Torsional vibration control coupling

Abstract

A torsional vibration control coupling (1) having a rotation axis (1a) and comprising a first coupling part (2) as the input side of the coupling (1), a second coupling part (3) as the output side of the coupling (1) and a damping unit (4) is characterized in that the damping unit (4) comprises at least one spring arrangement (10, 10') that is designed as a nonlinear spring arrangement (10, 10') having a degressive load deflection curve.

Description

[0001] Torsional vibration-isolated coupling

[0002] The present invention relates to a torsional vibration-insulated coupling according to the preamble of claim 1.

[0003] Torsional vibration-isolated couplings are used, for example, for stationary combustion engines.

[0004] Such stationary combustion engines are also known as genset engines (generating sets), which are used in combination with a generator to generate electrical energy. Their applications range from emergency power supplies to providing electrical energy for ship propulsion. These engines are typically powered by diesel fuel or natural gas. Another application is piston compressors.

[0005] In contrast to mobile car or truck drives, which are subject to both variable speed and frequently changing loads during ferry operation, these applications are characterized by a predominantly stationary operating point with a constant speed and a nearly constant load torque.

[0006] The current state of the art predominantly provides for torsional vibration-isolated couplings with a linear spring characteristic. The torsional spring stiffness of the torsional vibration isolation is usually dimensioned based on the drive torque to be transmitted.

[0007] There are two requirements for a torsional vibration-isolated coupling.

[0008] First, the primary requirement is the transmission of the static drive torque. The main task of such stationary applications is to provide a nearly constant torque at a fixed speed. This torque acts as a static load on the drive train and must be transmitted by the coupling. The torsional stiffness of the coupling must therefore be sufficiently high to be able to transmit the static torque.

[0009] Secondly, isolation of torque fluctuations, i.e., broadband vibration isolation, is required. Regarding the drivetrain dynamics during engine operation, the coupling must decouple the components connected to each other via the drivetrain (e.g., engine and generator or ship's propeller) from disturbing influences (e.g., fluctuations in drive or load torque). To achieve the broadest possible vibration isolation of the coupling, a correspondingly low torsional stiffness of the coupling is required. [SEP]

[0010] These two requirements result in a conflict of objectives regarding the optimal torsional stiffness of the coupling: On the one hand, this should be sufficiently high to transmit the static torque but, at the same time, as low as possible to isolate disruptive drive vibrations.

[0011] Since the primary function of the drivetrain is to transmit static torque, the coupling stiffness is typically selected accordingly. A disadvantage of these drivetrains is that additional components (e.g., torsional vibration dampers) are required to dampen the unwanted torsional vibrations, or the components must be designed for the increased torsional vibrations. This incurs additional costs and typically also leads to increased installation space requirements due to the increased axial length of the entire drivetrain. Furthermore, the damping effect of these additional components is usually tailored to a limited frequency or speed range.

[0012] The invention is therefore based on the object of creating a torsional vibration-isolated coupling which meets the two requirements, namely the transmission of the static torque and, at the same time, the broadband isolation of the drive train, and, in addition, no longer has the disadvantages of an increased installation space requirement and a limited frequency or speed range, or at least significantly reduces them.

[0013] This object is achieved by a torsional vibration-insulated coupling having the features of claim 1.

[0014] Accordingly, a torsional vibration-isolated coupling with a rotational axis comprises 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 configured as a non-linear spring arrangement with a degressive spring characteristic. The torsional vibration-isolated coupling with the damping unit featuring a non-linear spring arrangement with a degressive spring characteristic has the particular advantage of enabling static torque transmission in drivetrains operating in stationary applications until the operating point is reached.

[0015] In contrast to zero-stiffness concepts, which achieve vibration isolation solely through negligible stiffness and thus do not allow static load transfer, the torsional vibration-isolated coupling according to the invention offers the possibility of static torque transmission combined with vibration isolation at the operating point. The concept utilizes the nonlinearity of the degressive spring characteristic of the damping unit's spring arrangement.

[0016] In one embodiment, the at least one nonlinear spring arrangement comprises at least one spring element with a positive spring stiffness kpsE and at least one spring element with a negative spring stiffness kNSE. This enables an advantageously simple and compact design.

[0017] A further embodiment provides that the first clutch part as the input side of the clutch and the second clutch part as the output side of the clutch are coupled to the at least one non-linear spring arrangement via the damping unit.

