LOCKING AND BRAKE MODULE FOR A WIND POWER PLANT AS WELL AS GENERATOR AND WIND POWER PLANT WITH THE SAME

Description

[0001] The present invention relates to a locking and braking module for a wind turbine, according to the preamble of claim 1.

[0002] In the German application establishing priority, the German Patent and Trademark Office searched the following documents: DE 10 2009 017 531 A1, DE 10 2012 208 549 A1, DE 10 2012 215 575 A1 and EP 2 566 017A1.

[0003] Wind turbines of the aforementioned type are also referred to as wind turbines with external rotor generators. They differ from so-called internal rotor generators in that the generator stator is located radially inward, while the generator rotor rotates around it on the outside. Such generators have the well-known advantage that a larger air gap diameter can be achieved with the same outer diameter of the generator. With the same generator packing density, this allows for a higher power output compared to an internal rotor generator.

[0004] Wind turbines with external rotor generators are known, for example, from DE 10 2012 208 549.1.

[0005] Since wind turbines cannot be in constant operation, but must occasionally be shut down for necessary maintenance and inspection work, wind turbines typically have locking devices. In known wind turbines, the aerodynamic rotor or generator rotor is locked in a predetermined stationary position by one or more locking pins. The locking pin typically engages a correspondingly shaped recess and creates a positive locking action.

[0006] Out ofEP 2 896 824 A1 discloses a braking system for a generator of a wind turbine. The generator has a stator assembly with a stationary shaft and a rotor assembly rotating externally around the stator assembly. A flange with radially outwardly extending arms is arranged on the stationary shaft, at the ends of which brake calipers and rotor locking systems are provided.

[0007] Due to the sometimes very high turbine weights and the associated inertial masses, as well as the large wind attack surfaces, these locking pins must absorb significant holding forces in the range of several thousand kilonewtons. Therefore, special attention is paid to a mechanically secure, i.e., highly resilient, attachment of the locking pins to the wind turbine. The same applies to braking devices on wind turbines. Wind turbines are typically braked aerodynamically based on their operating speed. Additional braking devices are optionally used to decelerate the wind turbine from very low speeds to a standstill and to hold it there until the locking pins have locked the turbine in its standstill position.

[0008] In previous systems, the locking pins and braking devices are each completely mechanically isolated systems that are mounted independently of each other on the wind turbine. Since precise positioning is crucial for proper function, each of these systems requires appropriate alignment work. While this can be accomplished satisfactorily by the installers in practice, the required effort is considered disadvantageous.

[0009] Accordingly, the invention was based on the object of mitigating the disadvantages described above as far as possible. In particular, the invention was based on the object of improving the generally known wind turbines so that an improved assembly of the locking and braking devices can be achieved without compromising the performance of these devices. In any case, the object of the invention was to provide an alternative design.

[0010] The invention solves the underlying problem by specifying a locking and braking module with the features of claim 1. In particular, the invention proposes a locking and braking module for a wind turbine of the type initially described, which has a support structure, a number of locking bolts mounted on the support structure, which are designed to lock the generator rotor when stationary, and a number of braking devices mounted on the support structure, which are designed to brake the generator rotor and / or to hold it at least temporarily at a standstill.

[0011] The invention takes advantage of the finding that accommodating all locking pins and braking devices in a common support structure enables an extremely compact turbine design in the longitudinal direction, i.e., in the direction of the rotation axis. At the same time, the modular concept allows the installation of a braking and locking solution on a comparatively large effective diameter, particularly in an external rotor generator solution. These advantages are achieved without compromising ease of installation, since the provision of a centralized support structure still makes it possible to pre-install the locking pin(s) and the braking device(s) prior to erection of the wind turbine. This can be done at the installation site or remotely from the wind turbine installation site. In any case, the number of installation steps at the installation site is significantly reduced.All that's required is to lift the entire support structure, including all its braking and locking devices, onto the wind turbine tower using a crane. If necessary, the generator, including the locking and braking module, can be lifted onto the tower together. In particular, it's not necessary to transport individual brake components separately to the wind turbine tower.

[0012] The invention is advantageously further developed in that the support structure comprises connecting means for mounting between a machine support of the wind turbine and the generator of the wind turbine. In other words, the support structure is mounted on the machine support side to the generator, or on the generator side to the machine support or a journal attached to the machine support. For this purpose, the connecting means preferably comprise a flange for fastening the support structure to the machine support or to a journal of the wind turbine. The mounting support structure, using a flange on the wind turbine, is easy to handle by appropriately trained specialist personnel, can withstand high mechanical loads, and can be manufactured with close manufacturing tolerances. These advantages are provided simultaneously to all locking bolts and braking devices thanks to the centralized assembly.

