Frequency adaptive leaf spring damper

Abstract

The invention relates to a vibration damper or vibration absorber, which can be adapted within a certain range to the active disturbance frequency of a component to be damped or of a vibration system to be damped by means of a device (2) composed of a plurality of stacked, in particular profiled or curved leaf springs (2.1), wherein the position of the damper mass (1, 34) changes only slightly. The invention relates in particular to a one- and two-dimensionally active vibration damper. The vibration damper according to the invention is particularly suitable for use in devices, vehicles and machines which are subject to frequent changes in rotational speed, as a result of which disturbance frequencies often occur, which can be perceived in particular by the occurrence of structure-borne sound or other vibrations.

Description

Technical Field

[0001] This invention relates to a vibration damper or shock absorber that, by means of a device consisting of multiple stacked, specially shaped or bent leaf springs, can be adapted within a specific range to the operating frequency of the component or vibration system to be damped, wherein the position of the damper mass is substantially only slightly altered. The invention particularly relates to a vibration damper that operates in one-dimensional and two-dimensional modes.

[0002] The vibration damper according to the invention is particularly suitable for equipment, vehicles and machines that are subjected to frequent changes in rotational speed, thereby frequently generating interference frequencies, which can be detected in particular by the presence of solid-borne sound or other vibrations. Background Technology

[0003] Vibration dampers for reducing unwanted vibrations in machines, equipment, or their components are known in the prior art. Numerous solutions have been proposed for this purpose. Most of these solutions are associated with the desired relatively strong passive damping of the excited system, as described, for example, in EP 1 008 747, EP 1 327 726, or EP 2 816 177. The main functional component of these systems is an elastomer, which itself has a damping portion. The advantage of these systems is that the corresponding dampers can be used over a wide frequency range, including the inherent frequencies, so that they do not cause significant disturbance to the equipment. However, these systems only work effectively when the rotational speed of the rotating component remains constant or does not change significantly. However, rotating systems with varying rotational speeds are primarily prone to generating increased or enhanced solid-borne noise, which is particularly undesirable for wind power generation equipment.

[0004] WO 2017 / 186343 A1 describes a leaf spring damper that operates in a selected direction. Here, a preload element connected to the damper mass is arranged on a first flat side of the leaf spring, and a rolling element is arranged on a second flat side of the leaf spring. This rolling element is positioned between the surfaces of the leaf spring and the damper mass, and is capable of reciprocating along the leaf spring and can be fixed to a specific, selected, and variable position along the leaf spring by the preload element. This determines the length of the leaf spring that operates technically in vibration and, consequently, the frequency of the machine unit perpendicular to the leaf spring's vibration and to be damped by this frequency. While this one-dimensional damper works very effectively, the mechanically moving parts on or around the leaf spring are often difficult to adjust and require relatively frequent readjustment. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a leaf spring damper that achieves optimized damping over a wide frequency range in a similar manner, for example, by introducing a frequency-dependent force when the rotational speed of the rotating component involved in the system changes, but without the disadvantage of having to make difficult or frequent readjustments to the device in response to the frequency changes that occur.

[0006] The proposed task is solved by the vibration damper described below.

[0007] Therefore, the subject of this invention is a vibration damper for damping vibrations in vehicles, machines and equipment, especially wind power generation equipment, particularly in the range between 50 and 500 Hz, the vibration damper essentially comprising:

[0008] (i) Vibrating mass consisting of one or more units, which may be regularly or irregularly shaped (1).

[0009] (ii) One or more leaf spring devices (2), which are substantially composed of at least one, but preferably two or more, especially three, four, five, six or more individual leaf springs (2.1) stacked one on top of another, having a predetermined stiffness, and

[0010] (iii) A mechanism, particularly a moving mechanism (5), (6), (14)-(18), or an electrical or thermal mechanism having such function, such as a piezoelectric element or a bimetallic element, for changing the predetermined stiffness of the leaf spring device (2) and thus frequency-adapting the associated vibration system to the frequency of the disturbance, the mechanism being connected not only to the leaf spring device (2) but also to the load-bearing mechanism (11) of the vibration system.

[0011] The leaf spring device is designed and arranged in a special way, and is connected not only to the load-bearing unit (11) of the vibration system (equipment, machine, vehicle) but also to the damper mass (1) in such a way that no mechanically moving parts are involved in the force flow along a specific direction under excited conditions.

[0012] Therefore, compared to the solution disclosed in WO 2017 / 186343 A1, which discloses a damper with a leaf spring (the leaf spring can be shortened or lengthened in terms of its length during operation by a moving mechanism), the damper device according to the invention requires very little maintenance due to only minor wear.

