Adaptive vibration damper for damping low excitation frequencies

Abstract

The invention relates to a new type of vibration damper which is particularly suitable for damping low-frequency vibrations and which can therefore preferably be used as an erection damper when constructing or erecting high and slender structures, such as the tower of a wind power installation. The invention relates in particular to a pendulum vibration damper which has a first pendulum at which a mass is fixed and a second pendulum which is formed by a spring-like support device of different implementation and which operates with a gas-air volume such that the frequency of the vibration system can be adapted and adjusted by means of the support device.

Description

Technical Field

[0001] The present invention relates to a novel frequency-adaptive vibration damper, which is particularly suitable for different vibrations with damping <2Hz, especially <1Hz, preferably <0.5Hz, and is therefore preferably used as an erection damper when constructing or setting up tall and slender structures (such as towers of wind power equipment), but can also be used as a permanent damper.

[0002] The present invention relates in particular to a pendulum vibration damper having a first pendulum and a second pendulum, wherein a vibrating mass is fixed at the first pendulum and the second pendulum is formed by a spring-type support device of different implementations and operates using a gas-air volume such that the gravity of the mass can be affected by means of the support device and thus the frequency of the vibration system can be adapted and adjusted. Background Technology

[0003] Tall and slender structures are often subjected to varying forces that induce different vibrational states, necessitating damping at different frequencies. This is especially true when constructing tall and slender structures. The construction of tall and slender structures (such as wind turbines consisting of towers, nacelles, and rotor blades) can easily take longer periods, allowing weather-induced or otherwise excitation states to cause undesirable vibrations in the equipment under construction.

[0004] Thus, for example, the tower of a wind turbine alone has a natural frequency up to about 0.6 Hz. A fully erected wind turbine, however, has a natural frequency of less than 0.15 Hz. Such low frequencies are typically not achievable using common pendulum vibration dampers with their heavy mass and typical lengths of pendulum ropes or rods, or can only be achieved with significant expense.

[0005] To achieve lower frequencies, one possibility is to have the mass roll back and forth between radially arranged springs. This can be achieved using a roller in one direction and a kugelrolle in both directions. However, this requires changing or adapting the stiffness of the radial springs, which involves some overhead. Furthermore, if a conventional pendulum is used in the vibration damper, the pendulum length required to achieve frequencies below 0.15 Hz exceeds 11 m, which is practically only feasible with significant overhead and space constraints.

[0006] Another possibility for addressing such low frequencies in vibration dampers is the use of pulse dampers. However, these pulse dampers require approximately three times the mass of a pendulum damper and must move on pulleys to achieve the smaller frequencies, necessitating the use of easily worn ball rollers. Furthermore, for these lower frequencies, such pulse dampers must be precisely oriented horizontally, which is practically achievable only under certain conditions, as tilting positions that significantly impair function cannot always be avoided. Because only small accelerations are achieved or present at lower frequencies, the use of pulse dampers cannot reduce vibration to the same extent as typically achieved with pendulum dampers.

[0007] Therefore, there is an objective to provide a vibration damper for a sufficiently large mass but with the smallest possible vibration path, which can address and damp variable low frequencies below 2 Hz, preferably below 0.5 Hz. Summary of the Invention

[0008] This objective is achieved by providing a pendulum vibration damper, wherein, according to the invention, during pendulum motion, the gravity of the pendulum mass can be objectively or relatively reduced or increased by specially developed support spring elements, and thus can be specifically adapted to the natural frequency of the vibration system.

[0009] A pendulum functions due to the gravitational force acting on its mass. The higher the gravitational force, the higher the natural frequency (for the same pendulum length). Similarly, the shorter the pendulum length, the higher the frequency for the same mass (gravity). To reduce the gravitational force on a given pendulum mass, it is necessary to continuously increase the mass along the entire vibration path with minimal influence from other forces, thus reducing the load on the weight. Therefore, a selective reduction of the natural frequency of the vibration system can be achieved. According to the invention, this is achieved by a counter-pendulum acting on the pendulum mass from below, or, if necessary, from above, as described below. Conversely, when necessary, the gravitational force on the pendulum vibrating mass can also be increased by means of a pendulum vibration damper according to the invention to selectively increase the natural frequency of the vibration system.

[0010] Therefore, the pendulum vibration damper according to the invention can be controllably adjusted to the corresponding natural frequency of the vibration system, especially in the case of tall and slender structures, where in particular, frequencies <2Hz, for example, between 0.15 and 1.5Hz, are important.

[0011] The subject of this invention is therefore an adaptive pendulum vibration damper for adapting to low-frequency vibrations (<2Hz, preferably <1.5Hz) occurring in highly damped and slender structures. This pendulum vibration damper comprises:

[0012] (i) at least one first pendulum (4) having a length (4.1) and arranged vertically in the non-operating state, the first pendulum being connected at one end to the structure to be damped directly or via a carrier element (6) through a hinge (4.2).

[0013] (ii) At least one second pendulum (5) having a length (5.1) and arranged vertically in the non-operating state, the second pendulum being arranged completely or partially below or above the first pendulum (4), and having one end connected to the structure to be damped directly or via a carrier element (6) via a hinge (5.3).