[0013] In a preferred embodiment, the connecting means comprise one or more spacers for positioning the support structure relative to the generator stator.

[0014] According to the invention, the support structure is designed to encircle a longitudinal axis, particularly preferably annular. In the assembled state of the locking and braking module, the longitudinal axis is preferably aligned parallel, particularly preferably coaxially, to the rotational axis of the generator. For the purposes of the invention, annular is understood to mean a substantially annular geometric configuration in which the support structure is designed to be enclosed around an inner recess. A strictly cylindrical or hollow-cylindrical design of the ring is not absolutely necessary. The braking devices are preferably arranged so that the brake pads are located on essentially the same effective diameter.

[0015] In a preferred embodiment, the spacers are connected to the support structure and the generator stator in a reversibly detachable manner in the direction of the longitudinal axis. For the purposes of the invention, reversible detachability means that the spacers can be removed from the support structure or the generator stator and reconnected to it essentially as often as desired without causing damage.

[0016] The spacers are particularly preferably designed to precisely position the locking and braking module or the support structure relative to the generator stator and to fix it in the desired position. This allows, for example, the locking and braking module and the generator to be lifted together onto the tower of the wind turbine and positioned together on an axle journal mounted on the machine support of the wind turbine. The specification of defined distances between the locking and braking module on the one hand and the generator on the other hand simplifies the precise fitting of both the locking and braking module and the generator to the mounting points on the axle journal or to other corresponding elements of the wind turbine. The length of the spacers is particularly preferably a predetermined amount longer than the designated distance between the braking and locking module and the generator in the fully assembled state.The predetermined dimension is preferably selected so that when the generator and the brake and locking module are pushed onto the axle journal, the mounting flanges of both components do not rest on the axle journal at the same time. This means that not all flange connections are threaded onto the axle journal at the same time, but one after the other. After the first part (brake and locking module and generator) has been fully assembled on the wind turbine, the spacers can be easily removed, and the second part can also be mounted on the axle journal or machine support.

[0017] In a further preferred embodiment, the generator is designed as a ring generator, and the support structure is arranged at least partially inside the generator. This means that at least a portion of the support structure extends in the direction of the longitudinal axis into the radially inner free space of the generator. This simultaneously minimizes the space required for the locking and braking module in the direction of the longitudinal axis.

[0018] In preferred embodiments, the locking and braking module has an extension in the direction of the longitudinal axis in a range of 1 m or less, particularly preferably in a range of 80 cm or less. Furthermore, the support structure is preferably located within the generator by at least half of its extension in the direction of the longitudinal axis.

[0019] The locking bolts are mounted on the support structure so that they can move in the radial direction relative to the longitudinal axis.

[0020] According to the invention, the braking devices each have at least one brake pad, wherein the brake pads of the braking devices are mounted on the support structure so as to be movable in the radial direction relative to the longitudinal axis.

[0021] Further preferably, the braking devices are arranged along the outer circumference of the support structure and preferably project radially from the support structure relative to the longitudinal axis. The radial movement of the brake pads, in turn, has the advantage of minimizing the space required by the braking device in the direction of the longitudinal axis.

[0022] In a further preferred embodiment of the invention, the locking pins are operatively connected to a first drive and can be moved back and forth between a release position and a locking position by means of the drive, wherein the drive of the locking pins is designed as a fluidic drive, preferably as a hydraulic drive. The selection of the fluidic drive has the advantage that, with appropriate hydraulic media, very high fluid pressures and thus very high actuating forces can be achieved, while at the same time the actuators are still very compact in terms of their space requirements. For example, the drive is designed to apply a fluid pressure of 150 bar or more, particularly preferably in a range of 200 bar or more.

[0023] In a further preferred embodiment, the brake pads of the braking devices are each operatively connected to a second drive and can be moved back and forth between a release position and a braking position by means of the drive, wherein the drive of the braking devices is designed as an electromagnetic drive or as a fluidic drive, preferably as a hydraulic drive. In those embodiments in which the second drive is also designed as a fluidic drive, a first fluid circuit for the locking bolts and a dedicated second fluid circuit for the braking devices are preferably provided, wherein the fluid circuit for the braking devices preferably only needs to provide a reduced operating pressure.Preferably, the operating pressure in the fluid circuit for the braking devices is between 50 and 75%, particularly preferably in a range between 60 and 70% of the operating pressure of the fluid circuit for the locking bolts.

