CN114726121A - Generator and wind generating set - Google Patents

Abstract

The invention relates to a generator and a wind generating set, wherein the generator comprises a rotor and a stator, one of the rotor and the stator is sleeved on the other of the rotor and the stator, and an annular air gap is formed between the rotor and the stator, wherein the annular air gap is provided with a maximum air gap area and a minimum air gap area which are 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 is gradually reduced from the maximum air gap area to the minimum air gap area. According to the generator and the wind generating set provided by the embodiment of the invention, the generator can meet the requirement of electric energy conversion, the influence of the impeller on the air gap between the rotor and the stator can be weakened or avoided, and the safety performance of the generator is improved.

Description

Generator and wind generating set

Technical Field

The invention relates to the technical field of wind power, in particular to a generator and a wind generating set.

Background

The wind generating set can convert wind energy in the nature into electric energy which can be utilized, and the application is very wide. The wind generating set mainly comprises a direct-drive wind generating set and a double-fed wind generating set.

The rotor of the direct-drive wind generating set is connected with the hub of the impeller, and wind energy absorbed by the impeller can be directly transmitted to the rotating shaft connected with the rotor of the generator. However, the impeller generates bending moment under the action of wind shear, the bending moment acts on the rotor of the generator to cause the rotor to deform, so that an annular air gap formed by the rotor and the stator bracket is reduced, if the air gap value at the partial position of the annular air gap is equal to zero, the rotor and the stator of the generator generate friction, and the rotor and the stator of the generator fail in serious cases, so that potential safety hazards are brought to the safety performance of the generator.

Therefore, a new generator and a wind turbine generator set are needed.

Disclosure of Invention

The embodiment of the invention provides a generator and a wind generating set, wherein the generator can meet the requirement of electric energy conversion, and can weaken or avoid the influence of an impeller on an air gap between a rotor and a stator of the generator, so that the safety performance of the generator is improved.

In one aspect, a generator is provided according to an embodiment of the present invention, which includes a rotor and a stator, where one of the rotor and the stator is disposed around the other one of the rotor and the stator, and an annular air gap is formed between the rotor and the stator, where the annular air gap has a maximum air gap zone and a minimum air gap zone that are distributed at intervals in a circumferential direction of the rotor, and an air gap value of the annular air gap in a radial direction of the rotor gradually decreases from the maximum air gap zone to the minimum air gap zone.

According to one aspect of the embodiment of the present invention, the axis of the stator is radially parallel to and spaced apart from the axis of the rotor.

According to one aspect of the embodiment of the invention, the distance between the axis of the stator and the axis of the rotor is D, wherein D is more than or equal to 2mm and less than or equal to 3 mm.

According to one aspect of the embodiment of the invention, the stator includes a stator bracket having an annular mounting surface whose axis is disposed at a distance from an axis of the rotor, and a core winding connected to the annular mounting surface.

According to one aspect of the embodiment of the invention, the stator support comprises 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, wherein the surface of the stator outer cylinder facing away from the connecting flange forms an annular mounting surface.

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

According to an aspect of the embodiment of the present invention, the core winding includes two or more core winding units, and the two or more core winding units are sequentially distributed in a circumferential direction; and/or the stator support comprises more than two support units which are distributed in the circumferential direction in succession.

In another aspect, an embodiment of the present invention provides a wind turbine generator system, including: a tower; the engine room is arranged at one end of the tower in the height direction of the tower; the shafting structure comprises a movable shaft and a fixed shaft which are coaxially arranged and rotationally connected, and the fixed shaft is connected with the engine room; in the generator, the rotor is connected with the moving shaft, and the stator is connected with the fixed shaft; the impeller is connected with the moving shaft; wherein, the minimum air gap area and the maximum air gap area are oppositely arranged in the height direction.

According to one aspect of the embodiment of the invention, the rotor is coaxially arranged with the shafting structure, and the axis of the stator is arranged at an interval with the axis of the shafting structure.