[0013] The leaf spring device (2) of the shock absorber according to the present invention has the following special features:

[0014] (a) One, preferably two or more, parallel stacked or placed vertically, directly or indirectly in contact leaf springs (2.1), said leaf springs being pre-bent about their transverse axis in a state of no force, wherein the longitudinal axis of said leaf spring or leaf spring assembly is defined by the direction of the force applied during operation (2.1.3), wherein the bending of said leaf spring assembly (2) or leaf spring (2.1) is S-shaped, preferably centrally symmetrical S-shaped, and

[0015] (b) Two end regions (2.1.1) in the longitudinal direction, through which the leaf spring is tensioned and the two end regions are arranged parallel to each other, but offset or misaligned with each other with respect to their position relative to the longitudinal axis by a defined predetermined amount (2.1.2), wherein such predetermined offset (initial offset) corresponds to a specific stiffness of the leaf spring device and therefore to a specific frequency of the vibration system connected to the leaf spring device. One of the end regions is directly or indirectly connected to the damper mass (1), which is arranged such that it can vibrate along the longitudinal axis of the leaf spring device. According to the invention, the other end region (2.1.) of the leaf spring device (2) is connected to the aforementioned mechanism for changing the stiffness of the leaf spring device (2), which is arranged on the bearing mechanism (11) and can operate there.

[0016] According to the implementation, the offset of the leaf spring device (2) can be performed by means of the aforementioned mechanisms, for example by a moving mechanism or a rotating mechanism (5)(6)(14-18) or a mechanism with the same function.

[0017] The moving or rotating mechanism (5) or (6) connected to the vibrating mass (1) causes the leaf spring device (2) or the group of leaf springs (2.1) to bend along a direction perpendicular to its longitudinal axis (2.1.6, offset direction) or along the direction of movement (8) or torsion (19) when the mass moves or twists relative to the bearing unit (11) of the vibration system. This, in turn, causes the pre-defined offset (2.1.2) to expand or contract depending on the direction of movement or rotation. Thus, the pre-given stiffness of the leaf spring device along its longitudinal axis can be changed, and thereby the frequency of the vibration system can be adapted to the changed interference frequency. Through the corresponding positive or negative bending of the leaf spring device (corresponding to positive or negative movement or torsion), the frequency of the damper can be adapted accordingly to the changing rotational speed of the machine, equipment, or vehicle, and thus adapted to the correspondingly changed interference frequency. The frequency adjustment is thus achieved, according to the invention, by pure bending of the leaf spring device (2) by means of the moving mechanism (5) (6) or the rotating mechanism (14-18).

[0018] The bending or deflection of the leaf spring device can also be achieved, as mentioned, by a piezoelectric element, which is mounted on one or both sides of the leaf spring device. When a high voltage is applied, the excited piezoelectric element expands, thereby causing the corresponding bending of the leaf spring device. By unilaterally oriented excitation of the piezoelectric element, the adjustment range can be doubled.

[0019] As an alternative, the leaf spring (2) can be composed of two metals with different thermal expansions (bimetallic elements). Under the influence of temperature (passively by ambient temperature or actively by means of a heating element), the leaf spring bends accordingly, thereby affecting its stiffness and thus the frequency of the vibration system.

[0020] The leaf spring assembly typically consists of one relatively thick or preferably multiple thin (1-2 mm) leaf springs stacked one on top of the other. The individual leaf springs are usually separated by a narrow gap (≤2 mm, especially ≤1 mm), i.e., with a slit-like gap, but they can also be placed directly on top of each other. In the latter case, additional damping of the system is generated by friction that occurs during bending.

[0021] In one embodiment of the invention, the gaps between the leaf springs of the leaf spring assembly can also be filled with an elastic layer that must be able to absorb some of the significant shear forces that occur when the leaf springs bend without damage. In another embodiment of the invention, in order to influence and optimize the desired stiffness and to reduce mass in order to increase the natural frequency of the leaf springs, individual or all the leaf springs of the leaf spring assembly can have a central empty portion in the form of a circle or ellipse (2.1.4). Conversely, mass can also be placed on the leaf springs to reduce their natural frequency.

[0022] The leaf spring assembly or individual leaf springs used in the shock absorber according to the invention are preferably rectangular, wherein, in terms of outline, the base surface of the rectangle naturally has an S-shaped bend as described above, preferably having the bend centrally and symmetrically along the longitudinal axis. However, depending on functional, spatial requirements and arrangement in a particular machine or device, the leaf spring can also have an arbitrary, regular or irregular shape and size profile.

[0023] It has been confirmed that dampers with leaf spring devices or leaf springs are particularly effective at damping interference frequencies between 50 and 500 Hz, preferably between 100 and 300 Hz, wherein the leaf spring device or leaf spring, in a pre-bent, unloaded state, has an offset (initial offset) (2.1.2) relative to the longitudinal axis, which is 10-40%, preferably 15-30%, of the free spring length (2.1.5) along the longitudinal axis of the leaf spring or in the load direction (2.1.3). For common wind power generation equipment, depending on the size of the equipment, leaf spring devices with a free spring length (2.1.5) of 50-500 mm, preferably 100-300 mm, can be used.

