A semi-direct drive wind turbine generator unit

Abstract

The application relates to the technical field of wind driven generators, in particular to a semi-direct-drive wind driven generator set. The semi-direct-drive wind driven generator set comprises a generator, a gear box, a high-frequency grounding belt and a conductive component. The generator comprises a stator base, a stator winding and a rotor component. The gear box comprises a box body and an output shaft. The box body is connected with the stator base, and the output shaft is rotationally arranged in the box body and is in transmission connection with the rotor component. The box body and the stator base are respectively grounded through the high-frequency grounding belt. The output shaft is provided with a plurality of conductive components along the circumferential direction, so that the output shaft is respectively conducted with the high-frequency grounding belt through the plurality of conductive components. The output shaft is provided with the plurality of conductive components along the circumferential direction, so that the output shaft is respectively conducted with the high-frequency grounding belt through the plurality of conductive components, the grounding discharge amount of the current is increased, the shaft voltage on the output shaft is reduced, the electric corrosion of the bearing and the tooth surface on the output shaft is avoided, the protection of the output shaft is improved, and the vibration and noise of the gear box are reduced.

Description

Technical Field

[0001] This invention relates to the field of wind turbine technology, and more particularly to a semi-direct drive wind turbine generator set. Background Technology

[0002] like Figure 1 As shown, shaft voltage is the potential difference between the two ends of the output shaft 21' of the gearbox 2', the local area of ​​the output shaft 21', and the output shaft 21' relative to ground during the operation of generator 1'. In wind turbine generator sets, generator 1' is a large, high-speed generator, which generates more high-frequency common-mode voltage. When high-frequency discharge occurs, a considerable shaft current is instantaneously generated and acts on the surface of bearing 22' and output shaft 21', forming many melting pits on bearing 22' and tooth surface 23', causing damage to bearing 22' and tooth surface 23', resulting in vibration and noise.

[0003] like Figure 1 As shown, the generator 1' of the semi-direct drive wind turbine generator set adopts a permanent magnet synchronous motor. The rotor winding 11' of the generator 1' is mounted on the output shaft 21' of the gearbox 2' via the rotor bracket 12', and the connection is steel-to-steel. Bearings 22' are not installed on either side of the rotor winding 11', and the common-mode voltage that could cause electro-corrosion of the bearings 22' is transferred to the gearbox 2'. The bearings 22' mounted on the output shaft 21', and the tooth surfaces 23' of the gearbox 2' and generator 1' that are close to each other will be damaged due to electro-corrosion.

[0004] In existing technologies, shaft voltage is mainly reduced through the following methods: First, a carbon brush 13' is grounded on one side of the rotor support 12' to conduct the current generated on the rotor winding 11' to the ground, thereby reducing the current transmitted from the rotor winding 11' to the output shaft 21'. However, some current still flows into the output shaft 21', resulting in a poor effect on reducing shaft voltage. Furthermore, this method is difficult to maintain and inconvenient to use. Second, the bearing 22' of the output shaft 21' is an insulated bearing to avoid damage due to electro-corrosion. However, the insulation layer of the insulated bearing is easily damaged during installation and use, thus failing to provide effective protection. Neither of these two methods can effectively suppress the shaft voltage of the output shaft 21'. Summary of the Invention

[0005] The purpose of this invention is to provide a semi-direct drive wind turbine generator set to reduce the shaft voltage of the output shaft in the gearbox and avoid electro-corrosion of the bearings and gear teeth on the output shaft.

[0006] To achieve this objective, the technical solution adopted by the present invention is as follows:

[0007] A semi-direct-drive wind turbine generator set includes:

[0008] A generator, comprising a stator base, stator windings, and rotor assembly;

[0009] A gearbox includes a housing and an output shaft. The housing is connected to the stator base, and the output shaft is rotatably disposed within the housing and is connected to the rotor assembly for transmission.

