Decoupling device for oscillatory systems

Abstract

The invention relates to a decoupling device (50) for oscillatory systems, the decoupling device comprising: at least one nonlinear stiffness element having a negative stiffness knl(u) and comprising at least one first spring element (27); and at least one linear stiffness element which has a positive stiffness kl,stat, is connected in parallel with the at least one nonlinear stiffness element, and comprises at least one second spring element (28). The at least one nonlinear stiffness element having a negative stiffness knl(u) is connected in series with at least one further stiffness element having a linear stiffness Kl and comprising at least one third spring element (29), and this series connection is connected in parallel with the at least one linear stiffness element having a positive stiffness kl,stat, wherein a quasi-zero-stiffness isolator is formed with an increased magnitude of the negative stiffness knl,ser,tot(u).

Description

[0001] Decoupling device for vibrating systems

[0002] The present invention relates to a decoupling device for vibrating systems according to the preamble of claim 1.

[0003] The dynamic isolation or decoupling of structures using such decoupling devices is employed to reduce vibration transmission and noise emissions. This includes vibrations in both translational and rotational directions (torsional vibrations). Elastic bearings or couplings are typically used for isolation. These elements exhibit a positive and approximately constant stiffness. To achieve a sufficiently low overall stiffness for isolation purposes and simultaneously limit the deformation of each element to an acceptable level, several of these linear elements are, for example, connected in series.

[0004] Besides the use of linear decoupling elements, approaches also exist with nonlinear elements whose stiffness does not have a constant value, but varies depending on the deformation. These include, among others, so-called quasi-zero-stiffness concepts.

[0005] Figure 1a shows a schematic symbolic representation of a spring arrangement T from the prior art.

[0006] The spring arrangement T represents a parallel connection of stiffnesses ki.stat and kni(u) for vibration isolation (quasi-zero-stiffness isolator).

[0007] The “parallel connection” of stiffnesses or spring elements means that a first end of the first spring element is connected to a first end of the second spring element, and that a second end of the first spring element is connected to a second end of the second spring element.

[0008] The term "series connection" or "connected / arranged in series" means that a second end of a first spring element is connected to a first end of a second spring element, etc.

[0009] The spring arrangement T comprises a first spring element 2 and a second spring element 3. The first spring element 2 is a linear spring element with a constant stiffness ki.stat and is arranged in parallel to the second spring element 3, which is a nonlinear spring element 3 with a stiffness kni(u).

[0010] The spring elements 2, 3 are each attached at a first end to a frame 4, with their other ends attached to an exemplary plate 5, on which a load L acts in a direction of a path u and deflects the spring elements 2, 3 in the direction of the path u.

[0011] The second, nonlinear spring element 3 exhibits a negative stiffness for certain deformations. A stiffness characteristic curve 100 belonging to the first spring element 2 and a stiffness characteristic curve 101 belonging to the second spring element 3 are shown in a diagram of stiffness characteristics in Figure 2.

[0012] If the magnitude of the negative stiffness of the second spring element 3 corresponds to the stiffness value of the linear first spring element 2, then the parallel connection of both spring elements 2 and 3 results in a non-linear stiffness characteristic 104 with the stiffness kni,tot(u), which exhibits vanishing stiffness within the operating range. This achieves optimal vibration isolation of the system and simultaneously ensures the transmission of the static load (see load characteristics 200, 201 and 204 in Figure 3).

[0013] Document DE 10 2022 117 077 A1 describes an "Optimized torsional vibration isolation using a nonlinear characteristic curve of an element with negative torsional stiffness" and relates to a torsional vibration isolated coupling with a rotation axis, comprising a first coupling part as the input side of the coupling, a second coupling part as the output side of the coupling, and a damping unit. The damping unit has at least one spring arrangement designed as a nonlinear spring arrangement with a degressive spring characteristic curve.

[0014] Document DE 10 2022 128 006 A1 concerns a "coupling element for realizing a nonlinear torsional spring characteristic with negative torsional stiffness" and describes a torsionally isolated coupling element with one axis of rotation. It comprises an outer ring as the input side of the coupling element, an inner ring as the output side of the coupling element, and at least one energy storage unit with at least one energy storage element. The torsional vibration isolated coupling element exhibits a nonlinear torsional stiffness. A conflict of objectives exists between the transmission of static loads (forces and torques) and the decoupling of vibrations resulting from dynamic load fluctuations. High stiffness is required for the transmission of the static load with minimal deformation of the connecting element. Conversely, minimal stiffness is necessary for the dynamic decoupling of the system.To meet both requirements, a series connection of linear stiffness elements is typically used. This allows for low overall stiffness (insulation) combined with low static deformation per element. However, the minimum achievable overall stiffness ki.tot is limited to a lower value by the finite number N of interconnected stiffness elements ki, see equation (1).

[0015] Against this background, the use of nonlinear connecting elements with degressive stiffness is advantageous. Here, the transmitted load initially increases with increasing deformation of the element until a nearly constant load level is reached at the operating point (OP). These nonlinear elements with vanishing stiffness at the operating point (quasi-zero stiffness isolators) enable the transmission of static loads and also ensure optimal decoupling of the system from load fluctuations at the operating point.

