Torsional vibration-insulating coupling

Abstract

A torsional vibration isolation type coupling (1) having a torsional axis (1a), comprising a first coupling member (2) as an input side of the coupling (1), a second coupling member (3) as an output side of the coupling (1), and a damping unit (4). In the torsional vibration isolation type coupling (1), the damping unit (4) has at least one spring assembly (10, 10') formed as a non-linear spring assembly (10, 10') having a degressive spring characteristic line (13). The torsional vibration isolation type coupling (1) is characterized by this.

Description

[Technical Field]

[0001] The present invention relates to a torsional vibration-insulating coupling as described in the premise of claim 1.

[0002] Torsional vibration-insulating couplings are used, for example, in stationary internal combustion engines.

[0003] These stationary internal combustion engines are also known as generating sets, used in combination with generators to produce electrical energy. Their applications range from emergency power supply for ship engines to general electrical energy provision. In this case, the engine is typically powered by diesel fuel or natural gas. Another application is in piston compressors.

[0004] Unlike active passenger car or truck engines, which are exposed to variable rotational speeds and frequently changing loads during operation, this application is characterized primarily by a fixed operating point with a constant rotational speed and a nearly constant load moment.

[0005] For this reason, current prior art primarily assumes torsional vibration isolation couplings having linear spring characteristic curves. In this case, the torsional spring stiffness of the torsional vibration isolation is usually set based on the driving moment to be transmitted.

[0006] In this case, two requirements are imposed on the torsional vibration isolation coupling.

[0007] One requirement is the transmission of static drive moment. The primary role of such stationary-acting applications is to provide a nearly constant torsional moment at a given rotational speed. This torsional moment acts on the powertrain as a static load and must be transmitted by the coupling. Therefore, the torsional stiffness of the coupling must be sufficiently high to transmit the static torsional moment.

[0008] Another requirement is isolation of torsional moment fluctuations, that is, broadband vibration isolation.

[0009] Regarding the powertrain dynamics during engine operation, the coupling must isolate the components coupled to each other via the powertrain (e.g., the engine and generator or the ship's propeller) from the effects of faults (e.g., fluctuations in drive moment or load moment). Therefore, to achieve the broadest possible vibration isolation of the coupling, a correspondingly low torsional stiffness of the coupling is required.

[0010] These two requirements result in a trade-off regarding the optimal torsional stiffness of the coupling. That is, the torsional stiffness must be sufficiently high to transmit static torsional moments, but at the same time, it must be as low as possible to isolate disruptive drive vibrations.

[0011] Since the primary role of a powertrain is to transmit static torsional moments, coupling stiffness is typically chosen to be correspondingly high. Therefore, a drawback of powertrains is the need to design additional components (e.g., torsional vibration dampers) or components for enhanced torsional vibration to dampen undesirable torsional vibrations. This, in part, leads to additional costs and, usually, an increase in the required configuration space, based on the increased overall length of the train. Furthermore, the damping effect of additional components is typically limited to a restricted frequency or rotational speed range.

[0012] Therefore, the fundamental problem of the present invention is to provide a torsion vibration isolation coupling that satisfies both requirements, namely, the transmission of static torsional moments and broadband isolation of the powertrain, and furthermore, no longer has, or at least significantly reduces, the disadvantages of increased required configuration space and limitations on the frequency range or rotational speed range.

[0013] This problem is solved by a torsional vibration-insulating coupling having the features of claim 1.

[0014] Accordingly, a torsion vibration-insulating coupling having a torsional axis comprises a first coupling member as the input side of the coupling, a second coupling member as the output side of the coupling, and a damping unit. The damping unit has at least one spring assembly formed as a nonlinear spring assembly having a degressive spring characteristic curve.

[0015] Torsional vibration-isolated couplings with damping units having nonlinear spring assemblies with degressive spring characteristic curves offer a particular advantage in stationary-actuated powertrain applications: they enable static moment transmission until the operating point is reached.

[0016] Unlike the zero-rigidity concept, which achieves vibration isolation solely through extremely low rigidity and consequently makes static load transmission impossible, the torsional vibration isolation coupling according to the present invention provides the possibility of static moment transmission in combination with vibration isolation at the operating point. To this end, the concept utilizes the nonlinearity of the degressive spring characteristic curve of the spring assembly of the damping unit.

[0017] In one configuration, at least one nonlinear spring assembly has a positive spring stiffness k PSE A spring element having at least one such element and a negative spring stiffness k NSE It has at least one spring element having [a certain characteristic]. This allows for an advantageously simple and compact structure.

