Generator for wind turbine, stator of generator and wind turbine

Abstract

A generator for a wind turbine (7), the generator comprising an inner stator (10) and a rotatably mounted outer rotor (11), in which at least one braking member (21) is arranged on at least one braking support plate (23) of the generator (7), the invention relates to a stator (10) comprising at least one braking member (21) adapted to interact with at least one braking disc (22) attached to said rotor (11) in order to brake and / or lock the rotation of the rotor (11), where said at least one braking support plate (23) is one of several laminated stator plates (14) constituting the core (13) of said stator (10).

Description

Technical Field

[0001] The present invention relates to a generator for a wind turbine, comprising an inner stator and a rotatably mounted outer rotor, wherein at least one brake member is arranged on at least one brake support plate of the generator, wherein the at least one brake member is adapted to interact with at least one brake disk attached to the rotor to brake and / or lock the rotation of the rotor. The present invention also relates to an inner stator for the generator and a wind turbine. Background Art

[0002] In particular, for maintenance purposes, it may be necessary to brake or lock the rotation of a wind turbine's generator. The rotation of the generator or corresponding components of the wind turbine itself can pose a danger to service personnel working near these components. Therefore, a wind turbine's generator is required to include a braking system for slowing down and / or locking the rotation or movement of these components.

[0003] EP 2 896 824 A1 discloses a braking system for a wind turbine generator, wherein an annular component is connected to a flange of a stator assembly, wherein friction members are attached to the component to frictionally engage a brake disc connected to an outer rotor. Summary of the Invention

[0004] The object of the present invention is to create an enhanced concept for a braking system of a generator of a wind turbine, in particular with respect to the weight and the manufacturing process of the generator.

[0005] In order to solve the problem, the generator as initially described is characterized in that the at least one brake support plate is one of several laminated stator plates which constitute the core of the stator.

[0006] The present invention is based on the concept of using the stator plate in a coordinated manner to achieve the corresponding function, rather than having a separate component for attaching the brake member. Therefore, the annular component described in EP 2 896 824 A1 is no longer necessary for the generator according to the present invention. Consequently, the generator according to the present invention can be manufactured more easily and its overall weight is reduced.

[0007] Since the generator comprises an inner stator and an outer rotor, the rotor is a so-called outer rotor. At least part of the rotor extends along a section of the generator that is located radially outside the stator. The rotor is rotatably mounted relative to the axis of rotation. The stator may be cylindrical in shape, and the rotor may comprise a hollow cylindrical shape. The central axes of the respective cylinders are preferably identical and also identical to the axis of rotation of the rotor. Thus, the axis of rotation extends along the longitudinal or axial direction of the stator and / or rotor. Directions pointing perpendicularly away from the axis of rotation are defined as radial directions. Directions pointing perpendicularly away from the radial direction toward a point rotating about the axis of rotation are defined as circumferential directions.

[0008] The generator may be a permanent magnet generator having a plurality of permanent magnets on a rotor and an electrical circuit formed by a plurality of stator windings forming coils and arranged on the stator. The rotation of the rotor generates changes in the magnetic field in the conductors of the stator windings, which in turn generate an electric current. Assuming that the generator is provided in a wind turbine, the wind-driven rotation of the rotor generates rotation of the rotor and, therefore, generates an electric current in the electrical circuit, which is used for energy or power generation. The output power of the generator may be in the range of several megawatts, in particular between 1 and 40 megawatts.

[0009] The stator of the generator according to the present invention comprises a plurality of laminated stator plates, which form the core of the stator. The stator plates, and therefore the stator, may comprise a plurality of teeth, which protrude outwardly with respect to the radial direction, wherein two adjacent teeth transversely define slots, wherein sections of the stator winding extending in the longitudinal direction of the stator are arranged in the slots.

[0010] The brake disc may be an annular component. The brake disc may be attached to the rotor, in particular to the axial front face of the rotor. The brake disc may be made of metal.

[0011] In a preferred embodiment, the at least one brake support plate is at least one axial end plate of the core. The brake support plate forms the axial front face or end face of the stator. Preferably, the at least one brake member is attached to the corresponding axial end face. Alternatively, the at least one brake support plate is at least one axial center plate of the core. In this embodiment, the brake support plate is axially positioned between two other stator plates. In this embodiment, the brake member can be arranged on the circumferential surface of the brake support plate.

