Integrated semi-direct-drive permanent magnet wind driven generator rotor structure

Abstract

The invention relates to an integrated semi-direct-drive permanent magnet wind driven generator rotor structure, which is supported by a high-speed shaft of a gear box, and comprises a rotor bracket, a rotor shaft, a rotor shaft, a rotor shaft and a rotor shaft, labyrinth type sealing is adopted between the insulation flange plate and a gear box small end cover connected to the gear box rear end cover, a plurality of sets of double-wing type rotor magnetic poles are evenly arranged on the outer side of the rotor support in the circumferential direction, and the rotor support is formed by connecting a rotor support body, a shaft barrel and a flange. The generator rotor structure has the advantages of being compact, high in power density, low in cost, good in manufacturability, high in reliability and the like, and the problems that an existing lower half direct-driven wind driven generator is high in cost, free of shaft current restraining measures, difficult to maintain on line, large in weight, poor in sealing performance and the like are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine generators, and in particular to an integrated semi-direct-drive permanent magnet wind turbine generator rotor structure. Background Art

[0002] Wind energy is widely used around the world as a clean and renewable energy source. The wind power industry has developed rapidly in recent years. Semi-direct drive wind turbines are favored by people because of their high efficiency and low maintenance costs.

[0003] The advantages of direct-drive wind turbines are: high power generation efficiency, high reliability, low operation and maintenance costs, low noise, long life, and good grid access performance; the disadvantages are: complex structure, high cost, high dependence on permanent magnetic materials, large size and weight, and difficulty in lifting and transportation.

[0004] The advantages of doubly-fed wind turbines are: good speed regulation performance, improved power factor of the power grid, small excitation capacity, easy maintenance, mature technology and low cost; the disadvantages are: high maintenance cost, high operating noise, weak low voltage ride-through capability, slip ring carbon brush problems, high harmonic content and limited ability to respond to power grid faults.

[0005] Semi-direct drive wind turbines have the advantages of direct drive and doubly fed wind turbines, while avoiding the disadvantages of both. Under fierce market competition and cost pressure, semi-direct drive wind turbines and gearboxes are developing in the direction of integration, compactness, high power density, light weight, low cost, and high reliability. In order to meet the needs of cost reduction and efficiency improvement, the existing wind turbine topology needs to be optimized.

[0006] The current semi-direct drive permanent magnet wind turbines generally have the following problems: 1. Online maintenance is difficult; 2. The interfaces of different manufacturers and locations are various and lack unification and standardization; 3. The design awareness in terms of integration, lightweight, simplification and low cost is relatively weak; 4. It is impossible to effectively avoid the damage caused by shaft current to bearings and gears.

[0007] In view of this, this invention is proposed. Summary of the invention

[0008] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art. The present invention relates to a motor rotor, and in particular to an integrated semi-direct-drive permanent magnet wind generator rotor structure, which has the advantages of high integration, compact structure, high power density, low cost, good processability, high reliability, etc., and solves the problems of high cost, no shaft current suppression measures, diverse interface designs, difficult online maintenance, heavy weight, poor sealing performance, etc. of current semi-direct-drive wind generators. It not only reduces the weight of the system, but also allows online maintenance and replacement of components. It is suitable for the mainstream 10MW to 20MW semi-direct-drive permanent magnet wind generators in the current wind power market.

[0009] An integrated semi-direct-drive permanent magnet wind turbine rotor structure of the present invention is supported by a high-speed shaft of a gear box, and comprises: a rotor bracket, one end of which is connected to a brake disc, and the other end is sealed with an insulating flange, a labyrinth seal is adopted between the insulating flange and a small end cover of the gear box connected to the rear end cover of the gear box, a plurality of groups of double-wing rotor poles are evenly arranged on the outer circumference of the rotor bracket, and the rotor bracket is formed by a rotor bracket body, a shaft cylinder and a flange connection.

[0010] Furthermore, the shaft cylinder is located in the middle of the rotor support, a rotor support body is arranged at one end close to the insulating flange, and a connecting flange is arranged at one end away from the insulating flange.

