Generators and wind turbines

Abstract

The present invention relates to a generator and a wind turbine generator set, wherein the generator comprises a rotor and a stator, wherein one of the rotor and the stator is sleeved on the other and an annular air gap is formed between them, wherein the annular air gap has a maximum air gap area and a minimum air gap area which are spaced apart in the circumferential direction of the rotor, and the air gap value of the annular air gap in the radial direction of the rotor gradually decreases from the maximum air gap area to the minimum air gap area. The generator and the wind turbine generator set provided by the embodiments of the present invention can meet the requirements of electric energy conversion, and can weaken or avoid the influence of the impeller on the air gap between its rotor and stator, thereby improving the safety performance of the generator.

Description

Technical Field

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

[0002] Wind turbines can convert natural wind energy into usable electrical energy and are widely used. Wind turbines mainly include direct-drive wind turbines and doubly-fed wind turbines.

[0003] The rotor of a direct-drive wind turbine is connected to the hub of the impeller, and the wind energy absorbed by the impeller is directly transmitted to the rotating shaft connected to the rotor of the generator. However, the impeller will generate bending moment under the action of wind shear, which will cause the rotor to deform when acting on the rotor of the generator, thereby reducing the annular air gap formed by the rotor and the stator bracket. If the air gap value of some positions of the annular air gap is equal to zero, the rotor and stator of the generator will produce friction, which may cause the rotor and stator of the generator to fail in severe cases, posing a hidden danger to the safety performance of the generator.

[0004] Therefore, a new generator and wind turbine generator set are urgently needed. Summary of the invention

[0005] The embodiments of the present invention provide a generator and a wind turbine generator set. The generator can meet the demand for electric energy conversion and can weaken or avoid the influence of the impeller on the air gap between its rotor and stator, thereby improving the safety performance of the generator.

[0006] On the one hand, according to an embodiment of the present invention, a generator is proposed, including a rotor and a stator, one of the rotor and the stator is arranged inside the other and an annular air gap is formed between them, wherein the annular air gap has a maximum air gap area and a minimum air gap area distributed at intervals in the circumferential direction of the rotor, and the air gap value of the annular air gap in the radial direction of the rotor gradually decreases from the maximum air gap area to the minimum air gap area.

[0007] According to one aspect of the embodiments of the present invention, the axis of the stator and the axis of the rotor are parallel to and spaced apart from each other in the radial direction.

[0008] According to one aspect of the embodiments of the present invention, the distance between the axis of the stator and the axis of the rotor is D, wherein 2 mm ≤ D ≤ 3 mm.

[0009] According to one aspect of the embodiments of the present invention, the stator includes a stator support and a core winding, the stator support has an annular mounting surface, the axis of the annular mounting surface is spaced apart from the axis of the rotor, and the core winding is connected to the annular mounting surface.

[0010] According to one aspect of the embodiment of the present invention, the stator bracket includes a connecting flange, a stator outer cylinder arranged around the connecting flange, and a connecting body connecting the connecting flange and the stator outer cylinder, and the surface of the stator outer cylinder facing away from the connecting flange forms an annular mounting surface.

[0011] According to one aspect of the embodiments of the present invention, the connecting body includes two or more connecting rods spaced apart in the circumferential direction, one end of each connecting rod is connected to the connecting flange and the other end is connected to the stator outer cylinder.

[0012] According to one aspect of an embodiment of the present invention, the core winding includes more than two core winding units, which are distributed successively in the circumferential direction; and / or the stator bracket includes more than two bracket units, which are distributed successively in the circumferential direction.

[0013] On the other hand, according to an embodiment of the present invention, a wind turbine generator set is proposed, comprising: a tower; a nacelle, arranged at one end of the tower in its own height direction; an axis system structure, comprising a moving shaft and a fixed shaft coaxially arranged and rotatably connected, the fixed shaft being connected to the nacelle; the above-mentioned generator, the rotor being connected to the moving shaft, and the stator being connected to the fixed shaft; an impeller, connected to the moving shaft; wherein the minimum air gap area and the maximum air gap area are arranged relatively to each other in the height direction.

