Torsional Vibration Damper And Start-Up Element
20170284475 · 2017-10-05
Inventors
- Martin HERTEL (Bergrheinfeld, DE)
- Michael WINTERSTEIN (Gochsheim, DE)
- Joerg SUDAU (Niederwerrn, DE)
- Armin STÜRMER (Rannungen, DE)
- Christian WEBER (Ebersburg, DE)
- Christoph SASSE (Schweinfurt, DE)
- Thomas KRÜGER (Üchtelhausen, DE)
- Erwin WACK (Niederwerrn, DE)
Cpc classification
F16D3/12
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16H45/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16F15/13484
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16F15/12366
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16F15/1234
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16F2222/08
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16F2232/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
A torsional vibration damper has an input, an output and an intermediate mass arranged therebetween, a first plurality of spring elements coupled between the input and the intermediate mass that form a first stage, a second plurality of spring elements coupled between the intermediate mass and the output that form a second stage of the torsional vibration damper, at least one damper mass to damp the vibration component of the rotational movement. The first stage of the torsional vibration damper has a progressive first characteristic with at least one transition point. The second stage of the torsional vibration damper has a progressive, second characteristic with at least one transition point. All of the transition points of the first characteristic and the second characteristic are spaced apart from one another with respect to torque.
Claims
1.-15. (canceled)
16. A torsional vibration damper configured to damp a vibration component of a rotational movement, comprising: an input; an output; an intermediate mass arranged between the input and the output; a first plurality of spring elements coupled between the input and the intermediate mass that forms a first stage of the torsional vibration damper, the first stage of the torsional vibration damper has a progressive first characteristic with at least one transition point; a second plurality of spring elements coupled between the intermediate mass and the output that forms a second stage of the torsional vibration damper, the second stage of the torsional vibration damper has a progressive, second characteristic with at least one transition point; and at least one damper mass configured to perform an oscillation depending on the rotational movement to damp the vibration component of the rotational movement, wherein all of the transition points of the first characteristic of the first stage of the torsional vibration damper and the second characteristic of the second stage of the torsional vibration damper are spaced apart from one another with respect to torque.
17. The torsional vibration damper according to claim 16, wherein the transition points of the first characteristic and of the second characteristic have a distance from one another of at least 20 Nm with respect to torque.
18. The torsional vibration damper according to claim 16, wherein adjacent transition points of the first characteristic and of the second characteristic with respect to torque have a spacing of at most 100 Nm with respect to torque.
19. The torsional vibration damper according to claim 16, wherein at least one of the first characteristic and the second characteristic have at least one portion that is progressive in multiple steps and comprises the at least one transition point.
20. The torsional vibration damper according to claim 19, wherein the at least one of the first characteristic and the second characteristic have at least one portion with a characteristic that is progressive in at least three steps.
21. The torsional vibration damper according to claim 16, wherein at least one of the first plurality of spring elements and the second plurality of spring elements comprise at least one spring element with a characteristic that is at least partially progressive in multiple steps.
22. The torsional vibration damper according to claim 21, wherein the at least one spring element has an outer spring and an inner spring, and wherein the inner spring has a smaller outer diameter than an inner diameter of the outer spring and is arranged at least partially along a circumferential direction inside the outer spring.
23. The torsional vibration damper according to claim 22, wherein one of the outer spring and the inner spring is configured to contribute a torque component to the characteristic of a respective step only after exceeding a step twist angle.
24. The torsional vibration damper according to claim 16, wherein at least one of the first characteristic and the second characteristic have at least one continuously progressive portion comprising the at least one transition point.
25. The torsional vibration damper according to claim 16, wherein at least one of the first plurality of spring elements and the second plurality of spring elements comprise at least one spring element with an at least partially continuously progressive characteristic.
26. The torsional vibration damper according to claim 16, wherein the first stage of the torsional vibration damper is configured to deliver a first maximum torque, wherein the second stage of the torsional vibration damper is configured to deliver a second maximum torque, and wherein the first maximum torque can differ from the second maximum torque.
27. The torsional vibration damper according to claim 26, wherein the first maximum torque and the second maximum torque differ by a value between 10 Nm and 20 Nm.
28. The torsional vibration damper according to claim 16, further comprising: a damper mass carrier structure configured to moveably guide the at least one damper mass such that the at least one damper mass can perform the oscillation, wherein the damper mass carrier structure is one of connected to the output of the torsional vibration damper so as to be fixed with respect to rotation relative to it and is part of the intermediate mass of the torsional vibration damper.
29. A starting element for a powertrain of a motor vehicle, comprising: an first input; an first output; and a torsional vibration damper having an input and an output configured to damp a vibration component of a rotational movement, the torsional vibration damper coupled by the input and the output between the first input and the first output of the starting element, the torsional vibration damper, comprising: the input; the output; an intermediate mass arranged between the input and the output; a first plurality of spring elements coupled between the input and the intermediate mass that forms a first stage of the torsional vibration damper, the first stage of the torsional vibration damper has a progressive first characteristic with at least one transition point; a second plurality of spring elements coupled between the intermediate mass and the output that forms a second stage of the torsional vibration damper, the second stage of the torsional vibration damper has a progressive, second characteristic with at least one transition point; and at least one damper mass configured to perform an oscillation depending on the rotational movement to damp the vibration component of the rotational movement, wherein all of the transition points of the first characteristic of the first stage of the torsional vibration damper and the second characteristic of the second stage of the torsional vibration damper are spaced apart from one another with respect to torque.