[0011] Furthermore, a centrifugal fan is installed on the side end surface of the rotor support body away from the insulating flange.

[0012] Furthermore, observation holes are provided on the middle partition plate of the rotor support body and the shaft cylinder, and a detachable observation hole cover is provided on the outer side of the observation hole.

[0013] Furthermore, after the brake disc is integrally connected to the grounding ring, it is connected to the rotor bracket through a stopper by a transition fit.

[0014] Furthermore, a pole box is provided for each group of the double-wing rotor poles, and four permanent magnets are installed in the pole box. The double-wing rotor poles are fastened by pull rods in the axial direction and fixed to the rotor bracket in the radial direction by bolts. A positioning key is provided in the middle of the lower end of the double-wing rotor pole, which is matched and connected with a key slot provided on the rotor bracket.

[0015] Furthermore, based on the middle partition of the rotor support body, a plurality of first reinforcing ribs are arranged on the inner wall along one side of the rotor support body, and a plurality of second reinforcing ribs are arranged on the inner wall along the other side, and weight-reducing holes are opened on the first reinforcing ribs and the second reinforcing ribs.

[0016] Furthermore, a pressure ring is provided on one side of the insulating flange where the insulating layer is provided, and a portion of the insulating layer of the insulating flange that contacts the air is coated with insulating sealant.

[0017] Furthermore, a support tube is connected between the rear end cover of the gear box and the small end cover of the gear box, and a vent hole is provided on the side of the small end cover of the gear box close to the insulating flange. A labyrinth seal is adopted between the insulating flange and the small end cover of the gear box, and the axial sealing gap is 4 mm and the radial sealing gap is 1 mm.

[0018] Furthermore, one end of the gearbox high-speed shaft is fixedly connected to the small end cover of the gearbox, and the other end is connected to the insulating flange by transition fit and bolts, and the outer diameter of the support tube is smaller than the inner diameter of the shaft tube and the flange.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] (1) Easy online maintenance: An elliptical hole and a detachable observation hole cover are opened on the shaft of the rotor bracket, which increases the operating space for maintenance personnel and facilitates personnel to inspect the internal conditions of the motor while reducing the weight. The inner diameter of the shaft and flange of the rotor bracket is larger than the outer diameter of the support tube and insulating flange of the gearbox. When the shaft on the gearbox side fails, the support tube and insulating flange can be pulled out from the shaft for inspection and replacement. The purpose of this design is to enable faster online maintenance or replacement of parts. In addition, an observation hole cover is designed at the transmission end of the generator to check the connection status of the gearbox and the generator.

[0021] (2) Unified interface: A unified interface design is adopted, such as the strength, size, specifications of the connecting bolts, the diameter of each distribution circle, and the number of openings. This facilitates production management, reduces the number of parts, and reduces manufacturing and operation and maintenance costs.

[0022] (3) Adopt an integrated, lightweight, simplified and low-cost design: the integrated rotor bracket combines the rotor bracket, shaft tube and brake disc into an integrated rotor bracket, which saves costs and facilitates production management; the rotor bracket has multiple weight-reducing holes and operation and maintenance holes in the partition, reinforcement ribs and shaft tube, which reduces the weight of the rotor bracket, reduces the difficulty of operation and maintenance, and reduces energy consumption, which facilitates production management; the magnetic circuit is optimized to be the shortest, saves materials, improves motor efficiency, and improves comprehensive economic benefits;

[0023] (4) Combining dredging and blocking to prevent the harm of shaft current: In terms of dredging, a grounding ring is designed to use a grounding brush to conduct the shaft current. The grounding ring material is made of stainless steel to prevent rust. In terms of blocking, an insulating flange design is adopted. Insulating materials with high dielectric strength and mechanical strength are used to block the shaft current and transmit torque, thereby eliminating the electrical corrosion of the gearbox bearings and gears caused by the shaft current. In addition, the comprehensive cost of the insulating flange is much lower than that of the insulating bearing, and its performance is better than that of the insulating bearing.

