EP4352377A1

EP4352377A1 - Elastomeric spring and azimuth drive with elastomeric spring

Info

Publication number: EP4352377A1
Application number: EP22729574.8A
Authority: EP
Inventors: Michael SCHÄDDEL; Wolfgang Spatzig; Andreas Kehr
Original assignee: Effbe GmbH
Current assignee: Effbe GmbH
Priority date: 2021-06-07
Filing date: 2022-05-18
Publication date: 2024-04-17
Also published as: WO2022258323A1; CA3220012A1

Abstract

The present invention relates to an elastomeric spring for an azimuth brake of an azimuth drive for tracking a nacelle with a rotor in relation to a tower of a wind turbine, having an elastomeric body, which is produced from one piece and has an upper and a lower face facing a spring direction of the elastomeric body, for transferring spring forces in the spring direction, and a preloading component connecting the upper to the lower face and having a concavely bent lateral face.

Description

Elastomer spring and azimuth drive with elastomer spring

The present invention relates to an elastomer spring for an azimuth brake of an azimuth drive for tracking a nacelle with a rotor relative to a tower of a wind energy plant (WEA). Furthermore, the present invention relates to a yaw brake and a yaw drive for a wind turbine.

Wind turbines generally include a stationary tower, in particular one that is fixed to the foundation or the ground, on which a nacelle that can follow the wind and can be braked is rotatably mounted about a vertical axis via a rotary connection. The nacelle has a rotatably mounted rotor hub about which at least one rotor blade of a rotor can rotate.

The task of the azimuth drive is to track the nacelle and thus the rotor blade of the wind turbine rotor into the optimum nacelle position for energy conversion, depending on the wind direction. For example, slewing rings and electric drives are used. The slewing ring usually comprises a toothed rim fixed to the tower with teeth on the face, also called azimuth ring, on the face of which several motors interlock in order to rotate relative to the azimuth ring and thus track the nacelle.

To brake and secure the nacelle, for example in the case of maintenance, several friction brakes distributed over the circumference of the azimuth ring are used, which essentially have a C-shaped structure and grip the azimuth ring like a clamp, so that they can be connected to the top and bottom sides of the azimuth ring, which are oriented in the vertical direction Azimuth rings are in frictional contact. The yaw brake typically has sliding linings for contact with the yaw ring. Furthermore, disc spring packages are provided for preloading the sliding linings in the direction of the azimuth ring. About the extent the preload can be used to adjust the frictional resistance and thus the braking effect.

Disc springs generally have a failure probability of approx. 1% according to the manufacturer's information. Depending on the type of turbine, up to 270 disc springs are used in wind turbines, which multiplies the risk of damage to the yaw drive. The problem with disc spring packs is that if even one disc spring is damaged or fails, the complete preload of the pack is suddenly lost. As a result, the remaining load is distributed to the spring assemblies that have remained intact, which are thus permanently overloaded, so that the damage progression in the other disc spring assemblies accelerates. Wind turbine downtime and unscheduled maintenance operations occur, which are costly.

Yaw drives and yaw brakes of this type are known, for example, from EP 0945613 Bi or WO 2015/082114 Ai. EP 0945613 Ai and WO 2015/082114 Ai also disclose initial approaches to replacing the plate spring packs with alternative stores of potential energy, such as air springs, gas pressure springs, elastomer springs or torsion springs.

In the known azimuth systems, in addition to the high risk of failure of the plate spring assemblies, the large installation space required and the large number of parts have proven to be disadvantageous.

An object of the present invention is to overcome the disadvantages of the prior art, in particular to provide a more reliable and/or more durable yaw brake and/or yaw drive.

The object is solved by the subject matter of the independent claims.

According to this, an elastomer spring for an azimuth brake of an azimuth drive for tracking a nacelle, which has a rotor, is provided relative to a tower of a wind energy plant (WEA). The tower is usually stationary and/or fixed to the foundation. The elastomer spring basically serves to build up a frictional force. In particular, the elastomer spring is designed to the sliding linings To bring azimuth brake into contact with the azimuth ring in order to brake the nacelle when tracking relative to the tower of the wind turbine while building up a friction resistance and thus a braking effect.

The elastomer spring according to the invention comprises an elastomer body made in one piece. The elastomer body can be produced, for example, by polymerisation, polycondensation, polyaddition or vulcanisation. The elastomeric material can be, for example, a cast elastomer, in particular polyurethane, such as Ureiast.