[0010] High-frequency grounding strip, the enclosure and the stator base are respectively grounded through the high-frequency grounding strip; and

[0011] The output shaft is provided with a plurality of conductive components along its circumference, so that the output shaft is connected to the high-frequency grounding band through the plurality of conductive components respectively.

[0012] As a preferred embodiment, the housing is provided with a mounting hole, and the output shaft passes through the mounting hole;

[0013] The conductive component includes conductive blocks, a plurality of which are distributed circumferentially along the output shaft, with one end connected to the outer peripheral surface of the output shaft and the other end connected to the housing.

[0014] As a preferred embodiment, the conductive block includes:

[0015] A flange, coaxially arranged with the mounting hole, wherein the outer surface of the flange is connected to the wall of the mounting hole; and

[0016] A conductive brush is fixedly connected to the flange and abuts against the outer circumferential surface of the output shaft.

[0017] As a preferred embodiment, the conductive component further includes conductive fibers, and the conductive brush is tightly connected to the outer peripheral surface of the output shaft through the conductive fibers.

[0018] As a preferred embodiment, the conductive component includes conductive blocks, a plurality of conductive blocks are distributed circumferentially along the output shaft and one end of each conductive block is tightly connected to the wall of the inner hole of the output shaft, and the other end is grounded through the corresponding high-frequency grounding band.

[0019] As a preferred embodiment, the gearbox further includes a tube shaft, which is fixedly disposed within the gearbox body, and the output shaft is rotatably sleeved on the tube shaft;

[0020] The tube shaft has a shaft hole that extends through its axial direction; the tube shaft has a through hole that communicates with the shaft hole along its radial direction, and one end of the plurality of high-frequency grounding strips passes through the shaft hole and is grounded, and the other end passes through the through hole and is connected to the corresponding conductive block respectively.

[0021] As a preferred embodiment, the conductive block includes:

[0022] A flange, coaxially arranged with the inner hole of the output shaft and fixedly connected to the tube shaft, and multiple high-frequency grounding strips passing through the through hole are respectively connected to the corresponding flanges; and

[0023] A conductive brush is fixedly connected to the flange and abuts against the inner wall of the output shaft.

[0024] As a preferred embodiment, the conductive component further includes conductive fibers, and the conductive brush is connected to the inner wall of the output shaft through the conductive fibers.

[0025] As a preferred embodiment, the gearbox further includes an inner transparent cover, which is fixedly sleeved on the tube shaft, and the output shaft is rotatably sleeved on the inner transparent cover; the flange is fixedly disposed on the end face of the inner transparent cover near the rotor assembly.

[0026] As a preferred embodiment, a first positioning hole is provided on the flange, and a corresponding second positioning hole is provided on the inner transparent cover;

[0027] The conductive component also includes fasteners, which are sequentially inserted into the first positioning hole and the second positioning hole to lock the flange onto the inner transparent cover; a plurality of high-frequency grounding strips passing through the through hole are wound around the corresponding fasteners.

[0028] The beneficial effects of this invention are as follows:

[0029] The semi-direct-drive wind turbine generator set proposed in this invention uses a high-frequency grounding strip to ground the casing and stator base respectively. This allows the current transmitted from the rotor assembly to the output shaft to be discharged through the grounding of the casing and stator base, effectively reducing the shaft voltage of the output shaft. Simultaneously, multiple conductive components are arranged along the circumference of the output shaft, enabling the output shaft to be connected to the high-frequency grounding strip through these components. This forms multiple dense coupling loops, increasing the amount of current discharged through grounding, further reducing the shaft voltage on the output shaft, preventing electro-corrosion of the bearings and gear surfaces on the output shaft, improving the protection of the bearings and gears on the output shaft, and thus reducing vibration and noise during gearbox operation.

