Torsional vibration insulated 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 isolation type coupling described in the preamble of claim 1.

[0002] A torsional vibration isolation type coupling is used, for example, in a stationary internal combustion engine.

[0003] Such a stationary operating internal combustion engine is also called a so-called generating sets engine, which is used in combination with a generator for generating electric energy. Its fields of use range from emergency power supply for ship prime movers to the provision of electric energy. In this case, the engine is usually operated by diesel fuel or natural gas. Another field of use is a piston compressor.

[0004] During running operation, different from an active passenger car or truck prime mover that is exposed to variable rotational speeds and frequently changing loads, this application is mainly characterized by a fixed operating point with a constant rotational speed and a substantially constant load moment.

[0005] For this reason, the current prior art mainly assumes a torsional vibration isolation type coupling having a linear spring characteristic line. 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 type coupling.

[0007] One is the first requirement in the transmission of the static driving moment. The main role of such a stationary operating application is to provide a substantially constant torsional moment at a specified rotational speed. This torsional moment acts on the power train as a static load and must be transmitted by the coupling. Therefore, the torsional stiffness of the coupling must be correspondingly high so as to be able to transmit the static torsional moment.

[0008] On the other hand, it is necessary to insulate torsional moment fluctuations, that is, broadband vibration insulation.

[0009] Regarding the dynamic characteristics of the powertrain during engine operation, the coupling must disconnect the components (for example, the engine and the generator or the ship's propeller) coupled to each other via the powertrain from the influence of faults (for example, fluctuations in the driving moment or the load moment). Therefore, in order to achieve broadband vibration insulation of the coupling as much as possible, a correspondingly low torsional stiffness of the coupling is required.

[0010] As a result, a trade-off occurs regarding the optimal torsional stiffness of the coupling from both of these requirements. That is, the torsional stiffness is required to be high enough to transmit the static torsional moment on the one hand, but at the same time as low as possible for insulating the driving vibrations that cause problems.

[0011] Since the main role of the powertrain is to transmit the static torsional moment, the coupling stiffness is usually selected to be correspondingly high. Therefore, the drawback of the powertrain is that additional components (for example, torsional vibration dampers) or components for enhanced torsional vibrations have to be designed in order to attenuate unwanted torsional vibrations. This leads to additional costs on the one hand and usually also an increase in the required configuration space based on an increase in the overall length of the train. Furthermore, the damping effect of the additional components is usually tailored to a limited frequency range or rotational speed range.

[0012] Therefore, the underlying problem of the present invention is to provide a torsional vibration insulation type coupling that satisfies both requirements, that is, the transmission of the static torsional moment and at the same time the broadband insulation of the powertrain, and that no longer has or at least sufficiently reduces the drawbacks of an increase in the required configuration space and the limitation of the frequency range or rotational speed range.

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

[0014] Correspondingly, a torsional vibration isolation type coupling having a torsional axis includes 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 non-linear spring assembly having a degressive spring characteristic line.

[0015] A torsional vibration isolation type coupling provided with a damping unit having a non-linear spring assembly having a degressive spring characteristic line has a special advantage in that static moment transmission is possible until the operating point is reached in a power train for stationary operation applications.

[0016] Unlike the zero stiffness concept that achieves vibration isolation solely by extremely low stiffness and thus makes static load transmission impossible, the torsional vibration isolation type coupling according to the present invention provides the possibility of static moment transmission in combination with vibration isolation at the operating point. For this purpose, the concept utilizes the non-linearity of the degressive spring characteristic line of the spring assembly of the damping unit.

[0017] In one configuration, at least one non-linear spring assembly has at least one spring element having a positive spring stiffness k PSE and at least one spring element having a negative spring stiffness k NSE This advantageously enables a simple and compact structure.

[0018] A further configuration specifies that a first coupling member as the input side of the coupling and a second coupling member as the output side of the coupling are connected to at least one non-linear spring assembly via a damping unit.