[0014] The first pendulum (4) is connected directly or indirectly to the free end (5.2) of the second pendulum (5) via a common freely movable hinge (4.3)(5.2) at its free end (4.3).

[0015] (iii) A vibrating mass (1), which is fixed at the first pendulum (4) such that when a force is applied to the mass (1), the two pendulums (4) and (5) move together, and

[0016] (iv) A pressure-controlled support device (7) that can increase or decrease the gravity of the vibrating mass (1) by raising or lowering or reducing or increasing the load, and thus can achieve targeted frequency changes, wherein the support device is an integral part of the second pendulum (5) or the support device functions as a pendulum.

[0017] In a preferred embodiment of the invention, the support device (7) operates via a pressurized gas / air volume (7.6), wherein the pressure is chosen such that it causes a certain gravitational change in the vibrating mass (1), i.e., causing the vibrating mass to rise or fall, or to be unloaded or loaded by a certain amount. The gas / air volume (7.6) is located in a gas / air container (7.5), which is an integral part of the support device, or, if the available volume for this purpose is insufficient in a separate container, is located outside the actual support device (7). In the latter case, the separate container is connected to the actual support device (7) via corresponding lines / hooks (7.10)(7.14)(7.15)(7.17)(7.18).

[0018] According to the invention, the support device is preferably an air spring element (7.1) or a pneumatic cylinder (7.2), wherein the pneumatic cylinder functions as an air spring. The air spring unit (7.1) may be an elastic bellows (7.1.1) having a preferably small cross-section or an assembly of multiple elastic bellows stacked one on top of the other, or it may be a rubber bellows (7.1.2) (Roll-Balg).

[0019] Preferably, the air spring unit (7.1) is represented by a pneumatic cylinder (7.2) having separate gas- / air volumes (7.6) / gas- / air containers (7.5).

[0020] It is generally advantageous to select a total gas volume (7.6) that is large enough so that, during operation of the vibration damper, a maximum of 10%, preferably no more than 5-8%, of the total available volume is displaced or moved during the oscillation motion via the support device. The less volume (7.6) is moved during operation, the better for the function or selective frequency adaptation of the vibration damper. Therefore, it is advantageous for the damper to have a volume in the gas container (7.5) as large as possible compared to the volume displaced via the support device (7). Here, the total space occupied by the gas (7.6) should be understood as the container (7.5), i.e., in the actual support device itself and, if necessary, in a separate container.

[0021] In the case of the flexible bellows as the air spring unit (7.1), it can be advantageous that, during the oscillating motion of the shock absorber, the air spring unit comprises a plurality of vertically stacked flexible bellows (7.1.1), for example, an assembly of three to ten vertically stacked flexible bellows, the cross-section of which is as small as possible compared to the total gas volume (7.6). If necessary, for this purpose, an additional container may also be provided outside the supporting spring unit (7) to facilitate a relative reduction in the volume displaced relative to the total volume.

[0022] In an advantageous embodiment of the invention, the pendulum vibration damper according to the invention includes a pressure regulating unit (7.11) that operates automatically and with a corresponding sensor, whereby pressure fluctuations caused by changing external conditions during operation can be compensated for by the increase or decrease of the gas / air pressure (7.6) in the container (7.5) due to the supply or discharge of gas / air via a suitable connection (7.10). Therefore, the natural frequency of the vibration damper or vibration system can be adapted to changing conditions. It is significant that automatic pressure adaptation is only performed by the system when a certain preset maximum or minimum pressure is exceeded.

[0023] It has proven advantageous that the lengths (4.1) and (5.1) of the two interconnected pendulum rods (4) and (5) are different. Preferably, the length (4.1) of at least one first pendulum rod (4), such as the upper pendulum rod, is less than the length (5.1) of the second pendulum rod (5), such as the lower pendulum rod or the support device (7). Therefore, preferably, the (lower) second pendulum rod (5) or the support device (7) or the support spring unit (7.1) is 1.5 to 2 times longer than at least one first pendulum rod (4) or 50-100% longer.

[0024] In one embodiment of the invention, at least a first pendulum (4) represents the upper pendulum completely or partially, and at least a second pendulum (5) represents the lower pendulum completely or partially, and the two pendulums are connected to each other via a common hinge (4.3) / (5.2).

[0025] Alternatively, at least the first pendulum (4) fully or partially represents the lower pendulum, and at least the second pendulum (5) fully or partially represents the upper pendulum, and the two pendulums are connected to each other via a common hinge (5.2) / (4.3).

[0026] Furthermore, it is shown that if the vibrating mass (1) is positioned at the pendulum (4) such that the center of gravity of the mass (2) is near or coincides with the position of the hinge (4.3)(5.2), the pendulum vibration damper according to the invention can be adapted particularly well and selectively to low frequencies.

[0027] Preferably, the vibrating mass (1) is designed such that the support device (7) or air spring unit / support spring unit (7.1) is at least partially surrounded by the vibrating mass while maintaining the free movement of the second pendulum (5)(5.1). This can be achieved by a correspondingly positioned recess or free space (8) at the vibrating mass (1), into which the support device (7) extends at least its upper portion to such an extent that, as mentioned above, the hinge (5.2)(4.3) of the pendulum (5)(5.1) is positioned in the region of the center of gravity (2) of the vibrating mass (1). To save space, the air spring unit / support spring unit (7.1) may taper towards the end pointing to the hinge (5.2) so that it can fit well into the smaller recess (8) in the vibrating mass (1).