According to one aspect of the embodiment of the invention, the movable shaft is inserted into the fixed shaft, and the minimum air gap area is positioned on the side, away from the tower, of the maximum air gap area; or the fixed shaft is inserted in the movable shaft, and the maximum air gap area is positioned on the side of the minimum air gap area, which faces away from the tower.

According to the generator and the wind generating set provided by the embodiment of the invention, the generator comprises the rotor and the stator which are sleeved with each other and form the annular air gap between the rotor and the stator, when the generator is used for the wind generating set, the rotor can be connected with the moving shaft, the stator can be connected with the fixed shaft, and the rotor is driven to rotate relative to the stator through the impeller, so that the electric energy conversion requirement of the generator is met. Because the annular air gap has the maximum air gap area and the minimum air gap area in the circumferential direction of the rotor, and from the maximum air gap area to the minimum air gap area, the air gap value of the annular air gap in the radial direction of the rotor is gradually reduced, when wind shear acts on the impeller to cause the rotor to deform and move downwards to the side where the tower is located, the air gap value difference of the annular air gap in each circumferential position can be used for compensating the deformation of the rotor, the influence of the impeller on the annular air gap between the rotor and the stator under the limit working condition is weakened or avoided, the air gap value of each annular air gap is ensured to be always larger than zero, the design cost of the generator is reduced, the safety performance of the generator is improved, and the power generation benefit of the wind generating set can be ensured.

Drawings

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

FIG. 1 is a schematic view of the overall structure of a wind turbine generator system according to an embodiment of the present invention;

FIG. 2 is a schematic view of a partial structure of a wind turbine generator set according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of the generator and shafting configuration in accordance with an embodiment of the present invention;

FIG. 4 is a schematic diagram of a generator according to an embodiment of the present invention;

FIG. 5 is a schematic structural view of a stator of one embodiment of the present invention;

FIG. 6 is a schematic structural view of a stator of another embodiment of the present invention;

FIG. 7 is a schematic structural view of a stator of yet another embodiment of the present invention;

FIG. 8 is a schematic structural view of a rotor of one embodiment of the present invention;

fig. 9 is a schematic structural view of a generator according to another embodiment of the present invention.

Wherein:

100-a generator;

10-a rotor; 11-a rotor support; 111-a support; 112-rotor outer cylinder; 12-magnetic steel;

20-a stator; 21-a stator support; 21 a-a scaffold unit; 211-connecting flange; 212-a stator outer barrel; 212 a-annular mounting surface; 213-a linker; 213 a-connecting rod; 22-core windings; 22 a-core winding unit;

30-an annular air gap; 31-maximum air gap region; 32-minimum air gap zone;

200-a tower;

300-a nacelle; 301-a base;

400-an impeller; 410-a hub; 420-a blade;

500-shafting structure; 510-a moving shaft; 520-fixed axis;

x-circumferential direction; y-radial; z-height direction.

In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

Detailed Description

Features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended 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 some well-known structures and techniques have not been shown in detail in order to avoid unnecessarily obscuring the present invention; also, the dimensions of some of the structures may be exaggerated for clarity. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

The following description is given with the directional terms shown in the drawings, and is not intended to limit the specific structure of the generator and the wind turbine generator system of the present invention. In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "mounted" and "connected" are to be interpreted broadly, e.g., as either a fixed connection, a removable connection, or an integral connection; can be directly connected or indirectly connected. The specific meaning of the above terms in the present invention can be understood as appropriate to those of ordinary skill in the art.

For better understanding of the present invention, a generator and a wind turbine generator set according to an embodiment of the present invention will be described in detail with reference to fig. 1 to 9.