[0018] Further configurations indicate that a first coupling member, acting as the input side of the coupling, and a second coupling member, acting as the output side of the coupling, are connected to at least one nonlinear spring assembly via a damping unit.

[0019] Compared with a coupling having a linear spring characteristic curve, the torsional vibration isolation type coupling according to the present invention advantageously enables broadband torsional vibration isolation during stationary operation of the application while transmitting a static driving moment. Thus, the proposed concept provides the advantages of improved power train dynamics without additional damping components being required.

[0020] In another configuration, it is specified that at least one non-linear spring assembly forms an interface in the form of a plate for bidirectional force and motion transmission between the plate and at least one spring assembly cooperating with the first coupling member of the coupling. This advantageously enables a simple configuration.

[0021] A further configuration specifies that the plate is connected to the second coupling member of the coupling via a connecting rod. The connecting rod advantageously has a simple configuration.

[0022] If the plate is guided displaceably in the translational direction u in a receiving chamber provided in the first coupling member of the coupling, and the translational direction u extends in the tangential direction of the first coupling member of the coupling, a compact structure is advantageously possible.

[0023] At least one spring element having a negative spring stiffness k of at least one spring assembly NSE comprises two spring elements arranged in pairs and inclined with respect to the translational direction u, with the first ends of both spring elements being pivotally attached to the first coupling member of the coupling at a distance from each other, and the other ends of both spring elements being grouped together at a common pivot point and pivotally attached to the plate or to an intermediate plate cooperating with the plate. This enables a structure having a negative stiffness to be obtained with simple spring elements.

[0024] In this case, the spacing between the first ends of the spring element is specified to extend in a direction perpendicular to the translational direction u. The advantage of this case is its simple structure.

[0025] When the intermediate plate is positioned at the end face of the plate without being bonded to it, torsional vibration isolation can thus be advantageously achieved with a torsional vibration isolation coupling, both for positive and negative static moments T.

[0026] For a compact and simple structure, it is advantageous for the first coupling member and the second coupling member of the coupling to be arranged coaxially with each other.

[0027] In one configuration, a torsional vibration isolation coupling is used for powertrains in stationary applications, particularly for powertrains of stationary internal combustion engines. This advantageously enables broadband torsional vibration isolation of the powertrain.

[0028] This invention envisions a concept for a powertrain with a degressive spring characteristic curve for stationary applications. Unlike prior art, this concept satisfies both the requirements for static torsional moment transmission and broadband vibration isolation without additional functional units. By using a conventional coupling in combination with a negative stiffness element, a nonlinear spring characteristic curve is consequently obtained. In this case, the extremely low spring stiffness at the engine's fixed operating point enables nearly complete vibration isolation of the coupled components.

[0029] Further advantageous configurations of the present invention can be found in the dependent claims.

[0030] Several embodiments of the present invention are described below with reference to the accompanying drawings. The present invention is not limited to these embodiments. In particular, the individual features of the following embodiments can be used not only in these embodiments but also in other embodiments. [Brief explanation of the drawing]

[0031] [Figure 1] This is a schematic diagram of a first embodiment of the torsional vibration-insulating coupling according to the present invention in an unloaded state. [Figure 2] This is a schematic diagram of a first embodiment of the torsional vibration-insulating coupling according to the present invention in an unloaded state. [Figure 3] These are schematic diagrams of the first embodiment shown in Figures 1 and 2, under load conditions. [Figure 4] These are schematic diagrams of the first embodiment shown in Figures 1 and 2, under load conditions. [Figure 5] This is a schematic diagram of a second embodiment of the torsional vibration-insulating coupling according to the present invention in an unloaded state. [Figure 6] This is a schematic diagram of a second embodiment of the torsional vibration-insulating coupling according to the present invention in an unloaded state. [Figure 7] These are schematic diagrams of the second embodiment shown in Figures 5 and 6, under load conditions. [Figure 8] These are schematic diagrams of the second embodiment shown in Figures 5 and 6, under load conditions. [Figure 9] This is a symbolic diagram of a spring assembly. [Figure 10] This is a symbolic diagram of a spring assembly. [Figure 11] This is a diagram showing the spring characteristic curve of a spring assembly.

[0032] In the following, concepts such as "outside" or "inside" are based on the respective drawing planes, and concepts such as "axial direction" and "radial direction" are based on the torsional axis 1a of the torsional vibration isolation type coupling 1.