[0028] Next, the term support spring unit will be used synonymously with air spring unit (7.1).

[0029] The present invention also relates to a preferably two-dimensional effective adaptive pendulum vibration damper for tall and slender structures (such as towers of wind turbines), which dampes vibrations occurring at relatively small frequencies (particularly in the range of 0.1 to 1.5 Hz, preferably 0.1 to 1 Hz), and the pendulum vibration damper particularly includes the following elements:

[0030] (i) Vibration mass (1)

[0031] (ii) Preferably, at least one first swing arm (4)(4.1) is vertically mounted at the upper part when not in operation, having an upper hinged fixed point (4.2) and a lower fixed point (4.3), wherein the vibrating mass (1) is rigidly or, if necessary, hingedly mounted at the lower fixed point, depending on the implementation.

[0032] (iii) Optionally, at least one damping unit (3), such as an elastic damper, a pneumatic-hydraulic damper, or a magnetic damper, and

[0033] (iv) At least one support device (7) configured to support the spring unit (7.1), which is part of the second pendulum (5)(5.1) preferably at the lower part and is functionally connected to the vibrating mass (1) at the first pendulum and is arranged completely or partially under the mass (1), wherein the two pendulums are connected to each other via a common hinge (4.3)(5.2).

[0034] In this embodiment of the invention, the support spring unit (7.1) includes the following elements: (a) an integrated pressure-resistant gas or air container or reservoir (7.5) having an inlet / outlet device (7.10) for containing a gas or air volume (7.6); (b) an assembly of elastic bellows (7.1.2) or stacked elastic bellows for generating an upward force or, if necessary, a downward force, connected to the gas volume (7.6) and changing its stiffness and size according to a preset gas pressure, wherein the gas pressure in the container (7.5) and the air spring unit is adjusted such that the vibrating mass (1) is unloaded compared to a state of no pressure or reduced pressure, for example by increasing the air pressure and thus the lift of the air spring unit (7.1) in the vertical direction or in the direction of the vibrating mass (1), thereby reducing its weight according to the preset pressure; and (c) a freely movable hinge (5.2) at the top.

[0035] In principle, this hinge refers to the upper hinge of the lower rocker arm in this embodiment, which is represented here by the support spring unit (7.1), and is also the same as the hinge (4.3) of the upper rocker arm (4). The two rocker arms are thus also connected to each other here by a common freely movable hinge (4.3)(5.2).

[0036] The support device (7) or the support spring unit (7.1) or the lower rocker arm (5) here also has a lower hinge (5.3) connected to a carrier element (6) with a tall and slender structure. The hinge (5.3) can be constructed as a ball joint or as a universal joint. In this embodiment, the support spring unit (7) thus functionally represents the second rocker arm (5) (5.1), which moves together with the first rocker arm (4) (4.1) whose mass (1) is fixed therein.

[0037] In this embodiment, the pendulum vibration damper according to the invention thus includes at least one upper rigid first pendulum rod (4) and a lower second pendulum rod (5) acting substantially below the mass (1) in the form of a support spring unit (7) that generates an upward force, the mass (1) being fixed at the first pendulum rod, the second pendulum rod being guided and moved together with the vibrating mass (1).

[0038] In another embodiment of the invention, the vibration damper according to the invention is constructed as a transverse pendulum damper. If it is to be effective in two dimensions, such a vibration damper has three or more upper or lower first pendulum rods (4), the vibrating mass (1) is suspended at the first pendulum rod in the region of the corresponding lower or upper hinge (4.3), and the mass (1) is connected via the upper or lower hinge (5.3) to the lower or upper second pendulum rod (5), air spring- / support spring unit (7), such that the vibrating mass (1) can move horizontally in pendulum motion.

[0039] The vibration damper according to the invention preferably additionally includes one or more damping units (3). Hydraulic dampers, pneumatic dampers, elastic dampers, or magnetic dampers known per se in the prior art can be used. In specific cases, rotary dampers, especially magnetic rotary dampers, have proven particularly suitable. For example, corresponding (magnetic) rotary dampers are described in WO 2017 / 036581, WO 2019 / 154557, or WO 2019 / 029839.

[0040] In the above-described embodiment of the invention, the damping unit (3) is mounted in or thereon the hinge (4.2) of the pendulum (4). Advantageously, a universal joint with an integrated damping unit can be used here, as described in WO 2019 / 201471.

[0041] Additional damping units (3) can also be installed in terms of both quantity and strength at the periphery of the vibrating mass, such that the damping units can dampen vibrations from all directions of the horizontal plane of the vibration damper according to the invention. In the case of the described transverse pendulum damper, it is meaningful to install the damping units (3) between the mass (1) and the carrier element (6).

[0042] The vibration damper according to the invention is particularly designed for use during the erection or dismantling of tall and slender structures. Specifically, during the erection of towers or tower sections in the construction of wind power equipment, vibrations occur in the low-frequency range below 2 Hz, particularly between 1 and 1.5 Hz, depending on the construction progress. Since equipment assembly typically takes a longer period, vibration damping during this time interval is very important. After the complete equipment is erected, such a vibration damper can usually be discarded, even though it could theoretically be used during equipment operation.