As shown in fig. 1 to 3, an embodiment of the present invention provides a wind turbine generator set, which includes a tower 200, a nacelle 300, a generator 100, a shafting structure 500, and an impeller 400. The tower 200 is connected to a wind turbine foundation, and the nacelle 300 is disposed at one end of the tower 200 in the height direction Z thereof. Nacelle 300 includes a base 301, and nacelle 300 is capable of being coupled to tower 200 and shafting structure 500 via base 301. Shafting structure 500 includes a rotating mating moving shaft 510 and a fixed shaft 520, and fixed shaft 520 is connected to base 301 of nacelle 300. The generator 100 is provided 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 disposed on the other and an annular air gap is formed therebetween, the rotor 10 is connected to a 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, and the impeller 400 is connected to the moving shaft 510 through the hub 410. When wind acts on the blades 420, the blades 420 drive the hub 410 to rotate, and the moving shaft 510 of the shaft system structure 500 is connected to the hub 410, so that the moving shaft 510 can rotate relative to the fixed shaft 520, and further drive the rotor 10 to rotate relative to the stator 20, thereby realizing the power generation requirement of the wind generating set.

For a direct-drive wind generating set, as shown in fig. 2, under the action of wind shear force, the upper thrust F1 of the impeller 400 is greater than the lower thrust F2, and an impeller bending moment is generated. The bending moment of the impeller acts on the rotor 10 of the generator 100 through the moving shaft 510, so that the rotor 10 deforms, an annular air gap between the stator 20 and the rotor 10 of the generator 100 is reduced, once the annular air gap is reduced to zero or below, the generator 100 risks friction between the stator 20 and the rotor 10, and in a severe case, the generator 100 directly fails, and huge loss is brought to the wind generating set.

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 system, the embodiment of the present invention further provides a novel generator 100, which can be used as an independent component, and of course, can also be used for the wind turbine generator system provided in the above embodiment and be a component of the wind turbine generator system.

As shown in fig. 3 and 4, a generator 100 provided in an embodiment of the present invention includes a rotor 10 and a stator 20, one of the rotor 10 and the stator 20 is disposed by being sleeved on the other and an annular air gap 30 is formed therebetween, wherein the annular air gap 30 has a maximum air gap zone 31 and a minimum air gap zone 32 which are distributed at intervals in a circumferential direction X of the rotor 10, and an air gap value m of the annular air gap 30 in the maximum air gap zone 31 is greater than an air gap value n of the annular air gap 30 in the minimum air gap zone 32. The annular air gap 30 gradually decreases in air gap value in the radial direction Y of the rotor 10 from the maximum air gap zone 31 to the minimum air gap zone 32.

The generator 100 provided by the embodiment of the present invention has the annular air gap 30 having the largest air gap zone 31 and the smallest air gap zone 32 in the circumferential direction X of the rotor 10, and from the maximum air gap zone 31 to the minimum air gap zone 32, the air gap value of the annular air gap 30 in the radial direction Y of the rotor 10 gradually decreases, when wind shear acts on the impeller 400 to cause the rotor 10 to deform and move down the side of the tower 200, the air gap value difference of the annular air gap 30 at each position in the circumferential direction X can be used for compensating the deformation of the rotor 10, the deformation influence of the impeller 400 on the annular air gap 30 between the rotor 10 and the stator 20 under the extreme working condition is weakened or avoided, the risk that the annular air gap 30 is locally zero to cause the mutual friction and scratch between the rotor 10 and the stator 20 is reduced, and the sizes of the existing rotor 10 and stator 20 do not need to be changed, the design cost of the generator 100 is reduced, and the generating benefit of the wind generating set is ensured.

As an alternative embodiment, the axis of the stator 20 and the axis of the rotor 10 are arranged in parallel and spaced in the radial direction Y of the rotor 10. The performance requirement that the air gap value of the annular air gap 30 in the radial direction Y of the rotor 10 is gradually reduced from the maximum air gap zone 31 to the minimum air gap zone 32 is ensured by translating the stator 20 in the radial direction Y so that the axis of the stator 20 is parallel to and spaced from the axis of the rotor 10.