The elastomer body has a top side pointing in a spring direction of the elastomer body and a bottom side facing in the spring direction of the elastomer body, which is opposite the top side. The top and bottom serve to transmit spring forces in the direction of the spring. The elastomer body can, for example, consist of solid material and/or be made from it. The elastomeric body also extends in a longitudinal direction that is oriented parallel to the spring direction of the elastomeric body. In the spring direction, the elastomer body can in particular deform and compress elastically. The elastomer spring can be set up to apply and reduce the frictional force for braking the gondola by utilizing the particular elastic deformation, particularly compression and expansion.

The elastomer spring according to the invention also includes a pretensioning component which connects the upper and lower sides and has a concavely curved lateral surface. It is clear that the concavity of the lateral surface is to be understood when viewing the elastomer spring from the outside. When viewed from the opposite direction, i.e. viewed from the inside of the elastomer body, the lateral surface curvature is convex. The biasing component is made in one piece with a top and bottom. The top and bottom can each be realized by essentially flat plates or disks. The lateral surface connecting the top and bottom can have a constant radius of curvature and/or be closed circumferentially in the circumferential direction with respect to the direction of longitudinal extension of the elastomer body. Elastomeric bodies as elastomeric springs for azimuth brakes have therefore proved to be particularly advantageous when the elastomeric springs in the In contrast to the disk spring packages, they are characterized by excellent emergency running properties. Because if an elastomeric spring is damaged, the preload is never completely lost, so the elastomeric springs can be replaced during scheduled maintenance. An elastomer spring can replace a six-part disc spring assembly, so that the variety of parts can be greatly reduced and the risk of failure of the elastomer spring is also significantly lower than that of a six-part disc spring assembly. Due to the structure of the elastomer body according to the invention, in particular due to the shape deviating from a purely cylindrical shape by means of the concavely curved lateral surface, the elastomer spring can be subjected to very high loads, in particular the viscoelastic effect can be exploited. As a result, the space required for the necessary deformation can also be minimized. In contrast to purely cylindrical elastomer springs, the structure according to the invention makes it possible to achieve the desired tensioning force while retaining the available installation space in standard yaw brakes. If standard cylindrical elastomer springs were used, the cross-sectional area of the spring elements would have to be multiplied, in particular increased by a factor of two or three, in order to generate the same sufficient clamping force. By leaving out elastomer material in the area of the lateral surface of the elastomer body, on the one hand the material costs of the elastomer spring are reduced and on the other hand the free space remaining on the lateral surface as a result of the concavity, which surrounds the lateral surface, offers a large escape space for the elastomer material of the elastomer body, so that its deformation rate is increased.

The prestressing component, which can also be referred to as a deformation component, can be set up to be prestressed and/or deformed, in particular in the spring direction, such as in particular being elastically compressed or upset, as a result of which it generates a force directed in particular in the spring direction, in particular a reaction force such as a in particular elastic deformation restoring force can generate. The biasing component may have a passive state, in which it is undeformed and/or unbiased, and an active state, in which it is deformed and/or biased.

In an exemplary embodiment of the elastomer spring according to the invention, the pretensioning component is set up to close elastically during compression compress that the curvature of the lateral surface decreases. In other words, when the elastomer body deflects or compresses, its upper and lower sides are moved towards one another, which results in a particularly elastic deformation of the preload component insofar as the elastomer material of the preload component is compressed in the axial direction or spring direction, so that the elastomer material is displaced radially outward , whereby the radius of curvature of the lateral surface increases.

According to a further exemplary embodiment of the elastomer spring according to the invention, the prestressing component is also set up to expand in particular elastically during rebound in such a way that the curvature of the lateral surface increases, as a result of which the radius of curvature of the lateral surface in particular decreases. When rebounding or expanding the prestressing component, the opposite effect occurs in relation to the springing in or compression described above.

It should be clear that the degree of compression or degree of expansion of the pretensioning component can be set or limited, among other things, by its dimensions. The dimensions in the axial direction, in the radial direction and the radius of curvature are relevant here.

In a further exemplary embodiment of the present invention, the prestressing component compresses during compression, building up an elastic deformation restoring force, so that the elastomer body transmits the deformation restoring force as a prestressing force in the spring direction via the top and bottom. In other words, the particularly elastic compression of the prestressing component of the elastomer body can be used to generate a prestressing force via the resulting deformation restoring force, which the azimuth brake can use to brake the azimuth drive by building up frictional force.