[0043] Therefore, a vibration damper according to the invention is provided, which is mounted on a movable carrier element (6), which can be reversibly fixed or removed at a structure (e.g., at the tower of a wind turbine) during its installation or removal. To this end, according to the invention, the structure to be damped or a corresponding component or section of the structure is equipped with a fixing device for the pendulum vibration damper according to the invention. In one embodiment, the fixing device can be a simple suspension structure fixedly connected to the structure to be damped.

[0044] Therefore, in essence, the support device (7) is responsible for changing the gravity of the vibrating mass (1). In the particular variant already outlined above, the support device can be referred to as an independent innovation as part of the pendulum vibration damper according to the invention.

[0045] The subject of this invention is therefore a support spring device for a mass having an upward force adaptable to gas pressure, the support spring device comprising:

[0046] (a) A first connecting point, which is hinged if necessary for the mass (1) whose gravity is to be changed, and a second connecting point, which is hinged if necessary for the carrier element (6) positioned opposite to it; wherein the element of features (b)-(d) is arranged between the two connecting points, and the mass (1) and the carrier element (6) are arranged above and below it,

[0047] (b) At least one pressure-resistant container (7.5) containing a gas- or air volume (7.6) which can be supplied or withdrawn by an inlet-outlet device (7.10), wherein the container is preferably constructed as part of a support structure.

[0048] (c) At least one elastic air spring element (7.1)(7.1.1)(7.1.2) above or below the container (7.5), functionally connected to the gas volume in the container (7.5) and changing its stiffness and size according to a predetermined gas pressure, thereby causing an increase or decrease and thus a change in the lifting force of the air spring element along the longitudinal axis of the support device (7), and thus causing a rise or fall in the mass (1).

[0049] (d) A guide rod (7.4) for guiding and holding the gas / air container (7.5) and the elastic air spring elements (7.1)(7.1.1)(7.1.2), wherein the guide rod has a sliding bearing (7.3) between the air spring elements (7.1)(7.1.1)(7.1.2) and the gas / air container (7.5), such that the gas / air container (7.5) can move vertically along the guide rod accordingly by changing the lifting force of the air spring elements, and thus can affect the gravity of the mass, and optionally...

[0050] (e) Pressure regulation and control unit for adapting gas / air pressure (7.11)(7.12).

[0051] The same description as that already provided above in conjunction with vibration dampers applies to the dimensions and function of components of gas / air containers.

[0052] Such a support spring device can be used for a variety of purposes. Detailed Implementation

[0053] As explained at the beginning, for example, to reduce the gravity and frequency of a certain pendulum mass, it is necessary to raise or lower the load on the mass with minimal influence from other forces throughout the vibration path. According to the invention, this is achieved, for example, by an anti-pendulum (5) acting on the mass from below. This anti-pendulum is designed and implemented as a support device (7) or at least an air spring unit (7.1).

[0054] Here, an air spring unit (7.1) in the form of an air-filled elastic bellows, or a group of stacked elastic bellows (7.1.1), or as a pneumatic cylinder (7.1.2) is used. However, a spring unit made of steel bellows may also be used.

[0055] However, it should be noted that when using a closed bellows filled with gas (e.g., air), the force changes during the vibration path, which is equivalent to a spring, thereby increasing the vibration frequency again to the same extent. Therefore, according to the invention, a corresponding air spring is used, which is connected to an air or gas volume and can be compressed by a gas / air supply. If the air volume is sufficiently large compared to the volume of the air spring unit, the compression of the air no longer has a significant effect.

[0056] If the total air volume V of the supporting spring unit (which consists of the volume V1 of the gas reservoir and the volume V2 displaced by the air spring) is very large compared to the displaced volume V2, then the quotient (V1+V2) / V1 is close to the number 1. Therefore, the compression of air has no effect or only a small effect on the stiffness of the supporting spring. By increasing V1, the quotient takes a smaller value while V2 remains the same. For example, if 4L is displaced by the pendulum motion and the can's capacity is 80L, then (V1+V2) / V1 = 84 / 80 = 1.05, which corresponds to a sufficiently small force amplitude. If V1 is increased to 100L, a value of 1.04 is obtained. This means that during the pendulum motion, 5% or 4% of the total gas volume is displaced by the air spring unit (7.2).

[0057] Ideally, the gas storage tank (7.5) is integrated into the lower swing arm. However, a separate auxiliary tank (resonant or stationary) can also be used to contain the air volume. This auxiliary tank must then be connected to the air spring unit (7.1) via appropriate piping. In the case of a resonant storage tank, this can be a fixed pipe. In the case of a separately installed storage tank, a flexible hose (7.10) is required.

[0058] When a large force is introduced into or the load is reduced on the mass (1) by, for example, the lower pendulum (5), the mass tends to avoid the force, which causes the pendulum to move in a circular motion and thus, in turn, an undesirable increase in frequency. Therefore, it is advantageous to keep the first pendulum (4) significantly shorter or longer than the second pendulum (5). Thus, the pendulum recovery force of the first pendulum is greater than the pendulum recovery force caused by the lateral component that appears at the second pendulum, thereby achieving linear oscillating motion again. It has now been shown that, for example, it is advantageous to implement the second pendulum (5), which has a support device (7), to be about 1.5-2 times the length of the upper pendulum (4). However, the second pendulum (5) can also be made correspondingly shorter.