[0024] Typically, two or more leaf spring devices (2) are used in the damper according to the invention, depending on the desired damping. However, in principle, it is possible to equip a functional damper according to the invention with only one leaf spring device. However, it is preferred that each damper use at least two leaf spring devices. Here, it also depends on whether the damper is to operate in only one direction (linear damper) or in a plane.

[0025] Therefore, the subject of the present invention is also an adaptive, one-dimensionally functioning damper having at least two parallelly arranged leaf spring devices (2), which are fixedly connected to the vibrating mass (1) at opposite points via their first end regions or clamping regions (2.1.1) and fixedly connected to the bearing unit (11) via their second end regions or clamping regions (2.1.1).

[0026] The vibrating mass (1) is formed here by one or more plates assembled together between leaf spring devices and arranged such that the vibrating mass can vibrate essentially only along a specific, to be specified direction (9), for example, along the vertical direction.

[0027] In a preferred embodiment, the device for changing the predetermined stiffness of the leaf spring assembly (2) is a mechanical, hydraulic, pneumatic, or electric moving mechanism (5) / 6), which is connected on one side to the bearing unit (11) and on the other side to a vibrating mass (1), wherein the vibrating mass (1) connected to the leaf spring assembly is capable of moving back and forth along a direction (8) perpendicular to the vibration direction (9) (moving direction). Thus, if, for example, the vibration direction of the mass (1) is vertical, the moving direction is horizontal. Through such movement, the predetermined original offset (2.1.2) of the pre-bent leaf spring can be expanded or reduced by reversible deformation along the bending direction (2.1.6) and thus affect the stiffness of the leaf spring assembly.

[0028] As described above, the mass (1) moves along direction (8). To ensure that the vibrating mass (1) of such a one-dimensional damper does not skew when the leaf springs bend by means of the moving mechanism (5) (6) and remains oriented in the same manner relative to the bearing mechanism (11) and at least two leaf spring devices, according to the invention, guide springs (3) (4) are provided on the vibrating mass (1), the guide springs being arranged parallel to the moving direction (8) of the vibrating mass (1) and not significantly hindering the vibration of the mass (1). The guide springs are leaf springs, capable of slight movement along direction (9) and possessing high stiffness along the direction of movement (8), so as to accurately position the mass (1) in a predetermined position (5) (6). Simultaneously, the necessary fixation of the mass along direction (13) is achieved by the guide springs. Therefore, the mass only has the predetermined stiffness along direction (9) via the leaf spring device (2) and is restrained along other directions.

[0029] As already mentioned, it is possible to install more than two leaf spring devices in the damper according to the invention. Therefore, it is also possible to use three or more leaf spring devices, which can be arranged such that the damper operates not only in a linear direction but also in a defined plane. Such an implementation is also the subject of the invention. Here, the mass (1) of the damper is formed by a mass ring that is concentric around a concentrically supported load-bearing unit (11).

[0030] The subject of this invention is therefore specifically a two-dimensional vibration damper having two or more, preferably three to eight, leaf spring devices (2) arranged star-shaped relative to each other at the same or different spacing angles and fixedly connected outward through their first end region or clamping region (2.1.1) to annular, concentrically arranged vibrating masses (1) surrounding a support unit (11). The other end region or clamping region (2.1.1) of each leaf spring device (2) is directly connected to the concentrically supported support unit (11), which also has a rotating mechanism (14-18). Here, the annular vibrating masses are arranged such that they can vibrate radially in the plane of the concentrically supported support unit (11). In this embodiment, the bending of the circularly arranged leaf springs is achieved by the torsion of the concentrically supported bearing mechanism relative to the vibrating mass (1) via the aforementioned rotating mechanism on the bearing member (11). This alteration of the predetermined offset (2.1.2) and thus the change of its stiffness is achieved through the reversible deformation of all radially and star-shaped leaf springs (2) along the bending direction (2.1.6). If uniform damping in the plane is desired, the angles between the star-shaped leaf springs are preferably the same. If different damping effects are desired along the selected direction, the angles can also be different.

[0031] The inventive principles described herein can also be applied to systems with rotating components or machines and the resulting vibrations. In one particular embodiment, the aforementioned leaf spring device (2) is arranged tangentially to the rotating unit. It is also possible to arrange two leaf spring star-shaped elements stacked, which are twisted relative to each other and connected to a common mass.

