EP2368653A2 - Method for manufacturing a machine supporting base for a wind turbine, supporting base and wind turbine - Google Patents

Abstract

The method involves manufacturing a main beam (10) as a cast part by casting of a mold, and manufacturing a rear carrier (11) as a welded part. A weldable cast-in part i.e. cast steel part, is partially casted into a rear-side connection piece of the main beam during manufacturing the main beam. The cast-in part is connected with the rear carrier outside the main beam by welding. The cast-in part is preheated before casting of the cast-in part into the rear-side connection piece. The main beam together with the cast-in part or with the rear carrier is subjected to an annealing process. Independent claims are also included for the following: (1) a machine carrier comprising a weldable cast-in part (2) a wind energy plant comprising a machine carrier.

Description

The invention relates to a method for producing a machine carrier for a wind turbine, wherein a main carrier is produced by casting a casting as a casting and a rear carrier is made as a welded part. The invention further relates to a machine carrier for a wind power plant with a main carrier formed at least essentially as a casting and a rear carrier formed essentially as a welded part, and also a wind energy plant.

Wind turbines usually have a tower, at the top of which a nacelle with a rotor with a rotor hub with rotor blades is arranged, which drives a generator during operation. The gondola accommodates machine parts such as bearings, shafts and the generator, as well as, if necessary, a gearbox. The machine parts are carried by a floor platform or a machine carrier, which is rotatably mounted on the tower.

In the front part, the machine carrier transmits the entire rotor forces to the tower via the azimuth bearing, picks up the heavy loads of the machine parts and is correspondingly rigid and solid. Machine carriers can be designed completely in one piece as a welded construction or as a cast component. Alternatively, a machine carrier consists of two parts, wherein both the front main carrier and the rear carrier, which is connected to the main carrier at the rear side, may be welded or cast. In contrast to the heavily dynamically loaded main carrier, the main task of the rear carrier is to carry the weight of the generator and, where appropriate, of a transformer, an inverter and control cabinets. Here, the strength design is less critical than the highly stressed main beam. More important here is the stiffness design, as the generator must be exactly aligned with the gearbox. Dynamic loads of the rear carrier result mainly from vibrations and inertial forces.

Main girders are currently manufactured in some wind turbines as castings made of cast iron, so produced as a casting in a casting process. This has the advantage that even complicated shapes are easy to produce. In addition, the casting material has vibration-damping properties that a welded part made of steel does not have. This is in the environment in a nacelle of a wind turbine, in the strong vibrations and thus strong sound emissions may arise advantageous. In addition, cast iron, with a lower density than steel, has good compressive strength and, due to its embrittlement, good dimensional stability, which makes it particularly suitable for use as a machine carrier. An example of a suitable cast iron is spheroidal graphite cast iron, ie spherical graphite deposits additionally has a comparatively high tensile strength.

The rear carrier, like the main carrier, for cost reasons, be a welded part, that is welded together from several steel parts, ie steel beams, steel pipes and steel sheets, in particular of rolled steel. Because of the higher tensile and breaking strength compared to cast iron, the rear carrier with the same load capacity on a lower weight.

Since cast iron is not weldable, the connection between the main carrier and the rear carrier is usually designed as a flange connection. For this purpose, the rear carrier is flanged to the machine frame by means of suitable screw. Corresponding screw and flange connections between the main carriers and the rear carriers require regular maintenance in order to guarantee a lasting, stable hold. Flange connections are also space consuming and can be difficult to access due to the tight space in a nacelle.

The invention is therefore based on the object of providing a method for producing an improved machine carrier, an improved machine carrier and a wind energy plant with a corresponding machine carrier, which eliminate the aforementioned disadvantages.

This object is achieved by a method for producing a machine carrier for a wind turbine, wherein a main carrier is produced by casting a casting as a casting and a rear carrier is produced as a welded part, which is further developed by at least one weldable Eingussteil is provided during manufacture of the main vehicle in one Rear connector of the main carrier is partially poured and outside the main carrier with the rear carrier, in particular by welding, is connected or is.