[0012] The generator according to the invention may be a direct drive generator. In this embodiment, the wind turbine or generator is gearless, which means that the gearbox is replaced by a generator, which is a multi-pole generator, which preferably constitutes a synchronous generator.

[0013] Assuming that the generator is a direct-drive generator, one of the at least one brake support plate can be a non-driven end of a stator plate. In this embodiment, the stator includes a driven end and a non-driven end, which form opposite axial end faces or axial front faces of the stator and extend in a radial direction. The driven end can be tapered relative to the radial direction. The driven end faces the main shaft, which connects the rotor of the generator to the rotor of the wind turbine. However, it is also possible that one of the at least one brake support plate is a driven end stator plate.

[0014] The at least one brake member can be attached to an outer radial end of at least one brake support plate. The brake support plate can have a cylindrical geometry with a circumferential surface and two flat circular front faces, one of which can be a front face of the stator. The outer radial end can be defined as the portion of the brake support plate that includes the circumferential surface and a radially outer portion of the front face. The radially outer portion can be defined such that a radial distance between the axis of rotation and the portion is at least 30%, in particular at least 50%, and preferably at least 80% of the total radius of the circular brake support plate.

[0015] In a preferred embodiment of the generator according to the present invention, at least one of the at least one brake member can extend radially outward relative to the axis of rotation of the rotor, wherein at least one of the at least one brake disc can extend radially inward relative to the axis of rotation, wherein at least one section of the at least one brake member and at least one section of the at least one brake disc can be arranged adjacent to each other relative to the axis of rotation and / or in a radial direction. Moving the at least one brake member or at least a portion of the at least one brake member into an axial direction and / or a radial direction can then generate a mechanical interaction between the respective brake member and the brake disc to brake and / or lock the rotation of the rotor. In this embodiment, it is also possible for portions of the brake member to be located on two opposite sides of the brake disc with respect to the axial direction.

[0016] Preferably, several braking members are provided. In this embodiment, the mechanical loads generated by braking and / or locking the brake disc are not transmitted to the brake support plate via a single location, but rather are distributed across the support plate via multiple braking members. Consequently, yielding effects on the brake support plate caused by the corresponding mechanical stresses are reduced, and mechanical stability is enhanced.

[0017] The brake members may be arranged in the top section of the generator, in particular in the top quarter. The top section refers to the height of the generator, which typically extends perpendicular to the axis of rotation. Alternatively, the brake members may be arranged evenly distributed along the circumference of the stator.

[0018] The at least one brake member may comprise or be coupled to an actuator, in particular an electromechanical actuator, a hydraulic actuator, or a pneumatic actuator. In this embodiment, the brake member or at least a portion of the brake member is movable by the actuator to interact with the brake disk, thereby braking and / or locking the rotor from rotation.

[0019] In particular, at least one of the at least one braking member may be or comprise at least one brake caliper and / or at least one brake shoe, which are configured to frictionally interact with at least a portion of the at least one brake disc to brake and / or lock the rotation of the rotor. The caliper may comprise two brake shoes, which are arranged on opposite sides of the brake disc with respect to the axial direction. Braking or locking is produced by moving the brake shoes into opposite directions so that the brake pads come into contact (in particular, frictional contact) with the brake disc on opposite axial faces, in particular with respect to the axial direction. The at least one brake shoe may comprise a back plate, in particular a back plate made of steel, wherein friction material is bonded to a surface facing the brake disc.

[0020] At least one of the at least one brake member may be or include at least one locking pin and / or at least one locking bolt and / or at least one locking washer, which are configured to be brought into a position engaging with at least one recess and / or at least one hole of the at least one brake disc to lock the rotation of the rotor. Once the rotation of the rotor is stopped, in particular by the caliper, and the position of the recess or hole is aligned with the position of the locking pin or bolt or washer, the pin or bolt or washer can be moved in the axial direction into the recess or hole. Once the locking pin or locking bolt or locking washer engages with the corresponding recess or hole, the rotation of the brake disc, and therefore the rotation of the rotor, is locked.