In an exemplary development of the elastomer spring according to the invention, the elastomer body has at least one additional, in particular two or three additional, in particular identically shaped, prestressing component(s). The elastomer spring formed in this way can also be referred to as a sandwich construction. In particular, all biasing components are connected to the top and bottom and/or to each other made in one piece. The biasing components can be arranged in series in the direction of the spring. The series connection of the several prestressing components can be designed in such a way that the individual prestressing components can be deformed, in particular compressed and expanded, independently of one another. For example, the elastomer spring exhibits a deformation behavior similar to that of a bellows or an accordion.

According to an exemplary development of the elastomer spring according to the invention, two adjacent prestressing components are separated from one another by a particularly flat separating disk, which remains essentially undeformed during compression and/or rebound. The cut-off wheels are made in one piece with the preload components and/or the top and bottom. According to this embodiment, a bellows or accordion-like structure results whose deformation behavior is also similar to a bellows or an accordion. The individual biasing components compress and expand under load as the cutting discs and the top and bottom faces move toward and away from each other depending on whether there is deformation or expansion.

According to a further exemplary embodiment of the elastomer spring according to the invention, the separating disk, in particular the separating disks, have the same shape and/or the same external dimensions as the top and bottom. The elastomeric body can be rotationally shaped and/or axisymmetric with respect to a central axis, viewed both in the longitudinal direction and transversely thereto, with respect to the cross section of the elastomeric body.

According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, an azimuth brake for an azimuth drive for tracking a nacelle with a rotor relative to a tower of a wind energy plant (WEA) is provided. With regard to the basic structure, the mode of operation and the arrangement of the yaw brake in relation to the yaw drive and the associated nacelle, rotor and tower components, reference can be made to the previous statements. The Azimuth Drive comprises an azimuth ring connected in a rotationally fixed manner to the tower, which can be stationary and/or fixed to the foundation.

The azimuth brake according to the invention comprises a sliding disk in sliding contact with the azimuth ring and an elastomer spring in particular according to the invention, for example designed according to one of the previously described aspects or exemplary embodiments, for prestressing the sliding disk against the azimuth ring.

To apply a braking force to the azimuth ring, i.e. to brake the azimuth ring driven in rotation by the azimuth drive, a force can be applied to the sliding disk facing the azimuth ring by means of the elastomer spring in order to bring it into frictional contact with the azimuth ring or to an existing one Reinforce frictional contact so that the azimuth ring is slowed down.

According to the further aspect of the invention, the elastomer spring is made from a cast elastomer, in particular polyurethane, such as ureast, and/or from one piece, in particular in a manufacturing step and/or tool.

With regard to the basic advantages of using elastomer springs instead of disc spring assemblies, reference is made to the previous statements. Cast elastomers have proven to be advantageous for use in azimuth brakes in wind turbines in that they have a very low compression set, which is, for example, at least 10% or at least 15% lower than with standard elastomer components and/or is 5%, for example. Furthermore, cast elastomers are characterized by a high resistance to aging. When used in azimuth brakes, cast elastomers have an aging resistance of more than 20 years. Polyurethane is also characterized by a high tensile strength of about 40 N/mm ² and an elongation at break of about 500%. Compared to standard elastomers, this results in a significantly higher tensile strength and also a significantly higher elongation at break, in particular by at least 1.5 times, 2 times or 2.5 times.

According to an exemplary embodiment of the azimuth brake according to the invention, the azimuth brake has a mount for the elastomer spring, which is in particular fixed to the nacelle. in which the elastomer spring, in particular also the sliding disk, can be displaced in a translatory manner. In other words, the receptacle is provided in the nacelle itself or in a further component of the wind turbine that is connected to the nacelle in a rotationally fixed manner. The elastomer spring can in particular be translationally displaceable in the spring direction, so that the elastomer spring can be translationally displaced in the spring direction for compression and for expansion. The receptacle for the elastomer spring can be realized, for example, by a depression, in particular a cylindrical depression.

According to an exemplary development of the azimuth brake according to the present invention, the elastomer spring has at least two clamping sections which are arranged at a distance from one another in the spring direction of the elastomer spring, which are in circumferential contact with the receptacle and are connected to one another via a circumferentially closed, concavely curved lateral surface. The clamping sections can be formed by the top and bottom of the elastomeric spring. The clamping sections can define the maximum dimension of the elastomer spring transversely to its longitudinal direction, which is oriented parallel to the direction of the spring. In other words, the elastomeric spring is in peripheral contact via the clamping portions with the peripheral walls of the receptacle. The elastomeric spring need not necessarily be in contact with the bottom of the indentation, but may be located at a slight distance therefrom, at least in a compressed state.