The invention is based on the basic idea that the machine carrier is produced in a composite casting process. For this purpose, during the production of the main carrier casting a weldable Eingussteil partially poured into the main carrier or in a connecting piece of the main carrier so that it protrudes from the main carrier out. In the context of the present invention, the connecting piece is a part or region of the main carrier to which the rear carrier is attached. The protruding from the cast body of the main carrier out part of the sprue is or will be welded to the rear carrier, but may also be part of the rear carrier in the invention.

The composite casting technique offers the possibility of creating a permanent and maintenance-free connection between castings and steel parts. The embedding of the sprue in the cast body represents an at least partially cohesive connection, as well as a welded joint or an integral connection of the projecting out of the cast part of the sprue with the rear carrier. Thus, a connection between the main carrier and rear carrier is made, which is more durable and stronger than a bolted flange, which produces only a force and / or positive connection and can loosen under constantly changing load.

The method according to the invention offers increased design freedom in the arrangement of the connection point and a simple design possibility of the cast support. This leads both to a casting cost optimization and to a welding cost optimization. The elimination of the flange leads to a cost savings for flange material and flange processing and to a better utilization of the available in a nacelle of a wind turbine room. Thus, molded parts can also be arranged in inaccessible places in the nacelle, for example below the transmission. On the other hand, a screw flange has to be regularly maintained and therefore has to be arranged further to the rear, that is to say at a greater distance from the tower axis, in order to be accessible.

In addition, it is now possible to carry out the entire machine frame in one part, wherein the main carrier and rear carrier are interconnected. The difficult and time-consuming production of a connection between main carrier and rear carrier in the nacelle of the wind turbine is eliminated.

In an advantageous variant of the method according to the invention, the cast-in part is first partially cast in the rear-side connecting piece of the main carrier, and then the rear carrier is welded to a part of the sprue protruding on the main carrier. In this case, the at least one casting is particularly easy to position when casting the main carrier. The result of the casting process in this case is a cast main carrier with at least one partial casting projecting out of the cast body of the main carrier. This is used in the further manufacturing process as welding surface for the welded rear carrier.

Alternatively, it is also advantageously provided that first of all the rear carrier is produced with a cast-in part and then a part of the sprue part in the production of the main carrier in the rear-side connecting piece of the main carrier is poured. The cast-in part can already be a part of a carrier or steel carrier of the rear carrier or be welded thereto and serves to be molded in during the production of the main carrier. Thus, the connection of the main carrier with the rear carrier during manufacture of the main carrier is made by pouring instead of a subsequent welding. The advantage of this alternative approach is that a more solid connection of the sprue with the rear carrier is possible because the cast part is either already part of a supporting part of the rear carrier or welded to a supporting part of the rear carrier, with this approach, a better accessibility Welding site is given from all sides.

Both versions require a precise alignment of the rear carrier to the main carrier. When directly pouring the rear carrier or the carrier or carrier arms of the rear carrier in the cast component of the main carrier, a device for positioning and alignment is required because there are no correction options after the casting.

The method according to the invention is advantageously developed if the cast-in part is preheated prior to pouring into the rear-side connecting piece of the main carrier. This promotes alloy formation in the edge zone to the cast material. Also advantageously, the main carrier alone, together with a casting or together with the rear carrier subjected to an annealing process, whereby the desired material structure is set, which has the advantages of stability, damping properties and tensile and tear resistance.

The object underlying the invention is also achieved by a machine carrier for a wind turbine with a substantially as a casting, in particular made of a cast iron with nodular graphite, formed main carrier and a substantially formed as a welded part rear carrier, which is further developed by at least one weldable Eingussteil is provided, which is partially molded into a rear-side molded connection piece of the main carrier and outside the connector the main carrier is connected to the rear carrier, in particular by means of a welded connection. The cast-in part may also be integral with the rear carrier or with a supporting part of the rear carrier. In this case, a part of the sprue part protrudes from the connecting piece of the main carrier.