[0024] (5) The labyrinth seal + vent design of the insulating flange can effectively prevent the oil mist of the gearbox from entering the cabin, polluting the environment, bringing the risk of fire, and endangering personal safety; the insulating flange and insulating glue protect the insulating material and prevent the insulating material from becoming conductive and failing due to moisture. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1It is a schematic diagram of the rotor structure of the integrated semi-direct drive permanent magnet wind turbine generator of the present invention;

[0026] Figure 2 It is a schematic diagram of the rotor structure AA of the integrated semi-direct drive permanent magnet wind turbine generator of the present invention;

[0027] Figure 3 For the present invention Fig. 9 The schematic diagram of the structure of the connection between the insulating flange and the small end cover of the gearbox in the generator rotor structure in the middle part I;

[0028] Figure 4 It is a structural schematic diagram of coating insulating glue on the insulating flange in the generator rotor structure of the present invention;

[0029] Figure 5 It is a structural schematic diagram of a rotor support in the generator rotor structure of the present invention;

[0030] Figure 6 It is a schematic side view of the structure of the rotor support in the generator rotor structure of the present invention;

[0031] Figure 7 For the present invention Fig.10 The schematic diagram of the structure of the double-wing rotor pole in the generator rotor structure in the middle part III;

[0032] Figure 8 It is a schematic cross-sectional structure diagram of a double-wing rotor pole in the generator rotor structure of the present invention;

[0033] Fig. 9 It is a schematic diagram of the standardization of various interfaces of the rotor structure of the integrated semi-direct-drive permanent magnet wind turbine generator of the present invention;

[0034] Fig.10 It is a side schematic diagram of the standardization of various interfaces of the integrated semi-direct-drive permanent magnet wind generator rotor structure of the present invention.

[0035] Among them, 1-rear end cover of gearbox; 2-support cylinder; 3-high-speed shaft of gearbox; 4-small end cover of gearbox; 5-insulating flange; 6-pressure ring; 7-rotor bracket body; 8-brake disc; 9-grounding ring; 10-centrifugal fan; 11-observation hole cover; 12-first reinforcement rib; 13-second reinforcement rib; 14-rotor pole; 141-permanent magnet; 142-pull rod; 143-positioning key; 15-insulating sealant; 16-shaft cylinder; 17-flange; 18-vent. DETAILED DESCRIPTION

[0036] The embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0037] According to an embodiment of the present invention, referring to the attached Figure 1-2 As shown, the rotor structure of the integrated semi-direct drive permanent magnet wind turbine generator of the present invention is mainly divided into five parts, namely, the rear end cover 1 of the gearbox, the rotor bracket, the rotor pole 14, the insulating flange 5 and the brake disc 8. The rear end cover 1 of the gearbox does not belong to the category of the generator. The reason why it appears here is mainly because the integrated generator and the gearbox share the high-speed shaft of the gearbox, and the generator rotor is supported by the high-speed shaft 3 of the gearbox. Figure 3 As shown, the gearbox high-speed shaft 3 is supported by the gearbox rear end cover 1 for easy understanding. Specifically, one end of the rotor support is connected to the brake disc 8, and the other end is sealed with the insulating flange 5. The insulating flange 5 is connected to the gearbox small end cover 4 connected to the gearbox rear end cover 1 by a labyrinth seal, and multiple groups of double-wing rotor poles 14 are evenly arranged on the outer circumference of the rotor support.

[0038] According to an embodiment of the present invention, Figure 3 As shown, in order to prevent the high-temperature oil mist generated by the operation of the gearbox, the present invention designs a labyrinth seal between the insulating flange 5 and the small end cover 4 of the gearbox; in addition, a vent 18 is provided on the small end cover 4 of the gearbox to balance the internal and external air pressure. The insulating flange 5 is used to prevent the electrical corrosion of the shaft current on the bearing, and the insulating material with high insulation strength and mechanical strength is used to block the channel of the shaft current. Specifically, in order to prevent the high temperature of the gearbox operation from gasifying the lubricating oil, the oil mist diffuses into the cabin through the generator air gap, causing environmental pollution, affecting vision and judgment, and also posing a fire hazard. A labyrinth seal is used between the insulating flange 5 and the small end cover 4 of the gearbox. The radial clearance of the labyrinth is generally 1 mm, and the axial clearance is generally 4 mm. The specific values ​​are designed based on the assembly dimension chain and the manufacturing level of the parts and the level of the assembly process.