[0021] At least one of the at least one brake member can be attached to at least one brake support plate via at least one base element, wherein the at least one base element forms an axial gap between the at least one brake member and the axial front face of the core. The base element can be made of metal. In this embodiment, the base element extends axially and is positioned between the brake support plate and the brake member. Stator end windings of the stator can be arranged in the axial gap.

[0022] At least one of the at least one base element may include a base segment, wherein the base segment is attached to at least one brake support plate, in particular by a welded connection and / or a screwed connection and / or a threaded connection. The cross-section of the base element or the base segment may gradually widen toward the brake support plate, so that the side of the base element attached to the brake support plate forms a larger contact area between the brake support plate and the base element. In particular, the base segment may be attached to an attachment plate, which is attached to the brake support plate. The attachment plate and the base segment may also be manufactured from one piece.

[0023] The stator may include at least one opening on the axial front side of the core, wherein cooling air and / or coolant can be introduced into the stator via the at least one opening. The wind turbine may include a cooling system for introducing a cooling medium, such as cooling air and / or coolant, into the stator, in particular for cooling the stator windings. The cooling system may be an open system or a closed system, the closed system forming a cooling circuit. Since the stator plate is used as a brake support plate instead of a separate component, the cooling channels of the cooling system do not have to pass through the area of ​​the separate component but can be directly connected to the stator.

[0024] At least one functional component can be attached to the at least one brake support plate, wherein at least one of the at least one functional component is part of the air gap safety system or the lightning protection system of the generator. In this embodiment, the stator plate forming the brake support plate also serves as a holding device for other components of the generator (i.e., the functional component).

[0025] The present invention also relates to an inner stator for a generator according to the aforementioned description, wherein at least one brake member is arranged on at least one brake support plate of the stator, wherein the at least one brake member is adapted to interact with at least one brake disk attached to a rotatably mounted outer rotor of the generator in order to brake and / or lock the rotor in rotation, wherein the at least one brake support plate is one of several laminated stator plates forming the core of the stator. All advantages and features of the generator according to the invention are transferable to the inner stator according to the invention, and vice versa.

[0026] Furthermore, the invention relates to a wind turbine comprising at least one generator according to the above description. All advantages and features of the generator according to the invention and the inner stator according to the invention are transferable to the wind turbine according to the invention and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other objects and features of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. However, the accompanying drawings are merely schematic diagrams designed for illustrative purposes only and do not limit the present invention. The drawings show:

[0028] Figure 1 is a schematic diagram of a wind turbine according to an embodiment of the present invention, the wind turbine including a generator according to an embodiment of the present invention;

[0029] Figure 2 It runs through Figure 1 Schematic diagram of a radial section of a generator of a wind turbine in FIG, wherein the generator comprises an inner stator according to an embodiment of the present invention, wherein the section line is Figure 1 II–II indication in;

[0030] Figure 3 It runs through Figure 1 A schematic diagram of a longitudinal section of a generator of a wind turbine;

[0031] Figure 4 yes Figure 3 An enlarged view of a section of a generator in FIG. Figure 3 IV instructions in;

[0032] Figure 5 yes Figure 3 A schematic perspective view of the internal stator of the generator together with the brake disc;

[0033] Figure 6 is attached to Figure 5 a schematic diagram of the brake member of the internal stator; and

[0034] Figure 7 Is used according to Figure 6 Schematic diagrams of bottom elements of brake members of different embodiments are shown in FIG. DETAILED DESCRIPTION

[0035] Figure 1A wind turbine 1 according to an embodiment of the invention is shown. The wind turbine 1 comprises a tower 2 on which a nacelle 3 is arranged. At the front of the nacelle 3, a hub 4 with several, in particular three, blades 5 is provided. The hub 4 is mounted so that it can rotate about an axis of rotation 6. The wind-driven rotation of the hub 4 is transmitted to a generator 7 according to an embodiment of the invention, which is positioned in the nacelle 3 via a main shaft 8 extending along the axis of rotation 6. The axis of rotation 6 defines the axial direction of the generator 7. The axis of rotation 6 is arranged horizontally but can also be inclined with respect to the horizontal. Although the total height of the wind turbine 1 is of the order of tens or hundreds of meters, the output power of the wind turbine 1 generated by the generator 7 can be in the range of several megawatts, in particular between 1 and 40 megawatts.