[0059] The natural frequency of the system is lowered by increasing or decreasing the load through gas pressure. If the bellows is unpressurized, the frequency of the (shorter) first pendulum (4) is reached. With a pendulum length (4.1) of, for example, 0.8 m, the unpressurized frequency of the system is approximately 0.56 Hz. This frequency can be lowered by pressurizing gas (air) into the system. Thus, for example, with a pressure of approximately 70% of the pendulum's weight, a frequency of 0.1 Hz can be achieved. The pendulum length (4.1) also affects the frequency. Therefore, the system can be used as a frequency-adaptive damper.

[0060] In some embodiments of the support device (7) (e.g., with a pneumatic cylinder (7.2)), the gravity of the vibrating mass (1) can also be relatively increased by applying pressure to it, which results in a (relative) increase in the natural frequency of the pendulum's oscillation. Thus, the vibration system can be calibrated to higher and lower values ​​in terms of frequency.

[0061] In the case of vibrations with variable frequencies (e.g., wave excitation of wind power equipment or ships and other marine structures), the frequency of the excitation can be measured by a sensor, and the system can also be adapted to the interference frequency proportionally to that frequency by changing the air pressure in the support device (7).

[0062] Figure 1(ae) ​​shows various embodiments of the invention, each having an upper (first) rocker arm and a lower (second) rocker arm (5), wherein the support device is constructed as part of the lower (second) rocker arm, and an air spring unit (7.1) or alternatively a pneumatic cylinder (7.2) in the form of an elastic bellows (7.1.1) or a rubber bellows (7.1.2).

[0063] Figure 1(a) shows a side view of the pendulum vibration damper according to the invention. The vibrating mass (1) is located at the upper first pendulum rod. Hinges (4.3) (5.2) connect the first pendulum rod to the lower second pendulum rod (5) having a length (5.1). The vibrating mass (1) is designed here at its lower side such that the vibrating mass not only surrounds the upper part of the supporting spring unit (7) but also leaves so much free space (8) that the pendulum motion can be carried out without collision. For this purpose, corresponding holes or recesses can be provided in the mass; but the mass can also consist of individual elements that are respectively shaped and arranged around the free space (8).

[0064] The upper rocker arm (4), having a length (4.1), has an upper hinge (4.2) via which it is connected to the system's carrier element (not shown). In this embodiment, the upper hinge is a universal joint to which a rotational damper (3) is additionally integrated. Such a damper hinge is known, for example, from WO 2019 / 201471. However, in principle, a simple and undamped hinge, such as a ball joint, can also be used. Figure 2 The upper pendulum is formed by the length between the rotation axis of the universal joint and the center of gravity (2) of the mass (1), which is preferably located near or at the same location as the hinge (4.3)(5.2).

[0065] The lower pendulum (5), having a length of (5.1), is represented by a support device (7). This support device includes an air spring unit (7.1) and an integrated gas-air container (7.5) containing a gas / air mixture (7.6)(7.6.1). The container (7.5) tapers in the upper portion (7.5.1), thus allowing this portion to be more or less introduced into the free space (8) of the mass (1) and to move freely there with the pendulum (5). The pendulum (5) terminates in the upper portion at a hinge (5.2)(4.3). Ideally, this hinge should be located at the center of gravity (2) of the mass.

[0066] The support device (7), which is an integral part of the lower swing arm (5), has an additional hinge, preferably a ball joint, at its lower end, which establishes a connection with the structure to be damped or the carrier element (6) of the structure. However, the connection with the carrier element is not shown here.

[0067] The different lengths of the pendulum (4) and (5) are also known from the attached figure (4.1)(5.1).

[0068] Figure 1(b) shows a side view of the embodiment of Figure 1(a) rotated 90°. Additionally, the carrier element (6) is depicted here, which is connected to the complete pendulum vibration damper according to the invention via hinges (4.2) and (5.3).

[0069] Figure 1(b1) shows a top view of Figure 1(b), namely a universal joint connected to the carrier element (6), wherein the universal joint is equipped with two rotary damper units (3) which are arranged offset from each other at an angle of 90°.

[0070] Figure 1(c)(c1) shows further details of the support device (7) according to the invention shown in Figure 1(a).

[0071] The component consists of a container or reservoir (7.5) for containing a volume (7.6) of gas or air via an inlet / outlet device (7.10). The container (7.5) is divided here into a narrower upper container section (7.5.1) with a corresponding volume (7.6.1) and a larger lower container section (7.5) with a volume (7.6). The two container sections are pressure-connected to each other via a gas passage (7.7.1). Alternatively, instead of being divided into a smaller upper compartment and a larger lower compartment, a single continuous but upwardly tapering container may be used to provide sufficient space in the free space (8) within the region of mass (1).

[0072] An air spring unit (7.1) is arranged in the lower region of the support device (7), which is pressure-connected to the container (7.5) via a lower gas passage (7.7)(7.7.2) or to an additional container (7.5.1) via an upper gas passage (7.7)(7.7.1). In this variant, the air spring unit (7.1) includes three elastic bellows (7.1.1) that extend or compress vertically upwards in response to pressure changes in the containers (7.5)(7.5.1), thereby causing a corresponding change in the gravity of the mass (1) (not shown here) positioned and fixed on the pendulum (4).