[0039] According to an embodiment of the present invention, a support tube 2 is connected between the rear end cover 1 of the gearbox and the small end cover 4 of the gearbox, and a vent hole 18 is provided on the side of the small end cover 4 of the gearbox close to the insulating flange 5. The vent hole 18 is to maintain the balance of internal and external pressures to avoid damage to the gearbox caused by excessive internal pressure of the gearbox. In the present invention, the materials used for the rear end cover 1, support tube 2 and small end cover 4 of the gearbox are ductile iron, and the materials used for the insulating flange 5 are Q345D steel plate and EPGC epoxy glass cloth laminate. The labyrinth seal of the small end cover 4 of the gearbox and the coaxiality accuracy of the insulating flange 5 are required to be high, otherwise the labyrinth of the small end cover 4 of the gearbox and the insulating flange 5 will interfere, the air gap between the stator and the rotor will be uneven, vibration will be generated, and the performance of the motor will be affected. The insulating flange 5 and the high-speed shaft 3 of the gearbox are connected and transmitted by transition fit and bolts. The insulating flange 5 and the rotor bracket are connected and transmitted by transition fit and bolts.

[0040] According to the embodiment of the present invention, the insulating flange 5 is used to prevent the electric corrosion of the shaft current on the bearing. The insulating material EPGC laminate with high insulation strength and mechanical strength is used to block the passage of the shaft current. The thickness of the EPGC laminate is usually 6mm, which reduces the capacitance value of the insulating flange 5, because the capacitance is inversely proportional to the thickness (C = ε0ε r A / d, C is capacitance, unit is farad F; ε0 is the dielectric constant of vacuum 8.854187817×10 -12 , unit F / m; ε r is the relative dielectric constant of the material; A is the area covered by the two electrode plates, in m 2 ; d is the distance between the two electrode plates, unit m. ), thereby increasing the capacitive reactance value of the flange Xc = 1 / (2πfC) (Xc: is the capacitive reactance, unit Ω; f is the frequency of AC, unit Hz; C is the capacitance, unit Farad F.), except for the insulating material, the rest of the materials are Q345D steel plates, and in order to improve the ability to transmit torque, it is not advisable to use too high a precision of the surface roughness of the mating surface, which will reduce the friction coefficient. The insulating flange 5 uses transition fit and bolts for connection and torque transmission.

[0041] According to an embodiment of the present invention, Figure 4 As shown, the insulation performance of the insulating flange 5 is crucial. In operation, there are inevitably harsh environments such as humidity, heat, salt spray, and mold. After moisture enters the insulating material, the insulation performance is reduced or fails, and the shaft current cannot be effectively blocked. The insulating flange 5 is sealed with a high-strength insulating sealant 15 in contact with the air to prevent external moisture and foreign matter such as dust from entering the insulating material. A pressing ring 6 is provided on the side of the insulating flange 5 where the insulating layer is provided, and its function is to press the insulating layer, so that the insulating layer is evenly stressed as a whole, thereby increasing its service life. Instead of using bolts and steel washers to tighten one by one in a scattered manner.