[0036] The generator 7 includes an inner stator 10 and an outer rotor 11 according to an embodiment of the present invention. The stator 10 and the rotor 11 are arranged in a housing 9 of the generator 7. The stator is non-rotatable, while the rotor 11 is connected to the main shaft 8 so that the rotation of the hub 4 is transmitted to the rotor 11. Therefore, the rotor 11 can also rotate about the rotation axis 6.

[0037] Figure 2 A cross-section through a section of the generator 7 is shown, with the cross-section plane perpendicular to the axis of rotation 6. An air gap 12 having a thickness of several millimeters is located between a cylindrical stator 10 and a hollow cylindrical rotor 11. The stator 10 includes an iron core 13 having a plurality of laminated stator plates 14. The stator plates 14 are arranged perpendicular to the axis of rotation 6, such that the stack of stator plates 14 extends along the axis of rotation 6. The stator plates 14 (and thus the core 13) include a plurality of teeth 15, which protrude in a radial direction 16 extending perpendicularly outward from the axis of rotation 6. The teeth 15 are evenly spaced along a circumferential direction 17, which is defined as a direction perpendicularly away from the radial direction 16 and directed toward a point on the rotor 11 in the direction of rotation about the axis of rotation 6. Two adjacent teeth 15 laterally define slots, within which stator windings 18 forming coils are arranged. The winding 18 includes end windings 20 (at Figure 2 (not shown), the end windings each have a curved shape, and they connect the windings 18 of several slots (especially adjacent slots).

[0038] The rotor 11 includes permanent magnets 19 that are evenly spaced along a circumferential direction 17. The permanent magnets 19 of the rotating rotor 11 and the windings 18 of the stator 10 electromagnetically interact with each other, inducing current in the windings 18, thereby forming the power output of the generator 7.

[0039] Then, refer to Figure 3 and Figure 4 . Figure 3 A longitudinal section through the generator 7 along the axis of rotation 6 is shown. Figure 4 Show Figure 3 The enlarged portion of is indicated by box IV. Figure 3 and Figure 4 The housing 9 is not shown.

[0040] Several brake members 21 are attached to the inner stator 10. Brake disks 22 are attached to the outer rotor 11. The brake members 21 are adapted to interact with the brake disks 22 to brake and lock the rotation of the rotor 11, and thus the components connected to the rotor 11 (e.g., the main shaft 8 and the hub 4). Typically, if maintenance work is to be performed, the rotation of the hub 4, the main shaft 8, and the rotor 11 must be stopped to avoid danger to the associated service personnel. To stop the rotation, the pitch angle of each blade 5 is adjusted in a first step so that aerodynamic effects lead to a deceleration of the rotation. Once the corresponding rotation frequency drops below a certain value, the brake members 21 are activated in a second step to decelerate the rotation to zero, and in a third step, the rotation of the non-rotating rotor 11 is finally locked.

[0041] Braking member 21 is arranged and attached to a brake support plate 23, which is formed by one of the stator plates 14 and, in this embodiment, by way of example, by an axial end plate of core 13, which forms the non-drive-end stator plate of generator 7, which is a direct-drive generator. Braking support plate 23 thus forms an axial front face 24 of core 13, which is opposite the front end of core 13, which faces toward main shaft 8 and hub 4.

[0042] The brake support plate 23 has the geometry of a flat cylinder with a circularly curved circumferential surface 25 and two circular end-plane axial front faces 26, one of which constitutes the axial front face 24 of the core 13. The brake member 21 is attached to the brake support plate 23 at its outer radial end.

[0043] The rotor 11 has a hollow cylindrical shape with the rotation axis 6 as the center line, wherein a flange 27 is provided on the front face of the rotor 11 opposite the main shaft 8. The circular and annular brake disc 22 is attached to the flange 27 by screwing means 28.