[0016] To achieve the degressive spring characteristic, a spring element with a sufficiently high positive stiffness ki,stat (transmission of the static load) is supplemented by a parallel nonlinear stiffness element kni(u) with a corresponding negative stiffness at the operating point u*, as shown in Figure 1. kni,tot(u) = ki,stat + kni(u) m with knl(u*) < 0 (2)

[0017] The resulting total stiffness kni,tot(u*) at the operating point is defined by the decoupling degree s. knl,tot(U*) = (1 — s) kl .stat (3)

[0018] Optimal isolation (complete compensation of the linear stiffness ki, s tat) at the operating point, a decoupling degree s = 1 is achieved. knl,tot(U*) - kl .stat (3)

[0019] Various concepts exist for realizing nonlinear connecting elements with negative stiffness (hereinafter also referred to as NeSt elements). These are typically based on one or more energy storage elements. When a static load is applied, energy is initially stored in these elements (e.g., by tensioning or compressing mechanical springs). Above a certain degree of deformation, the stored energy reaches its maximum and is released again if the NeSt element deforms beyond this point. The released energy reduces the force or torque required for further deformation of the element, thus resulting in negative stiffness.

[0020] A fundamental problem with NeSt elements is their limitation in providing sufficiently high negative stiffness values. The technical limits to achieving high negative stiffness values ​​are determined, among other things, by the permissible stress values ​​and maximum load-bearing capacities of the components used in the NeSt elements (e.g., springs, levers, bearing elements, etc.).

[0021] The invention is therefore based on the objective of creating an improved decoupling device for oscillating systems.

[0022] This problem is solved by an improved decoupling device for vibrating systems with the features of independent claim 1.

[0023] In order to achieve the negative stiffness values ​​required for sufficient decoupling within the aforementioned limits, a concept for increasing the negative stiffness of a decoupling device is presented according to the invention.

[0024] The present invention presents a device for decoupling vibrating systems based on a nonlinear spring characteristic with zero stiffness at the operating point (quasi-zero stiffness isolator). Application areas include, for example, earthquake protection of buildings, isolation of measurement setups, or torsional vibration isolation of drive trains. Accordingly, a decoupling device for vibrating systems comprises at least one nonlinear stiffness element with negative stiffness kni(u), which includes at least one first spring element, and at least one linear stiffness element with positive stiffness ki.stat connected in parallel thereto, which includes at least one second spring element.The at least one nonlinear stiffness element with negative stiffness kni(u) is connected in series with at least one further stiffness element with a linear stiffness Ki, which has at least one third spring element (29), and this series connection is connected in parallel with the at least one linear stiffness element with positive stiffness ki.stat, forming a quasi-zero-stiffness isolator with an increase in the magnitude of the negative stiffness kni ,ser, tot(u).

[0025] The novel and advantageous feature of this decoupling device lies in the fact that, in addition to the parallel connection of the linear spring element and the nonlinear spring element with negative stiffness, the latter is supplemented by an additional linear spring element connected in series. This makes it possible to significantly increase the magnitude of the negative stiffness and to ensure almost linear behavior outside the operating range.

[0026] This additional reinforcement enables the use of NeSt elements with comparatively low negative stiffness values, which, due to the correspondingly low mechanical stresses, can be implemented much more easily within technical limits. Consequently, significantly higher decoupling coefficients (s) can be achieved with technically feasible NeSt mechanisms through the targeted tuning of the series-connected nonlinear and linear springs.

[0027] Further advantageous embodiments of the invention can be found in the dependent claims.

[0028] In one embodiment, the decoupling device comprises at least one stiffness unit, which includes an input element, at least one output element, at least one first spring element, at least one second spring element, at least one third spring element, a first slide, a second slide, and linear guides, wherein the second slide is slidably guided in / on the output element. This results in an advantageously simple and compact design. In another embodiment, the first slide is connected to the input element via the at least one third spring element and coupled to the second slide via a coupling unit, wherein the at least one first spring element is arranged between the second slide and the output element, and wherein the at least one output element is connected to the input element via the at least one second spring element.

[0029] By specifically matching the series-connected spring elements with ki and kni(u) according to equation (6) it is possible to generate a non-linear stiffness kni,ser(u) whose negative stiffness value is significantly larger than the corresponding stiffness value of the non-linear individual spring element (kni ,ser (U*) < knl(u) < 0).

[0030] In a further embodiment, the coupling unit has at least one lever which is articulated to the first slide with a first lever axis and to the second slide with a second lever axis.

[0031] Instead of the complex optimization of a sophisticated NeSt mechanism, the simple selection of a suitable linear stiffness element ki is advantageous. This concept also allows for the subsequent strengthening of existing NeSt elements and their adaptation to different applications through the appropriate selection or...

[0032] Adjustment of linear stiffness ki

[0033] The use of a lever or levers results in an advantageously simple construction.