[0042] According to an embodiment of the present invention, Figure 5-6As shown, the rotor bracket is designed in an integrated manner, and the rotor bracket is designed to be composed of a rotor bracket body 7, a shaft barrel 16 and a flange 17. The three-in-one integrated welding structure saves manufacturing costs, reduces the number of parts, and improves reliability. The materials are all Q345D steel plates. The integrated rotor bracket and the insulating flange 5 are connected and transmit torque by transition fit and bolts. The middle partition of the rotor bracket body 7 is provided with a weight-reducing hole and is equipped with a detachable observation hole cover 11. The shaft barrel 16, the first reinforcing rib 12 and the second reinforcing rib 13 are also designed with weight-reducing holes. The size of the weight-reducing holes conforms to ergonomics and is convenient for checking and maintaining the internal conditions of the generator. After the gearbox and the generator are integrated, the high-speed shaft 3 of the gearbox must be disassembled and repaired from the shaft barrel 16 and flange 17 of the rotor bracket of the generator, so the inner diameter of the shaft barrel 16 and the flange 17 must be larger than the outer diameter of the small end cover 3 of the gearbox before they can be disassembled and replaced. The shaft barrel 16 is located in the middle of the rotor bracket, and the rotor bracket body 7 is provided at one end close to the insulating flange 5, and the flange 17 is connected at the end away from the insulating flange 5. Observation holes are provided on the middle partition of the rotor support body 7 and the shaft cylinder 16 , and a detachable observation hole cover plate 11 is provided on the outer side of the observation hole.

[0043] According to an embodiment of the present invention, Figure 7-8 As shown, the magnetic circuit of the rotor pole 14 is optimized, and a pole box is provided for each group of the double-wing rotor poles 14. Four permanent magnets 141 are installed in the pole box. The double-wing rotor poles 14 are fastened by a pull rod 142 in the axial direction and are fixed to the rotor bracket by bolts in the radial direction. A positioning key 143 is provided in the middle of the lower end of the double-wing rotor pole 14. The double-wing rotor pole 14 is connected with the keyway provided on the rotor bracket to reduce the weight of the rotor bracket. Considering the factors such as generator efficiency, magnetic flux density, heat generation, mechanical strength, and cost, a double-wing magnetic circuit design is adopted to make the magnetic circuit as short as possible, with the highest efficiency, the lightest weight, and the lowest cost. The main material of the rotor pole 14 is 50WW400 silicon steel sheet with self-adhesive coating. The permanent magnet 141 is made of high-performance rare earth permanent magnet material neodymium iron boron (NdFeB). The permanent magnet 141 is installed in the pole box of the rotor pole 14. The rotor pole 14 is fastened into a whole by an axial pull rod 142 and is fastened to the rotor bracket in the radial direction with bolts.

[0044] According to an embodiment of the present invention, Figure 1-2As shown, a centrifugal fan 10 is installed on the side end face of the rotor support body 7 away from the insulating flange 5. A small centrifugal fan 10 is installed on the end face of the rotor support to stir the air during operation so that the temperature of the stator and rotor tends to be uniform. The centrifugal fan material is Q345D steel plate welded and fastened to the end face of the rotor support 7 by bolts. The brake disc 8 and the grounding ring 9 are two-in-one, which avoids the coaxiality deviation caused by the two-piece assembly, aggravates the vibration and wear of the brush, reduces the number of parts, and reduces the production and management costs. The material of the brake disc 8 is Q345D steel plate, and the material of the grounding ring is 304 stainless steel. After the brake disc 8 and the grounding ring 9 are two-in-one, they are connected to the rotor support 7 through the stop transition fit and then fastened together by bolts.

[0045] According to an embodiment of the present invention, Figure 9-10 As shown, the matching deviations of the matching diameters D1, D2, D3, D4, and D5, as well as the diameters of the distribution circles D6, D7, D8, and D9 and the number and size of the bolts are all unified into standardized sizes and matching, which is convenient for batch manufacturing and production management and reduces costs.

[0046] The present invention is an integrated semi-direct-drive permanent magnet wind turbine rotor structure. The overall rotor layout is highly integrated, and it has the advantages of being highly compact, high power density, low cost, and good processability. Compared with the traditional semi-direct-drive permanent magnet wind turbine rotor, it solves the problems of difficult online maintenance, inconsistent interfaces, integrated, lightweight, simplified, low-cost design, and the ability to effectively prevent shaft currents from damaging bearings and gears. It integrates a variety of advanced structures and concepts to form a classic rotor structure, which helps the technological development of the wind power industry. At the same time, this technology can be extended to other motor fields.