[0032] Therefore, the subject of this invention is also a corresponding vibration damper, wherein the vibrating mass (34) is arranged annularly around a concentrically supported load-bearing unit or the machine itself of a machine (30), which performs circular vibrations when excited by an interfering frequency. Here, the annular vibrating mass (34) consists of at least two, preferably three, four, five, six or more arc segments interconnected by a corresponding number of leaf spring devices (2), wherein the leaf spring devices (2) are arranged tangentially relative to their longitudinal axis such that these leaf spring devices act dampingly in the rotational vibration of the load-bearing unit or the machine (30), as described in more detail above and below. If a direction-independent damping effect is desired, it is preferable that the tangentially mounted leaf spring devices described here are also symmetrically or uniformly distributed around a circular shape.

[0033] The damper according to the invention can also have additional damping elements known per se (if needed or desired). Such damping elements can be, for example, elastomeric dampers, hydraulic dampers, eddy current dampers, or pneumatic dampers.

[0034] The main feature of the damper according to the invention is that the ratio of the vibration stroke caused by the mass (1) of the damper to the vibration stroke introduced by the vibration system to be stabilized when a force is applied in the specified direction is >50, >100, >200 or >300, wherein the ratio mentioned typically has a value between 100 and 400 under common operating conditions in an undamped state.

[0035] Furthermore, a key feature of the damper according to the invention is that when the pre-bent leaf spring device (2) is offset (2.1.2) relative to the original pre-bending by 30% in the direction of increasing the stiffness of the leaf spring device under load, an average increase of approximately two to three times is achieved relative to the initial offset frequency. Conversely, if the pre-bent leaf spring device (2) is offset by 30% relative to the original offset (2.1.2) in the opposite direction, that is, in the direction of decreasing the stiffness of the leaf spring device under load, then a decrease of 20-50% in frequency relative to the initial offset is achieved. In both cases, the corresponding values ​​depend on the leaf spring device or the selected initial stiffness of the leaf spring.

[0036] The vibration damper according to the invention described herein can be used to reduce or eliminate interference frequencies in machines, vehicles or equipment, particularly those caused by rotating components of transmission mechanisms, generators, drive systems, or by rotor blades or rotor hubs. Attached Figure Description

[0037] Figure 1 Two different perspective views of a shock absorber operating in one dimension according to the invention are shown;

[0038] Figure 2 It shows Figure 1 Top and side views of the vibration damper according to the present invention;

[0039] Figure 3 Details of a single leaf spring according to the invention are shown;

[0040] Figure 4 , Figure 5 and Figure 6 One embodiment of the vibration damper according to the present invention is shown;

[0041] Figure 7 Typical characteristic curves for three leaf spring devices with different initial stiffness are shown;

[0042] Figure 8 An embodiment of a vibration damper according to the invention is shown, the vibration damper having a circular or tangential arrangement of leaf spring devices;

[0043] Figure 9 A wind power generation device with a transmission mechanism is shown, in which a device is installed according to... Figure 8 A circular vibration damper according to the present invention;

[0044] Figure 10 It shows the use of according to Figure 8 A diagram of a wind turbine (without a transmission mechanism) that is directly driven in the case of a circular vibration damper;

[0045] Figure 11 It shows according to Figures 4-6 A modified embodiment of the vibration damper according to the present invention. Detailed Implementation

[0046] Figure 1 (a) and (b) show two different perspective views of a one-dimensionally operating damper according to the invention. The vibrating mass (1) here consists of a plurality of interconnected rectangular plates, the number and mass of which can be selected as required. The group of mass plates (1) is constrained on two sides by two leaf spring devices (2), which consist of a plurality of, in this case, five leaf springs stacked vertically (2.1). The leaf springs are pre-bent in the middle and in the same direction in an S-shape, wherein their two (upper and lower) end regions or clamping regions are oriented parallel to each other but staggered. In this embodiment, the individual leaf springs are separated from each other by a small pitch / gap (<2 mm). Each of the two leaf spring devices is arranged such that the upper end region (2.1.1) of the device is fixed to one side of the vibrating mass plate (1), while the lower end region or clamping region (2.1.1) is fixedly connected to the bearing unit (11) of the vibration system (equipment, machine, etc.). The bearing unit (11) has two fixed surfaces (10) for the vibration system to be damped.

[0047] Figure 1 (a) also shows an upper guide spring (3) which is fixedly connected to the assembly of the mass plate (1) at a position and guides the mass plate vibrating in the vertical direction (9) during operation to prevent it from tilting or falling off under force. The guide spring (3) is connected to a lower guide spring (4) (not shown here) via a support plate (7), which is fixed to the lower side of the vibrating mass (1) and has the same function as the upper guide spring (3). Figure 2 (a) shows an image taken from above, as per the invention. Figure 1 The view depicting the shock absorber shows the guide spring plate (3), which is held by two guide springs-bearing plates 7 so that the mass unit 1 does not move primarily in the lateral direction (13, vertical double arrows) under force. The direction (8) along which the vibrating mass moves via the bending of the leaf spring device (2) when the moving mechanism (5) (6) (not shown) is also drawn.