[0018] Compared to a clutch with a linear spring characteristic, the torsional vibration-isolated clutch according to the invention advantageously enables the transmission of the static drive torque while simultaneously providing broadband vibration isolation during stationary operation. Thus, the proposed concept benefits from improved drivetrain dynamics without the need for additional damping components.

[0019] In another embodiment, the at least one nonlinear spring arrangement forms an interface in the form of a plate between the at least one spring arrangement, which interacts with the plate and the first coupling part of the coupling, for bidirectional force and motion transmission. This enables an advantageously simple design.

[0020] Another embodiment provides that the plate is coupled to the second coupling part of the clutch via a connecting rod. The connecting rod is an advantageously simple design. If the plate is guided displaceably in a translation direction u in a receiving space of the first coupling part of the clutch, with the translation direction u running in a tangential direction of the first coupling part of the clutch, an advantageously compact design is possible.

[0021] It is advantageous if the at least one spring element of the at least one spring arrangement with the negative spring stiffness kNSE comprises two spring elements arranged in pairs and inclined to the translation direction u, wherein first ends of the two spring elements are articulated at a distance from one another on the first coupling part of the coupling, and the other ends of the two spring elements are joined at a common articulation point on the plate or on an intermediate plate that interacts with the plate. In this way, a structure with negative stiffness can be achieved with simple spring elements.

[0022] The distance between the first ends of the spring elements is intended to be perpendicular to the translation direction u. One advantage of this is a simple design.

[0023] If the intermediate plate is arranged on one end face of the plate without being connected to the plate, the torsional vibration-isolated coupling can advantageously enable torsional vibration isolation for both positive and negative static moments T.

[0024] For a compact and simple design, it is advantageous if the first coupling part of the coupling and the second coupling part of the coupling are arranged coaxially to each other.

[0025] In one embodiment, the torsional vibration-isolated coupling is a coupling of a drive train of a stationary application, in particular a drive train of a stationary internal combustion engine. This advantageously enables broadband vibration isolation of the drive train.

[0026] The present invention presents a concept with a degressive spring characteristic for drivetrains in stationary applications. In contrast to the prior art, this concept meets the requirements of both static torque transmission and broadband vibration isolation without the need for additional functional units. The use of a conventional coupling in combination with a negative stiffness element results in a nonlinear spring characteristic.

[0027] The vanishingly low spring stiffness at the stationary operating point of the engine enables almost complete vibration isolation of the connected components.

[0028] Further advantageous embodiments of the invention can be found in the subclaims.

[0029] 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. They show:

[0030] Figures 1 - 2: schematic representations of a first embodiment of a torsional vibration-isolated coupling according to the invention in an unloaded state;

[0031] Figures 3-4: schematic representations of the first embodiment according to Figures 1-2 in a loaded state;

[0032] Figures 5-6: schematic representations of a second embodiment of a torsional vibration-isolated coupling according to the invention in an unloaded state;

[0033] Figures 7-8: schematic representations of the second embodiment according to Figures 5-6 in a loaded state;

[0034] Figures 9-10 symbolic representations of spring arrangements; and

[0035] Figure 11 : a diagram with spring characteristics of a spring arrangement.

[0036] In the following, terms such as “outside” or “inside” refer to the respective drawing plane, and “axial” and “radial” refer to a rotational axis 1a of a torsional vibration-isolated coupling 1.

[0037] Figure 1 shows a schematic radial sectional view of a first embodiment of a torsional vibration-isolated coupling 1 according to the invention.

[0038] Figure 2 shows a schematic cross-section of the torsional vibration-isolated coupling 1 according to the invention shown in Figure 1 in an unloaded state. The torsional vibration-isolated coupling 1 comprises a first coupling part 2 as the input side in the form of a disc with a central recess 2a, a second coupling part 3 as the output side in the form of a hub or a circular cylinder, and a damping unit 4.

[0039] The first coupling part 2 and the second coupling part 3 are arranged concentrically to the rotational axis 1a of the coupling 1. The second coupling part 3 is arranged in the recess 2a of the first coupling part 2.

[0040] In a ring area 2b of the first coupling part 2, a damping unit 4 is arranged in a receiving space 5.