[0047] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

Claims

1. An integrated semi-direct drive permanent magnet wind turbine rotor structure, supported by a gearbox high-speed shaft (3), characterized in that: include: A rotor bracket, one end of the rotor bracket is connected to a brake disc (8), and the other end is sealed to an insulating flange (5), a labyrinth seal is used between the insulating flange (5) and a small end cover (4) of a gear box connected to a rear end cover (1) of the gear box, and a plurality of groups of double-wing rotor poles (14) are evenly arranged on the outer circumference of the rotor bracket, The rotor support is formed by connecting a rotor support body (7), a shaft cylinder (16) and a flange (17).

2. The integrated semi-direct drive permanent magnet wind turbine generator rotor structure according to claim 1 is characterized in that: The shaft cylinder (16) is located in the middle of the rotor support, and a rotor support body (7) is arranged at one end close to the insulating flange (5), and a connecting flange (17) is arranged at one end away from the insulating flange (5).

3. The integrated semi-direct drive permanent magnet wind turbine generator rotor structure according to claim 1 is characterized in that: A centrifugal fan (10) is installed on the side end surface of the rotor support body (7) away from the insulating flange (5).

4. The integrated semi-direct drive permanent magnet wind turbine generator rotor structure according to claim 1 is characterized in that: An observation hole is provided on the middle partition plate of the rotor support body (7) and the shaft cylinder (16), and a detachable observation hole cover plate (11) is provided on the outside of the observation hole.

5. The integrated semi-direct drive permanent magnet wind turbine generator rotor structure according to claim 1 is characterized in that: The brake disc (8) and the grounding ring (9) are connected integrally and then connected to the rotor bracket through a stopper by means of a transition fit.

6. The integrated semi-direct drive permanent magnet wind turbine rotor structure according to claim 1, characterized in that: Each group of the double-wing rotor poles (14) is provided with a pole box, in which four permanent magnets (141) are installed. The double-wing rotor poles (14) are fastened in the axial direction by a pull rod (142) and are fixed to the rotor bracket in the radial direction by bolts. A positioning key (143) is provided in the middle of the lower end of the double-wing rotor poles (14) and is matched and connected with a key slot provided on the rotor bracket.

7. The integrated semi-direct drive permanent magnet wind turbine generator rotor structure according to claim 1, characterized in that: Taking the middle partition of the rotor support body (7) as a reference, a plurality of first reinforcing ribs (12) are arranged along the inner wall of one side of the rotor support body, and a plurality of second reinforcing ribs (13) are arranged along the inner wall of the other side, and weight-reducing holes are opened on both the first reinforcing ribs (12) and the second reinforcing ribs (13).

8. The integrated semi-direct drive permanent magnet wind turbine generator rotor structure according to claim 1, characterized in that: A pressing ring (6) is provided on the side of the insulating flange (5) where the insulating layer is provided, and the portion of the insulating layer of the insulating flange (5) in contact with air is sealed with an insulating sealant (15).

9. The integrated semi-direct drive permanent magnet wind turbine generator rotor structure according to claim 1, characterized in that: A support cylinder (2) is connected between the rear end cover (1) of the gear box and the small end cover (4) of the gear box, and a vent hole (18) is provided on one side of the small end cover (4) of the gear box close to the insulating flange (5). The insulating flange (5) and the small end cover (4) of the gear box are connected by a labyrinth seal, with an axial sealing gap of 4 mm and a radial sealing gap of 1 mm.

10. The integrated semi-direct drive permanent magnet wind turbine generator rotor structure according to claim 9, characterized in that: One end of the gear box high-speed shaft (3) is fixedly connected to the gear box small end cover (4), and the other end is connected to the insulating flange (5) by transition fit and bolts. The outer diameter of the support cylinder (2) is smaller than the inner diameters of the shaft cylinder (16) and the flange (17).

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