Blade root connecting system of wind generating set

Abstract

The invention discloses a blade root connecting system of a wind generating set. The blade root connecting system comprises a hub, blades and a variable-pitch bearing, the outer ring of the variable pitch bearing is connected with the hub through a first bolt; the inner ring of the variable pitch bearing is connected with the blades through two circles of second bolts which are arranged in a staggered mode. The second bolt is located on the inner ring of the variable pitch bearing, so that the pitch circle size of the blade root of the blade connected with the second bolt is small, long-distance transportation of the blade on land (not limited by the size) is facilitated, the weight of the blade root can be reduced, and the cost is reduced; meanwhile, due to the fact that the second bolts are arranged in the double-circle staggered mode, enough blade root bearing capacity can be provided even under the small pitch circle size, and the connection strength between the blade and the variable pitch bearing is guaranteed.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of wind power, and in particular to a blade root connection system of a wind turbine generator set. Background Art

[0002] With the continuous development of wind power generation technology, the diameter and power of wind turbine impellers are getting larger and larger, and the blade root load is also getting higher and higher. In order to improve the strength of the blade root, the traditional approach is to increase the blade root pitch circle and increase the number and specifications of the blade root bolts. When the blade root size exceeds the land transportation limit, it cannot be transported to the wind farm. At the same time, single-row bolts have problems such as insufficient connection strength, easy loosening, and short fatigue life. Therefore, a new type of variable pitch connection system is urgently needed to improve the connection strength and stability, while solving the problem of blade transportation.

[0003] The announcement number is CN215890312, and the name is: A wind turbine pitch bearing bolt connection system. It discloses a solution to improve the blade connection system. The blade bolts are connected to the outer ring of the pitch bearing, and the inner ring uses a special threaded sleeve to improve the connection strength of the bolts. The solution still uses a single-row bolt connection system. The blades are on the outer ring of the pitch bearing. Under the premise of ensuring the same pitch bearing strength, the blade pitch circle diameter is larger and the blade weight is heavier. Summary of the invention

[0004] In view of the technical problems existing in the prior art, the present invention provides a blade root connection system for a wind turbine generator set with low cost and reliable connection.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] A blade root connection system for a wind turbine generator set, comprising a hub, a blade and a pitch bearing;

[0007] The outer ring of the pitch bearing is connected to the hub via a first bolt;

[0008] The inner ring of the pitch bearing is connected to the blade via two circles of second bolts arranged alternately.

[0009] As a further improvement of the above technical solution:

[0010] The flange surface of the hub is provided with a through hole, the outer ring of the pitch bearing is provided with a blind hole, and the first bolt passes through the through hole of the flange surface and extends into the blind hole of the outer ring of the pitch bearing to achieve the connection between the hub and the pitch bearing.

[0011] The second bolt is located at the inner ring of the pitch bearing, a bolt sleeve is arranged in the blade, and the second bolt is threadedly connected to the bolt sleeve of the blade to realize the connection between the pitch bearing and the blade.

[0012] A transition section is provided between the pitch bearing and the blade, the pitch bearing is connected to the transition section via a single circle of bolts, and the transition section is connected to the blade via two circles of second bolts arranged in an alternating manner.

[0013] A shear pin is pre-embedded in the contact surface between the pitch bearing and the blade.

[0014] The variable pitch bearing is a double-row ball variable pitch bearing.

[0015] The variable pitch bearing is a double-row four-point angular contact bearing.

[0016] The variable pitch bearing is a three-row cylindrical bearing.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] The second bolt of the present invention is located in the inner ring of the variable pitch bearing, so that the blade root pitch circle size of the blade connected to the second bolt is smaller, which is convenient for long-distance land transportation of the blade (not subject to size restrictions), and can also reduce the weight of the blade root and reduce costs; at the same time, since the second bolt is arranged in a double circle staggered manner, it can provide sufficient blade root bearing capacity even at a small pitch circle size, thereby ensuring the connection strength between the blade and the variable pitch bearing.

[0019] The hub flange surface of the present invention is provided with a through hole, and the outer ring of the pitch bearing is provided with a blind hole. The first bolt passes through the through hole of the flange surface and then extends into the blind hole of the outer ring of the pitch bearing to achieve the connection between the hub and the pitch bearing. Through this connection method, the corresponding first bolt is constructed inside the hub (the through hole provided on the conventional pitch bearing, the first bolt will extend out of the pitch bearing), and there is no need to match the hub cover, saving costs.

[0020] The contact surface between the inner ring of the variable pitch bearing and the blade of the present invention is pre-embedded with a shear pin, which can be used as a pre-positioning for installation and play a certain anti-shear role, thereby solving the slippage between the blade and the variable pitch bearing, the variable pitch bearing and the hub caused by construction technology and other reasons, and improving the docking accuracy and anti-slip performance of the joint surface.

[0021] The present invention achieves higher blade bolt connection strength and better fatigue performance and reduces maintenance requirements by optimizing the bolt connection structure and optimizing the anti-error and anti-slip measures of each joint surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional view of an embodiment of the pitch connection system of the present invention.

[0023] Figure 2 It is a stereoscopic diagram of an embodiment of the variable pitch connection system of the present invention.

[0024] Figure 3 for Figure 2A partial enlarged view of .

[0025] Figure 4 This is a schematic diagram of the shear pin installation position of the present invention.

