because the composite material is solidified and contracted, after the blades are assembled, the end faces of the blade root embedded bolt sleeves at the positions of the common die joint are obviously and commonly lower than the end faces of the bolt sleeves at other positions, and the larger the pitch circle of the blades, the larger the contraction of the positions of the die joint is. In order to ensure the flatness of the end face of the blade root embedded bolt sleeve, when the end face is polished, the end face of the blade root embedded bolt sleeve near the die joint is not polished, and the end faces of the blade root embedded bolt sleeves at other positions are polished to be level with the blade root composite material; when the high-speed metal polisher touches the composite material, the high-speed friction generates heat, and the composite material is easy to burn, so that the mechanical property of the composite material is poor.

(2) The area of the end face of the embedded bolt sleeve of the blade root is smaller, and when the embedded bolt sleeve contacts with the end face of the flange, the rigidity of a connected piece is smaller, and the fatigue life of the connecting bolt is reduced.

(3) In the traditional blade root embedded connection structure, only the bolt sleeve, the flange and the variable pitch bearing are pressed components, the blade root composite material is not compressed, the stiffness of the connected component is not contributed, and the maximum drawing force of the embedded bolt sleeve and the fatigue resistance of the connecting bolt are reduced.

The three defects cause that the process of the embedded blade is difficult to control during production, meanwhile, the fatigue life of the blade root bolt is short during the on-hook operation process, the blade root bolt is broken frequently, and the reliability and the service life of the wind power blade are reduced.

Disclosure of Invention

The invention aims to overcome at least one of the defects in the prior art and provide a blade root embedded part and fan blade root connecting structure. The embedded part changes the blade root connection design of the tensile form into the shear form. Because the pretightening force of the shear bolt generates pressure between the blade root and the variable-pitch bearing, the friction force between the blade root and the variable-pitch bearing is increased, and the friction force can resist the shearing force of a part of blade bending moment on the joint surface of the blade root and the variable-pitch bearing inner ring, so that the strength of blade root connection can be improved.

The aim of the invention can be achieved by the following technical scheme:

the invention aims at providing a blade root embedded part which is of a cylindrical structure, wherein the inner cylinder wall at the bottom of the blade root embedded part is provided with a plurality of rows of through holes for connecting with shear bolts.

Further, at least 1 row of through holes, preferably 2 rows of through holes, are arranged on the blade root embedded part, and the through holes in each row are uniformly distributed along the circumferential direction of the blade root embedded part.

Further, the number of through holes in each row is equal.

Further, adjacent through holes among different rows are arranged on the same bus of the blade root embedded part.

Further, adjacent through holes among different rows are not arranged on the same bus of the blade root embedded part.

Further, the inner surface and the outer surface of the embedded part of the blade root are respectively provided with a thread groove or a rotary groove. The fiber wires are wound on the outer surface of the embedded part of the blade root, and the inner surface is combined with the fiber materials of the blade, so that the combination strength with the fiber materials of the blade root is improved.

Further, the number of the through holes in each row is greater than or equal to 4.

Further, threads matched with the shear bolts are arranged on the inner walls of the through holes.

The second purpose of the invention is to provide a fan blade root connecting structure, which comprises a blade root, shear bolts, a variable pitch bearing and the blade root embedded part; the blade root embedded part is embedded to the bottom of the blade root, and the variable pitch bearing is connected with the blade root through a shear bolt penetrating through the blade root embedded part.

Further, the number of the embedded parts is at least 4, and the embedded parts are uniformly distributed along the circumference of the blade root.

Compared with the prior art, the blade root embedded part designed by the invention is of a cylindrical structure, the inner cylinder wall at the bottom of the embedded part is provided with a plurality of rows of through holes for connecting with shear bolts, and the blade root connection design of a tensile form is changed into a shear form by utilizing the embedded part. Because the pretightening force of the shear bolt generates pressure between the blade root and the variable-pitch bearing, the friction force between the blade root and the variable-pitch bearing is increased, and the friction force can resist the shearing force of a part of blade bending moment on the joint surface of the blade root and the variable-pitch bearing inner ring, so that the strength of blade root connection can be improved.

Drawings

Fig. 1 is a front view (a), a top view (b) and a cross-sectional view (c) of a root embedment in embodiment 1;

FIG. 2 is a front view of a root embedment in embodiment 2;

FIG. 3 is a schematic view of a blade root connection structure of embodiment 1;

the reference numerals in the figures indicate: 101-blade root; 102-blade root embedded parts; 1021-a cylindrical structure; 1022-via; 103-shear bolts; 104-a pitch bearing; 105-hub.

Detailed Description

The invention will now be described in detail with reference to the drawings and specific examples. The present embodiment is implemented on the premise of the technical scheme of the present invention, and a detailed implementation manner and a specific operation process are provided, but the protection scope of the present invention is not limited to the following embodiments.