In some alternative embodiments, the distance between the axis of the stator 20 and the axis of the rotor 10 may be D, wherein the value of D may be any value between 2mm and 3mm, including both 2mm and 3 mm. By setting the axial line of the stator 20 and the axial line of the rotor 10 to the above distance range, when the rotor 10 moves downwards due to deformation caused by wind shear action of the impeller 400, 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 can be better changed in the downward movement process of the rotor 10, so that the values of the two values tend to be consistent under the action of wind shear, thereby not only ensuring the power generation requirement, but also designing the radial dimensions of the rotor 10 and the stator 20 of the generator 100 to be smaller as required on the basis of meeting the power generation requirement of the generator 100, and saving the cost of the design of the generator 100 and the actual production of products.

In order to better understand the generator 100 provided by the embodiment of the present invention, the generator 100 is taken as an outer 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 the annular air gap 30 with the stator 20.

As shown in fig. 3 to 5, as an alternative implementation manner, in the generator 100 according to the embodiment of the present invention, the stator 20 includes a stator bracket 21 and a core winding 22, the stator bracket 21 has an annular mounting surface 212a, an axis of the annular mounting surface 212a is spaced from an axis of the rotor 10, and the core winding 22 is connected to the annular mounting surface 212 a. By arranging the axis of the annular mounting surface 212a of the stator bracket 21 and the axis of the rotor 10 at intervals, the iron core winding 22 mounted on the annular mounting surface 212a can be effectively ensured to be eccentrically arranged relative to the rotor 10, and the formation of the annular air gap 30 is facilitated.

In some alternative embodiments, the stator frame 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 212 a. The stator support 21 adopts the above structural form, which is beneficial 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.

Optionally, when the stator support 21 is formed, the axis of the stator support 21 may be set to coincide with the axis of the shafting structure 500 on the machine tool, and the bolt hole on the connecting flange 211 is machined. Then, the axis of the stator support 21 is shifted to one side of the axis deviated from the shafting structure 500, for example, to six o' clock direction, the shift amount can be any value between 2mm to 3mm, and then the stator outer cylinder 212 is processed, so that the forming of the stator support 21 is facilitated, the performance requirement of the annular air gap 30 is ensured, and the connection requirement of the stator 20 and the shafting structure 500 through the bolt hole on the connecting flange 211 can be effectively ensured.

As an alternative implementation manner, in the generator 100 provided by the embodiment of the present invention, the connection body 213 may include more than two connection rods 213a spaced in the circumferential direction X, and one end of each connection rod 213a is connected to the connection flange 211 and the other end is connected to the stator outer cylinder 212. The connecting body 213 has the above-mentioned structure, and has a simple structure, and can reduce the overall weight of the stator 20 while ensuring the strength requirement thereof.

In some alternative embodiments, the connecting bar 213a opposite to the maximum air gap zone 31 may be shorter than the connecting bar 213a opposite to the minimum air gap zone 32, which facilitates the formation of the annular air gap 30 in the embodiments of the present invention.

As shown in fig. 6, in some alternative embodiments, the core winding 22 includes more than two core winding units 22a, and the more than two core winding units 22a are distributed in succession in the circumferential direction X. The core winding 22 has the above structure, which is beneficial to the molding and can reduce the cost of the whole stator 20. Since the core winding 22 and other components of the stator 20 need to be formed in a vacuum environment, the vacuum equipment for forming the vacuum environment is expensive, and particularly, the vacuum equipment has a large volume. If the components such as the core winding 22 are integrally formed, the overall size thereof is large, and accordingly, a larger vacuum apparatus is required to create a vacuum environment, which will certainly increase the production cost of the stator 20 as a whole. Therefore, the core winding 22 is spliced by more than two core winding 22 units, so that the production cost of the stator 20 can be reduced on the basis of meeting the molding requirement of the core winding 22.

As shown in fig. 7, as an alternative implementation manner, the stator support 21 of the generator 100 provided in the embodiment of the present invention may include more than two support units 21a, and the more than two support units 21a are sequentially distributed in the circumferential direction X. Similarly, the stator support 21 is spliced by two or more support units 21a, so that the production cost of the whole stator 20 can be further reduced, and the transportation of the generator 100 is facilitated.