[0014] According to one aspect of the embodiment of the present invention, the rotor is coaxially arranged with the shaft system structure, and the axis of the stator is spaced apart from the axis of the shaft system structure.

[0015] According to one aspect of an embodiment of the present invention, the moving shaft is inserted into the interior of the fixed shaft, and the minimum air gap area is located on the side of the maximum air gap area away from the tower; or, the fixed shaft is inserted into the interior of the moving shaft, and the maximum air gap area is located on the side of the minimum air gap area away from the tower.

[0016] According to the generator and wind turbine generator set provided by the embodiment of the present invention, the generator includes a rotor and a stator which are mutually nested and have an annular air gap formed therebetween. When used in a wind turbine generator set, the rotor can be connected to the moving shaft, and the stator can be connected to the fixed shaft. The rotor is driven to rotate relative to the stator through the impeller to meet the power conversion requirements of the generator. Since the annular air gap has a maximum air gap area and a minimum air gap area in the circumferential direction of the rotor, and the air gap value of the annular air gap in the radial direction of the rotor gradually decreases from the maximum air gap area to the minimum air gap area, when the shear of the wind acts on the impeller to cause the rotor to deform and move downward to the side where the tower is located, the air gap value difference of the annular air gap at various locations in the circumferential direction can be used to compensate for the deformation of the rotor, weaken or avoid the influence of the impeller on the annular air gap between the rotor and the stator under extreme working conditions, ensure that the air gap value at various locations of the annular air gap is always greater than zero, reduce the design cost of the generator, improve its safety performance, and ensure the power generation efficiency of the wind turbine generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Features, advantages, and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

[0018] Figure 1 is a schematic diagram of the overall structure of a wind turbine generator set according to an embodiment of the present invention;

[0019] Figure 2 is a partial structural schematic diagram of a wind turbine generator set according to an embodiment of the present invention;

[0020] Figure 3 is a schematic diagram of the coordination between a generator and a shaft system structure according to an embodiment of the present invention;

[0021] Figure 4 is a schematic structural diagram of a generator according to an embodiment of the present invention;

[0022] Figure 5 is a schematic structural diagram of a stator according to an embodiment of the present invention;

[0023] Figure 6 is a schematic structural diagram of a stator according to another embodiment of the present invention;

[0024] Figure 7 is a structural schematic diagram of a stator according to another embodiment of the present invention;

[0025] Figure 8 is a schematic structural diagram of a rotor according to an embodiment of the present invention;

[0026] Fig. 9 It is a schematic structural diagram of a generator according to another embodiment of the present invention.

[0027] in:

[0028] 100 - generator;

[0029] 10- rotor; 11- rotor bracket; 111- support part; 112- rotor outer cylinder; 12- magnetic steel;

[0030] 20-stator; 21-stator bracket; 21a-bracket unit; 211-connection flange; 212-stator outer cylinder; 212a-annular mounting surface; 213-connector; 213a-connecting rod; 22-core winding; 22a-core winding unit;

[0031] 30-annular air gap; 31-maximum air gap area; 32-minimum air gap area;

[0032] 200-tower;

[0033] 300-cabin; 301-base;

[0034] 400-impeller; 410-hub; 420-blade;

[0035] 500-shaft structure; 510-moving shaft; 520-fixed shaft;

[0036] X-circumferential direction; Y-radial direction; Z-height direction.

[0037] In the drawings, the same reference numerals are used for the same components. The drawings are not drawn to scale. DETAILED DESCRIPTION

[0038] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed in order to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. In the drawings and the following description, at least part of the known structures and technologies are not shown in order to avoid unnecessary ambiguity of the present invention; and, for clarity, the size of some structures may be exaggerated. In addition, the features, structures or characteristics described below may be combined in one or more embodiments in any suitable manner.