[0024] In a further preferred embodiment of the invention, which is also an independent aspect of the invention, the support structure has a plurality of ventilation recesses which extend through the support structure, preferably in the direction of the longitudinal axis, wherein preferably one, several or all of the ventilation recesses are assigned a fan for generating an air flow. This development transforms the previously described locking and braking module into a locking, braking and ventilation module which, in addition to locking and braking, also performs the function of dissipating heat from the interior of the generator. No additional space is required in the direction of the longitudinal axis to accommodate the ventilation recesses and fans in the support structure, which makes this solution particularly advantageous with regard to the desired compact size of the wind turbine nacelle.

[0025] The invention has been described above in a first aspect with reference to the locking and braking module itself.

[0026] In a further aspect, the invention relates to a generator for a wind turbine having a rotor hub, wherein the generator is configured to be operatively connected to the rotor hub and to generate electrical energy.

[0027] The invention achieves the object described at the outset in such a generator in that the generator has a generator stator, a generator rotor rotating outside the generator stator and driven by the rotor hub, and a locking and braking module for braking, holding and locking the generator rotor, wherein the locking and braking module is designed according to one of the preferred embodiments described above.

[0028] The generator makes use of the same advantages and preferred embodiments as the locking and braking module or locking, braking and ventilation module described above, which is why reference is made to the above statements to avoid repetition.

[0029] To cooperate with the locking and braking module, the generator rotor has, in particular, a brake element configured to be at least partially annularly circumferential, and the brake pads of the locking and braking module are configured to engage the brake element in a frictional or force-locking manner. The brake element is particularly preferably configured as a circumferential ring or a plurality of partially circumferential ring segments.

[0030] Further preferably, the generator rotor preferably has a number of recesses for at least partially accommodating the locking pin(s) or one of the locking pins. Particularly preferably, the number of recesses extends in a radially inner circumferential wall of the generator rotor.

[0031] In a further aspect, the present invention relates to a wind turbine having a rotor hub and a generator operatively connected to the rotor hub for generating electrical energy.

[0032] The invention achieves the underlying problem, described above, in such a wind turbine by designing the generator according to one of the preferred embodiments described above. The wind turbine also utilizes the advantages and preferred embodiments of the locking and braking module according to the invention, which is why reference is also made to the above explanations in this regard to avoid repetition.

[0033] If, within the scope of the invention, a generator is referred to, preferably a separately excited synchronous generator, in particular a separately excited synchronous ring generator, or alternatively a permanently excited generator, is selected. The generator is preferably a multi-pole generator, in particular a multi-pole synchronous ring generator. "Multi-pole" is understood to mean a plurality of stator poles, in particular a design with at least 48 stator teeth, frequently even with significantly more stator teeth, such as in particular 96 stator teeth or even more. The magnetically active region of the generator, namely both the rotor, which can also be referred to as the runner, and the stator, is arranged in an annular region around the axis of rotation of the generator. Thus, in particular, a region from 0 to at least 50 percent of the radius of the air gap is free of materials that conduct electric current or the electric field of the generator.In particular, this interior space is completely free and, in principle, accessible. This area is frequently more than 0 to 50 percent of the air gap radius, in particular up to 0 to 70 percent or even 0 to 80 percent of the air gap radius. Depending on the design, a support structure may be present in this inner area, although in some embodiments this may be axially offset. The generator is preferably a slow-rotating generator, with rotational speeds of 100 revolutions per minute or less, in particular 50 revolutions per minute or less, and particularly preferably 30 revolutions per minute or less being understood as slow-rotating, the latter particularly when the wind turbine is a directly driven, i.e. gearless, wind turbine.

[0034] The invention is described in more detail below with reference to a preferred embodiment of the invention and the accompanying figures. Herein: Fig. 1: a wind turbine according to the present invention, Fig. 2: a schematic cross-sectional view of a nacelle of the wind turbine according to Figure 1 , Fig. 3: a schematic spatial view of a locking and braking module of a generator of the wind turbine of the Figures 1 and 2 , Fig. 4: a detailed view of the locking and braking module according to Figure 3 , and Fig. 5: another detailed view of the locking and braking module according to the Figures 3 and 4 .

[0035] Figure 1shows a wind turbine 100 with a tower 102 and a nacelle 104. A rotor hub 106 with three rotor blades 108 and a spinner 110 is arranged on the nacelle 104. The rotor blades 108 are arranged with their rotor blade roots on a rotor hub. During operation, the rotor hub 106 is set into rotation by the wind and thereby drives a generator (not shown) in the nacelle 104.