In some alternative embodiments, the number of the core winding units 22a may be the same as that of the support units 21a, and the core winding units 22a and the support units 21a may be arranged in a one-to-one correspondence, and by the above arrangement, the core winding units 22a and the support units 21a may be connected to each other, and then the support units 21a may be spliced to form the stator 20.

As shown in fig. 8, alternatively, the generator 100 according to the embodiment of the present invention may include a rotor 10 including a rotor frame 11 and a magnetic steel 12 disposed on the rotor frame 11, where the magnetic steel 12 is disposed on the rotor frame 11. The rotor bracket 11 includes a support portion 11 and a rotor outer cylinder 112, the magnetic steel 12 is disposed on a 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 for connecting with the rotor 10.

It is understood that the generator 100 provided in the above embodiments of the present invention is exemplified by the generator 100 being an outer rotor generator, which is an alternative embodiment. As shown in fig. 9, in some embodiments, the generator 100 may also be an internal rotor generator, that is, the stator 20 of the generator 100 is sleeved outside 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 zone 31 and a minimum air gap zone 32 which are 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 zone 31 to the minimum air gap zone 32, which can also meet the performance requirement of the generator 100.

The generator 100 provided by the embodiment of the invention breaks through the technical idea that the air gap values of the annular air gaps in the radial direction Y at all positions in the circumferential direction X of the rotor 10 in the conventional technology are the same, and adopts the technical scheme that even if the rotor 10 and the stator 20 are eccentrically arranged at the beginning of the design of the generator 100, the annular air gap 30 formed between the rotor 10 and the stator 20 has the maximum air gap zone 31 and the minimum air gap zone 32, and the air gap value of the annular air gap 30 in the radial direction Y of the rotor 10 is gradually reduced from the maximum air gap zone 31 to the minimum air gap zone 32.

When the wind turbine generator system is applied to a wind turbine generator system, the maximum air gap area 31 and the minimum air gap area 32 may be arranged opposite to each other in the height direction Z of the tower 200, and when the generator 100 is an external rotor generator, that is, the rotor 10 of the generator 100 is sleeved on the stator 20 of the generator 100, and the movable shaft 510 is inserted into the fixed shaft 520, at this time, the maximum air gap area 31 is located on a side of the minimum air gap area 32 away from the tower 200. When the generator 100 is an internal rotor generator, i.e. the stator 20 of the generator 100 is sleeved on the rotor 10 of the generator 100, the fixed shaft 520 is inserted into the movable shaft 510, and the minimum air gap zone 32 is located on a side of the maximum air gap zone 31 facing away from the tower 200. When the rotor 10 of the generator 100 is deformed and displaced due to the wind shear of the impeller 400, the rotor 10 is displaced towards the side of the tower 200 relative to the stator 20, in the form of an external rotor generator or an internal rotor generator, as shown in fig. 2, under the action of the acting forces F1 and F2, since F1 is greater than F2, the rotor 10 is moved towards 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 zone 31 and the minimum air gap zone 32 is gradually reduced, the deformation of the rotor 10 can be compensated, the air gap value of one side of the annular air gap 30 in the height direction Z is prevented from becoming zero, and the friction and the scratch between the rotor 10 and the stator 20 are effectively prevented.