Example 1

Fig. 1 is a front view (a), a top view (b) and a cross-sectional view (c) of the root embedment in embodiment 1. As shown in fig. 1, in the blade root embedded part 102, the blade root embedded part is a cylindrical structure 1021, and a plurality of rows of through holes 1022 for connecting with shear bolts 103 are formed in the inner wall of the bottom of the blade root embedded part 102.

At least 2 rows of through holes 1022 are arranged on the blade root embedded part 102, and the through holes 1022 in each row are uniformly distributed along the circumference of the blade root embedded part 102. The number of through holes 1022 in each row is equal. Adjacent 1022 through holes between different rows are disposed on the same bus of the blade root embedment 102. The inner surface and the outer surface of the embedded part 102 are respectively provided with a thread groove or a rotary groove. The number of through holes 1022 per row is 4 or more. The inner wall of the through hole 1022 is provided with threads matching the shear bolts 103.

Fig. 3 is a schematic view of a fan blade root connection structure. As shown in fig. 3, a fan blade root connection structure includes a blade root 101, a shear bolt 103, a pitch bearing 104, and a blade root embedded part 102. The blade root 101 is provided with the blade root embedded parts 102, at least 4 blade root embedded parts 102 are uniformly distributed along the circumferential direction of the blade root 101, and are embedded into the bottom of the blade root 101. More specifically, in the process of manufacturing the blade root, the inner surface of the embedded part 102 is combined with the fiber material of the blade, the outer surface of the embedded part is wound with glass fiber yarns, the outer surface of the yarns is flush with the outer surface of the embedded part 102 by a small enveloping cylinder, and then the embedded part is placed into the blade root layer to be integrally molded with other glass fiber materials of the blade root by pouring resin. In the process of installing the blade, the shear bolts 103 are screwed into the blade root embedded parts 102, so that the end surfaces of the blade roots 101 are tightly combined with the inner rings of the pitch bearings 104. The hub 105 and the pitch bearing 104 are connected in a matched manner through bolts.

Compared with the existing blade root connecting structure designed in a tension mode, the blade root bolt is designed to be in a shear mode, embedded parts are added to the blade root for improving the self strength of the blade root, and the embedded parts are distributed along the circumferential direction of the blade root. When the blade is loaded, the bending moment of the blade can lead the single side of the blade root to be pulled or pressed, and the shear bolt can bear and resist the contact surface shearing force of the blade root and the pitch bearing, thereby realizing the connection function of the blade root and the pitch bearing. Because the pretightening force of the shear bolt generates pressure between the blade root and the variable-pitch bearing, the friction force between the blade root and the variable-pitch bearing is increased, and the friction force can resist the shearing force of a part of blade bending moment on the joint surface of the blade root and the variable-pitch bearing inner ring, so that the strength of blade root connection can be improved.

Example 2

Fig. 2 is a front view of a root embedded part in embodiment 2, and as shown in fig. 2, the structure of the root embedded part in embodiment 2 is substantially the same as that of the root embedded part in embodiment 1, except that adjacent through holes 1022 between different rows on the root embedded part 102 are not arranged on the same bus of the root embedded part 102.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the invention in any way, and any person skilled in the art may make modifications or alterations to the disclosed technical content to the equivalent embodiments. However, any simple modification, equivalent variation and variation of the above embodiments according to the technical substance of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. The blade root embedded part is characterized in that the blade root embedded part (102) is of a cylindrical structure (1021), and a plurality of rows of through holes (1022) used for being connected with shear bolts (103) are formed in the inner cylinder wall at the bottom of the blade root embedded part (102).

2. The embedded blade root part according to claim 1, wherein the embedded blade root part (102) is provided with at least 1 row of through holes (1022), and the through holes (1022) of each row are uniformly distributed along the circumference of the embedded blade root part (102).

3. A blade root embedment according to claim 1, characterized in that the number of through holes (1022) in each row is equal.

4. A blade root embedment as claimed in claim 2, characterized in that adjacent (1022) through holes between the different rows are provided on the same bus of the blade root embedment (102).

5. A blade root embedment according to claim 2, characterized in that adjacent through holes (1022) between the different rows are not provided on the same bus of the blade root embedment (102).

6. The embedded part of the blade root according to claim 1, wherein the embedded part (102) of the blade root is provided with a thread groove or a rotary groove on the inner surface and the outer surface.

7. The blade root embedment of claim 1, wherein the number of through holes (1022) in each row is greater than or equal to 4.

8. The embedded blade root part according to claim 1, wherein the inner wall of the through hole (1022) is provided with threads matching with the shear bolt (103).

9. A fan blade root connection structure, characterized by comprising a blade root (101), a shear bolt (103), a pitch bearing (104) and a blade root embedment (102) according to any of claims 1-8;

the blade root embedded part (102) is embedded to the bottom of the blade root (101), and the variable-pitch bearing (104) is connected with the blade root (101) through a shear bolt (103) penetrating through the blade root embedded part (102).

10. The embedded blade root part according to claim 9, wherein the number of embedded blade root parts (102) is at least 4, and the embedded blade root parts (102) are uniformly distributed along the circumference of the blade root (101).