[0033] Figure 1 shows a schematic radial cross-sectional view of a first embodiment of the torsional vibration-insulating coupling 1 according to the present invention.

[0034] Figure 2 shows a schematic cross-sectional view of the torsional vibration-insulating coupling 1 according to the present invention, as shown in Figure 1, in an unloaded state.

[0035] The torsional vibration isolation type coupling 1 comprises a first coupling member 2 as the input side in the form of a disk having a central notch 2a, a second coupling member 3 as the output side in the form of a hub or cylindrical body, and a damping unit 4.

[0036] The first coupling member 2 and the second coupling member 3 are arranged concentrically with respect to the torsional axis 1a of the coupling 1. The second coupling member 3 is positioned within the notch 2a of the first coupling member 2.

[0037] In the annular region 2b of the first coupling member 2, the damping unit 4 is located within the housing chamber 5.

[0038] In the illustrated configuration, the housing chamber 5 is formed in a rectangular parallelepiped shape within the annular region of the first coupling member 2 and has inner side walls 5a and 5b that are positioned opposite each other in the tangential direction with respect to the torsional axis 1a. In the radial direction with respect to the torsional axis 1a, the housing chamber 5 is defined by an inner lower side wall 5c and an inner upper side wall 5d.

[0039] In the first embodiment, the damping unit 4 comprises a plate 6 and a spring assembly 10.

[0040] The plate 6 is guided within the containment chamber 5 by the lower wall 5c and the upper wall 5d so as to be displaceable in the translational direction u.

[0041] Between the plate 6 and the inner side wall 5a (located to the left of the plate 6 in the illustrated configuration), the spring assembly 10 connects the plate 6 to the inner side wall 5a of the housing chamber 5 of the first coupling member 2.

[0042] The spring assembly 10 has a positive spring stiffness k PSE A spring element 8 having a negative spring stiffness kNSE is formed as one non-linear spring assembly 10 having a spring element 9 with a positive spring stiffness k PSE a spring element 8 having a spring stiffness k NSE and a spring element 9 having a negative spring stiffness k are arranged in parallel connection.

[0043] The spring element 8 having a positive spring stiffness k PSE is pivotally attached to the inner side wall 5a of the accommodation chamber 5 of the first coupling member 2 at the first spring end, and thus is connected to the first coupling member 2.

[0044] The spring element 8 having a positive spring stiffness k PSE The other spring end of the spring element 8 is pivotally attached to the plate 6.

[0045] The spring element 9 having a negative spring stiffness k NSE is realized by two spring elements 9a, 9b arranged in pairs and inclined with respect to the translational direction u. The first ends of these spring elements 9a, 9b are pivotally attached to the inner side wall 5a of the accommodation chamber 5 of the first coupling member 2 at intervals from each other. The interval extends in a direction orthogonal to the translational direction u. In this case, both spring elements 9a, 9b are gathered at one common pivotal point at their other spring ends and are pivotally attached to the plate 6.

[0046] The connecting rod 7 connects the plate 6 and the second coupling member 3. Thus, the first coupling member 2 as the input side of the coupling 1 and the second coupling member 3 as the output side of the coupling 1 are connected to the spring assembly 10 via the damping unit 4 by the connecting rod 7 in the illustrated configuration.

[0047] Thus, in the illustrated configuration, plate 6 forms an interface for bidirectional force transmission between the first coupling member 2, the spring assembly 10, and the second coupling member 3 via the connecting rod 7. Furthermore, plate 6 forms the point of motion deflection of the motion of the connecting rod 7, which transmits the torsional motion of the second coupling member 3 to plate 6.

[0048] Figure 2 shows coupling 1 in an unloaded state, in which the moment T has a value of 0, and the twist angle φt between the first coupling member 2 and the second coupling member 3 around the torsional axis 1a also has a value of 0. In the unloaded state, all spring elements 8, 9a, and 9b of the spring assembly 10 are completely relaxed. In this case, plate 6 is located in the middle of the housing chamber 5, with the plate 6 being at an equal distance in the translational direction u from both inner side walls 5a and 5b of the housing chamber 5.

[0049] Figure 3 shows a schematic radial cross-sectional view of coupling 1, similar to that in Figure 1.

[0050] Figure 4 shows a schematic cross-sectional view of the torsional vibration-insulating coupling 1 according to the present invention, as shown in Figure 3, under load.

[0051] Figure 4 illustrates the coupling 1 at its operating point (WP, see also Figure 11) when it is loaded with a positive static moment T. In the illustrated example, the moment T acts counterclockwise around the torsional axis 1a. In this case, the torsional angle φt between the first coupling member 2 and the second coupling member 3 is not equal to 0.