[0073] Typically, 1-15, preferably 3-10, of such stacked bellows are used to achieve the required reduction in mass (1) due to gravity. However, this ultimately depends on the mass, volume (7.6)(7.6.1), and the volume displaced through the elastic bellows.

[0074] The lower end of the support device (7) has a ball joint (5.3), which is connected to the carrier element of the vibration system (not shown).

[0075] The support device (7) designed to support the spring unit, in this embodiment, further includes a guide rod (7.4) for providing sufficient stability to the component, since the component would otherwise bend under load in the area of ​​the bellows. The guide rod (7.4) is preferably guided in sliding bearings (7.3)(7.7), wherein, in specific cases, an upper sliding bearing (7.3.1) is used between the lower container (7.5) and the upper container (7.5.1), and a lower sliding bearing (7.3.2) is used between the air spring unit (7.1.1) and the lower container (7.5).

[0076] The air connection (7.10) can be connected to any location in an air-filled or gas-filled space (7.6)(7.6.1). Advantageously, the air connection is installed in the lower region of the support spring unit, where there is almost no movement. Meanwhile, additional containers can be connected using hoses or pipes to increase volume. An additional inlet / outlet device (7.10) with an adjusting unit (7.11) is provided at the lower end of the support spring unit. In its simplest case, this is a regulating valve.

[0077] The support spring unit described herein functions in such a way that by vertically changing the volume of the elastic bellows (7.1.1) along the guide rod (7.4) in the direction of the hinge (5.2), it presses against the portion of the unit located above it and the gas / air container (7.5)(7.5.1). Since the hinge (5.2), preferably constructed as a ball joint, is here the same as the hinge (4.3) of the upper first pendulum rod (4) where the vibrating mass (1) is fixed, a corresponding pressure or tension is thus applied to the vibrating mass (1), thereby enabling targeted frequency adaptation of the vibration system.

[0078] Another possibility is to equip an automatic pressure regulating unit, by means of which the pre-set pressure in the spring system (7) (if necessary, by means of a sensor) can be manually or automatically adapted to the changing natural frequency when external conditions in the vibration system change. This has the advantage that, for example, pressure changes caused by possible temperature fluctuations can be compensated. Furthermore, the natural frequency of the vibration damper can be continuously adapted to the requirements (adaptive operation) via such a regulating device. For example, the pressure regulating unit for maintaining a constant air pressure can consist of a pressure sensor, a three-way servo valve, and a compressor. The pressure sensor here continuously monitors the pressure in the container (7.5)(7.5.1). Advantageously, the controller only considers the maximum pressure that is always generated when the upper and lower rockers are aligned with each other, and therefore the minimum air volume during the movement is used for regulation. It is also recommended that the adaptation be performed automatically only when the pressure exceeds or falls below a certain maximum or minimum limit value. The regulator compares this pressure with a preset theoretical value and opens or closes the valve accordingly to increase or decrease the gas pressure in the container via the compressor or compressed air storage device. The preset theoretical value is a parameter that can be adjusted in a fixed way, or it is preset by the control unit for adaptive operation.

[0079] The tower's vibration frequency is detected by an accelerometer. The signal is transmitted to the computing unit. The required air pressure to reach the corresponding frequency is calculated from the system's pre-defined frequency-pressure curve. The resulting signal, as a theoretical value, is transmitted to the pressure regulating valve.

[0080] Figure 1(d)(d1) illustrates another embodiment of the invention. Instead of the air spring unit (7.1) constructed as an elastic bellows (7.1.1), a rubber bellows (7.1.2) is now used, which has the advantage that its cross-section does not change significantly during operation. In other respects, all other features and functions correspond to those in Figure 1(c)(c1).

[0081] Figure 1(e) shows another embodiment of the invention, namely a pneumatic cylinder (7.2) as part of the lower pendulum rod (5) of the pendulum vibration damper according to the invention. The upper pendulum rod (4) and the vibrating mass (1) are not shown. The pendulum rod (5) has an upper hinge (5.2) constructed as a ball joint. This hinge is also the lower hinge (4.3) of the upper pendulum rod (4). The pneumatic cylinder (7.2) includes a piston (7.2.3) that divides the cylinder chamber into an upper cylinder chamber (7.2.1) and a lower cylinder chamber (7.2.2). The piston (7.2.3) is moved by a piston rod (7.2.4). The vertical movement of the piston is achieved by a pressure-controlled gas / air volume (7.6). Because the cylinder chamber is too small, an air / gas container (7.5) is required outside the component to ensure the functionality of the pneumatic cylinder in the sense of selective and precise frequency adaptation. As needed, the gas volume in container (7.5) is guided under pressure into the lower or upper chamber of the cylinder. Appropriate valves (7.13)(7.16) and inlet / outlet lines (7.10)(7.14)(7.15)(7.17)(7.18) are provided, along with a regulating and control unit (7.11)(7.12) for the gas / air volume (7.6). During operation, the piston rod (7.2.4) moves vertically upward or downward by the corresponding gas pressure, thereby unloading or loading the vibrating mass (1) at the rocker arm (4) via the ball joint (5.2). Typically, the pneumatic cylinder (7.2) can operate in both the tension and pressure directions. To generate pressure, chamber 7.2.2 is loaded, while to generate tension, chamber 7.2.1 is loaded.