[0039] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the generator and wind turbine generator set of the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" 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 directly connected or indirectly connected. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0040] In order to better understand the present invention, Figures 1 to 9 A generator and a wind turbine generator set according to the embodiments of the present invention are described in detail.

[0041] like Figures 1 to 3As shown, an embodiment of the present invention provides a wind turbine generator set, including a tower 200, a nacelle 300, a generator 100, a shaft structure 500 and an impeller 400. The tower 200 is connected to the wind turbine foundation, and the nacelle 300 is arranged at one end of the tower 200 in its own height direction Z. The nacelle 300 includes a base 301, and the nacelle 300 can be connected to the tower 200 and the shaft structure 500 through the base 301. The shaft structure 500 includes a rotating shaft 510 and a fixed shaft 520, and the fixed shaft 520 is connected to the base 301 of the nacelle 300. The generator 100 is arranged in the nacelle 300. The generator 100 includes a rotor 10 and a stator 20, one of the stator 20 and the rotor 10 is arranged in a sleeve on the other and an annular air gap is formed between each other, the rotor 10 is connected to the fixed shaft 520, and the stator 20 is connected to the fixed shaft 520. The impeller 400 includes a hub 410 and a plurality of blades 420 connected to the hub 410. The impeller 400 is connected to the drive shaft 510 through the hub 410. When wind acts on the blades 420, the blades 420 drive the hub 410 to rotate. Since the drive shaft 510 of the shaft system structure 500 is connected to the hub 410, the drive shaft 510 can rotate relative to the fixed shaft 520, thereby driving the rotor 10 to rotate relative to the stator 20, thereby achieving the power generation demand of the wind turbine generator set.

[0042] For direct-drive wind turbines, Figure 2 As shown, under the action of wind shear force, the thrust F1 on the impeller 400 is greater than the thrust F2 on the bottom, generating an impeller bending moment. The impeller bending moment acts on the rotor 10 of the generator 100 through the moving shaft 510, causing the rotor 10 to deform, which will cause the annular air gap between the stator 20 and the rotor 10 of the generator 100 to decrease. Once the annular air gap decreases to zero or below, the generator 100 will have the risk of friction between the stator 20 and the rotor 10, which will cause the generator 100 to fail directly in severe cases, causing huge losses to the wind turbine generator set.

[0043] Therefore, in order to better weaken or avoid the influence of the impeller 400 on the deformation of the annular air gap between the rotor 10 and the stator 20 of the generator 100, improve the safety performance of the generator 100, and ensure the power generation efficiency of the wind turbine generator set, the embodiment of the present invention also provides a new type of generator 100, which can be used as an independent component, and of course can also be used in the wind turbine generator set provided in the above embodiment and as a component of the wind turbine generator set.

[0044] like Figure 3As shown in FIG. 4 , the generator 100 provided in the embodiment of the present invention comprises a rotor 10 and a stator 20, wherein one of the rotor 10 and the stator 20 is sleeved in the other and an annular air gap 30 is formed between them, wherein the annular air gap 30 has a maximum air gap area 31 and a minimum air gap area 32 distributed at intervals in the circumferential direction X of the rotor 10, and the air gap value m of the annular air gap 30 in the maximum air gap area 31 is greater than the air gap value n of the annular air gap 30 in the minimum air gap area 32. From the maximum air gap area 31 to the minimum air gap area 32, the air gap value of the annular air gap 30 in the radial direction Y of the rotor 10 gradually decreases.