[0052] The plate 6 is displaced toward the left inner side wall 5a of the housing chamber 5 of the first coupling member 2, in which case the spring elements 8, 9a, and 9b of the spring assembly 10 are compressed.

[0053] The illustrated spring assembly 10 makes it possible to transmit the static moment T without being affected by the direction of the static moment T. In this case, torsional vibration isolation by the torsional vibration isolation coupling 1 is achieved exclusively for static moments T acting in the positive direction (counterclockwise around the torsional axis 1a in the illustrated configuration). The concept of "positive direction" as used herein means that the moment T displaces the plate 6 of the damping unit 4 in the positive translational direction u, in which case the plate 6 compresses the spring elements 8, 9a, 9b toward the left inner side wall 5a of the housing chamber 5 of the first coupling member 2.

[0054] Figure 5 shows a schematic radial cross-sectional view of coupling 1, similar to that in Figure 1.

[0055] Figure 6 shows a schematic cross-sectional view of a second embodiment of the torsional vibration-insulating coupling 1 according to the present invention in an unloaded state (T=0).

[0056] Unlike the first embodiment shown in Figure 2, the damping unit 4 of the coupling 1 has two nonlinear spring assemblies 10, 10', which are arranged within the housing chamber 5 of the first coupling member 2 in a mirror-image symmetrical manner with respect to the radial virtual center line of the plate 6.

[0057] In a further difference from the first embodiment, the spring elements 8, 9a, and 9b of the first spring assembly 10 and the spring elements 8', 9'a, and 9'b of the second spring assembly 10', which is arranged mirror-symmetrically with respect to the first spring assembly 10, are pivotally attached to the intermediate plates 6c and 6d at their other ends, respectively. Thus, in this case, the nonlinear damping unit 4 has positive stiffness (K PSE Each of the spring elements 8,8' has a negative stiffness (k NSE It has two parallel connections with spring elements 9,9' which have ).

[0058] The first intermediate plate 6c is positioned on the first end face 6a of plate 6, and the second intermediate plate 6d is positioned on the second end face 6b of plate 6. However, the intermediate plates 6c and 6d are not bonded to plate 6.

[0059] In the second embodiment of coupling 1, in the first load state, which is illustrated in Figure 8 at the operating point (WP) when a load is applied by a positive static moment T, the intermediate plate 6d remains in its unloaded position. This is because the intermediate plate 6d is not coupled to the plate 6, and the other intermediate plate 6c is pressed toward the spring assembly 10 by the plate 6, and the spring elements 8, 9a, and 9b are compressed toward the inner side wall 5a.

[0060] Thus, the second embodiment of the torsional vibration isolation type coupling 1 makes it possible to isolate torsional vibrations from both positive and negative static moments T.

[0061] Figures 9 and 10 show symbolic diagrams of the spring assemblies 10 and 10'.

[0062] Figures 9 and 10 schematically illustrate the concept for torsional vibration isolation of the torsional vibration isolation type coupling 1.

[0063] The first spring assembly 10 has a positive spring stiffness k PSE A spring element 8 having a negative spring stiffness k consisting of spring elements 9a and 9b NSE The spring assembly 10 comprises a spring element 9 having the same properties. As already described above, the spring assembly 10 is positioned between the first coupling member 2 and the plate 6.

[0064] Spring element 8(k PSE ),9a,9b(k NSE As a result of the parallel connection of ), the total spring stiffness k total The result is obtained, and the stiffness of this total spring stiffness is the stiffness of both spring elements 8(k PSE),9(k NSE This is obtained by summing the spring characteristic curves 11 and 12 of ), and is schematically shown in Figure 10. This will be further explained below in conjunction with Figure 11.

[0065] The above explanation refers to the spring element 8'(k PSE ),9'a,9'b(k NSE The same applies to the second spring assembly 10' which has the following features.

[0066] The corresponding spring characteristic curves are shown in Figure 11, which includes the spring characteristic curves of the spring assemblies 10 and 10'.

[0067] The X-axis of the diagram plots the twist angle φt between coupling members 2 and 3 in degrees. The Y-axis plots the moment T in Nm.

[0068] The diagram shows a positive stiffness k. PSE The spring characteristic curve 11 of the spring elements 8,8' having and the negative stiffness k NSE The spring characteristic curve 12 of the spring elements 9,9' having and the total stiffness k total The degressive spring characteristic curve 13 of the spring assembly 10,10' having the following characteristics is shown.