[0082] Figure 2 (ac) shows an embodiment of the vibration damper according to the invention from different angles, wherein the air spring unit (7.1) of FIG1 is integrated into the carrier element (6). In contrast, the hinge (4.2) of the rocker arm (4) is a simple ball joint without a damping unit (3). The latter is therefore mounted in duplicate between the mass (1) and the carrier element (6) at a 90° angle to each other. A rotary damper is also provided here as a damping unit; however, a linear damper based on magnets, a hydraulic damper, or other dampers according to the prior art can also be used.

[0083] Figure 3(ac) shows three different views of another embodiment of the shock absorber according to the invention, namely a lateral pendulum shock absorber. A mass (1) is suspended here at three pendulum rods (4). Each pendulum rod (4) has an upper hinge (4.2) and a lower hinge (4.3), preferably a ball joint (4.3). The pendulum rods are connected to the carrier element (6) via the upper hinge and to the mass (1) via the lower hinge in such a way that the mass can only move horizontally during vibration. A damping element (3) is here disposed between the mass (1) and the carrier element (6) and is again designed as a rotary damper in this specific example, but other dampers of the prior art may also be used. For uniform damping at the periphery, two damping elements (3) in the upper suspension portion are sufficient in this embodiment having three pendulum rods (4) and six hinges (4.2) (4.3). However, three or more such dampers may also be used.

[0084] Figure 4 (ad) shows according to Figure 3 Four different views of another embodiment of the lateral damper. The support device (7) designed to support the spring- or air spring unit does not necessarily, or at least not desirablely, have to act at or directly near the center of gravity of the mass in the case of lateral swing. Therefore, the support device can act on the mass and thus perform through the mass, resulting in a smaller height of the component, which in turn reduces the required installation space.

[0085] Figure 4 (a) shows how the support spring unit (7) is guided through the opening in the mass (1). The upper hinge (5.2) of the same pendulum rod (5) as the support device (7) is now arranged on the vibrating mass (1) and fixed to a bracket (6.1), which in turn is connected to the mass. The opening in the mass is designed such that it allows sufficient free space for the movement of the lower pendulum (5) or the support spring unit (7). In this embodiment, it can also be seen that the upper pendulum rod (4) has a significantly shorter length (4.1) compared to the length (5.1) of the lower pendulum rod (5).

[0086] Figure 4 (b) shows the results according to Figure 4 (a) is a side view of the vibration damper according to the invention. Additionally, a rotational damper unit (3) with three rotating disks can also be seen, which is fixed at the mass and functions when the mass vibrates.

[0087] Figure 4 (c) A cross-section is shown according to Figure 4 (a) Vibration damper.

[0088] Figure 4 (d) Shows the perspective view based on Figure 4 (c) is a component.

[0089] exist Figure 2-4 In this embodiment, the support device (7) includes an air spring element (7.1) according to the invention. However, it is configured to use the same embodiment as depicted and described, but with a pneumatic cylinder (7.2) according to FIG. 1(e).

[0090] Figure 5 A pendulum vibration damper according to the invention is shown, which has a pneumatic cylinder (7.2) as the core component of a support device (7). Unlike Figure 1(e), which only shows the (lower) second pendulum (5) with the pneumatic cylinder (7.2), in this embodiment, the second pendulum (5) with the corresponding pneumatic cylinder (7.2) is set as the upper pendulum (5) and the first pendulum (4) with the vibrating mass (1) is set as the lower pendulum (4). A ball joint or universal joint (4.2) with a rotational damping element (3) is arranged accordingly at the lower end of the carrier element (6), while a freely movable hinge (5.3) now causes the support device to end upward and connect there to the carrier element. The shape and arrangement of the vibrating mass (1) at the pendulum (4) roughly correspond to the arrangement of the pendulum (5). Figure 4 The corresponding part.

[0091] Figure 6 In principle, it is shown that according to Figure 5 The same arrangement is used in the pendulum vibration damper according to the invention, except that the pneumatic cylinder (7.2) is replaced by an air spring unit (7.1), and in particular a rubber bellows (7.1.2). The rubber bellows transmits the force to the mass (1) at the lower first pendulum rod (4) via a member (7.1.3) that can move relative to each other.

Claims

1. An adaptive pendulum vibration damper for adapting to low-frequency vibrations (<2Hz) occurring in highly damped and slender structures, the pendulum vibration damper comprising: (i) At least one first pendulum (4) having a length (4.1) and arranged vertically in the non-operating state, the first pendulum being connected at one end to the structure to be damped directly or via a carrier element (6) via a hinge (4.2). (ii) At least one second pendulum (5) having a length (5.1) and arranged vertically in the non-operating state, the second pendulum being arranged completely or partially below or above the first pendulum (4), and having one end connected to the structure to be damped directly or via a carrier element (6) via a hinge (5.3). The first pendulum (4) is directly or indirectly connected to the free end of the second pendulum (5) at its free end via a freely movable hinge (4.3) (5.2). (iii) A vibrating mass (1), which is fixed at the first pendulum (4) and connected to the second pendulum (5) via the hinge (4.3)(5.2) such that when a force is applied to the vibrating mass (1), the two pendulums (4)(5) move together, and (iv) A pressure-controlled support device (7) that can increase or decrease the lifting force acting on the vibrating mass (1) by reducing or increasing the load, and thus can achieve targeted frequency changes, wherein the support device is an integral part of the second pendulum (5).