30. The starting element according to claim 29, configured as a torque converter, wherein the starting element further comprises: a turbine connected to one of the output of the torsional vibration damper so as to be fixed with respect to rotation relative to it and is part of the intermediate mass of the torsional vibration damper.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] Various examples will be described and discussed in the following with reference to the accompanying drawings.
[0046]
[0047]
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[0049]
[0050]
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[0055]
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[0058]
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0059] Identical or comparable components are denoted by identical reference numerals in the following description of the accompanying drawings. Further, collective reference numerals are used for components and objects which occur more than once in an embodiment example or diagram but which are described collectively with respect to one or more features. Components or objects which are denoted by identical reference numerals or collective reference numerals may be constructed identically or possibly also differently with respect to one or more or all features, for example, their dimensions, unless otherwise explicit or implicit from the description.
[0060] In many areas of plant engineering, mechanical engineering and vehicle engineering, a challenge consists in removing, or at least damping, one or more torsional vibration components from a rotational movement. Corresponding torsional vibration components of a rotational movement can occur in prime movers operating on the principle of reciprocating pistons by reason of their construction and design. Examples include Otto engines and diesel engines in which an abrupt development of force takes place which can lead to the corresponding rotational irregularities and, therefore, corresponding torsional vibration components.
[0061] In order to keep corresponding torsional vibration components away from downstream components, or at least to reduce them, torsional vibration dampers can be used, for example, in which a transmission of torque takes place via one or more spring elements. The spring element or spring elements serve to temporarily absorb the surplus energy contained in the torsional vibration components, vis-à-vis a mean energy of the rotational movement, which can be given back to the rotational movement again in correct phase from the spring elements. Accordingly, a temporary excessive increase in energy or torque can be captured and coupled into the rotational movement again in correct phase through the use of one or more corresponding spring elements.
[0062] A large number of boundary conditions which differ in part must be taken into account when adapting or configuring a corresponding torsional vibration damper to the specific application. Apart from the actual damping of the torsional vibrations or rotational irregularities, an easy implementation and production of a torsional vibration damper of this type, the installation space required by it and the reliability of the torsional vibration damper and of the system that comprises the torsional vibration damper are not the least of the goals to be met. For example, torsional vibration dampers are used in the realm of torque converters with speed-adaptive vibration absorbers in combination with a two-damper converter, i.e., a two-tiered or two-stage torsional vibration damper arrangement. In this way, a decoupling of vibrations in which, for example, the rotational irregularities brought about by the internal combustion engine can at least be reduced, can be achieved. In systems of this kind, the speed-adaptive vibration absorber, also known as tuned mass vibration damper, is frequently arranged either on the intermediate mass between the relevant spring sets or on the secondary side, i.e., downstream of the second spring set, at the output of the torsional vibration damper.
[0063] Not least of all for ecological reasons, a goal and effort of the vehicle manufacturer is to reduce carbon dioxide (CO.sub.2) emissions while at the same time reducing expenditure as much as possible, for example, so as to lower costs. These goals are realized with respect to the engine by reducing the cubic capacity and lowering the speed of the rate of rotation of the internal combustion engines and other components of the powertrain. These steps are also referred to as downsizing or downspeeding.
[0064] However, this can lead to an increase in the rotational irregularities and torsional vibrations in a powertrain of this kind. Therefore, in order to maintain comfort and to maintain operating reliability it may be advisable to implement systems for decoupling rotational irregularities, i.e., torsional vibration dampers, for example, which enable improved damping of torsional vibrations. In this respect, in spite of the technical steps mentioned above, the trend is to realize a reduction in residual rotational irregularities and accordingly to counteract losses in comfort and/or in service life.
[0065] The use of a torsional vibration damper such as that described in the following can accordingly enhance the decoupling quality of a torque converter, for example, or of another starting element, for example, in the lower speed range which is regarded as particularly critical, so that a potential for reducing the starting speed may possibly also be realized in this case.
[0066]
[0067] The starting element 100 shown in
[0068] The pump-turbine arrangement 180 further comprises a stator 210 coupled via a freewheel, not shown in
[0069] Since the starting element 100 is a torque converter 170, the clutch 160 is also referred to as a lockup clutch for the pump-turbine arrangement 180.