[0041] The receiving space 5 is formed in a cuboid shape into the ring area of ​​the first coupling part 2 and has inner side walls 5a and 5b that are opposite one another in the tangential direction relative to the rotation axis 1a. In the radial direction relative to the rotation axis 1a, the receiving space 5 is defined by an inner bottom wall 5c and an inner top wall 5d.

[0042] In this first embodiment, the damping unit 4 comprises a plate 6 and a spring arrangement 10.

[0043] The plate 6 is guided in the receiving space 5 by the bottom wall 5c and the ceiling wall 5d in a translation direction u.

[0044] Between the plate 6 and the one inner side wall 5a (here arranged on the left side of the plate 6), the spring arrangement 10 connects the plate 6 to the one inner side wall 5a of the receiving space 5 of the first coupling part 2.

[0045] The spring arrangement 10 is designed as a non-linear spring arrangement 10 with a spring element 8 with a positive spring stiffness kpsE and a spring element 9 with a negative spring stiffness kNSE. The spring element 8 with the positive spring stiffness kpsE and the spring element 9 with the negative spring stiffness kNSE are arranged in a parallel circuit.

[0046] The spring element 8 with the positive spring stiffness kpsE is articulated with a first spring end to the inner side wall 5a of the receiving space 5 of the first coupling part 2 and thus coupled to the first coupling part 2. The other spring end of the spring element 8 with the positive spring stiffness kpsE is articulated to the plate 6.

[0047] The spring element 9 with the negative spring stiffness kNSE is realized from two spring elements 9a and 9b arranged in pairs and inclined to the translation direction u. The first ends of the spring elements 9a, 9b are hinged at a distance from each other to the inner side wall 5a of the receiving space 5 of the first coupling part 2. This distance runs in a direction perpendicular to the translation direction u. The two spring elements 9a, 9b are hinged to the plate 6 with their other spring ends joined at a common articulation point.

[0048] A connecting rod 7 couples the plate 6 and the second clutch part 3. In this way, the first clutch part 2 as the input side of the clutch 1 and the second clutch part 3 as the output side of the clutch 1 are coupled here by the connecting rod 7 via the damping unit 4 to the spring arrangement 10.

[0049] In this way, the plate 6 forms an interface for the bidirectional force transmission between the first clutch part 2, the spring arrangement 10 and the second clutch part 3, here via the connecting rod 7. In addition, the plate 6 forms a movement deflection of the movement of the connecting rod 7, which transmits the rotational movement of the second clutch part 3 to the plate 6.

[0050] Figure 2 shows the coupling 1 in an unloaded state, in which a moment T has the value 0 and a twist angle <pt zwischen dem ersten Kupplungsteil 2 und dem zweiten Kupplungsteil 3 um die Drehachse 1 a ebenfalls den Wert 0 aufweist. In dem unbelasteten Zustand sind alle Federelemente 8, 9a, 9b der Federanordnung 10 vollständig entspannt. Dabei befindet sich die Platte 6 in der Mitte des Aufnahmeraums 5, in welcher sie zu beiden inneren Seitenwänden 5a, 5b des Aufnahmeraums 5 gleiche Abstände in Translationsrichtung u aufweist.

[0051] Figure 3 shows the coupling 1 as in Figure 1 in a schematic radial section. Figure 4 shows a schematic cross-section of the torsional vibration-isolated coupling 1 according to the invention according to Figure 3 in a loaded state.

[0052] Figure 4 shows an example of coupling 1 at an operating point (WP, see also Figure 11) under load by a positive static moment T. In the example shown, the moment T acts counterclockwise around the rotation axis 1a. The angle of rotation cpt between the first coupling part 2 and the second coupling part 3 is not equal to 0.

[0053] The plate 6 is displaced against the left inner side wall 5a of the receiving space 5 of the first coupling part 2, wherein the spring elements 8, 9a, 9b of the spring arrangement 10 are compressed.

[0054] The spring arrangement 10 shown enables the transmission of the static moment T regardless of its direction. The torsional vibration isolation by the torsional vibration-isolated coupling 1 is achieved exclusively for a static moment T acting in a positive direction (here counterclockwise around the rotational axis 1a). The term "positive direction" here means that the moment T causes a displacement of the plate 6 of the damping unit 4 in the positive translation direction u, whereby the plate 6 compresses the spring elements 8, 9a, 9b against the left inner side wall 5a of the receiving space 5 of the first coupling part 2.