[0030] In addition, multiple conductive components are arranged in a ring around the output shaft. Compared with the overall ring structure, the multiple conductive components are arranged in a separate ring structure, which facilitates the installation and maintenance of the conductive components, and the number of conductive components can be flexibly increased or decreased according to actual needs. Attached Figure Description

[0031] Figure 1 This is a partial structural diagram of an existing semi-direct drive wind turbine generator set;

[0032] Figure 2This is a partial structural schematic diagram of the semi-direct drive wind turbine generator set provided in Embodiment 1 of the present invention;

[0033] Figure 3 yes Figure 2 A magnified view of a section at point A in the middle;

[0034] Figure 4 This is a partial structural schematic diagram of the semi-direct drive wind turbine generator set provided in Embodiment 2 of the present invention;

[0035] Figure 5 yes Figure 4 A magnified view of a section at point B.

[0036] The component names and labels in the diagram are as follows:

[0037] 1' Generator; 11' Rotor winding; 12' Rotor support; 13' Carbon brush; 2' Gearbox; 21' Output shaft; 22' Bearing; 23' Tooth surface;

[0038] 1. Generator; 11. Stator base; 12. Stator winding; 13. Rotor assembly; 131. Rotor winding; 132. Rotor support;

[0039] 2. Gearbox; 21. Housing; 211. Outer cover; 212. Inner cover; 22. Output shaft; 23. Bearing; 24. Gear tooth surface; 25. Tube shaft; 251. Shaft hole; 252. Through hole;

[0040] 3. High-frequency grounding strip; 4. Carbon brush; 5. Conductive component; 51. Conductive block; 511. Flange; 512. Conductive brush; 52. Conductive fiber; 53. Fastener. Detailed Implementation

[0041] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0042] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0044] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0045] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0046] Example 1

[0047] like Figure 2 As shown, this embodiment proposes a semi-direct drive wind turbine generator set, which includes a generator 1 and a gearbox 2. The generator 1 includes a stator base 11, a stator winding 12 and a rotor assembly 13. The gearbox 2 includes a housing 21 and an output shaft 22. The housing 21 is connected to the stator base 11, and the output shaft 22 is rotatably disposed in the housing 21 and is connected to the rotor assembly 13 for transmission.

[0048] Specifically, the rotor assembly 13 includes a rotor winding 131 and a rotor support 132. The rotor support 132 is connected to both the rotor winding 131 and the output shaft 22 inside the housing 21. That is, the rotor winding 131 is connected to the output shaft 22 via the rotor support 132 in a steel-to-steel connection. The output shaft 22 is rotatably mounted inside the housing 21 via a bearing 23. A gear is provided on the output shaft 22, and the tooth surface 24 of the gear meshes with the gear inside the gearbox 2.

[0049] To reduce the shaft voltage of the output shaft 22, the semi-direct-drive wind turbine generator set also includes a high-frequency grounding strip 3. The housing 21 and stator base 11 are grounded through the high-frequency grounding strip 3. Specifically, carbon brushes 4 and the high-frequency grounding strip 3 are used for grounding on one side of the rotor support 132 (the non-drive end of the generator 1). Simultaneously, the current generated by the rotor winding 131 is transmitted to the output shaft 22 and then discharged through the housing 21, stator base 11, and high-frequency grounding strip 3, reducing the current flowing to the output shaft 22, thus lowering the shaft current. The high-frequency grounding strip 3 increases the current discharge, further reducing the shaft current in the output shaft 22 region. Furthermore, the bearing 23 on the output shaft 22 can be an insulated bearing to avoid damage due to electro-corrosion. The high-frequency grounding strip 3 is a mature product and can be purchased externally.

[0050] Currently, even with carbon brush 4 grounded via high-frequency grounding strip 3, some current inevitably flows to the output shaft 22 area, making it difficult to effectively reduce the shaft current on the output shaft 22. Furthermore, the insulation layer of the insulated bearing 23 is easily damaged during installation and use, thus failing to provide protection.