For example, if the value of the air gap in the radial direction Y at each position of the annular air gap 30 defined in the conventional design is 5mm, the deformation of the rotor 10 to the side of the tower 200 due to the wind shear of the impeller 400 is 3mm, which results in the reduction of the annular air gap by 3mm, the value of the air gap between the rotor 10 and the stator 20 at the side close to the tower 200 of the generator 100 will become 2mm, the stator 20 will expand outwards under the action of the thermal stress due to the main heat distribution of the generator 100 on the core windings 22 of the stator 20, and the loss on the rotor 10 is relatively small, and the thermal expansion amount of the rotor 10 is relatively small. Therefore, the annular air gap 30 between the stator 20 and the rotor 10 of the generator 100 is reduced, and if the value of the annular air gap caused by the deformation of the stator 20 is reduced to 2mm due to the thermal stress, the value of the air gap between the stator 20 and the rotor 10 on the side of the generator 100 close to the tower 200, such as the 6 o' clock direction, is reduced to zero, and the friction contact is scraped, which undoubtedly brings a hidden danger to the safe operation of the generator 100 and even the wind generating set. If the conventional design manner is adopted, in order to avoid friction and rubbing 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, for example, to a value of 6mm, 7mm or even higher, which not only increases the design cost, but also increases the sizes of the rotor 10 and the stator 20, and the increase of the air gap value affects the generated energy of the generator 100, which is not beneficial to the generation benefit of the wind generating set.

In the generator 100 according to the embodiment of the present invention, since the rotor 10 and the stator 20 are already eccentrically disposed in the initial state, the formed annular air gap 30 has the maximum air gap zone 31 and the minimum air gap zone 32, the air gap value of the maximum air gap zone 31 in the initial state is set to be 7mm, the air gap value of the minimum air gap zone 32 is set to be 3mm, and the air gap value of the annular air gap 30 between the two is gradually changed. When the wind shear causes the deformation and displacement of the rotor 10 by 3mm, the air gap value change value of the maximum air gap area 31 of the annular air gap 30 is 4mm, and the air gap value change corresponding to the minimum air gap area 32 is 6mm, even if the air gap value is reduced by 2mm due to the synchronous occurrence of the thermal deformation of the stator 20, the maximum air gap area 31 is changed to 2mm, and the minimum air gap area 32 is changed to 4mm, so that the contact and scratch phenomena of the rotor 10 and the stator 20 caused by the deformation of the rotor 10 and the stator 20 can be avoided.

And the size of the rotor 10 and/or the stator 20 of the generator 100 does not need to be increased, and in some examples, the size of the rotor 10 or the stator 20 of the power generation part can be reduced on the existing basis, so that the design and the production cost of the generator 100 are saved. And since the iron core winding 22 of the stator 20 of the generator 100 is formed by connecting coils at different circumferential positions in series for each phase, the problem of unbalanced three-phase voltage caused by static eccentricity of the rotor 10 and the stator 20 itself is avoided. Meanwhile, because the direct-drive wind generating set is in a normal installation state, the gravity of the rotor 10 acts, the bearings used for connecting the moving shaft 510 and the fixed shaft 520 in the shafting structure 500 can be under the action of gravity load, and the eccentric arrangement of the rotor 10 and the stator 20 is adopted, so that the magnetic field suction force of one side (six o 'clock direction of the generator 100) of the generator 100 close to the tower frame 200 is larger than the suction force of one side (twelve o' clock direction of the generator 100) far away from the tower frame 200, the stress of the bearing in the radial direction can be reduced, and the service life of the shafting structure 500 is prolonged.

In addition, after the generator 100 provided by the embodiment of the invention adopts the eccentric arrangement scheme between the rotor 10 and the stator 20, the design air gap of the generator 100 can be reduced, so that the usage amount of the NdFeB permanent magnets of the motor rotor 10 is reduced.

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, i.e.

T∝B×I

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

where k is a coefficient close to 1, i.e., a kappa coefficient, in relation to the slot size and the air gap length of the stator 20.

It can be seen that if the same air gap 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, so that the purpose of reducing the usage amount of the NdFeB permanent magnet is achieved, and the overall cost of the generator 100 is reduced.

As an alternative implementation manner, when the generator 100 is used in a wind turbine generator system, the rotor 10 may be coaxially disposed with the shafting structure 500, and the axis of the stator 20 may be spaced from the axis of the shafting structure 500. Through the arrangement, on the basis of meeting the requirement of eccentric arrangement of the rotor 10 and the stator 20 and ensuring the performance requirement of the annular air gap 30, the kinetic energy obtained by the shafting structure 500 through the impeller 400 can be ensured to drive the rotor 10 and the stator 20 to move relatively, so that the conversion requirement of electric energy is met.