Also in this context, according to the invention is understood by a connector, a part or area of the main carrier to which or to which the rear carrier is recognized. The main carrier and the connector are preferably molded together as a unit.

An inventive machine carrier is manufactured in a composite casting technique and has no bolted flange connection between main carrier and rear carrier. The associated advantages have already been described in connection with the method according to the invention.

If preferably the casting at least in the area which is cast in the main carrier, having a profiled surface or a profiled edge, whereby the casting and the connecting piece of the main carrier are positively connected to each other, in addition to the material connection of the sprue connection and a positive connection between the casting and reached the surrounding casting of the main carrier. The additional positive locking prevents slipping out of the sprue the cast body of the main carrier even if the cohesive connection loses part of its strength due to material fatigue. A corresponding profiled surface or profiled edge may for example be a sawtooth profile or a suitable other profile.

Due to the form fit in the shape of the castings, a crash of the electrical components is prevented even in a possible loosening of the connection. Inserting vibrations due to the elimination of the material bond but would be recognized by conventional vibration sensors and lead to a shutdown of the affected wind turbine.

In an advantageous development or refinement, the rear carrier has two or more carriers or carrier arms, each with one or more sprues. As a result, coupled pendulum or oscillatory movements of the rear carrier are kept small. The sprues are preferably designed as paired horizontal plates. When each carrier or carrier arm of the rear carrier has in pairs at least one upper die and at least one lower die, the upper die is stressed primarily to train and the lower die primarily to pressure, so that an effective distribution of the stresses is achieved.

In this case, the at least one upper cast part can be formed with a larger cast surface than the at least one lower cast part. This takes into account the fact that the upper die is subjected to a tensile load and tends to pull this die from the casting of the main carrier, while the lower die under a compressive load tends to slide into the main carrier is pressed into it.

Preferably, at least one casting is designed as a substantially horizontally or vertically arranged sheet metal or as a sheet having in cross-section an L-profile, a C-profile, a U-profile a box section or a tubular cross-section. Corresponding sheets are for example burned out of sheet steel, laser cut or punched. The substantially horizontally arranged sheets efficiently absorb loads resulting from the weight of the generators and inverters arranged on the rear carrier, while substantially vertically accommodating sheets, in particular loads from transverse accelerations, for example, from movements of the nacelle about the tower axis transferred to the main carrier. It can also be advantageously arranged a plurality of vertically and horizontally arranged sheets or castings in an L-shape, C-shape, U-shape or box shape to each other.

In order to safely absorb transverse forces, for example from tower transversal oscillations or yaw oscillations around the tower axis, when using only two sheet-metal molded parts per carrier or carrier arm, the carrier or carrier arms of the rear carrier by means of diagonal braces, diagonal braces or thrust plates become additionally or alternatively advantageously provided Pushing Association are connected. This serves to absorb loads from lateral accelerations and prevents parallelogram movement with the casting parts as pivotal points.

In an advantageous development, at least one casting is designed as a cast steel part. Steel castings make an ideal transition between the softer cast iron of the main beam and the welded rear carrier, since the material properties of cast steel, in particular strength, density and damping properties, lie between those of the main carrier and those of the rear carrier. This reduces damage to the connection of the rear carrier and the main carrier, resulting from the stress of a joint between materials with different mechanical properties. Steel castings have the advantage that they are easy to shape due to the casting process. They are also weldable.

For the castings their suitability for welding is decisive. The choice of material for the castings must be made accordingly. In addition to steel castings in particular fine-grained steels come into question.

A cohesive embedding of molded parts in the casting of the main carrier is advantageously favored if at least one casting is coated, in particular with zinc, tin or a Zn-Al alloy. The coating promotes alloy formation and thus the intermetallic connection between the cast part and the cast material. The coating may preferably be applied by spray metallizing, for example by thermal spray galvanizing or zinc flame spraying.

