A connecting structure for solving electrocorrosion of a semi-direct-drive gearbox, and a semi-direct-drive gearbox and a wind turbine generator set

Abstract

This utility model discloses a connection structure for solving the electro-corrosion problem of a semi-direct drive gearbox, as well as a semi-direct drive gearbox and a wind turbine generator set, relating to the wind power field. The structure includes a connecting flange for connecting the gearbox's output end and the generator's rotor, with a gasket made of insulating material placed between the connecting flange and the gearbox's output end. This structure addresses the induced voltage generated at the connecting flange connecting the gearbox and the generator rotor, reducing or even eliminating the electro-corrosion phenomenon caused by the induced voltage at this location in the semi-direct drive gearbox.

Description

Technical Field

[0001] This utility model relates to the field of wind power, and in particular to a connection structure for solving the electro-corrosion of a semi-direct drive gearbox, as well as a semi-direct drive gearbox and a wind turbine generator set. Background Technology

[0002] In wind turbine generators, compact semi-direct drive gearboxes are commonly used transmission chains, with their input end connected to the wind turbine shaft and their output end connected to the generator. Electro-corrosion within semi-direct drive gearboxes is a prevalent problem in the industry, generally attributed to shaft voltage during operation. While engineers have implemented various measures to address this issue, such as using filters, common-mode rejection technology, insulated bearings, or grounded carbon brushes, these methods can reduce or even eliminate electro-corrosion caused by shaft current. However, in practice, electro-corrosion still exists within semi-direct drive gearboxes even with these methods. Therefore, further research is needed to investigate the causes and solutions for electro-corrosion in semi-direct drive gearboxes. Utility Model Content

[0003] The purpose of this utility model is to provide a connection structure for solving the electro-corrosion of semi-direct drive gearboxes, as well as a semi-direct drive gearbox and a wind turbine generator set, in order to address the problems mentioned above. This structure is designed to address the induced voltage generated by the connecting flange connecting the gearbox and the rotor of the generator, thereby reducing or even eliminating the electro-corrosion phenomenon caused by the induced voltage at the aforementioned location in the semi-direct drive gearbox.

[0004] Through practical experience, it was discovered that voltage exists on the hollow tubes and connecting flanges in compact semi-direct drive gearboxes. This voltage forms a current loop within the gearbox, leading to bearing galvanic corrosion and gear pitting. The voltage on the hollow tubes is primarily concentrated on the section connecting the pitch slip ring (for simplicity, this section will be referred to as the connecting section). Because this connecting section is closer to the generator interior, and in some cases even partially located within the generator, electromagnetic induction and stray capacitance coupling result in voltage on the connecting section and connecting flanges, which are rotating components. The voltage is collectively referred to as induced voltage. In a semi-direct drive gearbox, the gears or bearings are in direct or indirect contact with the connecting section and connecting flange. If the induced voltage exceeds the insulation threshold of the oil film at the gear or bearing, partial discharge will occur. The instantaneous high temperature (up to several thousand degrees Celsius) will cause the metal surface to melt and oxidize, forming pitting or pits. The induced voltage generated by the connecting flange has a more severe impact. Therefore, the technical solution adopted by this utility model is as follows: A connection structure for solving the electro-corrosion of a semi-direct drive gearbox, including a connecting flange for connecting the output end of the gearbox and the rotor of the generator, and a gasket made of insulating material is provided between the connecting flange and the output end of the gearbox.

[0005] Furthermore, the two ends of the connecting flange are respectively bolted to the output end of the gearbox and the rotor of the generator.

[0006] Furthermore, after the connecting flange and the output end bolt of the gearbox are engaged, an insulating support sleeve is fitted onto the bolt thread, and the insulating support sleeve is located in the engagement hole on the connecting flange and / or the output end of the gearbox for bolt engagement; an insulating gasket is fitted onto the bolt thread, and the insulating gasket is located between the bolt nut and the end face of the connecting flange, or / and the insulating gasket is located between the bolt nut and the end face of the output end.

[0007] Furthermore, the bolt passes through the washer.

[0008] Furthermore, the insulating pad and the insulating support sleeve are integrally formed.

[0009] Furthermore, an insulating sleeve is fitted onto the screw, which covers the portion of the screw not covered by the insulating support sleeve.

[0010] A semi-direct drive gearbox has the aforementioned connection structure for solving the electro-corrosion problem of the semi-direct drive gearbox, wherein the two ends of the connecting flange are respectively connected to the output end of the gearbox and the rotor of the generator by bolts.