[0019] Compared with a coupling having a linear spring characteristic line, the torsional vibration isolation type coupling according to the present invention advantageously enables broadband torsional vibration isolation while transmitting a static driving moment during the stationary operation of the application. Therefore, according to the proposed concept, the advantages of improved power train dynamic characteristics can be obtained without additional damping components 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 displaceably guided 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 has two spring elements arranged in a pair and inclined with respect to the translational direction u, and the first ends of both spring elements are pivotally attached to the first coupling member of the coupling at intervals from each other, and the other ends of both spring elements are grouped at a common pivot point and pivotally attached to the plate or pivotally attached to an intermediate plate cooperating with the plate, which is advantageous. In this way, a structure having a negative stiffness can be obtained with simple spring elements. NSE

[0024] ​In this case, it is specified that the spacing between the first ends of the spring elements extends in a direction orthogonal to the translational direction u. The advantage in this case is the simple structure.

[0025] If the intermediate plate is arranged on the end face of the plate without being connected to the plate, in this way, by means of a torsional vibration insulating coupling, torsional vibration insulation can advantageously be achieved both for a positive static moment T and for a negative static moment T.

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

[0027] In one configuration, a torsional vibration insulating coupling is a coupling for a power train for stationary operation applications, in particular for a power train of a stationary internal combustion engine. Thereby, advantageously, broadband torsional vibration insulation of the power train becomes possible.

[0028] The present invention assumes a concept having a degressive spring characteristic line for a power train for stationary operation applications. In this case, this concept, unlike the prior art, satisfies both the requirement for static torsional moment transmission and the requirement for broadband vibration insulation without additional functional units. From using a conventional coupling in combination with a negative stiffness element, a non-linear spring characteristic line is consequently obtained. In this case, due to the extremely low spring stiffness at the fixed operating point of the engine, almost complete vibration insulation of the connected components becomes possible.

[0029] Further advantageous configurations of the present invention can be known from the dependent claims.

[0030] Hereinafter, several embodiments of the present invention will be described based on 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 Description of the Drawings

[0031]

Figure 1

Figure 2

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Figure 11

[0032] Hereinafter, concepts such as "outer" or "inner" are based on each drawing plane, 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] FIG. 1 shows a schematic radial cross-sectional view of a first embodiment of a torsional vibration isolation type coupling 1 according to the present invention.

[0034] Figure 2 shows a schematic cross-sectional view of the torsional vibration isolation type coupling 1 according to the present invention shown in Figure 1 in a no-load state.

[0035] The torsional vibration isolation type coupling 1 includes a first coupling member 2 as an input side in the form of a disk having a central notch 2a, a second coupling member 3 as an output side in the form of a hub or a cylinder, 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 arranged 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 arranged within the accommodation chamber 5.

[0038] The accommodation chamber 5 is formed in a rectangular parallelepiped shape within the annular region of the first coupling member 2 in the illustrated configuration, and has inner side walls 5a, 5b that face 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 accommodation 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 includes a plate 6 and a spring assembly 10.

[0040] The plate 6 is guided displaceably in the translational direction u by the lower side wall 5c and the upper side wall 5d within the accommodation chamber 5.

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

[0042] The spring assembly 10 has a spring element 8 having a positive spring stiffness k PSE and a spring element 9 having a negative spring stiffness kNSE formed as a single non-linear spring assembly 10 having a spring element 9 with a positive spring stiffness k PSE a spring element 8 having a positive spring stiffness k, and a spring element 9 having a negative spring stiffness k NSE 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 receiving 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 a pair 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 receiving 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 a common pivotal point at their other spring ends and 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, the 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. Further, the plate 6 forms the turning point of the movement of the connecting rod 7 that transmits the torsional movement of the second coupling member 3 to the plate 6.

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

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

[0050] Figure 4 shows a schematic cross-sectional view of the torsional vibration isolation type coupling 1 according to the present invention shown in FIG. 3 in the loaded state.

[0051] Figure 4 illustrates the coupling 1 at the operating point (WP, see also FIG. 11) when the coupling 1 is loaded by a positive static moment T. In the illustrated example, the moment T acts in the counterclockwise direction about 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 inner side wall 5a on the left side of the receiving chamber 5 of the first coupling member 2. In this case, the spring elements 8, 9a, 9b of the spring assembly 10 are compressed.