[0055] Figure 5 shows the coupling 1 as in Figure 1 in a schematic radial section.

[0056] Figure 6 shows a schematic cross section of a second embodiment of the torsional vibration-isolated coupling 1 according to the invention in an unloaded state (T=0).

[0057] In contrast to the first embodiment according to Figure 2, the damping unit 4 of the coupling 1 has two non-linear spring arrangements 10 and 10', which are arranged in mirror image to an imaginary radial center line of the plate 6 in the receiving space 5 of the first coupling part 2.

[0058] In a further difference from the first embodiment, the spring elements 8, 9a, 9b of the first spring arrangement 10 and the spring elements 8', 9'a, 9'b of the second spring arrangement 10', which is arranged in a mirror image of the first spring arrangement 10, are each hinged at their other ends to an intermediate plate 6c, 6d. Thus, the nonlinear damping unit 4 comprises two parallel circuits, each comprising a spring element 8, 8' with positive stiffness (KPSE) and a spring element 9, 9' with negative stiffness (kNSE).

[0059] The first intermediate plate 6c is arranged on a first end face 6a of the plate 6 and the second intermediate plate 6d on a second end face 6b of the plate 6. However, the intermediate plates 6c, 6d are not connected to the plate 6. In the loaded states of the second exemplary embodiment of the clutch 1, a first loaded state of which is shown as an example at the operating point (WP) when loaded by a positive static moment T in Figure 8, the intermediate plate 6d remains in its unloaded position since it is not connected to the plate 6, the other intermediate plate 6c being pressed by the plate 6 against the spring arrangement 10 and compressing the spring elements 8, 9a, 9b against the inner side wall 5a.

[0060] In this way, the second embodiment of the torsional vibration-isolated coupling 1 enables torsional vibration isolation for both positive and negative static moments T.

[0061] Figures 9 and 10 show symbolic representations of the spring arrangements 10, 10'.

[0062] The concept for torsional vibration isolation of the torsional vibration isolated coupling 1 is shown schematically in Figures 9 and 10.

[0063] The first spring arrangement 10 comprises the spring element 8 with positive spring stiffness kpsE and the spring element 9 with negative spring stiffness kNSE, consisting of the spring elements 9a and 9b. The spring arrangement 10 is arranged between the first coupling part 2 and the plate 6, as already described above.

[0064] The parallel connection of the spring elements 8 (kpsE) and 9a, 9b (kNSE) results in a total spring stiffness ktotai, whose stiffness results from the addition of the spring characteristics 11, 12 of both spring elements 8 (kpsE) and 9 (kNSE) and is schematically illustrated in Figure 10. This is further explained below in connection with Figure 11.

[0065] The above description applies equally to the second spring arrangement 10' with the spring elements 8' (kpsE) and 9'a, 9'b (kNSE).

[0066] The corresponding spring characteristics are shown in Figure 11, which is a diagram with spring characteristics of the spring arrangement 10, 10'.

[0067] On the X-axis of the diagram the angle of rotation is <pt in Grad zwischen den Kupplungsteilen 2, 3 aufgetragen. Auf der Y-Achse ist das Moment T in Nm aufgetragen. Das Diagramm zeigt eine Federkennlinie 11 des Federelementes 8, 8’ mit der positiven Steifigkeit kpsE, eine Federkennlinie 12 des Federelementes 9, 9’ mit der negativen Steifigkeit kNSE und eine degressive Federkennlinie 13 der Federanordnung 10, 10’ mit der Gesamtsteifigkeit ktotai.

[0068] The operating point of the clutch 1 , in which the torque T = 5000 Nm is transmitted and a static clutch twist with a twist angle of <pt = 2° erreicht wird, ist mit dem Bezugszeichen 14 gekennzeichnet. In diesem Arbeitspunkt 14 wird die Steifigkeit des Federelementes 8, 8’ mit der positiven Steifigkeit kpsE durch das Federelement 9, 9’ mit der negativen Steifigkeit kNSE kompensiert, sodass die resultierende degressive Federkennlinie 13 der Kupplung 1 in diesem Arbeitspunkt 14 eine verschwindende Gesamtsteifigkeit aufweist (horizontaler Verlauf der Federkennlinie 13).