A typical tower head diameter for a 2 megawatt wind turbine is between 2.4 m and 3 m. An advantageously compact design, the cost savings, is achieved in this context, when the main carrier has a tower flange whose center is located on a tower axis, wherein a distance of a sprue to the center of the tower flange less than 250% of a radius of a bolt circle of Turmflansches is, more preferably less than 200%, more preferably less than 180%.

Preferably, the machine carrier can be produced or produced in a method according to the invention as described above.

Finally, the object underlying the invention is also achieved by a wind energy plant with a machine support according to the invention as described above.

The properties, features and advantages mentioned with regard to the individual subject matter of the invention, that is to say the method for producing a machine carrier for a wind energy plant, the machine carrier and the wind energy installation, apply without restriction to the other objects of the invention.

Fig. 1

eine schematische Darstellung einer Gondel einer Windenergieanlage,

Fig. 2

eine schematische Draufsicht auf einen erfindungsgemäßen Hauptträger,

Fig. 3

eine schematische Seitenansicht des Hauptträgers gemäß Fig. 2,

Fig. 4

eine schematische Rückansicht des Hauptträgers gemäß Fig. 2,

Fig. 5

eine schematische Perspektivdarstellung des Hauptträgers gemäß Fig. 2,

Fig. 6

eine weitere schematische Perspektivdarstellung des Hauptträgers gemäß Fig. 2.

The invention will be described below without limiting the general inventive idea by means of embodiments with reference to the drawings, reference being expressly made to the drawings with respect to all in the text unspecified details of the invention. Show it:

Fig. 1

a schematic representation of a nacelle of a wind turbine,

Fig. 2

a schematic plan view of a main carrier according to the invention,

Fig. 3

a schematic side view of the main carrier according to Fig. 2 .

Fig. 4

a schematic rear view of the main carrier according to Fig. 2 .

Fig. 5

a schematic perspective view of the main carrier according to Fig. 2 .

Fig. 6

a further schematic perspective view of the main carrier according to Fig. 2 ,

In the following figures, identical or similar elements or corresponding parts are provided with the same reference numerals, so that a corresponding renewed idea is dispensed with.

In Fig. 1 a nacelle 1 of a wind turbine is shown schematically from the side. The gondola 1 is followed by a rotor hub 2 with three rotor blade connections 3 for rotor blades 4. A rotor blade 4 is also shown with its blade root end. The rotor blade connections 3 each have flanges for connecting a rotor blade 4 and blade angle adjustment devices for setting and determining the rotor blade angle. A flange is provided with the reference numeral 5.

Within the nacelle 1, a bearing 6 of a slow rotor shaft connects to the rotor hub 2, which is connected directly to the rotor hub 2. The slow shaft is connected to a gear 7, with which the speed of the slow rotor shaft is increased and transmitted to a fast shaft. The fast shaft, which adjoins the transmission 7, leads to a generator 8, which is arranged at the rear end of the nacelle 1. Also shown is an inverter 9, which adjusts the electric current generated by the generator 8 so that it is in a private or public power grid can be fed.

In the lower part of the nacelle 1, a machine carrier with a main carrier 10 and a rear carrier 11 is shown. The main carrier 10 supports the support 6 of the slow shaft and the rotor hub 2 and the gearbox 7. The rear carrier 11 carries electrical components such as the generator 8, control and switching cabinets and optionally a transformer and the inverter 9. For azimuthal rotation, that is to Rotation of the nacelle 1 on the longitudinal axis of the tower 13, 10 azimuth drives 12 are arranged on the main carrier, which rotate the nacelle 1 on the tower 13 via a gear and sprocket gear.

The nacelle 1 also has wind sensor technology and lightning protection 14 at its rear end. Another unillustrated lightning protection is usually arranged in the region of the transition between the nacelle 1 and the rotor hub 2 in order to discharge lightning strikes from the rotor blade into the tower.