[0069] The operating point of coupling 1, where a moment T = 5000 Nm is transmitted and a static coupling twist is achieved at a twist angle of φt = 2°, is denoted by the symbol 14. At this operating point 14, positive stiffness k PSE The stiffness of the spring element 8,8' having a negative stiffness k NSE The spring elements 9,9' cancel each other out, and as a result, the degressive spring characteristic curve 13 of the coupling 1 that occurs at the operating point 14 has disappeared, resulting in a total stiffness (horizontal transition of the spring characteristic curve 13).

[0070] Outside of the operating point 14, the degressive spring characteristic curve 13 of coupling 1 has a moment T that increases as the displacement increases, that is, as the twist angle φt increases. This nonlinearity of the degressive spring characteristic curve 13 of coupling 1 allows for the transmission of moment T, which is a statically acting coupling moment, and also allows for the isolation of the powertrain from fluctuations in moment T that occur at the stationary operating point 14. [Explanation of symbols]

[0071] 1 Coupling 1a Torsion axis 2. First coupling member 2a notch 2b Circular region 3. Second coupling member 4 Damping Unit 5 Confinement Rooms 5a,5b side wall 5c lower wall 5d upper wall 6 plates 6a,6b end face 6c, 6d Intermediate Plate 7 Connecting rod 8,8' spring element 9,9a,9b;9',9'a,9'b spring element 10,10' Spring Assembly 11, 12, 13 Spring characteristic curves 14. Operating point k spring stiffness u translational direction T moment φt Helix angle

Claims

1. A torsion vibration-insulating coupling (1) having a torsional axis (1a), comprising a first coupling member (2) as the input side of the coupling (1), a second coupling member (3) as the output side of the coupling (1), and a damping unit (4), The damping unit (4) has at least one spring assembly (10, 10') formed as a nonlinear spring assembly (10, 10') having a degressive spring characteristic curve (13), The nonlinear at least one spring assembly (10, 10') comprises at least one spring element (8, 8') having a positive spring stiffness k PSE and at least one spring element (9, 9') having a negative spring stiffness k NSE. The first coupling member (2) as the input side of the coupling (1) and the second coupling member (3) as the output side of the coupling (1) are connected to the nonlinear at least one spring assembly (10, 10') via the damping unit (4). A torsion vibration-insulating coupling (1), characterized in that the at least one nonlinear spring assembly (10, 10') forms a plate (6) interface for bidirectional force and motion transmission between the plate (6) and the at least one spring assembly (10, 10') cooperating with the first coupling member (2) of the coupling (1).

2. The torsional vibration-insulating coupling (1) according to claim 1, characterized in that the plate (6) is connected to the second coupling member (3) of the coupling (1) via a connecting rod (7).

3. The torsional vibration-insulating coupling (1) according to claim 1 or 2, characterized in that the plate (6) is guided to be displaceable in the translational direction u within a housing chamber (5) provided in the first coupling member (2) of the coupling (1), and the translational direction u extends in the tangential direction of the first coupling member (2) of the coupling (1).

4. The negative spring stiffness k of the at least one spring assembly (10, 10') ＮＳＥ The torsional vibration-insulating coupling (1) according to claim 3, wherein the at least one spring element (9, 9') having a pair of spring elements (9a, 9b) arranged at an angle with respect to the translation direction u, the first ends of both spring elements (9a, 9b) being pivotally attached to the first coupling member (2) of the coupling (1) at a distance from each other, and the other ends of both spring elements (9a, 9b) being joined together at one common pivot point and pivotally attached to the plate (6), or pivotally attached to intermediate plates (6c, 6d) cooperating with the plate (6).

5. The torsional vibration insulating coupling (1) according to claim 4, characterized in that the distance between the first ends of the spring elements (9a, 9b) extends in a direction perpendicular to the translational direction u.

6. The torsional vibration insulating coupling (1) according to claim 4, characterized in that the intermediate plates (6c, 6d) are not bonded to the plate (6) but are arranged on the end faces (6a, 6b) of the plate (6).

7. The torsional vibration-insulating coupling (1) according to claim 1 or 2, characterized in that the first coupling member (2) and the second coupling member (3) of the coupling (1) are arranged coaxially with respect to each other.

8. The torsional vibration-insulating coupling (1) according to claim 1 or 2, characterized in that the coupling (1) is a coupling (1) for a powertrain used in stationary operation, particularly for a powertrain of a stationary internal combustion engine.

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