[0034] An alternative design provides for the coupling unit to have a rolling mechanism (with a contour) and a rolling element. This allows for a simple design and easy assembly of the coupling unit.

[0035] In a further embodiment, the rolling mechanism contour is arranged on the first slide and the rolling element on the second slide, or the rolling mechanism contour is arranged on the second slide and the rolling element on the first slide. This design offers the advantages of simple construction and assembly. Advantageously, the rolling element of the rolling mechanism can be a rotatably mounted ball, which is available as a cost-effective component of high quality.

[0036] In another alternative design, the coupling unit has at least one beam element. This offers the advantage of a simple, compact design.

[0037] Another embodiment provides that the decoupling device has a first stiffness unit and a second stiffness unit with identical construction, wherein the two stiffness units are arranged rotated by 180° within an interior space of the input element. This is particularly advantageous because it allows for the compensation of undesired force components.

[0038] In a further embodiment, the two stiffness units have a common first slide which is connected to the input element via the at least one first spring element, resulting in an advantageous compact design.

[0039] Furthermore, the following special advantages arise:

[0040] Instead of a complex optimization of a complex NeSt mechanism, the simple selection of a suitable linear stiffness element ki is used.

[0041] This concept also enables the subsequent strengthening of existing NeSt elements and their adaptation to different applications through the appropriate selection or adjustment of the linear stiffness ki.

[0042] Some embodiments of the invention are described below with reference to the accompanying drawings. The invention is not limited to these embodiments. In particular, individual features of the following embodiments can be used not only in these but also in other embodiments. The drawings show:

[0043] Figure 1a shows a schematic symbolic representation of a spring arrangement from the prior art; Figures 1b to 1c show schematic symbolic representations of reinforcement concepts according to the invention for a nonlinear stiffness of a spring arrangement;

[0044] Figure 2 shows exemplary representations of stiffness characteristic curves;

[0045] Figure 3 shows exemplary representations of load characteristics;

[0046] Figures 4a to 4g show schematic representations of embodiments of the invention for nonlinear stiffness units with increased negative stiffness; and

[0047] Figures 5a-5c, 6a-6c, 7a-7c show schematic representations of exemplary embodiments of decoupling devices according to the invention with nonlinear stiffness and increased negative stiffness.

[0048] In the following, terms such as "outside" or "inside", "below" or "above" refer to the respective drawing plane as well as "axial" and "radial".

[0049] Coordinates y and z, as well as path u, serve for orientation within the figures.

[0050] Figure 1a from the prior art has already been described above.

[0051] Figure 1b shows a schematic symbolic representation of a first reinforcement concept according to the invention for a nonlinear stiffness of a spring arrangement 1”.

[0052] Figure 1c is a schematic symbolic representation of a second reinforcement concept according to the invention for a nonlinear stiffness of a spring arrangement T”.

[0053] Figure 2 shows exemplary representations of stiffness characteristic curves.

[0054] Figure 3 shows exemplary representations of load characteristics.

[0055] The structure of a reinforcement concept for the nonlinear stiffness of the NeSt element is shown schematically in Figure 1b. The corresponding stiffnesses and load distributions are shown in Figures 2 and 3 as examples for an optimal decoupling degree s = 1.

[0056] Figure 1b shows a series connection of stiffnesses ki and ki(u) to increase the magnitude of the negative stiffness NeSt. In Figure 1b, the first spring element 2 and the second spring element 3 (viewed from the point of application of the load L) are connected in series and attached to the frame 4. The series connection of the first spring element 2 with a linear stiffness ki and the second spring element 2 with a negative stiffness (NeSt stiffness) ki(u*) results in the nonlinear stiffness ki,ser(u*) according to equation (5).

[0057] Figure 1c shows a parallel and series connection of stiffnesses ki, ki.stat and kni(u) for vibration isolation (quasi-zero-stiffness isolator) with an increase in the magnitude of the negative stiffness.

[0058] Figure 1c shows the series connection of the two spring elements 2, 3 according to Figure 1b, to which a further spring element 2a with a static stiffness ki.stat is connected in parallel.

[0059] In combination with this parallel static stiffness ki.stat, the nonlinear total stiffness kni.ser.tot(u) results according to equations (2) and (3).

[0060] To achieve the desired degree of isolation s at the operating point u*, the linear stiffness ki is adjusted according to equation (6).

[0061] It should be noted that the magnitude of the negative stiffness can be increased arbitrarily in this way. However, the theoretically infinitely high gain values ​​for a vanishing denominator (ki = kni(u*)) in equation (5) are irrelevant for a technical application in vibration isolation, since the overcompensation (s > 0) of the static stiffness ki.stat would result in an instability of the overall system (kni,ser,tot(u*) < 0). Alternative applications for energy recovery are conceivable in this case.

[0062] By specifically adjusting the series-connected spring elements 2, 3 with ki and kni(u) according to equation (6) it is possible to generate a non-linear stiffness kni ,ser (u) whose negative stiffness value is significantly larger than the corresponding stiffness value of the non-linear single spring element 3 (kni ,ser (U*) < knl(u) < 0).