[0036] In Figure 2 The interior of the nacelle 104 of the wind turbine 100 is shown schematically. In the nacelle 104, a machine support 111 is rotatably mounted on the tower 102 via an azimuth drive. A journal 113 is attached to the machine support 111 via a flange connection. The journal can be constructed in one piece, as shown, or alternatively in multiple pieces.

[0037] A generator 50 is mounted on the axle journal 113. The generator 50 has a stator 51, which is attached to a stator support structure 53 and arranged on the axle journal 113 via the stator support structure 53. A generator rotor 55 rotates outside the stator 51. The generator 50 is therefore an external rotor generator.

[0038] A locking and braking module 1 according to the present invention is arranged on the machine support side of the generator 50. In the presently shown embodiment, the locking and braking module 1 is attached to the axle journal 113 between the machine support 111 and the generator 50. Alternatively, the locking and braking module 1 could also be attached directly to the machine support 111.

[0039] The locking and braking module 1 is positioned relative to the generator 50, and in particular to the stator 51 of the generator 50, by means of one or more spacers 21 and held in position until the spacers 21 are removed. The spacers 21 enable simplified positioning of both the generator stator 51 and the locking and braking module 1, one after the other, relative to the axle journal 113.

[0040] As will become more apparent from the following figures, the locking and braking module 1 comprises a support structure 3 on which a plurality of locking pins 5 are arranged for radial movement. The locking pins 5 are configured to engage in corresponding recesses 57 of the generator rotor 55 and, in the engaged state, to prevent relative movement between the generator stator 51 and the generator rotor 50, or between the axle journal 113 and the generator rotor 55.

[0041] In addition, the locking and braking module 1 has a number of braking devices 7, each of which has at least one radially movable brake pad 9. The brake pad 9 is designed to be movable between a release and a braking position relative to an annular braking element 59.

[0042] To illustrate the structural arrangement of the various functional elements, Figure 3 The locking and braking module 1 is shown in isolation. The locking and braking module 1 has a first end face 11 and a second end face 13, which is formed opposite the first end face 11. The first end face 11 is the machine support-side end face of the locking and braking module 1.

[0043] The support structure 3 has a plurality of ventilation openings 15 that extend through the support structure 3 from the first end face 11 to the second end face 13. Preferably, each of the ventilation openings 15 is associated with a fan 17. In the present embodiment, the fan is arranged on the second end face of the support structure 3.

[0044] On the first end face 11, a fastening flange 19 is formed in order to fasten the locking and braking module 1 to the axle journal or the machine carrier (cf. Figure 2 ).

[0045] The braking devices 7 are each attached to a projection projecting outwards in the radial direction on the first end face 11 of the support structure 3 and extend with the brake pads 9 in the direction of the second end face 13 so that, in the mounted state of the support structure 3, they can produce a frictional connection with the annular braking element 59 by moving radially inwards towards the longitudinal axis L in the direction of the arrow P 1.

[0046] The locking bolts 5 are essentially completely enclosed in the support structure 3 and are also radially movable relative to the longitudinal axis L in the direction of the arrow P 2 (only one shown) between a release position and a locking position. The arrangement of the brake pads 9 relative to the brake element 59 is shown in Figure 4 shown. From Figure 4It is also evident that the positioning of the locking pins 5 and the braking devices 7 does not have to be in the same plane, but rather is particularly preferably offset in the circumferential direction on the generator 50 in order to achieve a uniform distribution of the loads on the locking and braking module 1. To ensure individual replacement, the braking device 7 is screwed to the support structure 3 of the locking and braking module 1.

[0047] As can be seen from the Figures 2 and 4 The locking and braking module 1 is at least partially mounted internally in the generator 50 in order to require as little additional installation space as possible in the direction of the longitudinal axis L. With the exception of the braking devices 7, essentially the entire locking and braking module 1 is arranged internally in the generator 50.

[0048] The braking devices of the illustrated embodiment are optionally designed as electromagnetically operated brakes or as hydraulically operated brakes, while the locking pins are preferably designed as hydraulically actuated elements. In the case where both functional groups are designed as hydraulically actuated elements, two separate fluid circuits are preferably provided to ensure the highest possible reliability and to be able to design the respective fluid circuit for the corresponding task (locking or braking / holding).

[0049] After the arrangement of the braking device 7 from Figure 4 shows Figure 5a preferred arrangement of the locking bolts 5 offset from the braking devices 7 in the generator 50. In the generator rotor 55, radially inwardly from the annular braking element 59, a plurality of recesses 57 are formed for receiving the locking bolt 5 in order to enable the generator rotor 55 to be locked in different angular positions.