[0048] Figure 2 (b) shows Figure 1 A side view of the shock absorber according to the invention. Two externally arranged S-shaped leaf spring devices can now be seen, each consisting of multiple individual leaf springs separated from each other. The fixed condition with the vibrating mass (1) can be seen in the upper end region. In the lower end region, the spring assembly is fixedly connected to the bearing mechanism (11). A moving mechanism is mounted on the bearing mechanism, which is capable of moving along the lateral connection of the bearing mechanism in the direction (8). In the illustrated embodiment, this moving mechanism is equipped with a drive system (6): here, (6.1): drive motor, (6.2): ​​moving spindle, (6.3): spindle nut. The moving mechanism can be operated manually, pneumatically, hydraulically or pneumatically. The moving unit 5, which is capable of moving back and forth along the direction 8, is connected to the bearing mechanism 1 of the guide springs (3) (4) on the left side. When the mechanism (5) moves to the right ( Figure 8 The vibrating mass (1) thus also moves to the right, thereby causing the leaf spring devices (2) on both sides to bend further relative to their original curvature or to deflect further along the direction (8) (expanding the original "S-shape"). This reduces the stiffness of the leaf spring device with respect to the vibrating force acting vertically (9), which causes a decrease in the frequency of the system. Therefore, when moving to the left, the original deflection of the leaf spring decreases (shrinks the "S-shape"), which causes an increase in stiffness and a higher frequency.

[0049] Figure 3 (a) and (b) show details of a single leaf spring (2.1) according to the invention, which is preferably used as a group of multiple such leaf springs in a damper according to the invention. Figure 3(a) shows a side view of the spring in a non-loaded state (direction of solid lines). (2.1.1) represents the end region where the spring is clamped or fixed. The drawn dimension (2.1.2) represents the original pre-bending offset of the spring, corresponding to the characteristic S-shape of the spring. Dimension 2.1.6 indicates the direction of the additional or reduced offset of the spring as the mass moves along the direction (2.1.6) relative to the initial offset (2.1.2). The corresponding spring is drawn accordingly (dotted line). When the mass (1) vibrates, the leaf spring elastically bends along the load direction (2.1.3). In addition, the free spring length (2.1.5) is drawn for the three spring states. Figure 3 (b) Shown for the purpose of explanation Figure 3 (a) Multiple perspective views of the leaf spring. In another particular embodiment, such a leaf spring or leaf spring device has a centrally located recess (2.1.4) that can be used for dynamic changes in the natural frequency of the spring.

[0050] Figure 4 , Figure 5 and Figure 6 An embodiment of a vibration damper according to the invention is shown, which operates two-dimensionally, i.e., in a selected plane. Figure 4 (a) shows a perspective view of this embodiment. Figure 4 (b) shows a view from above or below, and Figure 4(c) The view is shown in a side view. Here, (1) represents the vibrating mass, which preferably has an annular shape and is rotatably supported about an imaginary axis perpendicular to the annular plane at the center point of the circle formed by the mass. However, any other geometry, such as a triangle, square, rectangle or arbitrary polygon, can also be chosen. Importantly, free space is left inside the mass body 1 for the leaf springs. The bearing units (11) having a connection surface (10) for the vibration system are also arranged concentrically. The mass ring is connected to the aforementioned concentrically supported bearing units (11) by a plurality of (six in the case shown) S-shaped pre-bent leaf spring devices (2) that are uniformly distributed and arranged in a star shape in the specific case (the leaf spring devices can also be non-uniformly distributed if it is desired that damping should be applied in different directions at different frequencies). Here, the end regions or clamping regions (2.1.1) of the leaf spring devices are connected to the mass ring (1), and the second end regions or clamping regions are connected to the bearing units. The load-bearing unit can be twisted relative to the mass ring via a rotatable adjusting rod and a drive device (6), thereby causing all the existing leaf spring devices (2) to bend more or less according to the direction of rotation compared to their initial bending. Therefore, the stiffness of the damper can be easily adjusted and adapted to the disturbance frequency of the vibration system.