[0045] The generator 100 provided by the embodiment of the present invention has an annular air gap 30 with a maximum air gap area 31 and a minimum air gap area 32 in the circumferential direction X of the rotor 10, and the air gap value of the annular air gap 30 in the radial direction Y of the rotor 10 gradually decreases from the maximum air gap area 31 to the minimum air gap area 32. When the wind shear acts on the impeller 400 to cause the rotor 10 to deform and move downward to the side where the tower 200 is located, the air gap value difference of the annular air gap 30 at various locations in the circumferential direction X can be used to compensate for the deformation of the rotor 10, weaken or avoid the influence of the impeller 400 on the deformation of the annular air gap 30 between the rotor 10 and the stator 20 under extreme working conditions, reduce the risk of friction and scraping between the rotor 10 and the stator 20 caused by the local zero annular air gap 30, and there is no need to change the sizes of the existing rotor 10 and the stator 20, thereby reducing the design cost of the generator 100 and ensuring the power generation efficiency of the wind turbine generator set.

[0046] As an optional embodiment, the axis of the stator 20 and the axis of the rotor 10 are parallel and spaced apart in the radial direction Y of the rotor 10. By translating the stator 20 in the radial direction Y, the axis of the stator 20 and the axis of the rotor 10 are parallel and spaced apart, which is conducive to the formation of the annular air gap 30 and can ensure that the air gap value of the annular air gap 30 in the radial direction Y of the rotor 10 gradually decreases from the maximum air gap area 31 to the minimum air gap area 32.

[0047] In some optional embodiments, the distance between the axis of the stator 20 and the axis of the rotor 10 can be set to D, wherein the value of D can be any value between 2 mm and 3 mm, including the two end values ​​of 2 mm and 3 mm. By setting the axis of the stator 20 and the axis of the rotor 10 to the above distance range, when the rotor 10 is deformed and moves downward due to the wind shear effect on the impeller 400, the rotor 10 can better change the air gap value of the annular air gap 30 in the maximum air gap area 31 and the air gap value of the minimum air gap area 32 during the downward movement, so that the values ​​of the two tend to be consistent under the effect of wind shear, which can not only ensure the power generation requirements, but also on the basis of meeting the power generation requirements of the generator 100, the radial dimensions of the rotor 10 and the stator 20 of the generator 100 can be designed to be smaller as needed, saving the design of the generator 100 and the cost of actual product production.

[0048] In order to better understand the generator 100 provided in the embodiment of the present invention, the generator 100 is taken as an external rotor generator as an example, that is, the rotor 10 of the generator 100 is sleeved on the stator 20 of the generator 100 and forms an annular air gap 30 with the stator 20.

[0049] like Figures 3 to 5 As shown, as an optional implementation, the generator 100 provided in the embodiment of the present invention, the stator 20 includes a stator bracket 21 and an iron core winding 22, the stator bracket 21 has an annular mounting surface 212a, the axis of the annular mounting surface 212a is spaced apart from the axis of the rotor 10, and the iron core winding 22 is connected to the annular mounting surface 212a. By making the axis of the annular mounting surface 212a of the stator bracket 21 spaced apart from the axis of the rotor 10, it can effectively ensure that the iron core winding 22 installed on the annular mounting surface 212a is eccentrically arranged relative to the rotor 10, which is conducive to the formation of the annular air gap 30.

[0050] In some optional embodiments, the stator support 21 includes a connecting flange 211, a stator outer cylinder 212 disposed around the connecting flange 211, and a connecting body 213 connecting the stator outer cylinder 212 and the connecting flange 211, and a surface of the stator outer cylinder 212 facing away from the connecting flange 211 forms an annular mounting surface 212a. The stator support 21 adopts the above-mentioned structural form, which is conducive to the molding of the stator support 21 and can effectively ensure the formation of the annular air gap 30 between the stator 20 and the rotor 10.

[0051] Optionally, when the stator bracket 21 is formed, the axis of the stator bracket 21 can be set on a machine tool to coincide with the axis of the shaft structure 500, and the bolt holes on the connecting flange 211 can be processed. Then the axis of the stator bracket 21 is offset to the side away from the axis of the shaft structure 500, for example, to the six o'clock direction, and the offset can be any value between 2mm and 3mm, and then the stator outer cylinder 212 is processed, which is conducive to the forming of the stator bracket 21, ensuring the performance requirements of the annular air gap 30, and can effectively ensure the connection requirements of the stator 20 with the shaft structure 500 through the bolt holes on the connecting flange 211.