[0051] To solve the above problems, such as Figure 3 As shown, the semi-direct drive wind turbine generator set also includes conductive components 5. Multiple conductive components 5 are arranged along the circumference of the output shaft 22, allowing the output shaft 22 to be connected to the housing 21 through these components. The multiple conductive components 5 along the circumference of the output shaft 22 connect the output shaft 22 to the housing 21 and then to the ground via the high-frequency grounding strip 3. The multiple conductive components 5 connecting the output shaft 22 to the high-frequency grounding strip 3 form multiple dense coupling loops, increasing the grounding current output and further reducing the shaft voltage on the output shaft 22. This prevents electrolytic corrosion of the bearings 23 and gears 24 on the output shaft 22, improving protection for the bearings 23 and gears on the output shaft 22, thereby reducing vibration and noise during gearbox 2 operation.

[0052] In addition, multiple conductive components 5 are arranged in a ring shape along the circumference of the output shaft 22. Compared with the overall ring structure, multiple conductive components 5 are arranged in a ring shape in a split structure, which facilitates the installation and maintenance of conductive components 5, and allows for flexible increase or decrease in the number of conductive components 5 according to actual needs.

[0053] like Figure 3 As shown, a mounting hole is provided inside the housing 21, and the output shaft 22 passes through the mounting hole. The conductive component 5 includes conductive blocks 51, and multiple conductive blocks 51 are distributed along the circumference of the output shaft 22, with one end connected to the outer circumferential surface of the output shaft 22 and the other end connected to the housing 21.

[0054] Specifically, the housing 21 includes a main housing and an outer cover 211. The main housing has a first hole, and the outer cover has a second hole. The first hole and the second hole are coaxial and interconnected to form a mounting hole. The output shaft 22 passes through the first hole and the second hole in sequence, and the output shaft 22 is rotatably mounted in the first hole via a bearing 23. The main housing and the outer cover 211 are fixedly connected by bolts to achieve a conductive connection between them.

[0055] In this embodiment, part of the current generated by the rotor assembly 13 of the generator 1 is grounded through the carbon brush 4 of the rotor support 132 and the high-frequency grounding strip 3, and the other part of the current is grounded through the rotor support 132, the output shaft 22, the conductive component 5, the outer transparent cover 211, the housing 21 and the stator base 11 and then through the high-frequency grounding strip 3.

[0056] In this embodiment, the conductive block 51 includes a flange 511 and a conductive brush 512. The flange 511 is coaxially arranged with the mounting hole, and the outer side of the flange 511 is connected to the wall of the mounting hole. The conductive brush 512 is fixedly connected to the flange 511 and abuts against the outer peripheral surface of the output shaft 22. Specifically, the conductive block 51 is installed in the second hole so that the current transmitted from the rotor support 132 flows directly to the outer cover 211 and the main housing after passing through the conductive block 51, minimizing the current flowing to the output shaft 22 area in the first hole, thereby effectively suppressing or isolating the common-mode voltage generated by the generator 1 outside the main housing of the gearbox 2.

[0057] Specifically, the flange 511 is arc-shaped, and one side of the flange 511 can completely fit against the wall of the second hole of the outer cover 211 to achieve good conductivity. In this embodiment, there are generally four, five, or six conductive components 5, with multiple flanges 511 forming a ring structure. Of course, the number of conductive components 5 can be flexibly adjusted according to the actual situation, that is, the number of conductive blocks 51 can be increased or decreased.

[0058] Furthermore, the conductive component 5 also includes conductive fibers 52, and the conductive brush 512 is tightly connected to the outer peripheral surface of the output shaft 22 through the conductive fibers 52. The conductive fibers 52 can ensure a reliable conductive connection between the conductive brush 512 and the outer peripheral surface of the output shaft 22, enhance the conductivity, and at the same time prevent wear of the conductive brush 512.