According to a further exemplary embodiment of the azimuth brake according to the invention, the clamping sections are supported on the receptacle when the elastomer spring compresses in order to increase the prestressing force on the sliding disk and/or to apply a prestressing force to the sliding disk in such a way that they are moved towards one another and the curvature of the lateral surface decreases. Due to the particularly elastic compression of the elastomer spring, which takes place as a result of the clamping sections moving towards one another, material of the elastomer spring is displaced radially outwards, as a result of which the curvature of the lateral surface decreases. The displaced material of the elastomer spring can thus expand or deviate into an escape space resulting between the inner wall of the receptacle and the lateral surface. According to a further exemplary embodiment of the present invention, the prestressing force can be adjusted via a degree of compression of the elastomer spring. For example, the prestressing force and thus the braking force of the azimuth brake increases, in particular linearly, with the increasing degree of compression of the elastomer spring.

In a further exemplary embodiment of the yaw brake according to the present invention, the yaw brake further comprises a mechanical or hydraulic or pneumatic device for compressing the elastomeric spring. For example, the device can be coupled to an electronic controller that controls the compression or expansion of the elastomer spring. For example, the device can have a screw. For example, the screw protrudes into the receptacle in such a way that to compress the elastomer spring, the screw is increasingly screwed into the receptacle space, so that the screw presses on one of the clamping sections and presses it in the direction of the other clamping section while compressing the elastomer spring.

Furthermore, the present invention also provides an azimuth drive for tracking a pod having a rotor relative to a tower of a wind turbine. The azimuth drive according to the invention comprises at least one servomotor, which drives an azimuth ring, for example, and an azimuth brake designed according to one of the above aspects or exemplary embodiments, which can have an elastomer spring according to the invention.

Preferred embodiments are specified in the dependent claims.

In the following, further properties, features and advantages of the invention become clear by means of a description of preferred embodiments of the invention using the attached exemplary drawings, in which:

FIG. 1 shows a perspective schematic basic sketch of a section of an azimuth drive of a wind turbine;

Figure 2 is a schematic side view of a yaw brake of the

azimuth drive from FIG. Figure 3 is a sectional view taken along line III - III of Figure 2;

Figure 4 is a sectional view taken along line IV - IV of Figure 2;

FIG. 5 shows an exemplary embodiment of an elastomer spring according to the invention in a side view;

FIG. 6 shows the elastomer spring from FIG. 5 in a compressed state;

FIG. 7 shows the elastomer spring from FIGS. 5 and 6 in a perspective view; and

FIG. 8 shows a further exemplary embodiment of an elastomer spring according to the invention in a side view.

In the following description of exemplary embodiments of the present invention, an elastomer spring according to the invention for a yaw brake of a yaw drive of a wind energy plant (WEA) is generally provided with the reference number 1 . A yaw brake in accordance with the present invention is generally designated by the reference numeral 10 and the associated yaw drive is generally designated by the reference numeral 100 .

FIG. 1 shows a perspective basic sketch of a section of an azimuth drive 100 of a wind energy installation. A wind turbine generally comprises a stationary tower 101 and a nacelle 103 rotatably connected to the tower 101. The nacelle 103 can be rotated about a vertical axis via the slewing ring, in order to rotate the nacelle 103 and a rotor (not shown) with at least one rotor blade to track the wind and brake again. As a result, the rotor blades are always in the optimal position for energy conversion in relation to the wind direction. In FIG. 1, the rotary connection between the tower 101 and the gondola 103 is realized by the azimuth drive 100.