[0011] A wind turbine generator set having the aforementioned semi-direct drive gearbox.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0013] The key point of this utility model is to solve the technical problem of "the induced voltage generated on the connecting flange forming a current loop in the semi-direct drive gearbox, leading to bearing electro-erosion and gear pitting". Due to the blocking effect of the gasket made of insulating material, the induced voltage on the connecting flange will not form a closed electrical loop in the semi-direct drive gearbox. As a result, the phenomenon of metal surface melting and oxidation caused by the induced voltage will not occur in the semi-direct drive gearbox, further reducing or even eliminating the phenomenon of electro-corrosion in the semi-direct drive gearbox. Attached Figure Description

[0014] This utility model will be described by way of example and with reference to the accompanying drawings, wherein:

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is an assembly diagram of the pad, insulating pad, and insulating support sleeve;

[0017] The markings in the diagram are: 1-output end; 2-connecting flange; 3-rotor; 4-gasket; 5-bolt; 51-nut; 52-screw; 61-insulating gasket; 62-insulating sleeve; 63-insulating support sleeve. Detailed Implementation

[0018] In the description of this specification, it should be noted that if terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," or "outer" appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, they are only for the convenience of describing this specification and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this specification.

[0019] Furthermore, the use of terms such as "horizontal" or "vertical" in this specification does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0020] In the description of this specification, it should also be noted that, unless otherwise expressly specified and limited, the terms “set up,” “install,” “connect,” and “link” should be interpreted broadly. For example, a link can be a fixed link, a detachable link, or an integral link; it can be a mechanical link or an electrical link; it can be a direct link or an indirect link through an intermediate medium; it can be a connection within two components.

[0021] Example 1

[0022] like Figure 1-2 As shown, a connection structure for solving electro-corrosion in a semi-direct drive gearbox includes a connecting flange 2 for connecting the gearbox output end 1 and the generator rotor 3. A gasket 4 made of insulating material is provided between the connecting flange 2 and the gearbox output end 1. Addressing the technical problem of "induced voltage generated on the connecting flange 2 forming a current loop in the semi-direct drive gearbox, leading to bearing electro-corrosion and gear pitting," the gasket 4, due to its blocking effect, prevents the induced voltage from forming a closed electrical loop within the semi-direct drive gearbox. Consequently, the phenomenon of metal surface melting and oxidation caused by the induced voltage will not occur within the semi-direct drive gearbox, further reducing or even eliminating electro-corrosion in the semi-direct drive gearbox.

[0023] It should be noted that the connecting flange 2 is made of metal, which ensures its strength, and therefore it will also generate induced voltage. The connecting flange 2 is connected to the generator rotor 3, which is electrically connected to a grounding wire. The grounding wire is grounded (this also exists in the prior art, and those skilled in the art are aware of this, so it will not be described in detail here). Therefore, the induced voltage generated by the connecting flange 2 will be grounded through the generator rotor 3 and the grounding wire. Therefore, the induced voltage generated on the connecting flange 2 will not accumulate excessively, and there will be no situation where the voltage is too high and breaks down the gasket 4. That is, the structure can work for a long time.

[0024] Furthermore, the two ends of the connecting flange 2 are respectively connected to the output end 1 of the gearbox and the rotor 3 of the generator by bolts 5. Bolts 5, screws 52 and washers 4 achieve detachable connection for easy maintenance.

[0025] Furthermore, such as Figure 2 As shown, after the connecting flange 2 and the output end 1 of the gearbox are engaged with bolt 5, an insulating support sleeve 63 is fitted onto the threaded rod 52 of bolt 5, and the insulating support sleeve 63 is located in the engagement hole on the connecting flange 2 and / or the output end 1 of the gearbox for the bolt 5 to engage; an insulating gasket 61 is fitted onto the threaded rod 52 of bolt 5, and the insulating gasket 61 is located between the nut 51 of bolt 5 and the end face of the connecting flange 2, or / and the insulating gasket 61 is located between the nut 51 of bolt 5 and the end face of the output end 1; both the insulating gasket 61 and the insulating support sleeve 63 are made of insulating material, and the insulating support sleeve 63 supports the threaded rod 52, so that the threaded rod 52 and the connecting flange 2 and / or the gearbox are engaged. A gap is formed between the inner walls of the engagement hole on the output end 1, thereby preventing the screw 52 from contacting the connecting flange 2 and / or the output end 1 of the gearbox. At the same time, the insulating gasket 61 can also prevent the nut 51 from contacting the end face of the connecting flange 2 and / or the output end 1 of the gearbox. In summary, by using the insulating gasket 61 and the insulating support sleeve 63 together, the screw 52 and nut 51 in the bolt 5 can be effectively isolated from contact with the output end 1 of the gearbox, thereby achieving the purpose of isolating electrical connection and effectively preventing the induced voltage on the connecting flange 2 from being electrically connected to the output end 1 of the gearbox through the bolt 5. On the other hand, this design of the insulating gasket 61 and the insulating support sleeve 63 also facilitates installation and disassembly.