[0051] Figure 5 (a) and (b) show details of the torsion unit (14-18) at the center of the damper. Here, (14) represents the adjusting rod, (15) represents the torsion bar, (16) represents the rotary bearing, (17) represents the torsion tube, and (18) represents the torsion bar. The torsion tube (17) and the torsion bar (18) are connected in series to achieve the necessary degrees of freedom of motion for the mass (1). These elements together form a torsion bar that can be easily bent. In order to minimize the influence of the rotary bearing structure on the radial stiffness of the entire system even at low frequencies, multiple tubes can be arranged in a zigzag pattern among each other. Figure 6 It shows the relationship with Figure 4 and Figure 5 The same implementation method is used. 2.1 here represents the leaf spring device before the adjustment begins, while (2.1.a) shows the same leaf spring device after it has been rotated relative to the concentrically supported load-bearing unit in the direction of the illustrated arrow 19, which causes a large bending (offset) of the individual leaf spring devices and thus causes a reduced stiffness and thus causes a movement to a lower frequency.

[0052] Figure 7Typical characteristic curves (frequency change of the vibration system relative to the axial movement of the leaf springs) for three leaf spring assemblies with different initial stiffness are shown. The initial stiffness is typically determined primarily by the number of individual springs, the thickness of individual springs, the free spring length, and the initial S-shaped pre-bending. The solid line in the middle represents the characteristic curve for a leaf spring assembly with a specific stiffness. The upper dashed characteristic curve depicts the variation for a leaf spring assembly with relatively high stiffness, while the lower dashed characteristic curve represents the corresponding relationship for a relatively soft spring assembly. The X-axis value indicates the percentage (0%) of positive or negative movement or torsion relative to the unforced pre-bending spring. It can be seen that the leaf spring orientation becomes steeper with positive movement (0 to +50%), resulting in a significant increase in frequency. Negative movement (0 to -50%) results in a flatter leaf spring orientation and thus a lower frequency. It can be seen from all three curves that the frequency of the damper system decreases when the springs are additionally offset / bent and increases when the offset / bending decreases. Here, if the reduced offset is +20% relative to the initial offset, the frequency increases by approximately 100% relative to the initial frequency. A 150-200% frequency increase has been achieved with a relative reduction of +30% in offset / bending, and a further +40% reduction in bending relative to the initial offset results in a frequency increase of up to 400%. Conversely, if the original offset / bending is increased relative to the initial value (negative on the X-axis) by a corresponding reverse movement or torsion, the stiffness of the leaf spring decreases, causing a drop in frequency. A 20% increase (-20%) in offset results in a frequency drop of approximately 20%, a 30% increase (-30%) in offset results in a frequency drop of approximately 40%, and a 40% increase (-40%) in offset results in a frequency drop of approximately 50%. Further increases in offset have only a minor effect on the frequency.

[0053] Figure 8(a) and (b) show one embodiment of the damper according to the invention, which has a circular or tangential arrangement of leaf spring devices. This allows for adaptive damping of rotating components. Here, the damper mass (34) is coupled to the circularly vibrating machine or its load-bearing component via a tangentially arranged group of leaf spring devices (2). In a specific case, four (but possibly three to eight) preferably evenly distributed groups of leaf spring devices (2) (comprising 20-40 individual curved leaf springs) are fixed to the damper mass. The damper mass itself comprises corresponding preferably circular segments interconnected by the aforementioned leaf spring devices. As described above, the leaf spring devices are equipped with corresponding moving mechanisms (6) for adjusting the spring stiffness. Thus, the frequency of the system is adjusted by moving the spring unit (2) along its moving direction (8) (→ changing the curved S-shape). Furthermore, the shock absorber mass segment (34) is connected to the rotating load-bearing unit (30) or to the rotating machine itself via correspondingly arranged guide springs (31) (33).

[0054] Figure 9 A wind power generation device with a transmission mechanism is shown, in which a device is installed according to... Figure 8 The circular damper according to the invention comprises (2) (5) (9) (6) (31) (32) (34). The damper is mounted on the transmission mechanism such that it can absorb torsional vibrations of the transmission mechanism. Instead of the annular damper according to the invention, a damper according to... Figure 1 or Figure 2 The vibration dampers are arranged in a corresponding circular pattern. Positions (40) and (41) here represent fixed points on the wind power generation equipment. The vibration dampers according to the invention can also be connected to the rotor hub.

[0055] Figure 10 It shows the use of according to Figure 8 The illustration shows a wind turbine (without a transmission mechanism) directly driven in the case of a circular vibration damper. This circular vibration damper according to the invention can be installed not only in the stator of the generator but also in the rotor. Other aspects apply the same as in the device with a transmission mechanism described above.

[0056] Figure 11 The perspective view shows the following according to Figures 4-6 A modified embodiment of the shock absorber according to the invention. (a) shows a cross-section of half of the annular shape of the shock absorber, while (b) shows the complete annular shape.

[0057] In this embodiment, two star-shaped members, each consisting of a leaf spring or a leaf spring assembly, are connected together to an annular mass (1). Here, there are a front leaf spring stack (51) and a rear leaf spring stack (50) in the form of star-shaped members. These are arranged opposite to each other and are movable, such that the two star-shaped members obtain the same radial stiffness change when twisted relative to each other. The hub (52) and pivot (53) are twisted relative to each other using a flange-connected transmission mechanism or levers and force elements to set the desired stiffness.