2. The adaptive pendulum vibration damper according to claim 1, characterized in that, The support device (7) operates using a gas volume (7.6) under pressure that causes a change in the lifting force acting on the vibrating mass (1), wherein the gas volume is provided in a gas container (7.5) which is either an integral part of the support device or partially separate from it.

3. The adaptive pendulum vibration damper according to claim 2, characterized in that, The gas volume (7.6) is selected such that less than 10% of the volume is displaced or moved by the support device (7) during the oscillation motion of the vibration damper.

4. The adaptive pendulum vibration damper according to any one of claims 2 to 3, characterized in that, The support device (7) is an air spring element (7.1) or a pneumatic cylinder (7.2).

5. The adaptive pendulum vibration damper according to claim 4, characterized in that, The air spring element (7.1) is an assembly of an elastic bellows or multiple stacked elastic bellows (7.1.1), a rubber bellows or sequentially arranged rubber bellows (7.1.2).

6. The adaptive pendulum vibration damper according to claim 5, characterized in that, The flexible bellows or its components have a smaller cross-section compared to the gas volume (7.6).

7. The adaptive pendulum vibration damper according to any one of claims 1 to 3, characterized in that, The length (4.1) of the at least one first pendulum (4) is different from the length (5.1) of the second pendulum (5).

8. The adaptive pendulum vibration damper according to claim 7, characterized in that, The at least one first pendulum (4) is 50-100% shorter or longer than the at least one second pendulum (5).

9. The adaptive pendulum vibration damper according to any one of claims 1 to 3, characterized in that, The at least one first pendulum (4) represents the upper pendulum completely or partially, and the at least one second pendulum (5) represents the lower pendulum completely or partially, and the two pendulums are connected to each other via a common hinge (4.3) / (5.2).

10. The adaptive pendulum vibration damper according to any one of claims 1 to 3, characterized in that, The at least one first pendulum (4) represents the lower pendulum completely or partially, and the at least one second pendulum (5) represents the upper pendulum completely or partially, and the two pendulums are connected to each other via a common hinge (5.2) / (4.3).

11. The adaptive pendulum vibration damper according to any one of claims 1 to 3, characterized in that, The hinge (4.2) of the first rocker arm (4) connected to the structure to be damped and / or the hinge (5.3) of the second rocker arm (5) connected to the structure to be damped are universal joints.

12. The adaptive pendulum vibration damper according to any one of claims 1 to 3, characterized in that, The hinges (4.3) and (5.2) that connect to the free ends of the first pendulum (4) and the second pendulum (5) are ball joints.

13. The adaptive pendulum vibration damper according to any one of claims 1 to 3, characterized in that, The support device (7) has a guide rod (7.4).

14. The adaptive pendulum vibration damper according to any one of claims 2 to 3, characterized in that, The adaptive pendulum vibration damper includes pressure regulating units (7.11) and (7.12) that can compensate for pressure fluctuations caused by changing external conditions during operation by increasing or decreasing the pressure of the gas volume (7.6) via the connection (7.10) when a preset limit value is reached.

15. The adaptive pendulum vibration damper according to any one of claims 1 to 3, characterized in that, The vibrating mass (1) is fixed at the first pendulum (4) such that the center of gravity (2) of the vibrating mass is near or at the same point as the hinge (4.3)(5.2) that connects to the free ends of the first pendulum (4) and the second pendulum (5).

16. The adaptive pendulum vibration damper according to claim 15, characterized in that, The vibrating mass (1) is designed in three dimensions such that there is a correspondingly shaped free space (8) in which the second pendulum (5) extends at least partially to the free end of the second pendulum (5) via a hinge (5.2) connected to the free end of the second pendulum (5), and there is a position for pendulum motion in the operating state.

17. The adaptive pendulum vibration damper according to any one of claims 1 to 3, characterized in that, The vibrating mass (1) is connected to an equal number of first pendulum rods (4) of equal length via two or more hinges (4.3) and to a second pendulum rod (5) via the hinges (5.2), so that the vibrating mass can move in a horizontal plane.

18. The adaptive pendulum vibration damper according to any one of claims 1 to 3, characterized in that, The adaptive pendulum vibration damper has at least one additional damping unit (3) which is mounted at the hinge (4.2) of the first pendulum (4) connected to the structure to be damped and / or at the periphery of the vibrating mass (1).

19. The adaptive pendulum vibration damper according to claim 18, characterized in that, The at least one additional damping unit (3) is a rotary damper.

20. The adaptive pendulum vibration damper according to any one of claims 1 to 3, characterized in that, The adaptive pendulum vibration damper is mounted on a movable carrier element (6), which can be reversibly fixed or removed from the structure during its installation or dismantling.

21. A wind power device comprising a nacelle, a rotor, and a tower, characterized in that, The wind power equipment has a vibration damper according to any one of claims 1 to 20, the vibration damper being permanently or temporarily fixed at the tower or at the nacelle.

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