[0052] As an optional implementation, the generator 100 provided in the embodiment of the present invention, its connector 213 may include two or more connector rods 213a spaced apart in the circumferential direction X, one end of each connector rod 213a is connected to the connecting flange 211 and the other end is connected to the stator outer cylinder 212. The connector 213 adopts the above-mentioned structural form, which is simple in structure and can reduce the overall weight of the stator 20 while ensuring the strength requirements of the stator 20.

[0053] In some optional embodiments, the connecting rod 213a disposed opposite to the maximum air gap area 31 may be shorter than the connecting rod 213a disposed opposite to the minimum air gap area 32, which is beneficial to the formation of the annular air gap 30 in the embodiment of the present invention.

[0054] like Figure 6 As shown, in some optional embodiments, the core winding 22 includes more than two core winding units 22a, and the more than two core winding units 22a are distributed successively in the circumferential direction X. The core winding 22 adopts the above-mentioned structural form, which is conducive to its molding and can reduce the overall cost of the stator 20. Since the core winding 22 and other components of the stator 20 need to be molded in a vacuum environment, the vacuum equipment used to form the vacuum environment is relatively expensive, especially the vacuum equipment with a larger volume. If the core winding 22 and other components are molded as a whole, due to their larger overall size, larger vacuum equipment is required to create a vacuum environment, which will undoubtedly increase the overall production cost of the stator 20. Therefore, by adopting the splicing form of more than two core winding 22 units for the core winding 22, the production cost of the stator 20 can be reduced on the basis of meeting the molding requirements of the core winding 22.

[0055] like Figure 7 As shown, as an optional implementation, the generator 100 provided in the embodiment of the present invention, its stator bracket 21 may include more than two bracket units 21a, and the more than two bracket units 21a are distributed successively in the circumferential direction X. Similarly, by using the stator bracket 21 in the form of splicing more than two bracket units 21a, the overall production cost of the stator 20 can be further reduced, and the transportation of the generator 100 is facilitated.

[0056] In some optional embodiments, the number of core winding units 22a can be the same as the number of bracket units 21a and can be arranged one-to-one. Through the above arrangement, the formed core winding units 22a and the corresponding bracket units 21a can be connected to each other, and then the bracket units 21a can be spliced ​​to form the stator 20.

[0057] like Figure 8 As shown, optionally, the generator 100 provided in the embodiment of the present invention, its rotor 10 may include a rotor support 11 and a magnetic steel 12 arranged on the rotor support 11, and the magnetic steel 12 is arranged on the rotor support 11. The rotor support 11 includes a support portion 11 and a rotor outer cylinder 112, the magnetic steel 12 is arranged on the surface of the rotor outer cylinder 112 facing the stator 20, and the support portion 111 is located at one end of the rotor outer cylinder 112 on the shaft system and is used to connect with the rotor 10.

[0058] It is understandable that the generator 100 provided in the above embodiments of the present invention is described by taking the generator 100 as an outer rotor generator as an example, which is an optional implementation. Fig. 9 As shown, in some embodiments, the generator 100 can also be an inner rotor generator, that is, the stator 20 of the generator 100 is sleeved on the outside of the rotor 10 of the generator 100, and the annular air gap 30 formed between the rotor 10 and the stator 20 has a maximum air gap area 31 and a minimum air gap area 32 distributed at intervals in the circumferential direction X of the rotor 10, and the air gap value of the annular air gap 30 in the radial direction Y of the rotor 10 gradually decreases from the maximum air gap area 31 to the minimum air gap area 32, which can also meet the performance requirements of the generator 100.