[0026] In one feasible implementation, the screw 52 of the bolt 5 passes through the washer 4, so that the washer 4 can be supported by the screw 52, ​​thereby improving the positional stability of the washer 4.

[0027] In one feasible implementation, the outer diameter of the insulating support sleeve 63 matches the inner diameter of the engagement hole, and the inner diameter of the insulating support sleeve 63 matches the diameter of the screw 52. This method ensures that after the insulating support sleeve 63 is made into the screw 52, ​​the axis of the screw 52 is collinear with the axis of the engagement hole. On the one hand, this improves the stability of the structure and avoids positional fluctuations; on the other hand, it avoids the situation where a certain position is too close, causing voltage breakdown of the air and resulting in failure of the electrical connection.

[0028] Furthermore, the insulating gasket 61 and the insulating support sleeve 63 are integrally formed, forming a sleeve-shaped structure with a T-shaped cross section. This structure can use the end face of the insulating gasket 61 as the positioning surface, which can effectively improve the dimensional accuracy for the coaxial installation of the insulating support sleeve 63.

[0029] In one feasible implementation, as described above, although there is a gap between the screw 52 and the inner wall of the engagement hole under the action of the insulating support sleeve 63, there is still a possibility that the air in the gap may be broken down due to excessive voltage. In order to prevent this from happening and to ensure the effect of isolating the screw 52 and nut 51 in the isolation bolt 5 from the output end 1 of the gearbox, and to prevent the induced voltage generated at the connecting flange 2 from conducting with the output end 1 of the gearbox, a further design is that the screw 52 is also fitted with an insulating sleeve 62, which covers the part of the screw 52 that is not covered by the insulating support sleeve 63.

[0030] Further design allows the insulating support sleeve 63 to be integrally formed with the insulating sleeve 62.

[0031] Example 2

[0032] A semi-direct drive gearbox has the connection structure described in Embodiment 1 for solving the electro-corrosion of the semi-direct drive gearbox. The two ends of the connecting flange 2 are respectively connected to the output end 1 of the gearbox and the rotor 3 of the generator by bolts 5.

[0033] It should be noted that the other structures of the semi-direct drive gearbox are known to those skilled in the art and will not be described in detail in this specification.

[0034] Example 3

[0035] A wind turbine generator set having the semi-direct drive gearbox described in Example 2.

[0036] It should be noted that the structure of the wind turbine generator set is known to those skilled in the art, and the assembly of the semi-direct drive gearbox and the remaining structure of the semi-direct drive gearbox will not be described in detail in this specification.

[0037] This invention is not limited to the specific embodiments described above. This invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A connection structure for solving electro-corrosion in a semi-direct drive gearbox, characterized in that: Includes a connecting flange (2) for connecting the output end (1) of the gearbox and the rotor (3) of the generator, with a gasket (4) made of insulating material between the connecting flange (2) and the output end (1) of the gearbox.

2. The connection structure according to claim 1, characterized in that: The two ends of the connecting flange (2) are connected to the output end (1) of the gearbox and the rotor (3) of the generator respectively by bolts (5).

3. The connection structure according to claim 2, characterized in that: After the connecting flange (2) and the output end (1) of the gearbox are engaged by the bolt (5), there is an insulating support sleeve (63) on the thread (52) of the bolt (5), and the insulating support sleeve (63) is located in the engagement hole on the connecting flange (2) and / or the output end (1) of the gearbox for the bolt (5) to engage; there is an insulating gasket (61) on the thread (52) of the bolt (5), and the insulating gasket (61) is located between the nut (51) of the bolt (5) and the end face of the connecting flange (2), or / and the insulating gasket (61) is located between the nut (51) of the bolt (5) and the end face of the output end (1).

4. The connection structure according to claim 3, characterized in that: The bolt (5) passes through the washer (4).

5. The connection structure according to claim 3, characterized by: The insulating pad (61) and the insulating support sleeve (63) are integrally formed.

6. The connection structure according to claim 3, characterized by: An insulating sleeve (62) is also fitted on the screw (52), which covers the part of the screw (52) that is not covered by the insulating support sleeve (63).

7. A semi-direct drive gearbox, characterized by: The connection structure for solving the electro-corrosion of the semi-direct drive gearbox as described in any one of claims 1-6 is provided, wherein the two ends of the connecting flange (2) are respectively connected to the output end (1) of the gearbox and the rotor (3) of the generator by bolts (5).

8. A wind power unit, characterized by: The wind turbine has the semi-direct drive gearbox as described in claim 7.

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