[0053] The illustrated spring assembly 10 enables the transmission of the static moment T without being swayed in the direction of the static moment T. In this case, torsional vibration insulation by the torsional vibration insulation type coupling 1 is achieved for the static moment T acting exclusively in the positive direction (in the illustrated configuration, the counterclockwise direction about the torsion axis 1a). The concept of the "positive direction" in this specification means that the moment T displaces the plate 6 of the damping unit 4 in the positive translation direction u, and in this case, the plate 6 compresses the spring elements 8, 9a, 9b toward the inner side wall 5a on the left side of the accommodation chamber 5 of the first coupling member 2.

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

[0055] Figure 6 shows a schematic cross-sectional view of a second embodiment of the torsional vibration insulation type coupling 1 according to the present invention in a no-load state (T = 0).

[0056] Unlike the first embodiment shown in Figure 2, the damping unit 4 of the coupling 1 has two non-linear spring assemblies 10, 10', and these two spring assemblies 10, 10' are arranged symmetrically with respect to the virtual center line in the radial direction of the plate 6 and within the accommodation chamber 5 of the first coupling member 2.

[0057] Further different from the first embodiment, the spring elements 8, 9a, 9b of the first spring assembly 10 and the spring elements 8', 9'a, 9'b of the second spring assembly 10' arranged symmetrically with respect to the first spring assembly 10 are pivotally attached to the intermediate plates 6c, 6d at the other ends of both. Thus, in this case, the non-linear damping unit 4 has two parallel connections of one spring element 8, 8' each having a positive stiffness (K PSE ) and spring elements 9, 9' having a negative stiffness (k NSE ).

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

[0059] Among the plurality of load states of the second embodiment of the coupling 1, in the first load state among these load states, in the load state illustrated in FIG. 8 at the operating point (WP) when the load is applied by the positive static moment T, the intermediate plate 6d remains in its no-load position. This is because the intermediate plate 6d is not coupled to the plate 6, and the other intermediate plate 6c is pressed by the plate 6 toward the spring assembly 10, and the spring elements 8, 9a, 9b are compressed toward the inner side wall 5a.

[0060] Thus, according to the second embodiment of the torsion vibration isolation type coupling 1, torsion vibration isolation is possible for both the positive static moment T and the negative static moment T.

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

[0062] FIGS. 9 and 10 schematically show the concept for torsion vibration isolating the torsion vibration isolation type coupling 1.

[0063] The first spring assembly 10 includes a spring element 8 having a positive spring stiffness k PSE and a spring element 9 composed of spring elements 9a, 9b having a negative spring stiffness k NSE . As already described above, the spring assembly 10 is disposed between the first coupling member 2 and the plate 6.

[0064] As a result of the parallel connection of the spring elements 8 (k PSE ), 9a, 9b (k NSE ), a total spring stiffness k total is obtained, and the stiffness of this total spring stiffness is that of both spring elements 8 (k PSE), 9(k NSE ) is obtained based on summing the spring characteristic lines 11, 12 and is schematically shown in FIG. 10. This will be further described below in conjunction with FIG. 11.

[0065] The above description is similarly applicable to the second spring assembly 10' having spring elements 8'(k PSE ), 9'a, 9'b(k NSE ).

[0066] The corresponding spring characteristic lines are shown in FIG. 11 which shows a diagram including the spring characteristic lines of spring assemblies 10, 10'.

[0067] On the X-axis of the diagram, the twist angle φt between the coupling members 2, 3 is plotted in degrees. On the Y-axis, the moment T is plotted in Nm.

[0068] In the diagram, the spring characteristic line 11 of the spring elements 8, 8' having a positive stiffness k PSE , the spring characteristic line 12 of the spring elements 9, 9' having a negative stiffness k NSE , and the degressive spring characteristic line 13 of the spring assemblies 10, 10' having a combined stiffness k total are shown.