[0063] Instead of the complex optimization of a sophisticated NeSt mechanism, the simple selection of a suitable linear stiffness element ki is used. This concept also allows for the subsequent strengthening of existing NeSt elements and their adaptation to different applications through the appropriate selection or adjustment of the linear stiffness ki.

[0064] Figure 2 shows a diagram in which stiffnesses k are plotted against the path u, with stiffness characteristics 100 to 104 being assigned to the above-mentioned stiffnesses k as follows:

[0065] Stiffness characteristic curve 100 kl.stat

[0066] Stiffness characteristic 101 knl(u)

[0067] Stiffness characteristic curve 102 ki

[0068] Stiffness characteristic curve 103 knl,ser(u)

[0069] Stiffness characteristic 104 knl,tot(u)

[0070] Stiffness characteristic curve 105 kni ,ser, tot(u)

[0071] In the diagram of Figure 3, loads L are plotted against the path u, with load characteristics 200 to 204 being assigned to the stiffnesses k mentioned above as follows:

[0072] Load characteristic curve 200 ki.stat

[0073] Load characteristic curve 201 kni(u)

[0074] Load characteristic 202 ki

[0075] Load characteristic 203 kni,ser (u)

[0076] Load characteristic curve 204 kni,tot(u)

[0077] Load characteristic 205 kni,ser, tot(u)

[0078] The reference symbol OP denotes the operating point.

[0079] Figures 4a-4g show schematic representations of embodiments of the invention for nonlinear stiffness units 10 with enhanced negative stiffness. The stiffness units 10 are also referred to as negative stiffness mechanisms (NeSt mechanisms). The embodiments in Figures 4a-4f show translational stiffness units 10. However, these embodiments can also be converted into corresponding rotational elements. An example of this is shown in Figure 4g.

[0080] A first embodiment of the stiffness unit 10 in Figure 4a comprises an input element 11, two slides 12, 12a, two first spring elements 13, levers 14 with lever axes 14a, 14b, an output element 15 and a second spring element 16.

[0081] The input element 11 is also referred to as the input side of the stiffness unit 10, while the output element 15 is also called an output side of the stiffness unit 10.

[0082] The input element 11 and the output element 15 are connected via a coupling unit KE, which connects the first slide 12, mounted on the first spring elements 13, to the second slide 12a, which is in contact with the second spring element 16. In this first embodiment, the coupling unit KE is formed by the stiffness unit 10 from the levers 14.

[0083] The entrance element 11 has a base wall 11a that extends in the direction of the path u. The base wall 11a is provided at both ends with a side wall 11b. The side walls extend downwards at right angles to the u-direction and define an interior space 11c between themselves and the underside of the base wall 11a.

[0084] The first slide 12 is arranged to be displaceable in the u-direction within the interior space 11c of the entrance element 11. A first spring element 13 is located between each end face of the first slide 12 and the opposite side wall 11b. The first spring elements 13 are pre-tensioned such that the first slide 12 is positioned centrally within the interior space 11c.

[0085] The first slide 12 is pivotally connected to the levers 14 on a respective outer side in a first lever axis 14a.

[0086] In the second lever axis 14b of the levers 14, these are pivotally connected to the outer sides of a second slide 12a. The second slide 12a is arranged in an interior space 15b of the output element 15 between two side walls 15a of the output element 15, displaceable in a z-coordinate perpendicular to the u-direction and perpendicular to the direction of movement of the first slide 12. The second spring element 16 is installed between a bottom surface of the second slide 12a and a bottom wall 15c of the output element 15.

[0087] The NeSt element to be reinforced is achieved by the compression and relaxation of the second spring element 16 in the output element 15 by the lever(s) 14. The increase in the resulting nonlinear stiffness is achieved by the first slide 12, which is elastically mounted in the input element 11 by the first spring elements 13.

[0088] A variant of the first embodiment of the stiffness unit 10 according to Figure 4a is shown in Figure 4b.

[0089] The variant according to Figure 4b, like the first embodiment, has an input element 11, but only one first slide 12 profiled on its underside, two first spring elements 13, an output element 15 and a second spring element 16.

[0090] The input element 11 is also referred to as the input side of the stiffness unit 10, while the output element 15 is also called an output side of the stiffness unit 10.

[0091] In contrast to the first embodiment, this variant does not have levers 14, but a rolling mechanism which is formed from a contour 17 of the profiled underside of the first slide 12 and a rolling element 18 of the output element 15.

[0092] The input element 11 and the output element 15 are connected via the coupling unit KE, which connects the first slide 12, supported by the first spring elements 13, to the second slide 12a, which is in contact with the second spring element 16. In this variant of the first embodiment, the coupling unit KE is formed by the stiffness unit 10 from the rolling mechanism with contour 17 and the rolling element 18.