The azimuth drive 100 includes a ring gear 105 with external teeth, which is also referred to as an azimuth ring, which is connected to the tower 101 in a rotationally fixed manner. The azimuth drive 100 also includes a plurality of servomotors or electric motors 107, which are rotatably connected to the nacelle 103 and each a gear wheel 106 meshingly engages the external teeth of the azimuth ring 105 in order to rotate relative to the azimuth ring 105 and thus to move the nacelle 103 . For braking the gondola 103, the yaw drive 100 in Figure 1 also includes four yaw brakes 10 distributed evenly over the circumference of the yaw ring 105. In Figure 1 it can be seen that the yaw brakes 10 each have a substantially C-shaped structure and the yaw ring 105 like a clamp embrace. In order to brake the nacelle 103, frictional contact is provided between an azimuth brake 10 and an upper side 108 and lower side 110 of the azimuth ring 105 viewed in the vertical direction, normally in the form of sliding linings 3 on the azimuth brake 10. Elastomer springs 1 according to the invention are used in the azimuth brake 10 in FIG. In Figure 1 it can be seen that a yaw brake 10, due to the C-shaped structure, has both sliding linings 3 and associated elastomer springs 1, which make frictional contact with the underside 110 of azimuth ring 105, and sliding linings 3 and associated elastomer springs 1, which make frictional contact with the top 108 of the azimuth ring 105. In this way, the braking effect of the azimuth brake 10 can be increased.

The use of elastomer springs 1 according to the invention for a yaw brake 10 has proven to be advantageous because the elastomer springs 1 are characterized by excellent emergency running properties, in contrast to the disk spring assemblies used in the prior art. The reason for this is that the preload is not completely lost when an elastomeric spring 1 is damaged, so it can easily be replaced at the next scheduled maintenance. In addition, the risk of failure with elastomer springs 1 according to the invention is lower than with disk spring assemblies. The elastomer springs 1 according to the invention are discussed below with reference to FIGS.

FIG. 2 shows a yaw brake 10 of the yaw drive 100 from FIG. 1 in a schematic side view. The yaw brake 10 in FIG. 2 represents the lower part of a yaw brake 10 from FIG. The azimuth brake 10 can also use the upper part of the Azimuth brake 10 include from Figure 1, which creates a frictional contact with the top 108 of the azimuth ring 105, and is constructed substantially identically. However, the upper part of the azimuth brake 10 is not shown in the embodiment in FIG.

The embodiment of a yaw brake 10 according to the invention in Figures 2 to 4 comprises four sliding disks 3 in sliding contact with the yaw ring 105 and four elastomer springs 1 according to the invention, each assigned to one of the sliding disks 3, which are described in detail later, for prestressing the sliding disks 3 against the Azimuth ring 105 to create frictional contact.

FIGS. 3 and 4 show the yaw brake 10 from FIG. 2 in a sectional view along the lines III-III and IV-IV in order to clarify the functioning of an elastomer spring 1 according to the invention or a yaw brake 10 according to the invention. FIG. 3 shows an elastomer spring 1 in an unstressed state, which means that the azimuth brake unit 10 assigned to the elastomer spring 1 does not build up any braking force on the azimuth ring 105 . Another elastomer spring 1 is shown in a tensioned state in FIG. The biasing force of the yaw brake 10 or an individual yaw brake unit 10 can be adjusted via a degree of compression of the elastomer springs 1 . The degree of compression of an elastomer spring 1 indicates how much the elastomer spring 1 can be compressed and determines the deformation restoring force that can be generated by the compression of the elastomer spring 1 .

The azimuth brake 10 has a receptacle 5 for the elastomer springs 1 which is connected to the nacelle 103 in a rotationally fixed manner. In the embodiments in FIGS. 2 to 4, the receptacle 5 has an L-shaped structure and is arranged in the vertical direction below the azimuth ring 105 and above the tower 101 (not shown in FIGS. 2 to 4) in the wind turbine. The receptacle 5 thus borders on the azimuth ring 105 with an upper side 6 and on the tower 101 with a lower side 8 . There is no direct contact with the tower 101 on the underside 8 in order to allow the receptacle 5 to rotate with respect to the tower 101 . At the top 6 of the recording there is either no direct contact with the azimuth ring 105 or the top 6 of the Receptacle 5 and the underside 110 of the azimuth ring 105 are designed in such a way that they do not impair a rotation of the receptacle 5 relative to the azimuth ring 105 which is non-rotatably connected to the tower 101 .