[0059] The generator 100 provided in the embodiment of the present invention breaks the technical idea in the conventional technology that the air gap values ​​of the annular air gaps in the circumferential direction X of the rotor 10 are the same at all locations in the radial direction Y. Instead, the generator 100 is designed so that the rotor 10 and the stator 20 are eccentrically arranged at the beginning, and the annular air gap 30 formed between the rotor 10 and the stator 20 has a maximum air gap area 31 and a minimum air gap area 32, and the air gap value of the annular air gap 30 in the radial direction Y of the rotor 10 gradually decreases from the maximum air gap area 31 to the minimum air gap area 32.

[0060] When it is applied to a wind turbine generator set, the maximum air gap area 31 and the minimum air gap area 32 can be arranged relative to each other in the height direction Z of the tower 200. When the generator 100 is an outer rotor generator, that is, the rotor 10 of the generator 100 is sleeved on the stator 20 of the generator 100, and the moving shaft 510 is plugged into the inside of the fixed shaft 520, the maximum air gap area 31 is located at the side of the minimum air gap area 32 away from the tower 200. When the generator 100 is an inner rotor generator, that is, the stator 20 of the generator 100 is sleeved on the rotor 10 of the generator 100, and the fixed shaft 520 is plugged into the inside of the moving shaft 510, the minimum air gap area 32 is located at the side of the maximum air gap area 31 away from the tower 200. When the rotor 10 of the generator 100 is deformed and displaced due to the impeller 400 being subjected to wind shear, the rotor 10 will be displaced relative to the stator 20 to the side where the tower 200 is located, whether it is an outer rotor generator or an inner rotor generator, such as Figure 2 As described in, under the action of the forces F1 and F2, since F1 is greater than F2, the rotor 10 will move in the direction of the tower 200 along the height direction Z, so that the difference between the air gap values ​​of the maximum air gap area 31 and the minimum air gap area 32 is gradually reduced, which can compensate for the deformation of the rotor 10, avoid the air gap value of the annular air gap 30 on one side of the height direction Z from becoming zero, and effectively avoid friction and scratching between the rotor 10 and the stator 20.

[0061] For example, if the annular air gap 30 in the conventional design is limited to an air gap value of 5 mm at each location in the radial direction Y, the rotor 10 is deformed and displaced 3 mm toward the side where the tower 200 is located due to the wind shear of the impeller 400, which will cause the annular air gap to decrease by 3 mm. Then, the air gap value between the rotor 10 and the stator 20 of the generator 100 on the side close to the tower 200 will become 2 mm. Since the main heat of the generator 100 is distributed on the core winding 22 of the stator 20, the stator 20 will expand outward under the action of thermal stress, while the loss on the rotor 10 is relatively small, and the thermal expansion of the rotor 10 is relatively small. This will cause the annular air gap 30 between the stator 20 and the rotor 10 of the generator 100 to decrease. If the annular air gap value decreases by 2mm due to the deformation of the stator 20 caused by thermal stress, the air gap value between the stator 20 and the rotor 10 of the generator 100 on the side close to the tower 200, such as the side at 6 o'clock, will be reduced to zero, and frictional contact will cause scratches, which will undoubtedly bring hidden dangers to the safe operation of the generator 100 and even the wind turbine. If the conventional design method is used, in order to avoid frictional scratches between the stator 20 and the rotor 30, the air gap value of the annular air gap 30 between the rotor 10 and the stator 20 needs to be increased, such as increasing to 6mm, 7mm or even higher values, which not only increases the design cost, but also will lead to an increase in the size of the rotor 10 and the stator 20. In addition, the increase in the air gap value will affect the power generation of the generator 100, which is not conducive to the power generation efficiency of the wind turbine.