[0093] The rolling element 18 is a sphere that is in contact with the second spring element 16 in the interior 15b of the output element 15 and is rotatably and displaceably arranged within it in the z-coordinate. The rolling element 18 protrudes upwards from the interior 15b through an upper opening in the interior 15b and contacts the contour 17 of the first slide 12. The spring force of the second spring element 16 presses the rolling element 18 against the contour 17.

[0094] The stiffness of the NeSt element to be reinforced is achieved by the compression and relaxation of the second spring element 16 by the rolling element 18, which rolls on the contour 7 of the profiled first slide 12. The increase in the resulting nonlinear stiffness is achieved by the first slide 12 being elastically mounted with the first spring elements 13 in the interior 11c of the input element 11.

[0095] Figure 4c shows a second embodiment of the stiffness unit 10.

[0096] The second embodiment according to Figure 4c has, like the first embodiment, an input element 11, but only a first slide 12, an output element 15 and a beam element 20.

[0097] Here too, the input element 11 is also referred to as the input side of the stiffness unit 10, while the output element 15 is also called an output side of the stiffness unit 10.

[0098] The first slide 12 is arranged to be displaceable in the interior 11c of the entrance element 11 with the two first spring elements 13, as in the first embodiment according to Figure 4a and the variant according to Figure 4b.

[0099] The input element 11 and the output element 15 are connected via the coupling unit KE, which connects the first slide 12, supported by the first spring elements 13, to the output element 15, which is designed as a slide. In this second embodiment, the coupling unit KE is formed from the beam element 20 of the stiffness unit 10.

[0100] From the underside of the input element 11, a first end of the bending beam 20 is attached to the input element 11. The beam element 20 extends downwards—here with two bulges—its imaginary centerline running perpendicular to the direction of displacement u. The other end of the beam element 20 is attached to the output element 15. The output element 15 can, for example, also be a type of slide. The NeSt element to be reinforced is achieved by compressing and buckling the beam element 20. The increase in the resulting nonlinear stiffness is achieved by the first slide 12, which is elastically supported by the first spring elements 13.

[0101] Figure 4d shows a variant of the second embodiment according to Figure 4c.

[0102] The variant according to Figure 4d comprises an input element 11, an output element 15, a slide 19 and a beam element 20.

[0103] The input element 11, for example, is a sled that is guided in a longitudinally displaceable manner in the direction of the path u.

[0104] The input element 11 and the output element 15 are connected via the coupling unit KE, which connects the input element 11, designed as a slide, to the output element 15, also designed as a slide. In this variant of the second embodiment, the coupling unit KE is formed from the beam element 20 of the stiffness unit 10.

[0105] The beam element 20 connects the input element 11 and the output element 15. The carriage 19 is slidably guided on the beam element 20 in the direction of an imaginary longitudinal axis of the beam element 20. The carriage 19 divides the beam element 20 into a part with a bulge 20a and a part designed as a rod 21. The part of the beam element 20 with the bulge 20a is located between the input element 11 and the carriage 19, with the section of the beam element 20 between the carriage 19 and the output element 15 being the rod 21.

[0106] Beam element 20 is shown here as an example of a bending beam designed as a leaf spring.

[0107] The NeSt element to be reinforced is realized by compressing and buckling the beam element 20. The increase in the resulting nonlinear stiffness is achieved by the slide 19, which is elastically mounted to the beam element 20.

[0108] The spring elements shown in Figures 4a to 4c can also be replaced by alternative spring concepts. Figure 4e shows a third embodiment of the stiffness unit 10.

[0109] The third embodiment comprises an input element 11, an output element 15, a slide 19, a beam element 20 and a rod 21.

[0110] The input element 11 and the output element 15 are connected via the coupling unit KE, which connects the input element 11, designed as a slide, to the output element 15, also designed as a slide. In this variant of the second embodiment, the coupling unit KE is formed from the beam element 20 of the stiffness unit 10.

[0111] The beam element 20 is connected at one end to the input element 11 and at the other end to a slide 19. The slide 19, in turn, is supported on the output element 15 via a rod 21.

[0112] The NeSt element to be reinforced is realized by compressing and buckling the beam element 20. The increase in the resulting nonlinear stiffness is achieved by the slide 19, which is elastically mounted to the rod 21 designed as a bending beam.

[0113] The NeSt element to be reinforced is realized by compressing and buckling the beam element 20. The increase in the resulting nonlinear stiffness is achieved by the slide 19, which is elastically mounted to the rod 21 designed as a bending beam.

[0114] Figure 4f shows a variant of the third embodiment of the stiffness unit 10 according to Figure 4e.

[0115] This variant is constructed like the third embodiment, except that the beam element 20 is present three times.

[0116] The NeSt element to be reinforced is achieved by compressing and buckling the beam elements 20. The resulting nonlinear stiffness is increased by the slide 19, which is elastically supported by the rod 21 designed as a bending beam.

[0117] Figure 4g shows a fourth embodiment of the stiffness unit 10 in radial form with an axis 10a. The stiffness unit 10 comprises a circular input element 11, a similarly circular output element 15, beam elements 20 and rods 21, and a hub 22.