[0026] Legend: 1. Blade; 2. Bolt sleeve; 3. Second bolt; 4. Pitch bearing; 5. First bolt; 6. Hub; 7. Shear pin. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0028] like Figure 1 As shown, the blade root connection system of the wind turbine generator set according to the embodiment of the present invention comprises a hub 6, a blade 1 and a pitch bearing 4; the outer ring of the pitch bearing 4 is connected to the hub 6 via a first bolt 5; the inner ring of the pitch bearing 4 is connected to the blade 1 via two circles of high-strength second bolts 3 arranged in an alternating manner. Since the second bolts 3 are located in the inner ring of the pitch bearing 4, the blade root pitch circle size of the blade 1 connected to the second bolts 3 is small, which is convenient for long-distance land transportation of the blade 1 (not limited by size), and can also reduce the weight of the root of the blade 1 and reduce costs; at the same time, as Figure 2-Figure 3 As shown, since the second bolts 3 are arranged in double circles in a staggered manner, sufficient blade root bearing capacity can be provided even under a small pitch circle size, thereby ensuring the connection strength between the blade 1 and the pitch bearing 4.

[0029] Specifically, the flange surface of the hub 6 is provided with a through hole, the outer ring of the pitch bearing 4 is provided with a blind hole, and the first bolt 5 passes through the through hole of the flange surface and then extends into the blind hole of the outer ring of the pitch bearing 4 to achieve the connection between the hub 6 and the pitch bearing 4. Through this connection method, the corresponding first bolt 5 is constructed inside the hub 6 (the through hole provided on the conventional pitch bearing 4, the first bolt 5 will extend out of the pitch bearing 4), and the hub 6 cover does not need to be matched, saving costs.

[0030] Specifically, the second bolt 3 is located at the inner ring of the pitch bearing 4, and two circles of staggered bolt sleeves 2 are also pre-embedded in the blade 1, and the bolt sleeves 2 correspond to the positions of the second bolts 3. The second bolt 3 is threadedly connected with the bolt sleeve 2 of the blade 1 to achieve the connection between the pitch bearing 4 and the blade 1. The above structure is simple and the connection operation is simple.

[0031] In another embodiment, a transition section is provided between the pitch bearing 4 and the blade 1 , the pitch bearing 4 is connected to the transition section via a single circle of bolts, and the transition section is connected to the blade 1 via two circles of staggered second bolts 3 .

[0032] Specifically, a shear pin 7 is embedded in the contact surface between the inner ring of the pitch bearing 4 and the blade 1. Figure 4As shown, it can be used as a pre-positioning for installation and play a certain role in preventing shearing, thereby solving the slippage between the blade 1 and the pitch bearing 4, and between the pitch bearing 4 and the hub 6 due to construction technology and other reasons, and improving the joint surface connection accuracy and anti-slip performance.

[0033] Specifically, the pitch bearing 4 is a double-row ball pitch bearing or a double-row four-point angular contact bearing or a three-row cylindrical bearing or a three-row roller bearing.

[0034] The present invention achieves higher bolt connection strength and better fatigue performance of the blade 1 and reduces maintenance requirements by optimizing the bolt connection structure and optimizing the anti-error and anti-slip measures of each joint surface.

[0035] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "assemble", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A blade root connection system for a wind turbine generator set, characterized in that: It comprises a hub (6), blades (1) and a pitch bearing (4); The outer ring of the variable pitch bearing (4) is connected to the hub (6) via a first bolt (5); The inner ring of the variable pitch bearing (4) is connected to the blade (1) via two circles of second bolts (3) arranged in an alternating manner.

2. The wind turbine blade root connection system according to claim 1, characterized in that: The flange surface of the wheel hub (6) is provided with a through hole, the outer ring of the variable pitch bearing (4) is provided with a blind hole, and the first bolt (5) passes through the through hole of the flange surface and extends into the blind hole of the outer ring of the variable pitch bearing (4) to achieve the connection between the wheel hub (6) and the variable pitch bearing (4).

3. The wind turbine blade root connection system according to claim 1 or 2, characterized in that: The second bolt (3) is located on the inner ring of the pitch bearing (4); a bolt sleeve (2) is provided in the blade (1); the second bolt (3) is threadedly connected to the bolt sleeve (2) of the blade (1) to achieve connection between the pitch bearing (4) and the blade (1).

4. The wind turbine blade root connection system according to claim 1 or 2, characterized in that: A transition section is provided between the variable pitch bearing (4) and the blade (1); the variable pitch bearing (4) is connected to the transition section via a single circle of bolts; and the transition section is connected to the blade (1) via two circles of second bolts (3) arranged in an alternating manner.

5. The wind turbine blade root connection system according to claim 1 or 2, characterized in that: A shear pin (7) is pre-embedded in the contact surface between the variable pitch bearing (4) and the blade (1).

6. The wind turbine blade root connection system according to claim 1 or 2, characterized in that: The variable pitch bearing (4) is a double-row ball variable pitch bearing (4).

7. The wind turbine blade root connection system according to claim 1 or 2, characterized in that: The variable pitch bearing (4) is a double-row four-point angular contact bearing.

8. The wind turbine blade root connection system according to claim 1 or 2, characterized in that: The variable pitch bearing (4) is a three-row cylindrical bearing.

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