The main carrier 10 is made of a cast body which has sufficient strength to support the components resting on the main carrier 10 and whose comparatively soft material properties are well suited to dampening vibrations that continually occur during operation of the wind turbine. In particular, the Gus carrier is particularly resistant to fatigue loads due to its notch-free geometry, which must be transferred from the rotor into the tower. The rear carrier is welded from steel parts and absorbs the weight forces and torques of the generator 8 and the inverter 9 and transmits them by means of a connection between the main carrier 10 and the rear carrier 11 on the main carrier 10 and the tower 13. The rear carrier 11 is one-sided clamped cantilever executed sufficiently stiff to safely avoid compression of the generator 8 during operation.

In Fig. 2 to Fig. 6 an inventive main carrier 10 is shown schematically from different directions. In Fig. 2 is a top view of the main carrier 10 is shown, wherein the main carrier 10 has a bearing block 22 for a rotor main bearing at its front, ie the rotor hub end end. Laterally this is followed by mounts 21 for azimuth drives, which in Fig. 1 are provided with the reference numeral 12.

In Fig. 2 It can also be seen that two symmetrical connecting pieces 24 adjoin one another at the longitudinal side to a rear carrier, not shown, into which in each case sprues 25 are partially cast. In the illustrated embodiment, the rear carrier consists of two rear support arms, which are each attached to one of the connectors 24. The present invention also covers the case that a rear carrier is designed with three or more rear support arms.

A portion of the sprue 25 protrudes from the connector 24 respectively and forms a welding surface for a support arm for a rear carrier. The cast-in part of each sprue part 25 has a profiled edge 26, in this case a sawtooth shape, which prevents fatigue of the material bond between the cast-in part 25 and the cast body of the connecting piece 24 from causing the cast-in part 25 to slip out of the cast body. At the bottom of an azimuth flange 23 with a bolt circle, not shown, for the Turmanbindung of the main carrier 10 can be seen. The diameter of the bolt circle corresponds roughly to the outer diameter of the tower.

In Fig. 3 is the main carrier 10 according to Fig. 2 shown schematically from the side. It can be seen that the connecting piece 24 has at its upper and lower ends in each case a cast-in part 25, that is to say a total of two molded parts 25 per rear support arm. These absorb the forces acting in the vertical direction from the rear carrier and introduce them into the main body 10.

In Fig. 4 is the main carrier 10 according to the invention according to Fig. 2 schematically in a view from the back, so from the direction of the rear carrier shown. It can be seen that in each case two sprues 25 are arranged horizontally on each of the two connecting pieces 24 of the main carrier 10 substantially parallel to each other. These are arranged in pairs, which have a greater extent in the horizontal direction than in the vertical direction. It can be seen that the respective upper sprues 25 are somewhat wider than the respective lower sprues 25, so that the upper sprues 25 have a larger surface, which forms a material connection with the casting of the main carrier 10. Thus, the upper sprues 25, which are subjected to a tensile load, are anchored more strongly in the main beam 10 than the lower sprues 25, which are subjected to a compressive load.

Alternatively or in addition to this, vertical plates can also be cast in, which can absorb the transverse acceleration, that is, acceleration about the longitudinal axis of the tower. On either side of the machine carrier or main carrier 10 either one or two vertical sheets can be poured for this, so that there is a U-profile or a box profile on each side.

In Fig. 5 is a first perspective view of the main carrier 10 according to the invention according to Fig. 2 shown while in Fig. 6 another perspective view is shown. It can be seen from both figures that the bearing block 22 for a rotor main bearing has a pitch circle recess for supporting a circular rotor main bearing. It can also be seen how the sprues 25 are arranged in the cast body of the main carrier 10.

All mentioned features, including the drawings alone to be taken as well as individual features that are disclosed in combination with other features are considered alone and in combination as essential to the invention. Embodiments of the invention may be accomplished by individual features or a combination of several features.