[0118] The circular input element 11, the circular output element 15, and the hub 22 are arranged coaxially with respect to the axis 10a of the stiffness unit 10. The circular input element 11 is connected to the hub 22 via the radially arranged beam elements 20. Similarly, the bars 21 connect the hub 22 and the circular output element 15. The beam elements 20 and the bars 21 are arranged in pairs adjacent to each other in the axial direction.

[0119] The NeSt element to be reinforced is achieved by compressing and buckling the beam elements 20. The resulting nonlinear stiffness is increased by the hub 4, which is elastically supported by the bars 21 designed as bending beams. The symmetrical arrangement of the beam elements 20 and bars 21 also leads to a compensation of the radial forces between opposing elements.

[0120] The exemplary stiffness units 10 shown in Figures 4a to 4g are, as respective functional units, components of decoupling devices 50, which are described below.

[0121] These decoupling devices 50 each have two opposing NeSt mechanisms or stiffness units 10, 10' for compensating undesired force components. In addition to the translational concepts shown, corresponding rotational designs are also conceivable.

[0122] Figure 5a shows a schematic perspective view of a first embodiment of a decoupling device 50.

[0123] Figure 5b shows a sectional view of the decoupling device 50 according to Figure 5a in a uz-plane.

[0124] Figure 5c shows a sectional view of the decoupling device 50 according to Figure 5a in a yz plane.

[0125] The decoupling device 50 comprises two stiffness units 10, 10'.

[0126] Each stiffness unit 10, 10' has the following: a cuboid input element 11, two output elements 15 as a respective output slide 23 (corresponding to the output element 15 of Figure 4a), a second slide 24 (corresponding to the second slide 12a of Figure 4a), a first slide 25 (corresponding to the first slide 12 of Figure 4a), first spring elements 27 (corresponding to the second spring element 16 of Figure 4a), second spring elements 28, third spring elements 29 (corresponding to the first spring element 13 of Figure 4a), two adjusting elements ST, linear guides 30, and a coupling unit KE, which here consists of at least one lever 26 (corresponding to the lever 4 of Figure 4a).

[0127] First, the first stiffness unit 10 is described.

[0128] The cuboid entrance element 11 consists of two parallel wide base walls 11a and two parallel narrow side walls 11b. These walls 11a and 11b enclose an interior space 11d in which two NeSt mechanisms or stiffness units 10 opposite each other in the z-direction are arranged.

[0129] Each coupling unit KE of the two stiffness units 10, 10' is constructed with a lever mechanism with levers 26 similar to the first embodiment of the stiffness unit 10 according to Figure 4a.

[0130] The first slide 25 is mounted here via third spring elements 29 on a respective inner side of a side wall 11 b centrally in the middle of the input element 11 and is guided in the z-direction by a respective linear guide 30 also on a respective inner side of a base wall 11a of the input element 11.

[0131] The output slide 23 forms the output element 15 as the output side and is supported on both sides in the u-direction by a second spring element 28 with a respective inner side wall 11b of the input element 11. The output slide 23 is slidably mounted in the z-direction relative to the two base walls 11a of the input element 11 by a respective linear guide 30.

[0132] An opening 23a of the output slide 23 faces the center of the interior 11d of the input element 11 and forms a receptacle for the second slide 24 and the first spring element 27. The first spring element 27 is arranged between the second slide 24 and a base 23b of the opening 23a and is in contact with the adjusting element ST, here a screw. The adjusting element ST serves to adjust the spring tension of the first spring element 27, which can, for example, also consist of several individual spring elements.

[0133] The second slide 24 is slidably guided in the z-direction within the opening 23a. The adjusting element ST extends from the base 23b of the opening 23a through the output slide 23 to the outside in the z-direction and can be rotated from the outside, e.g., by means of a tool, to adjust the z-position of the second slide 24 and to tension the first spring element 27 in an internal thread of the output slide 23. Of course, other adjusting mechanisms are also possible.

[0134] The levers 26 are articulated in a first lever axis 26a to the first slide 25 and in a second lever axis 26b to the second slide 24.

[0135] The second stiffness unit 10' is constructed in the same way as the first stiffness unit 10 described above and is rotated by 180° around the u-coordinate in the interior 11d of the entrance element 11 and, like the first stiffness unit 10, is mounted on the inner sides of the side walls 11b via second spring elements 28 and third spring elements 29 and is guided slidably on the inner sides of the base walls 11a of the entrance element 11 by means of linear guides 30.

[0136] The levers 26 of the second stiffness unit 10' are articulated in a first lever axis 26a on the second slide 24 opposite the levers 26 of the first stiffness unit 10.

[0137] The stiffness of the NeSt element to be reinforced is achieved by the compression and relaxation of the first spring elements 27 by the levers 26. The resulting nonlinear stiffness is increased by the third spring elements 29. The preload of the first spring elements 27 can be varied via the adjusting elements ST (e.g., screws). The parallel stiffness ki.stat for absorbing the static load is achieved by the second spring elements 28. The carriages 23 and 25 are supported by the linear guides 30.