[0062] In the generator 100 provided by the embodiment of the present invention, since the rotor 10 and the stator 20 are eccentrically arranged in the initial state, the annular air gap 30 formed has a maximum air gap area 31 and a minimum air gap area 32. The air gap value of the maximum air gap area 31 in the initial state is set to 7mm, and the air gap value of the minimum air gap area 32 is set to 3mm, and the air gap value of the annular air gap 30 is in a gradual state between the two. When the wind shear causes the rotor 10 to deform and shift by 3mm, the air gap value of the maximum air gap area 31 of the annular air gap 30 will change by 4mm, and the corresponding air gap value of the minimum air gap area 32 will change to 6mm. Even if the stator 20 is heated and deformed at the same time, causing the air gap value to decrease by 2mm, the maximum air gap area 31 will change to 2mm, and the corresponding air gap area 32 will change to 4mm, which can avoid the contact and scraping between the rotor 10 and the stator 20 due to the deformation of the rotor 10 and the stator 20.

[0063] And there is no need to increase the size of the rotor 10 and / or stator 20 of the generator 100. In some examples, the size of the rotor 10 or stator 20 of the generator 100 can be reduced on the existing basis, saving the design and production costs of the generator 100. And because each phase of the core winding 22 of the stator 20 of the generator 100 is composed of coils in series at different circumferential positions, the problem of three-phase voltage imbalance will not be caused by the static eccentricity of the rotor 10 and the stator 20. At the same time, because the gravity of the rotor 10 acts on the direct-drive wind turbine generator set in a normal installation state, the bearings used to connect the moving shaft 510 and the fixed shaft 520 in the shaft structure 500 will be subject to the gravity load. The eccentric setting of the rotor 10 and the stator 20 will make the magnetic field suction force of the generator 100 close to the tower 200 side (the six o'clock direction of the generator 100) greater than the suction force away from the tower 200 side (the twelve o'clock direction of the generator 100), thereby reducing the force on the bearing in the radial direction and improving the service life of the shaft structure 500.

[0064] In addition, by using the generator 100 provided in the embodiment of the present invention, after adopting an eccentric arrangement between the rotor 10 and the stator 20 , the designed air gap of the generator 100 can also be reduced, thereby reducing the amount of NdFeB permanent magnets used in the motor rotor 10 .

[0065] According to the design principle of the generator 100, the torque T of the generator 100 is approximately proportional to the air gap flux density B and the stator 20 current I, that is,

[0066] T∝B×I

[0067] The relationship between the air gap flux density B, the thickness hm of the magnetic steel 12 and the radial air gap value gap of the annular air gap 30 is as follows:

[0068]

[0069] Wherein, k is a coefficient close to 1 related to the slot size and air gap length of the stator 20, namely, the Carter coefficient.

[0070] It can be seen that if the same air gap magnetic flux density B needs to be obtained, when the air gap value gap of the generator 100 is reduced, the thickness hm of the magnetic steel 12 can also be reduced accordingly, thereby achieving the purpose of reducing the amount of NdFeB permanent magnets used, and further reducing the overall cost of the generator 100.

[0071] As an optional implementation, the generator 100 provided in the embodiment of the present invention, when used in a wind turbine generator set, can make the rotor 10 and the shaft structure 500 coaxially arranged, and the axis of the stator 20 and the axis of the shaft structure 500 spaced apart. Through the above arrangement, on the basis of satisfying the eccentric arrangement of the rotor 10 and the stator 20 and ensuring the performance requirements of the annular air gap 30, it can also ensure that the kinetic energy of the impeller 400 is obtained through the shaft structure 500 to drive the rotor 10 and the stator 20 to move relative to each other, so as to achieve the conversion requirements of electric energy.