Claims

1. An adaptive one-dimensional or two-dimensional vibration damper for a vibration system capable of adapting to an interference frequency, said vibration system comprising a device subjected to an interference frequency to be damped, said vibration damper comprising... (i) Vibration mass (1, 34), (ii) At least one vibrating leaf spring device (2) in the presence of force flow, the leaf spring device being fixedly connected, on the one hand, directly or indirectly, to the load-bearing unit of the aforementioned device, and on the other hand, being fixedly connected, directly or indirectly, to the vibrating mass (1, 34) and having a predetermined stiffness, and (iii) A means for changing the predetermined stiffness of the leaf spring device (2) and thereby frequency-matching the vibration system to the interference frequency, wherein the means for changing the predetermined stiffness of the leaf spring device (2) is connected not only to the leaf spring device (2) but also to the load-bearing unit of the vibration system. Its features are, (iv) The at least one leaf spring device (2) has one or more parallel stacked leaf springs (2.1), which are pre-bent about their transverse axis in a non-loaded state and have a free spring length (2.1.5) offset along the longitudinal axis by 10-40% in the direction of the pre-bent non-loaded state, wherein the longitudinal axis of the leaf spring device is defined by the direction of the force applied during operation (2.1.3). (v) The two end regions or clamping regions (2.1.1) of the leaf spring device (2) are offset by a predetermined amount with respect to their position relative to the longitudinal axis, wherein such predetermined offset (2.1.2) corresponds to a specific stiffness of the leaf spring device and therefore to a specific frequency of the vibration system connected to the leaf spring device, and (vi) The device for changing the predetermined stiffness of the leaf spring device (2) includes a moving mechanism (5, 6) or a rotating mechanism (14-18), wherein the device for changing the predetermined stiffness of the leaf spring device (2) is designed and arranged such that the device for changing the predetermined stiffness of the leaf spring device (2) enables a reversible bending of the pre-bent leaf spring device along a direction perpendicular to the longitudinal axis (2.1.6), and thereby increases or decreases a predetermined offset (2.1.2) of the pre-bent leaf spring device according to the direction of movement or rotation caused by the device for changing the predetermined stiffness of the leaf spring device (2), thereby enabling the change of the predetermined stiffness of the leaf spring device along its longitudinal axis, and thereby enabling the frequency of the vibration system to be adapted to the changed interference frequency.

2. The adaptive vibration damper according to claim 1, characterized in that, The leaf spring device (2) is bent into an S-shape.

3. The adaptive vibration damper according to claim 2, characterized in that, The leaf spring device (2) is symmetrically bent into an S-shape in the middle region.

4. The adaptive vibration damper according to any one of claims 1 to 3, characterized in that, The two end regions or clamping regions (2.1.1) of the leaf spring device (2) are arranged parallel to each other.

5. The adaptive vibration damper according to any one of claims 1 to 3, characterized in that, The leaf spring device has at least two leaf springs (2.1).

6. The adaptive vibration damper according to any one of claims 1 to 3, characterized in that, The stacked leaf springs (2.1) of the leaf spring device (2) have a spacing of <2 mm between each other or are directly on top of each other, thereby providing additional frictional damping to the vibration system.

7. The adaptive vibration damper according to claim 6, characterized in that, The stacked leaf springs (2.1) of the leaf spring device (2) are separated from each other by an elastic layer with a thickness of >0 and <2 mm.

8. The adaptive vibration damper according to any one of claims 1 to 3, characterized in that, The leaf spring device (2) has a free spring length (2.1.5) along the longitudinal axis in a pre-bent, unloaded state. 15-30% offset from 2.1.3).

9. The adaptive vibration damper according to claim 8, characterized in that, The free spring length (2.1.5) is 50-500 mm depending on the equipment.

10. The adaptive vibration damper according to any one of claims 1 to 3, characterized in that, The leaf spring (2.1) of the leaf spring device (2) has a circular or elliptical hole (2.1.4) in the middle region to affect the dynamic natural frequency of the spring.

11. The adaptive, one-dimensionally operating damper according to any one of claims 1 to 3, characterized in that, The vibrating mass is formed by one or more plates assembled together and is limited at opposite points on the sides by at least two parallel leaf spring devices (2), each leaf spring device being fixedly connected to the vibrating mass via its first end region or clamping region (2.1.1) and fixedly connected to the bearing unit (11) via its second end region or clamping region (2.1.1), wherein the vibrating mass is capable of vibrating along a direction (9) corresponding to the longitudinal axis (2.1.3) of the leaf spring device (2).