[0050] The operation of the braking devices 7 and the locking bolts 5 is preferably coordinated in such a way that the generator rotor 55 is held in a predetermined locking position by means of the braking devices 7, or is braked from low speed to a standstill in such a position, in which a holding force is then applied by means of the braking devices 7, which holds the generator rotor 55 until the locking bolts are retracted into the recesses 57 in the direction of the arrow P2, and in this way assume a locking position in which further movement of the generator rotor 55 is not possible.

Claims

1. A latching and braking module (1) for a wind turbine (100) which comprises a rotor hub (106) and a generator (50) which is operationally connected with said rotor hub (106) to produce electric energy, wherein said generator (50) comprises a generator stator (51) and a generator rotor (55) which is arranged to extend externally circumferentially about said generator stator (51) and to be driven by said rotor hub (106), with said latching and braking module (1) comprising: - a support structure (3), - a number of latching bolts (5) mounted on said support structure (3), adapted to latch said generator rotor (55) in its stopped position, and - a number of braking devices (7) mounted on said support structure, adapted to brake, and / or at least temporarily hold, said generator rotor (55) in said stopped position, wherein said support structure (3) is configured to extend circumferentially about a longitudinal axis (L), preferably annularly, characterized in that: said braking devices (7) each comprise at least one brake lining (9), and wherein said brake linings (9) of said braking devices (7) are received on said support structure (3) to be movable in the radial direction relative to said longitudinal axis (L).

2. The latching and braking module (1) according to claim 1, wherein said support structure (3) comprises connection means (19, 21) for installation between a base frame (111) of said wind turbine (100) and said generator (50) of said wind turbine (100), preferably wherein said connection means comprise a flange (19) for attaching said support structure (3) to said base frame (111) or a kingpin (113) of said wind turbine (100).

3. The latching and braking module (1) according to claim 2, wherein said connection means comprise one or more spacers (21) for positioning said support structure (3) relative to said generator stator (51).

4. The latching and braking module (1) according to claim 3, wherein said spacers (21) are connected with said support structure (3) and said generator stator (51) to be reversibly detachable.

5. The latching and braking module (1) according to any one of the preceding claims, wherein said generator (50) is configured as a ring generator, and wherein said support structure (3) is arranged at least partially inside said generator (50).

6. The latching and braking module (1) according to any one of claims 1 to 5, wherein said latching bolts (5) are received on said support structure (3) to be movable in the radial direction relative to said longitudinal axis (L).

7. The latching and braking module (1) according to any one of claims 1 to 6, wherein said braking devices (7) are arranged along said outer circumference of said support structure (3) and preferably project radially from said support structure (3) relative to said longitudinal axis (L).

8. The latching and braking module (1) according to any one of the preceding claims, wherein said latching bolts (5) are operatively connected with a first drive and are reciprocatable by said drive between a released position and a latched position, wherein said drive of said latching bolts (5) is configured as a fluidic drive, preferably as a hydraulic drive.

9. The latching and braking module (1) according to any one of the preceding claims, wherein said brake linings (7) of said braking devices (9) each are operatively connected with a second drive and are reciprocatable between a released position and a braked position by said drive, wherein said drive of said braking devices is configured as an electromagnetic drive or as a fluidic drive, preferably as a hydraulic drive,.

10. The latching and braking module (1) according to any one of the preceding claims, wherein said support structure (3) comprises a plurality of venting recesses (15) which, preferably in the direction of said longitudinal axis (L), extend through said support structure (3), and wherein a blower (17) for producing an air stream is associated with preferably one, some or all of the venting recesses (15).

11. A generator (50) for a wind turbine (100) comprising a rotor hub (106), wherein said generator (50) is adapted to be operatively connected with said rotor hub (106) and to produce electric energy, comprising - a generator stator (51), - a generator rotor (55) arranged to extend externally circumferentially about said generator stator (51) and driven by said rotor hub (106), and a latching and braking module (1), wherein said latching and braking module (1) is configured according to any one of the preceding claims.

12. The generator (50) according to claim 11, wherein said generator rotor (55) comprises a braking component (59) which is configured to extend at least partially annularly circumferentially, and the brake linings (9) of said latching and braking module (1) are adapted to engage with said braking component (59) in friction-fitting or force-fitting manner.

13. The generator (50) according to claim 11 or 12, wherein said generator rotor (55) comprises a plurality of recesses (57) to at least partially receive one of said latching bolts (5) each.

14. A wind turbine comprising a rotor hub (106) and a generator (50) operatively connected with said rotor hub (106) to produce electric energy, wherein said generator (50) is configured according to any one of claims 11 to 13.