[0069] For 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°, a reference numeral 14 is attached. At this operating point 14, the stiffness of the spring elements 8, 8' having a positive stiffness k PSE is canceled out by the spring elements 9, 9' having a negative stiffness k NSE . As a result, the degressive spring characteristic line 13 of coupling 1 that occurs at operating point 14 has a zero combined stiffness (horizontal shift of spring characteristic line 13).

[0070] Outside the operating point 14, the degressive spring characteristic line 13 of the coupling 1 has a moment T that increases as the displacement increases, i.e., as the twist angle φt increases. Due to this non-linearity of the degressive spring characteristic line 13 of the coupling 1, on the one hand, the transmission of the moment T, which is a coupling moment acting statically, becomes possible, and on the other hand, the power train can be disengaged from the fluctuations of the moment T occurring at the stationary operating point 14.

Explanation of Signs

[0071] 1 Coupling 1a Twist axis 2 First coupling member 2a Notch 2b Annular region 3 Second coupling member 4 Damping unit 5 Receiving chamber 5a, 5b Side walls 5c Lower side wall 5d Upper side wall 6 Plate 6a, 6b End faces 6c, 6d Intermediate plates 7 Connecting rod 8, 8’ Spring elements 9, 9a, 9b; 9’, 9’a, 9’b Spring elements 10, 10’ Spring assemblies 11, 12, 13 Spring characteristic lines 14 Operating point k Spring stiffness u Translational direction T Moment φt Twist angle

Claims

1. 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), characterized in that it is a torsional vibration isolation type coupling (1).

2. Said at least one non-linear spring assembly (10, 10') has a positive spring stiffness k ＰＳＥ and at least one spring element (8, 8') having a negative spring stiffness k ＮＳＥ The torsional vibration isolation type coupling (1) according to claim 1, characterized by having at least one spring element (9, 9').

3. 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 at least one non-linear spring assembly (10, 10') via the damping unit (4), characterized in that it is the torsional vibration isolation type coupling (1) according to Claim 2.

4. The at least one non-linear spring assembly (10, 10') forms an interface in the form of a plate (6) for bidirectional force transmission 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), characterized in that it is the torsional vibration isolation type coupling (1) according to Claim 3.

5. The plate (6) is connected to the second coupling member (3) of the coupling (1) via a connecting rod (7), characterized in that it is the torsional vibration isolation type coupling (1) according to Claim 4.

6. The plate (6) is guided displaceably in a translational direction u within a receiving chamber (5) provided in the first coupling member (2) of the coupling (1), and the translational direction u extends in a tangential direction of the first coupling member (2) of the coupling (1), characterized in that it is the torsional vibration isolation type coupling (1) according to Claim 4 or 5.

7. The negative spring stiffness k of the at least one spring assembly (10, 10') ＮＳＥ The at least one spring element (9, 9') having the negative spring stiffness k comprises two spring elements (9a, 9b) arranged in a pair and inclined with respect to the translational direction u, and the first ends of both spring elements (9a, 9b) are pivotally attached to the first coupling member (2) of the coupling (1) at intervals from each other, and the other ends of both spring elements (9a, 9b) are gathered at a common pivot point and pivotally attached to the plate (6) or pivotally attached to an intermediate plate (6c, 6d) cooperating with the plate (6). The torsion vibration insulating coupling (1) according to claim 6, characterized in that it is so.

8. The interval between the first ends of the spring elements (9a, 9b) extends in a direction orthogonal to the translational direction u, characterized in that it is the torsional vibration isolation type coupling (1) according to Claim 7.

9. The torsional vibration insulating coupling (1) according to claim 7 or 8, characterized in that the intermediate plates (6c, 6d) are arranged on the end faces (6a, 6b) of the plate (6) without being coupled to the plate (6).

10. The torsional vibration insulating coupling (1) according to any one of claims 1 to 9, characterized in that the first coupling member (2) of the coupling (1) and the second coupling member (3) of the coupling (1) are arranged coaxially with each other.

11. The torsional vibration insulating coupling (1) according to any one of claims 1 to 10, characterized in that the coupling (1) is a coupling (1) for a power train for stationary operation applications, particularly for a power train of a stationary internal combustion engine.

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