[0059] Example 2

[0060] like Figure 4 As shown, this embodiment proposes a semi-direct drive wind turbine generator set. The overall structure of the semi-direct drive wind turbine generator set provided in this embodiment is basically the same as that in Embodiment 1. The main difference is that the conductive component 5 is set in a different position.

[0061] Specifically, the conductive component 5 includes conductive blocks 51. Multiple conductive blocks 51 are distributed circumferentially along the output shaft 22, with one end of each block tightly connected to the wall of the inner hole of the output shaft 22, and the other end grounded through a corresponding high-frequency grounding strip 3. The output shaft 22 is connected to the high-frequency grounding strip 3 through multiple conductive components 5, thereby forming multiple dense coupling loops, increasing the grounding current output, further reducing the shaft voltage on the output shaft 22, preventing electro-corrosion of the bearing 23 and gear tooth surface 24 on the output shaft 22, improving the protection of the bearing 23 and gear on the output shaft 22, and reducing vibration and noise during the operation of the gearbox 2.

[0062] In this embodiment, part of the current generated by the rotor winding 131 is grounded through the carbon brush 4 of the rotor support 132 and the high-frequency grounding strip 3, and the other part of the current is directly grounded through the high-frequency grounding strip 3 after passing through the rotor support 132, the output shaft 22, and the conductive component 5.

[0063] In addition, multiple conductive components 5 are arranged in a ring shape along the circumference of the output shaft 22. Compared with the overall ring structure, multiple conductive components 5 are arranged in a ring shape in a split structure, which facilitates the installation and maintenance of conductive components 5, and allows for flexible increase or decrease in the number of conductive components 5 according to actual needs.

[0064] like Figure 4 and Figure 5 As shown, the gearbox 2 also includes a tube shaft 25, which is fixedly installed inside the housing 21. The output shaft 22 is rotatably sleeved on the tube shaft 25. The tube shaft 25 has a shaft hole 251 extending through its axial direction, and a through hole 252 communicating with the shaft hole 251 is opened along its radial direction. One end of a plurality of high-frequency grounding strips 3 passes through the shaft hole 251 and is grounded, and the other end passes through the through hole 252 and is connected to the corresponding conductive block 51 respectively.

[0065] In this embodiment, there are generally four, five, or six conductive components 5, with multiple flanges 511 forming a ring structure. Of course, the number of conductive components 5 can be flexibly adjusted according to actual conditions, i.e., conductive blocks 51 can be added or removed. The number of through holes 252 is the same as the number of conductive blocks 51, and they are arranged directly opposite each other. Similarly, the shaft hole 251 has the same number of high-frequency grounding bands 3 as the through holes 252.

[0066] It should be noted that the high-frequency grounding band 3 inside the shaft hole 251 can be grounded through the two openings of the shaft hole 251. The arrangement trajectory of the high-frequency grounding band 3 can be flexibly adjusted, and no specific limitation is made here.

[0067] In this embodiment, the conductive block 51 includes a flange 511 and a conductive brush 512. The flange 511 is coaxially arranged with the inner hole of the output shaft 22 and fixedly connected to the tube shaft 25. Multiple high-frequency grounding strips 3 passing through the through hole 252 are respectively connected to the corresponding flanges 511. The conductive brush 512 is fixedly connected to the flange 511 and abuts against the wall of the inner hole of the output shaft 22.

[0068] Furthermore, the conductive component 5 also includes conductive fibers 52, and the conductive brush 512 is tightly connected to the inner wall of the output shaft 22 through the conductive fibers 52. The conductive fibers 52 can ensure reliable conductive connection between the conductive brush 512 and the inner wall of the output shaft 22, enhance the conductivity, and at the same time prevent wear of the conductive brush 512.

[0069] like Figure 5 As shown, the gearbox 2 also includes an inner cover 212, which is fixedly sleeved on the tube shaft 25, and the output shaft 22 is rotatably sleeved on the inner cover 212. A flange 511 is fixedly installed on the inner cover 212 near the end face of the rotor assembly 13.