[0044] Especially if Figure 3 and Figure 4 As can be seen in FIG, the brake member 21 extends radially outward, and the brake disc 22 extends radially inward, so that a section of each of the brake member 21 and a section of the brake disc 22 are arranged adjacent to each other in the axial direction.

[0045] Figure 5 A perspective view of the stator 10 and the brake disc 22 is shown. As can be seen, the generator 7 includes several functional components 43, 44, which are attached to the brake support plate 23. The first functional component 43 constitutes an air gap safety system, and the second functional component 44 constitutes the lightning protection system of the generator 7. Exemplarily, the brake members 21 are arranged in the top section of the generator 7, i.e., in the top quarter. The top section refers to the height of the generator 7, which extends perpendicular to the axis of rotation 6. Alternatively, the brake members 21 are arranged evenly distributed along the circumferential direction 17 of the stator 10.

[0046] Figure 6 An enlarged view of one of the brake members 21 is shown. Figures 4 to 6 , details about the brake members 21 are described. Each of the brake members 21 includes a brake caliper 29 having two brake pads or brake shoes 30, which are arranged in an axial direction and place the brake disc 22 therebetween. The brake shoes 30 are configured to interact frictionally with the brake disc 22. Specifically, the brake shoes 30 can be moved toward each other to come into frictional contact with the brake disc 22, thereby generating a corresponding rotational deceleration. To this end, the brake shoes 30 are connected to an actuator, in particular an electromechanical, hydraulic or pneumatic actuator, which is not shown in the figure.

[0047] like Figure 4 As can be seen in FIG, the brake member 21 comprises a locking pin 31 which can be moved in the radial direction 16 into a position engaging in a hole 32 or a groove of the brake disc 22 in order to lock the rotation of the rotor 11. Instead of a locking pin, at least one locking bolt and / or at least one locking washer of the brake member 21 can be provided.

[0048] Regarding the locking process of the rotor 11, once the corresponding rotation has been aerodynamically slowed down as described above, the brake caliper 29 is used to frictionally decelerate the rotation of the rotor 11 to zero, wherein the brake disc 22 is brought into a position in which each hole 32 is aligned with a locking pin 31. Subsequently, the locking pins 31 are brought into a position in which they engage with the holes 32. For this purpose, an actuator of the locking device 21 (not shown in the figure) is provided.

[0049] The brake members 21 are each attached to the brake support plate 23 via a bottom element 33, wherein the bottom element 33 forms an axial gap 34 between the respective brake member 21 and the axial front face 24. The axial gap 34 provides space for the stator end winding 20, so that in particular Figure 4As can be seen in FIG, the stator end winding 20 is arranged in the axial gap 34 between the iron core 13 and the brake member 21.

[0050] Each base element 33 includes a base section 35, which is attached to the brake support plate 23, exemplarily by screw connections 36. To this end, the base section 35 is connected to an attachment plate 37 of the base element 33, which forms a large contact area between the base element 33 and the brake support plate 23. The cross-section of the base section 35 gradually widens toward the brake support plate 23. The base section 35 and the attachment plate 37 are exemplarily welded to one another. On the side of the base section 35 opposite the brake support plate 23, a surface 45 of the base element 33 is provided, wherein the brake device 21 is attached to the surface 45, for example, by screw connections.

[0051] Figure 7 Another possible embodiment of the present invention is shown, with differences regarding the base element 33. For better visibility, the brake member 21 is not shown in this figure. In this embodiment, the base element 33 is made from one piece, without the attachment plate 37. The base section 35 includes a widened portion 46 to increase the contact area between the base element 33 and the brake support plate 23. The base element 33 and the brake support plate 23 are welded to each other.

[0052] Reference again Figure 3 and Figure 5 , explains aspects of a cooling system 39 of a wind turbine 1 for cooling the generator 7. The stator 10 comprises several openings 38 on the axial front face 24 of the core 13, wherein a cooling medium, such as cooling air or a coolant, can be introduced into and removed from the stator 10 via the openings 38. Exemplarily, the cooling system 39 is a closed air cooling system 39, in particular comprising a fan 40 and an air cooling unit 41, in particular comprising a heat exchanger and / or other cooling components, for cooling the cooling air. The cooling system 39 forms a cooling circuit having cooling channels or guides 42 for guiding the cooling air. The guides 42 can be hoses and / or pipes and / or tubes.