The wind generating set provided by the embodiment of the invention comprises the generator 100 provided by each embodiment, on the basis of meeting the requirement of converting wind energy into electric energy, because the annular air gap 30 has a maximum air gap zone 31 and a minimum air gap zone 32 in the circumferential direction X of the rotor 10, and from the maximum air gap zone 31 to the minimum air gap zone 32, the air gap value of the annular air gap 30 in the radial direction Y of the rotor 10 gradually decreases, when wind shear acts on the impeller 400 to cause the rotor 10 to deform and move down the side of the tower 200, the air gap value difference of the annular air gap 30 at each position in the circumferential direction X can be used for compensating the deformation of the rotor 10, the influence of the impeller 400 on the annular air gap 30 between the rotor 10 and the stator 20 under the limit working condition is weakened or avoided, the air gap value of each position of the annular air gap 30 is always larger than zero, the design and production processing cost is reduced, and the safety performance and the power generation benefit are higher.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (10)

1. Generator (100) comprising a rotor (10) and a stator (20), one of said rotor (10) and said stator (20) being arranged one over the other with an annular air gap (30) formed therebetween,

wherein the annular air gap (30) has a maximum air gap zone (31) and a minimum air gap zone (32) which are 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) is gradually reduced from the maximum air gap zone (31) to the minimum air gap zone (32).

2. The electrical generator (100) of claim 1, wherein the axis of the stator (20) is parallel to and spaced from the axis of the rotor (10) in the radial direction (Y).

3. The generator (100) of claim 2, characterised in that the distance between the axis of the stator (20) and the axis of the rotor (10) is D, wherein D is 2mm ≦ 3 mm.

4. The generator (100) of claim 1, wherein the stator (20) includes a stator bracket (21) and a core winding (22), the stator bracket (21) having an annular mounting surface (212a), an axis of the annular mounting surface (212a) being spaced apart from an axis of the rotor (10), the core winding (22) being connected to the annular mounting surface (212 a).

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

6. The generator (100) according to claim 5, wherein the connecting body (213) comprises two or more connecting rods (213a) spaced apart in the circumferential direction (X), and each connecting rod (213a) has one end connected to the connecting flange (211) and the other end connected to the stator outer cylinder (212).

7. The generator (100) according to claim 4, wherein the core winding (22) comprises more than two core winding units (22a), the more than two core winding units (22a) being distributed one after the other in the circumferential direction (X);

and/or the stator support (21) comprises more than two support units (21a), and the more than two support units (21a) are distributed in the circumferential direction (X) in sequence.

8. A wind turbine generator set, comprising:

a tower (200);

a nacelle (300) provided at one end of the tower (200) in the height direction (Z) thereof;

the shafting structure (500) comprises a movable shaft (510) and a fixed shaft (520) which are coaxially arranged and rotatably connected, wherein the fixed shaft (520) is connected to the engine room (300);

the electrical generator (100) of any one of claims 1 to 7, the rotor (10) being connected to the moving shaft (510), the stator (20) being connected to the fixed shaft (520);

an impeller (400) connected to the moving shaft (520);

wherein the minimum air gap zone (32) and the maximum air gap zone (31) are arranged opposite in the height direction (Z).

9. Wind park according to claim 8, wherein the rotor (10) is arranged coaxially with the shafting structure (500), and wherein the axis of the stator (20) is spaced apart from the axis of the shafting structure (500).

10. Wind park according to claim 8, wherein the moving shaft (510) is plugged inside the dead axle (520), the minimum air gap zone (32) being located at a side of the maximum air gap zone (31) facing away from the tower (200);

or the fixed shaft (520) is inserted into the moving shaft (510), and the maximum air gap area (31) is positioned on the side, away from the tower (200), of the minimum air gap area (32).

Images