In the embodiment in Figures 2 to 4, the receptacle 5 has a cylindrical depression 7 for each elastomer spring 1, in which the elastomer spring 1 and the associated sliding disk 3, which is arranged in the vertical direction between the elastomer spring 1 and the azimuth ring 105, translationally are relocatable. The indentations 7 extend from the upper side 6 of the receptacle 5 facing the azimuth ring 105 into the interior of the receptacle 5. The translational displacement capability makes it possible for the elastomer spring 1 to be able to compress in the indentation 7. In addition, the translational displaceability makes it possible to ensure that when the elastomer spring 1 is in a relaxed state, as shown in FIG , which would generate frictional resistance when the gondola 103 rotates. It can be seen in FIG. 3 that a gap 12 is formed between the sliding disk 3 and the azimuth ring 105 in the unstressed state. When the elastomer spring 1 is compressed, as shown in FIG. 4, it is first moved translationally in the direction of the azimuth ring 105 so that there is no longer a gap 12 between the sliding disk 3 and the azimuth ring 105 and only then is the elastomer spring 1 compressed. This creates a distance between the elastomer spring 1 and a depression base 25 of the depression 7. The gap 12 is dimensioned in such a way that on the one hand it is large enough to ensure that in the relaxed state of the elastomer spring 1 there is no contact between the sliding disk 3 and the azimuth ring 105 and on the other hand is small enough to delay the braking effect as little as possible when the yaw brake 10 or the yaw brake unit 10 is actuated. The cylindrical indentations 7 have the same diameter as the elastomer springs 1 so that the elastomer spring 1 is in circumferential contact with the inner walls 23 of the indentation 7 .

In the embodiment in FIGS. 2 to 4, the receptacle 5 comprises a device for compressing the elastomer springs 1, which has a screw 9 for compressing the respective elastomer spring 1 for each elastomer spring. The screw 9 protrudes from the Underside 8 of the receptacle 5 into the receptacle 5 or the cylindrical recess 7 in such a way that it is increasingly screwed into the receptacle 5 or the cylindrical recess 7 to compress the elastomer spring 1 and presses on the elastomer spring 1 . For the uniform transmission of the force from the screw 9 to the elastomer spring 1, a washer 11 is provided between the screw 9 and the elastomer spring 1, which has the same outer dimensions as the elastomer spring 1 and the recess 7. When the yaw brake unit 10 is actuated, the disk 11 is pressed by the screw 9 in the cylindrical depression 7 in the direction of the yaw ring 105 in order to compress the elastomer spring 1 and generate a prestressing force on the sliding disk 3 . The elastomer spring 1 is therefore supported on the disk 11 of the mount 5 during compression to increase the prestressing force on the sliding disk 3. The elastomer spring 1 thus presses the sliding disk 3 against the azimuth ring 105 and the mount 5 or the gondola 103 connected to it braked.

The structure of an elastomer spring 1 according to the invention is described in detail below with reference to FIGS. FIG. 5 shows the elastomer spring 1 in the unstressed state, as shown in FIG. 3, in a side view and in FIG. 7 in a perspective view. FIG. 6 shows the elastomer spring 1 in the tensioned state, as shown in FIG.

An elastomer spring 1 according to the invention comprises an elastomer body 2 produced in one piece, which can be produced, for example, by polymerisation, polycondensation, polyaddition or vulcanisation. The elastomeric material can be, for example, a cast elastomer, in particular polyurethane, such as Ureiast. The elastomer body 2 can deform and compress elastically in the spring direction F. The elastomer body 2 is rotationally shaped and axisymmetric with respect to a central axis M, which also defines the spring direction F.

The elastomer spring 1 has an upper side 13 pointing in the spring direction F of the elastomer body 2 and an underside 15 pointing in the spring direction F of the elastomer body 2 , which is opposite the upper side 13 . The upper side 13 and the lower side 15 are each realized as flat discs 14, 16 and are used to transmit spring forces in the spring direction F. The embodiment of the elastomer spring 1 in FIGS. 5 to 7 includes in addition, two identically shaped pretensioning components 17, which connect the upper side 13 and the lower side 15 of the elastomer body 2 to one another and each have a lateral surface 19 that is concavely curved when viewed from the outside. The prestressing components 17 are arranged in series when viewed in the spring direction F. Between the two prestressing components 17 there is a flat separating disk 21 which separates the two prestressing components 17 from one another. The cutting disc 21 has the same shape and the same external dimensions as the discs 14 , 16 on the upper side 13 and the lower side 15 of the elastomer body 2 . The discs 14, 16 on the top 13 and the bottom 15, the biasing components 17 and the cutting disc 21 are made according to the invention in one piece.