[0070] Specifically, a first positioning hole is provided on the flange 511, and a corresponding second positioning hole is provided on the inner transparent cover 212. The conductive component 5 also includes a fastener 53, which is sequentially inserted into the first positioning hole and the second positioning hole to lock the flange 511 onto the inner transparent cover 212. Multiple high-frequency grounding strips 3 passing through the through hole 252 are wound around the corresponding fasteners 53.

[0071] In this embodiment, the fastener 53 is a bolt, which is threaded into the second positioning hole. By wrapping the high-frequency grounding strip 3 around the bolt, when the bolt is tightened, not only can the flange 511 be fixedly installed on the inner cover 212, but the high-frequency grounding strip 3 can also be locked onto the side of the flange 511, thereby achieving a reliable and stable conductive connection between the flange 511 and the high-frequency grounding strip 3.

[0072] The above embodiments merely illustrate the basic principles and characteristics of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A semi-direct-drive wind turbine generator set, characterized in that, include: The generator (1) includes a stator base (11), stator windings (12) and rotor assembly (13). The gearbox (2) includes a housing (21) and an output shaft (22). The housing (21) is connected to the stator base (11), and the output shaft (22) is rotatably disposed in the housing (21) and is connected to the rotor assembly (13) in a transmission connection. A high-frequency grounding strip (3) is provided, through which the enclosure (21) and the stator base (11) are respectively grounded; and Conductive components (5), the output shaft (22) is provided with a plurality of conductive components (5) along its circumference, so that the output shaft (22) is connected to the high frequency grounding band (3) through the plurality of conductive components (5); The conductive component (5) includes conductive blocks (51), a plurality of conductive blocks (51) are distributed circumferentially along the output shaft (22) and one end of each is tightly connected to the wall of the inner hole of the output shaft (22), and the other end is grounded through the corresponding high-frequency grounding band (3). The gearbox (2) also includes a tube shaft (25), which is fixedly installed inside the housing (21), and the output shaft (22) is rotatably sleeved on the tube shaft (25); The tube shaft (25) has a shaft hole (251) that extends through its axial direction; the tube shaft (25) has a through hole (252) that communicates with the shaft hole (251) along its radial direction; one end of each of the multiple high-frequency grounding strips (3) passes through the shaft hole (251) and is grounded, and the other end passes through the through hole (252) and is connected to the corresponding conductive block (51) respectively.

2. The semi-direct drive wind turbine generator set according to claim 1, characterized in that, The conductive block (51) includes: A flange (511) is coaxially arranged with the inner hole of the output shaft (22) and fixedly connected to the tube shaft (25). Multiple high-frequency grounding strips (3) passing through the through hole (252) are respectively connected to the corresponding flanges (511); and The conductive brush (512) is fixedly connected to the flange (511) and abuts against the inner wall of the output shaft (22).

3. The semi-direct drive wind turbine generator set according to claim 2, characterized in that, The conductive component (5) further includes conductive fibers (52), and the conductive brush (512) is connected to the inner wall of the output shaft (22) through the conductive fibers (52).

4. The semi-direct drive wind turbine generator set according to claim 2, characterized in that, The gearbox (2) also includes an inner cover (212), which is fixedly sleeved on the tube shaft (25), and the output shaft (22) is rotatably sleeved on the inner cover (212); the flange (511) is fixedly installed on the inner cover (212) near the end face of the rotor assembly (13).

5. The semi-direct drive wind turbine generator set according to claim 4, characterized in that, The flange (511) has a first positioning hole, and the inner cover (212) has a corresponding second positioning hole; The conductive component (5) also includes a fastener (53), which is sequentially inserted into the first positioning hole and the second positioning hole to lock the flange (511) onto the inner transparent cover (212); a plurality of high-frequency grounding strips (3) passing through the through hole (252) are wound around the corresponding fasteners (53).

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