LIST OF REFERENCE NUMBERS

1

gondola

2

rotor hub

3

Rotor blade connection

4

rotor blade

5

flange

6

Storage of the slow rotor shaft

7

transmission

8th

generator

9

inverter

10

main carrier

11

rear carrier

12

azimuth drive

13

tower

14

lightning protection

21

Mount for azimuth drives

22

Bearing block for rotor main bearing

23

Azimutflansch for Turmanbindung

24

Connector to the rear carrier

25

cast-

26

profiled edge

Claims (15)

Method for producing a machine carrier (10, 11) for a wind energy plant, wherein a main carrier (10) is produced by casting a casting as a casting and a rear carrier (11) is produced as a welded part, characterized in that at least one weldable casting (25) is provided, which in the manufacture of the main carrier (10) in a rear-side connecting piece (24) of the main carrier (10) is partially poured and outside of the main carrier (10) with the rear carrier (11), in particular by means of welding, is or is. A method according to claim 1, characterized in that the Eingussteil (25) is first partially poured into the rear-side connecting piece (24) of the main carrier (10) and then the rear carrier (11) on a from the main support (10) protruding out part of the sprue (25) welded becomes. A method according to claim 1, characterized in that first of the rear carrier (11) is produced with a Eingussteil (25) and then a part of the sprue (25) in the manufacture of the main carrier (10) in the rear-side connector (24) of the main carrier ( 10) is poured. Method according to one of claims 1 to 3, characterized in that the Eingussteil (25) is preheated prior to pouring into the rear-side connecting piece (24) of the main carrier (10). Method according to one of claims 1 to 4, characterized in that the main carrier alone, together with a Eingussteil (24) or together with the rear carrier (11) is subjected to an annealing process. Machine carrier (10, 11) for a wind turbine with a main cast part, in particular cast iron with nodular graphite formed main carrier (10) and a substantially formed as a welded part rear carrier (11), characterized in that at least one weldable Eingussteil (25) is provided, which is partially cast in a rear-side molded connecting piece (24) of the main carrier (10) and outside of the connecting piece (24) of the main carrier (10) to the rear carrier (11) is connected, in particular by means of a welded connection. Machine carrier (10, 11) according to claim 6, characterized in that the cast-in part (25) has a profiled surface at least in the region which is cast in the main carrier (10) or a profiled edge (26), whereby the Eingussteil (25) and the connecting piece (24) of the main carrier (10) are positively connected to each other. Machine carrier (10, 11) according to claim 6 or 7, characterized in that the rear carrier (11) has two or more carrier or support arms, each with one or more sprues (25), which are designed in particular as paired horizontal plates. Machine support (10, 11) according to any one of claims 6 to 8, characterized in that at least one Eingussteil (25) is formed as a substantially horizontally or vertically arranged sheet metal or as a sheet, which in cross section an L-profile, a C-profile , a U-profile has a box section or a tubular cross-section. Machine carrier (10, 11) according to any one of claims 6 to 9, characterized in that a plurality of vertically and horizontally disposed sprues are arranged in an L-shape, C-shape, U-shape or box shape to each other. Machine carrier (10, 11) according to any one of claims 6 to 10, characterized in that carrier or carrier arms of the rear carrier (11) are connected by means of diagonal bracing, diagonal struts or thrust plates to a pushing association. Machine support (10, 11) according to one of claims 6 to 11, characterized in that at least one casting part (25) is designed as a cast steel part. Machine carrier (10, 11) according to any one of claims 6 to 12, characterized in that at least one casting (25) is coated, in particular with zinc, tin or a Zn-Al alloy. Machine carrier (10, 11) according to one of claims 6 to 13, characterized in that the machine carrier (10, 11) in a method according to one of claims 1 to 5 can be produced or manufactured. Wind energy plant with a machine carrier (10, 11) according to one of claims 6 to 14.

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