[0138] Figure 6a shows a schematic perspective view of a second embodiment of a decoupling device 50. Figure 6b shows a sectional view of the decoupling device 50 according to Figure 6a in a uz-plane.

[0139] Figure 6c shows a sectional view of the decoupling device 50 according to Figure 6a in a yz plane.

[0140] The decoupling device 50 of the second embodiment of the decoupling device 50 comprises two stiffness units 10, 10'.

[0141] Each stiffness unit 10, 10' comprises the following: a cuboid input element 11, two output elements 15 as a respective output slide 23 (corresponding to the output element 15 of Figure 4b), a second slide 24 (corresponding to the second slide 12a of Figure 4b), a first slide 25 (corresponding to the first slide 12 of Figure 4b), first spring elements 27 (corresponding to the second spring element 16 of Figure 4a), second spring elements 28, third spring elements 29 (corresponding to the first spring element 13 of Figure 4a), two adjusting elements ST, linear guides 30, and a coupling unit KE, which here consists of a rolling mechanism with a contour 17 and a rolling element 18 (corresponding to the contour 17 and the rolling element 18 of Figure 4b).

[0142] First, the first stiffness unit 10 is described.

[0143] The cuboid-shaped input element 11 is constructed and described in the same way as the input element 11 of the first embodiment according to Figures 5a, 5b, 5c.

[0144] The first slide 25 is attached here like the first slide 25 of the first embodiment according to Figure 5a, 5b with the third spring elements 29 and is mounted via linear guides 30 and described there.

[0145] In contrast to the first embodiment according to Figures 5a, 5b, 5c, the first slide 25 has opposite contours 17 of the coupling unit KE.

[0146] The output slide 23 with its opening 23a, the second slide 24, and the first spring element 27 is constructed and mounted as described in the first embodiment. In contrast to the first embodiment, here, instead of levers, the rolling element 18 of the rolling mechanism of the coupling unit KE is rotatably arranged in the second slide 24. The rolling element 18 is in contact with the contour 17.

[0147] The second stiffness unit 10' is constructed in the same way as the first stiffness unit 10 described above and is rotated by 180° around the u-coordinate in the interior 11 d of the entrance element 11 via second spring elements 28 and third spring elements 29 on the inner sides of the side walls 11 b and is guided slidably by means of linear guides 30 on the inner sides of the base walls 11a of the entrance element 11.

[0148] The rolling element 18 of the second stiffness unit 10' is in contact with a further contour 17 on the first slide 25 opposite the contour 17, which interacts with the rolling element of the first stiffness unit 10.

[0149] Instead of one rolling element 18, two or more rolling elements 18 can also be used.

[0150] The stiffness of the NeSt element to be reinforced is achieved by the compression and relaxation of the first spring elements 27 by the rolling elements 18, which roll on the respective contour 17 of the first slide 25, which is profiled with the contours 17. The resulting nonlinear stiffness is increased by the third spring elements 29. The preload of the first spring elements 27 can be varied via the adjusting elements ST (e.g., screws). The parallel stiffness ki.stat for absorbing the static load is achieved by the second spring elements 28. The slides 23 and 25 are supported by the linear guides 30.

[0151] Figure 7a shows a schematic perspective view of a third embodiment of a decoupling device 50.

[0152] Figure 7b shows a sectional view of the decoupling device 50 according to Figure 7a in a uz-plane.

[0153] Figure 7c shows a sectional view of the decoupling device 50 according to Figure 7a in a yz plane.

[0154] The decoupling device 50 of the third embodiment of the decoupling device 50 comprises two stiffness units 10, 10'.

[0155] Each stiffness unit 10, 10' has the following: a cuboid input element 11, two output elements 15 as a respective output slide 23 (corresponding to the output element 15 of Figure 4c), a first slide 25 (corresponding to the first slide 12 of Figure 4c), second spring elements 28, third spring elements 29 (corresponding to the first spring elements 13 of Figure 4c), two adjustment elements ST, linear guides 30, and a coupling unit KE, which here consists of a beam element 20 (corresponding to the beam element 20 of Figure 4c).

[0156] The cuboid-shaped input element 11 is constructed and described in the same way as the input element 11 of the first and second embodiments according to Figures 5a, 5b, 5c and 6a, 6b, 6c respectively.

[0157] The first slide 25 is attached here like the first slide 25 of the first embodiment according to Figure 5a, 5b with the first spring elements 25a and is mounted via linear guides 30 and described there.

[0158] In contrast to the first and second embodiments, the first sled 25 has fastenings on both sides for a respective inner end of the beam element 20.

[0159] The output slide 23 forms the output element 15 as the output side and is supported on both sides in the u-direction by a second spring element 28 with a respective inner side wall 11b of the input element 11. The output slide 23 is slidably mounted in the z-direction relative to the two base walls 11a of the input element 11 by a respective linear guide 30.

[0160] Each of the two stiffness units 10, 10' is constructed with the beam element 20 in a similar manner to the second embodiment of the stiffness unit 10 according to Figure 4d.