The mode of operation of the elastomer spring 1 according to the invention can be seen in a comparison of FIG. 5 and FIG. 6 as well as in a synopsis with FIGS. During compression, the disks 14 , 16 on the upper side 13 and the lower side 15 of the elastomer body 2 or the separating disk 21 are moved towards one another between the two prestressing components 17 . The discs 14, 16 and the cutting disc 21 remain undeformed. As a result, the pretensioning components 17 are elastically compressed between the discs 14, 16, 21, so that a bellows-like or accordion-like structure of the elastomer spring 1 results. Due to the compression of the prestressing components 17, the curvature of the respective lateral surface 19 decreases because the elastomer material of the prestressing components 17 is displaced radially outwards. Therefore, the curvature of the lateral surfaces 19 of the prestressing components 17 in the compressed state of the elastomer spring 1 in Figure 6 and Figure 4 is less than in the relaxed state of the elastomer spring 1 in Figure 5 and Figure 3. When the elastomer spring 1 is no longer compressed, the Discs 14, 16 on the top 13 and the bottom 15 or the separating disc 21 correspondingly move away from each other again during rebound, so that the prestressing components 17 expand again and the curvature of the lateral surfaces 19 increases. The two prestressing components 17 can be compressed and expanded independently of one another by the separating disk 21, so that different curvatures of the two lateral surfaces 19 are also possible.

During deflection, an elastic deformation restoring force is built up by the compression of the prestressing components 17, which is transmitted by the elastomer body 2 the discs 14,16 on the top 13 and the bottom 15 can be transmitted as a biasing force in the spring direction F. This prestressing force can, for example, generate the frictional force required in an azimuth brake 10 for braking the nacelle 103 of a wind power plant. In FIG. 3, the discs 14, 16, 21 are far apart, so that the prestressing components 17 are not compressed and the elastomer spring 1 is relaxed. So no deformation restoring force and thus no prestressing force is generated. In FIG. 4, the elastomer spring 1 and the sliding disk 3 arranged directly above it in the vertical direction are first pushed in the direction of the azimuth ring 105 by screwing in the screw 9 in the recess 7 for braking. When there is contact between the sliding disk 3 and the azimuth ring 105, i.e. when the gap 12 between the sliding disk 3 and the azimuth ring 105 is closed, the disks 14,16,21 of the elastomer spring 1 move towards one another, so that the prestressing components 17 are compressed and the curvature of the lateral surfaces 19 decreases. This generates a deformation restoring force that can be used as a preload force. Since the underside 15 of the elastomer spring 1 in the embodiment in Figure 4 rests firmly on the disk 11 connected to the screw 9 and consequently cannot move, the prestressing force is transmitted via the upper side 13 of the elastomer spring 1 to the sliding disk 3, which is thereby counteracted the azimuth ring 105 is pressed. This creates a frictional force between the sliding disk 3 and the azimuth ring 105, which decelerates the receptacle 5 in which the elastomer spring 1 is accommodated and the nacelle 103 of the wind power plant connected thereto.

The elastomer spring 1 can be exposed to very high loads due to the concavely curved lateral surface 19 of the prestressing components 17 because a viscoelastic effect can be used in this way. In addition, compared to elastomer springs with a cylindrical cross-section, the space required and the material costs can be reduced. The concavely curved lateral surface 19 of the prestressing components 17 also creates a larger escape space for the elastomer material of the prestressing components 17, so that the deformation rate or the degree of compression of the elastomer spring 1 is increased. In order to adjust the degree of compression or the degree of expansion of the prestressing components 17 and thus of the elastomer spring 1, the dimensions in the axial direction and in the radial direction of the elastomer body 2 or the prestressing components 17 and the radius of curvature of the lateral surfaces 19 of the prestressing components 17 are relevant.

With reference to Figure 3 and Figure 4 it can be seen that the discs 14,16 on the top 13 and the bottom 15 and the cutting disc 21 represent clamping sections which form circumferential contact with the receptacle 5 or the cylindrical recess 7 and the elastomer spring 1 center and fix in the recess 7. The clamping sections 14 , 16 , 21 thus determine the maximum dimension of the elastomer spring 1 transversely to the spring direction F. When the elastomer spring 1 is compressed, the clamping sections 14 , 16 , 21 slide along the inner surfaces 23 of the depression 7 . It can also be seen that the elastomeric material of the pretensioning components 17 can expand or deviate into an escape space resulting between the inner wall 23 of the recess 7 and the jacket surface 19 when the elastomer spring 1 is compressed.

FIG. 8 shows a further exemplary embodiment of an elastomer spring 1 according to the invention in a side view. In the embodiment in FIG. 8, the upper side 13 and the lower side 15 of the elastomer body 2 are connected by three identically shaped prestressing components 17, each with a concave lateral surface 19. Two adjacent prestressing components 17 are separated from one another by a separating disk 21 . It is also possible for an elastomer spring 1 according to the invention to have more than three prestressing components 17 or only a single prestressing component 17 between the upper side 13 and the lower side 15 of the elastomer body 2 .