[0053] Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the disclosed examples, and those skilled in the art may derive other variations from the disclosed examples without departing from the scope of the present invention.

Claims

1. A generator for a wind turbine (7), comprising an inner stator (10) and a rotatably mounted outer rotor (11), wherein: At least one brake member (21) is arranged on at least one brake support plate (23) of the generator (7), wherein the at least one brake member (21) is suitable for interacting with at least one brake disc (22) attached to the rotor (11) to brake and / or lock the rotation of the rotor (11), characterized in that the at least one brake support plate (23) is one of several laminated stator plates (14) constituting the core (13) of the stator (10).

2. The generator according to claim 1, characterized in that The at least one brake support plate (23) is at least one axial end plate of the core (13).

3. The generator according to claim 2, characterized in that The generator (7) is a direct drive generator, wherein one of the at least one brake support plate (23) is a non-drive end stator plate (14).

4. A generator according to any one of the preceding claims, characterised in that The at least one brake member (21) is attached to an outer radial end of the at least one brake support plate (23).

5. A generator according to any one of the preceding claims, characterised in that At least one of the at least one brake member (21) extends radially outward relative to the rotation axis (6) of the rotor (11), wherein at least one of the at least one brake disc (22) extends radially inward relative to the rotation axis (6), wherein at least one section of the at least one brake member (21) and at least one section of the at least one brake disc (22) are arranged adjacent to each other relative to the rotation axis (6) and / or the radial direction (16).

6. A generator according to any one of the preceding claims, characterised in that Several brake members (21) are provided, wherein the brake members (21) are arranged in a top section of the generator (7), in particular a top quarter region, or are evenly distributed along a circumferential direction (17) of the stator (10).

7. A generator according to any one of the preceding claims, characterised in that At least one of the at least one brake member (21) is or includes at least one brake caliper (29) and / or at least one brake shoe (30), the brake caliper and / or brake shoe being configured to frictionally interact with at least one portion of the at least one brake disc (22) to brake and / or lock the rotation of the rotor (11).

8. A generator according to any one of the preceding claims, characterised in that At least one of the at least one brake member (21) is or comprises at least one locking pin (31) and / or at least one locking bolt and / or at least one locking washer, the locking pin, locking bolt and / or locking washer being configured to be brought into a position engaging at least one groove and / or at least one hole (32) of the at least one brake disc (22) to lock the rotation of the rotor (11).

9. A generator according to any one of the preceding claims, characterised in that At least one of the at least one brake member (21) is attached to the at least one brake support plate (23) via at least one bottom element (33), wherein the at least one bottom element (33) forms an axial gap (34) between the at least one brake member (21) and an axial front face (24) of the core (13).

10. The generator according to claim 9, characterized in that The stator end winding (20) of the stator (10) is arranged in the axial gap (34).

11. The generator according to claim 9 or 10, characterized in that: At least one of the at least one bottom element (33) comprises a base section (35), wherein the base section (35) is attached to the at least one brake support plate (23), in particular by welding and / or bolting and / or screwing (36).

12. A generator according to any one of the preceding claims, characterised in that The stator (10) comprises at least one opening (38) on the axial front side (24) of the core (13), wherein cooling air and / or cooling liquid can be introduced into the stator (10) via the at least one opening (38).

13. A generator according to any one of the preceding claims, characterised in that At least one functional component (43, 44) is attached to the at least one brake support plate (23), wherein at least one of the at least one functional component (43, 44) is part of an air gap safety system or a lightning protection system of the generator (7).

14. An inner stator for a generator (7) according to any one of the preceding claims, wherein At least one brake member (21) is arranged on at least one brake support plate (23) of the stator (10), wherein the at least one brake member (21) is adapted to interact with at least one brake disc (22) attached to a rotatably mounted outer rotor (11) of the generator (7) to brake and / or lock the rotation of the rotor (11), wherein the at least one brake support plate (23) is one of several laminated stator plates (14) constituting the core (13) of the stator (10).

15. A wind turbine comprising at least one generator (7) according to any one of claims 1 to 13.

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