[0072] The wind turbine generator set provided by the embodiment of the present invention includes the generator 100 provided by the above embodiments. On the basis of meeting the demand for converting wind energy into electric energy, since the annular air gap 30 has a maximum air gap area 31 and a minimum air gap area 32 in the circumferential direction X of the rotor 10, and from the maximum air gap area 31 to the minimum air gap area 32, the air gap value of the annular air gap 30 in the radial direction Y of the rotor 10 gradually decreases. When the wind shear acts on the impeller 400, causing the rotor 10 to deform and move downward to the side where the tower 200 is located, the air gap value difference of the annular air gap 30 at various locations in the circumferential direction X can be used to compensate for the deformation of the rotor 10, weaken or avoid the influence of the impeller 400 on the annular air gap 30 between the rotor 10 and the stator 20 under extreme working conditions, ensure that the air gap value at each location of the annular air gap 30 is always greater than zero, reduce the design and production and processing costs, and have higher safety performance and power generation efficiency.

[0073] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A generator (100), characterized in that: The invention comprises a rotor (10) and a stator (20), wherein one of the rotor (10) and the stator (20) is sleeved on the other and an annular air gap (30) is formed between the two. The annular air gap (30) has a maximum air gap area (31) and a minimum air gap area (32) which are spaced apart in the circumferential direction (X) of the rotor (10); the air gap value of the annular air gap (30) in the radial direction (Y) of the rotor (10) gradually decreases from the maximum air gap area (31) to the minimum air gap area (32); and the axis of the stator (20) and the axis of the rotor (10) are parallel in the radial direction (Y) and are spaced apart.

2. The generator (100) according to claim 1, characterized in that: The distance between the axis of the stator (20) and the axis of the rotor (10) is D, wherein 2 mm ≤ D ≤ 3 mm.

3. The generator (100) according to claim 1, characterized in that: The stator (20) comprises a stator support (21) and an iron core winding (22); the stator support (21) has an annular mounting surface (212a); the axis of the annular mounting surface (212a) is spaced apart from the axis of the rotor (10); and the iron core winding (22) is connected to the annular mounting surface (212a).

4. The generator (100) according to claim 3, characterized in that: The stator support (21) comprises a connecting flange (211), a stator outer cylinder (212) arranged around the connecting flange (211), and a connecting body (213) connecting the connecting flange (211) and the stator outer cylinder (212); a surface of the stator outer cylinder (212) facing away from the connecting flange (211) forms the annular mounting surface (212a).

5. The generator (100) according to claim 4, characterized in that: The connecting body (213) comprises more than two connecting rods (213a) spaced apart in the circumferential direction (X), one end of each connecting rod (213a) being connected to the connecting flange (211) and the other end being connected to the stator outer cylinder (212).

6. The generator (100) according to claim 3, characterized in that: The iron core winding (22) comprises more than two iron core winding units (22a), and the more than two iron core winding units (22a) are distributed successively in the circumferential direction (X); And / or, the stator support (21) includes more than two support units (21a), and the more than two support units (21a) are distributed successively in the circumferential direction (X).

7. A wind turbine generator set, characterized in that: include: Tower (200); A cabin (300) is arranged at one end of the tower (200) in its own height direction (Z); A shaft system structure (500) comprises a moving shaft (510) and a fixed shaft (520) which are coaxially arranged and rotatably connected, wherein the fixed shaft (520) is connected to the nacelle (300); The generator (100) according to any one of claims 1 to 6, wherein the rotor (10) is connected to the moving shaft (510), and the stator (20) is connected to the fixed shaft (520); An impeller (400) connected to the moving shaft (510); The minimum air gap area (32) and the maximum air gap area (31) are arranged relative to each other in the height direction (Z).

8. The wind turbine generator set according to claim 7, characterized in that: The rotor (10) and the shaft system structure (500) are coaxially arranged, and the axis of the stator (20) and the axis of the shaft system structure (500) are spaced apart.

9. The wind turbine generator set according to claim 7, characterized in that: The moving shaft (510) is inserted into the interior of the fixed shaft (520), and the minimum air gap area (32) is located on a side of the maximum air gap area (31) away from the tower (200); Alternatively, the fixed shaft (520) is inserted into the interior of the moving shaft (510), and the maximum air gap area (31) is located on a side of the minimum air gap area (32) away from the tower (200).

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