[0069] Outside of this working point 14, the degressive spring characteristic curve 13 of the clutch 1 has a with increasing deflection, ie with increasing angle of rotation <pt, steigendes Moment T auf. Diese Nichtlinearität der degressiven Federkennlinie 13 der Kupplung 1 ermöglicht einerseits die Übertragung eines statisch wirkenden Kupplungsmoments Moment T und andererseits eine Entkopplung des Antriebsstrangs von auftretenden Schwankungen des Moments T im stationären Arbeitspunkt 14.

[0070] List of reference symbols

[0071] Coupling rotation axis 1a First coupling part 2 Recess 2a Ring area 2b

[0072] Second coupling part 3 Damping unit 4 Receiving space 5 Side wall 5a, 5b Floor wall 5c Ceiling wall 5d

[0073] Plate 6

[0074] Front side 6a, 6b Intermediate plate 6c, 6d Connecting rod 7 Spring element 8, 8' Spring element 9, 9a, 9b; 9', 9'a, 9'b Spring arrangement 10, 10' Spring characteristic curve 11, 12, 13

[0075] Working point 14

[0076] Spring stiffness k T ranslation direction u Moment T Angle of rotation (pt

Claims

Claims Torsional vibration-isolated coupling (1) with a rotational axis (1a) with a first coupling part (2) as the input side of the coupling (1), a second coupling part (3) as the output side of the coupling (1) and a damping unit (4), characterized in that the damping unit (4) has at least one spring arrangement (10, 10') which is designed as a non-linear spring arrangement (10, 10') with a degressive spring characteristic curve (13). Torsional vibration-isolated coupling (1) according to claim 1, characterized in that the at least one non-linear spring arrangement (10, 10') has at least one spring element (8, 8') with a positive spring stiffness kpsE and at least one spring element (9, 9') with a negative spring stiffness kNSE.Torsional vibration-isolated coupling (1) according to claim 2, characterized in that the first coupling part (2) as the input side of the coupling (1) and the second coupling part (3) as the output side of the coupling (1) are coupled to the at least one non-linear spring arrangement (10, 10') via the damping unit (4). Torsional vibration-isolated coupling (1) according to claim 3, characterized in that the at least one non-linear spring arrangement (10, 10') forms an interface in the form of a plate (6) between the at least one spring arrangement (10, 10'), which interacts with the plate (6) and the first coupling part (2) of the coupling (1), for bidirectional force transmission and movement transmission. Torsional vibration-isolated coupling (1) according to claim 4, characterized in that the plate (6) is coupled to the second coupling part (3) of the coupling (1) via a connecting rod (7).Torsional vibration-insulated coupling (1) according to claim 4 or 5, characterized in that the plate (6) is guided displaceably in a receiving space (5) of the first coupling part (2) of the coupling (1) in a translation direction u, wherein the translation direction u runs in a tangential direction of the first coupling part (2) of the coupling (1).

7. Torsional vibration-isolated coupling (1) according to claim 6, characterized in that the at least one spring element (9, 9') of the at least one spring arrangement (10, 10') with the negative spring stiffness KNSE has two spring elements (9a, 9b) arranged in pairs and inclined to the translation direction u, wherein first ends of the two spring elements (9a, 9b) are articulated at a distance from one another on the first coupling part (2) of the coupling (1), and the other ends of the two spring elements (9a, 9b) are brought together at a common articulation point and articulated on the plate (6) or on an intermediate plate (6c, 6d) which interacts with the plate (6).

8. Torsional vibration-insulated coupling (1) according to claim 7, characterized in that the distance between the first ends of the spring elements (9a, 9b) extends in a direction perpendicular to the translation direction u.

9. Torsional vibration-insulated coupling (1) according to one of claims 7 or 8, characterized in that the intermediate plate (6c, 6d) is arranged on an end face (6a, 6b) of the plate (6) without being connected to the plate (6).

10. Torsional vibration-isolated coupling (1) according to one of the preceding claims, characterized in that the first coupling part (2) of the coupling (1) and the second coupling part (3) of the coupling (1) are arranged coaxially to one another.

11. Torsional vibration-insulated clutch (1) according to one of the preceding claims, characterized in that the clutch (1) is a clutch (1) of a drive train of a stationary application, in particular a drive train of a stationary internal combustion engine.

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