The features disclosed in the above description, the figures and the claims can be important both individually and in any combination for the implementation of the invention in the various configurations. REFERENCE LIST

1 elastomer spring

10 azimuth brake

100 azimuth drive

2 elastomer bodies

3 sliding disc

5 recording

6 Top of the recording

7 cylindrical recess

8 Underside of the recording

9 screw

11 disc

12 column

13 top

14 disc

15 underside i6 disk 17 prestressing component 19 lateral surface 21 cutting disk 23 inner surface of the receptacle 25 base of the depression 101 tower 103 gondola

105 azimuth ring

106 gear

107 electric motor

108 Top of azimuth ring 110 Bottom of azimuth ring

Claims

EXPECTATIONS

1. Elastomer spring (l) for an azimuth brake (io) of an azimuth drive (too) for tracking a nacelle (103) with a rotor relative to a tower (101) of a wind turbine, comprising an elastomer body (2) made in one piece with an in a spring direction (F) of the elastomer body (2) pointing top and bottom (13,15) for transmitting spring forces in the spring direction (F) and the top and bottom (13,15) connecting prestressing component (17), the one has a concavely curved lateral surface (19).

2. Elastomer spring (1) according to claim 1, wherein the prestressing component (17) is adapted to be elastically compressed during compression in such a way that the curvature of the lateral surface (19) decreases.

3. Elastomer spring (1) according to claim 1 or 2, wherein the prestressing component (17) is adapted to expand during rebound in such a way that the curvature of the lateral surface (19) increases.

4. elastomer spring (1) according to any one of the preceding claims, wherein the

Prestressing component (17) is elastically compressed during compression, building up an elastic deformation restoring force, in such a way that the elastomer body (2) transmits the deformation restoring force as a prestressing force in the spring direction (F) via the upper and lower sides (13,15).

5. elastomer spring (1) according to any one of the preceding claims, wherein the

The elastomeric body (2) has at least one, in particular two or three, further, in particular identically shaped, prestressing components (17), the prestressing components (17) being arranged in series in the spring direction (F).

6. The elastomer spring (1) according to claim 5, wherein two adjacent prestressing components (17) are separated from one another by an in particular flat separating disk (21) which remains essentially undeformed during compression and/or rebound.

7. Elastomer spring (1) according to claim 5 or 6, wherein the separating disc/s (21) has/have the same shape and/or external dimensions as the top and bottom (13, 15).

8. Yaw brake (10) for an yaw drive (100) for tracking a nacelle (103) with a rotor relative to a tower (101) of a wind turbine, the yaw drive (100) having an yaw ring (105 ) comprising a sliding contact with the azimuth ring (105) and an elastomer spring (1) designed in particular according to one of the preceding claims for prestressing the sliding disc (3) against the azimuth ring (105), the elastomer spring ( 1) is made from a cast elastomer, particularly polyurethane such as Ureiast.

9. azimuth brake (10) according to claim 8, further comprising a particular pod-fixed receptacle (5) for the elastomer spring (1), in which the elastomer spring (1), in particular also the sliding disk (3), is translationally displaceable.

10. Yaw brake (10) according to claim 9, wherein the elastomer spring (1) has at least two clamping sections (14,16,21) which are arranged at a distance from one another in the spring direction (F) of the elastomer spring (1) and which are in circumferential contact with the Recording (5) are and a concave curved lateral surface (19) are connected to each other.

11. Azimuth brake (19) according to claim 10, wherein the clamping sections (14,16,21) during compression of the elastomer spring (1) to increase the biasing force on the sliding disk (3) on the receptacle (5) are supported in such a way that they are on each other to be moved and the curvature of the lateral surface (19) decreases.

12. Azimuth brake (10) according to any one of claims 8 to 11, wherein the biasing force is adjustable via a degree of compression of the elastomer spring (1).

13. Yaw brake (10) according to any one of claims 8 to 12, further comprising a mechanical, hydraulic or pneumatic device for compressing the elastomeric spring (1), wherein in particular the device comprises a screw (9).

14. Azimuth drive (100) for tracking a nacelle (103) with a rotor relative to a tower (101) of a wind turbine, comprising at least one Servomotor (105) and a yaw brake (10) designed according to one of Claims 8 to 13.