12. The adaptive vibration damper according to claim 11, characterized in that, The device for changing the predetermined stiffness of the leaf spring device (2) is a mechanical, hydraulic, pneumatic or electric moving mechanism arranged on a bearing unit (11) above or below the vibrating mass and the leaf spring device.

13. The adaptive vibration damper according to claim 12, characterized in that, The vibrating mass is guided and held by guide springs (3, 4) in a manner parallel to the direction of movement (8) caused by the altered offset of the leaf spring device (2) along the direction of movement (8), wherein the direction of movement (8) extends perpendicular to the longitudinal axis of the leaf spring device (2).

14. The adaptive, two-dimensionally operating damper according to any one of claims 1 to 3, characterized in that, The vibrating mass is arranged in a ring around the concentrically supported bearing unit (11) such that the vibrating mass can vibrate radially in the plane of the bearing unit and is connected to the bearing unit by three to eight leaf spring devices (2), which are arranged star-shaped and relative to each other at the same or different intervals of a selected number of angles within the vibrating mass, and are connected to the vibrating mass by their first end region or clamping region (2.1.1) and to the concentrically supported bearing unit (11) by their second end region or clamping region (2.1.1).

15. The adaptive vibration damper according to claim 14, characterized in that, The device for changing the predetermined stiffness of the leaf spring device (2) includes a concentrically supported rotating mechanism (14-18) that operates mechanically, hydraulically, pneumatically or electrically, by means of which the torsion (19) of the concentric vibrating mass relative to the concentrically supported bearing unit (11) can be implemented, thereby achieving a change in the predetermined offset (2.1.2) of all radially arranged leaf spring devices (2).

16. The adaptive torsional damper according to any one of claims 1 to 3, characterized in that, The vibrating mass is arranged in a ring around a concentrically supported bearing unit of the device, which performs circular vibrations when excited, and the ring vibrating mass consists of at least two arc segments connected by a corresponding number of leaf spring devices (2), wherein the leaf spring devices (2) are arranged tangentially relative to their longitudinal axis such that the leaf spring devices act in a damping manner in the rotational vibration of the bearing unit or the device.

17. The adaptive vibration damper according to any one of claims 1 to 3, characterized in that, In the undamped state, the ratio of the vibration stroke of the vibrating mass to the introduced vibration stroke of the vibration system to be stabilized under force is >100-400.

18. The adaptive vibration damper according to any one of claims 1 to 3, characterized in that, The pre-bent leaf spring device (2) is further offset by a predetermined offset along the direction that increases the stiffness of the leaf spring device under load. When the value of 2.1.2) is 30%, the frequency is increased by two to three times based on the initial stiffness of the leaf spring device.

19. The adaptive vibration damper according to any one of claims 1 to 3, characterized in that, The pre-bent leaf spring device (2) is further offset by the preset offset in the direction of reducing the stiffness of the leaf spring device under load. When the value of 2.1.2) is 30%, the frequency is reduced by 20-50% based on the initial stiffness of the leaf spring device.

20. The adaptive vibration damper according to any one of claims 1 to 3, characterized in that, The adaptive damper has one or more additional damping elements.

21. The adaptive vibration damper according to claim 1, characterized in that, The device is a vehicle.

22. The adaptive vibration damper according to claim 1, characterized in that, The device is a machine.

23. The adaptive vibration damper according to claim 1, characterized in that, The device for changing the pre-given stiffness of the leaf spring device (2) includes a piezoelectric element.

24. The adaptive vibration damper according to claim 1, characterized in that, The device for changing the pre-given stiffness of the leaf spring device (2) includes a bimetallic element.

25. The adaptive vibration damper according to claim 5, characterized in that, The leaf spring device has three, four, five or six leaf springs (2.1).

26. The adaptive torsional damper according to claim 16, characterized in that, The ring-shaped vibrating mass consists of three circular arc segments.

27. The adaptive vibration damper according to claim 9, characterized in that, The length of the free spring (2.1.5) is 100-300 mm depending on the equipment.

28. The application of the damper according to any one of claims 1 to 27 for reducing or eliminating interference frequencies in equipment caused by rotating components of a transmission mechanism.

29. The application according to claim 28, characterized in that, The device is a vehicle.

30. The application according to claim 28, characterized in that, The device is a machine.

31. The application according to claim 28, characterized in that, The interference frequency is caused by the rotating components of the generator.

32. The application according to claim 28, characterized in that, The interference frequency is caused by the rotating components of the transmission system.

33. The application according to claim 28, characterized in that, The interference frequency is caused by the rotor blades or rotor hub.

34. An apparatus comprising a vibration damper according to any one of claims 1 to 27.

35. The device according to claim 34, characterized in that, The equipment is a vehicle or a wind power generation device.

36. The device according to claim 34, characterized in that, The device is a machine.

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