[0161] One end of the beam element 20 is fixed in the opening 23a of the output slide 23 and interacts with the adjusting element 29. The beam element 20 extends into the interior 11d of the input element 11, its imaginary center line running perpendicular to the direction of travel u in the z-direction. The other end of the beam element 20 is fixed in / to the first slide 25.

[0162] The second stiffness unit 10' is constructed in the same way as the first stiffness unit 10 described above and is rotated by 180° around the u-coordinate in the interior 11 d of the entrance element 11 via second spring elements 28 on the inner sides of the side walls 11 b and guided slidably by means of linear guides 30 on the inner sides of the base walls 11a of the entrance element 11.

[0163] The second end of the beam element 20 of the second stiffness unit 10' is attached to the first slide 25 opposite the second end of the beam element 20 of the first stiffness unit 10.

[0164] The NeSt element to be reinforced is achieved by compressing and buckling the beam elements 20. The resulting nonlinear stiffness is increased by the third spring elements 29. The preload of the beam elements 20 can be varied via the adjusting elements ST (e.g., screws). The parallel stiffness ki.stat for absorbing the static load is achieved by the second spring elements 28. The carriages 23 and 25 are supported by the linear guides 30.

[0165] The invention is modifiable within the scope of the attached claims.

[0166] Reference symbol list

[0167] Spring arrangement T, 1”, T” First spring element 2, 2a Second spring element 3 Frame 4 Plate 5

[0168] Stiffness unit 10, 10' axis 10a

[0169] Input element 11 Base wall 11a Side wall 11b Inside 11c Interior 11d First slide 12 Second slide 12a First spring element 13 Lever 14 Lever axle 4a, 14b Output element 15 Side wall 15a Interior 15b Bottom wall 15c Second spring element 16 Contour 17 Rolling element 18 Slide 19 Beam element 20 Rod 21 Hub 22 Output slide 23 Opening 23a Bottom 23b Second slide 24 First slide 25 Lever 26 Lever axle 26a, 26b First spring element 27 Second spring element 28

[0170] Third spring element 29

[0171] Linear guide 30 Decoupling device 50

[0172] Stiffness characteristic curve 100-105

[0173] Load characteristic curve 200-205

[0174] Spring stiffness k Coupling unit KE Load L

[0175] Operating point OP setting element ST path u coordinate y, z

Claims

Claims 1. Decoupling device (50) for vibrating systems, comprising at least one nonlinear stiffness element with negative stiffness kni(u) having at least one first spring element (27), and at least one linear stiffness element with positive stiffness ki.stat connected in parallel thereto, having at least one second spring element (28), characterized in that the at least one nonlinear stiffness element with negative stiffness kni(u) is connected in series with at least one further stiffness element with a linear stiffness Ki, having at least one third spring element (29), and that this series connection is connected in parallel with the at least one linear stiffness element with positive stiffness ki.stat, wherein a quasi-zero-stiffness isolator with an increase in the magnitude of the negative stiffness kni.ser.tot(u) is formed.

2. Decoupling device (50) according to claim 1, characterized in that the decoupling device (50) has at least one stiffness unit (10, 10') comprising an input element (11), at least one output element (15) comprising at least one first spring element (27), at least one second spring element (28) and at least one third spring element (29), a first slide (25) and a second slide (24) and linear guides (30), wherein the second slide (24) is slidably guided in / on the output element (15).

3. Decoupling device (50) according to claim 2, characterized in that the first slide (25) is connected to the input element (11) via the at least one third spring element (29) and is coupled to the second slide (24) via a coupling unit (KE), wherein the at least one first spring element (27) is arranged between the second slide (24) and the output element (15), and wherein the at least one output element (15) is connected to the input element (11) via the at least one second spring element (28).

4. Decoupling device (50) according to claim 3, characterized in that the coupling unit (KE) has at least one lever (26) which is articulated to the first slide (25) with a first lever axis (26a) and to the second slide (24) with a second lever axis (26b).

5. Decoupling device (50) according to claim 3, characterized in that the coupling unit (KE) has a rolling mechanism with a contour (17) and a rolling element (18).

6. Decoupling device (50) according to claim 5, characterized in that the contour (17) of the rolling mechanism is arranged on the first slide (25) and the rolling element (18) on the second slide (24), or that the contour (17) of the rolling mechanism is arranged on the second slide (25) and the rolling element (18) on the first slide (24).

7. Decoupling device (50) according to claim 6, characterized in that the rolling element (18) of the rolling mechanism is a rotatably mounted ball.

8. Decoupling device (50) according to claim 3, characterized in that the coupling unit (KE) has at least one beam element (20, 21 ).

9. Decoupling device (50) according to one of claims 2 to 8, characterized in that the decoupling device (50) has a first stiffness unit (10) and a second stiffness unit (10') with the same structure, wherein the two stiffness units are arranged rotated by 180° in an interior space (11 d) of the input element (11 ).

10. Decoupling device (50) according to claim 9, characterized in that the two stiffness units (10, 10') have a common first slide (25) which is connected to the input element (11) via the at least one first spring element (29).

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