[0070] The torsional vibration damper 130 has a first plurality of spring elements 230, also denoted as C1 in
[0071] The first plurality of spring elements 230 and the second plurality of spring elements 250 are shown schematically as two springs arranged one after the other in order to show that the first stage of the torsional vibration damper 130 and the second stage of the torsional vibration damper 130 both have a progressive characteristic with at least one transition point. Although, additionally or alternatively, parallel arrangements of springs can often be used instead of a series arrangement in actual implementation, corresponding progressive characteristics can certainly also be realized by serial arrangements of springs. The first stage of the torsional vibration damper 130, i.e., the first plurality of spring elements 230, is also denoted in
[0072] The torsional vibration damper 130 further has at least one damper mass 260 coupled with the intermediate mass 240 in the starting element shown here and is referred to as a DAT (speed-adaptive damper). In other examples of a starting element 100 or of a torsional vibration damper 130, the at least one damper mass 260 can also be coupled, for example, with output 150, i.e., the secondary mass, of the torsional vibration damper 130. As will be shown later, the at least one damper mass 260 can be moveably guided through a damper mass carrier structure such that the at least one damper mass 260 is able to perform a corresponding oscillation depending on the rotational movement in order to damp a vibration component of the rotational movement. Depending on the specific configuration, the damper mass carrier structure can be part of the intermediate mass 240, for example, but can also be connected to output 150 so as to be fixed with respect to rotation relative to it and accordingly form part of the secondary mass. The damper mass carrier structure can be constructed as a separate component part, but also as part of another component.
[0073] The input 110 of the starting element 100 can be coupled, for example, to an internal combustion engine, while the output 150 can be connected, for example, to a transmission input shaft of a transmission, not shown in
[0074] The first characteristic of the first stage of the torsional vibration damper 130 has at least one transition point because of its progressive shape. Correspondingly, the second characteristic of the second stage of the torsional vibration damper 130 also has at least one corresponding transition point because of its progressive shape. The transition points of the first characteristic and of the second characteristic are spaced apart from one another with respect to the torque. Depending on the specific configuration, the torsional vibration damper 130 can be constructed such that, for example, the transition points have a distance from one another of at least 20 Nm with respect to the torque. Adjacent transition points of the first characteristic and of the second characteristic can have a distance of at most 100 Nm from one another and between different characteristic lines, for example. As a result of a corresponding configuration, it can now be possible to realize a total characteristic of both stages of the torsional vibration damper in cooperation with the tuned mass vibration damper and the at least one damper mass 260 so that the decoupling quality for rotational irregularities or torsional vibrations can be improved to the extent that starting is possible even at low speeds.
[0075]
[0076] The internal combustion engine can be a reciprocating piston engine, for example, i.e., an Otto engine or a diesel engine. However, other internal combustion engines may also be used. Likewise, the internal combustion engine 280 can comprise additional components of an electric motor, for example, in order to form a hybrid drive unit. A corresponding hybrid module can be constructed, for example, as part of the internal combustion engine 280, starting element 100 or transmission 290 in its entirety or partially.
[0077] While
[0078] The two-step configuration can be produced in this case by using shorter inner springs, since the latter only make contact at the aimed-for or intended limit torque, also referred to as bending torque, and are accordingly not active until the spring element continues to twist and the spring stiffness of the stage in question is increased via this parallel arrangement of individual springs.
[0079]
[0080] The housing 300 has, more precisely, a first housing shell 320, also referred to as cover, connected via welding 330 to a second housing shell 340. As a result of the welding 330, the two housing shells 320, 340 form a fluidically sealed volume inside of which the torsional vibration damper 130 is arranged. The clutch 160, also referred to as converter lockup clutch, is likewise arranged in the inner volume. This clutch 160 has a plurality of outer disks 350 which engage with the first housing shell 320 via a corresponding toothing structure in order to transmit a rotational movement from the first housing shell 320 of housing 300 to the outer disks 350. Accordingly, housing 300 or the first housing shell 320 thereof forms an outer disk carrier 355 with which the outer disks 350 engage. The clutch 160 further has inner disks 360 which are arranged between the outer disks and which can have friction linings, for example, in order to form a frictionally engaging contact with the outer disks 350. The inner disks 360 engage with an inner disk carrier 370 likewise via a corresponding toothing.
[0081] A piston 380 is displaceable along an axis 390 so as to displace the inner disks 360 and the outer disks 350 along axis 390 and accordingly bring them into frictional engagement. The piston 380 is sealed relative to the rest of the interior of the housing 300 via a seal 400. The piston space which is accordingly formed between the first housing shell 320 and piston 380 can be supplied with pressure via a corresponding inlet bore so as to produce or cancel the frictional engagement in a specific configuration of the clutch 160. The clutch 160 further has a spring element 410 riveted to the first housing shell 320 and sealed via a further seal 420.
[0082] In the embodiment of the torsional vibration damper 130 shown here, the inner disk carrier 370 is connected to a central disk 430 so that the torque coupled in via the inner disk carrier 370 or the rotational movement coupled in via the inner disk carrier 370 is coupled into the torsional vibration damper 130. The inner disk carrier 370 can accordingly be viewed as input 140 of the torsional vibration damper 130. The central disk 430 now makes contact with the first plurality of spring elements 230. The corresponding spring elements form the stiffness of the first stage of the torsional vibration damper 130. The spring element of the first plurality of spring elements 230 makes contact with two cover plates 440 via which the rotational movement is transmitted from the first plurality of the spring elements 230 to the second stage of the torsional vibration damper 130. The cover plates 440 are connected to one another so as to be fixed with respect to relative rotation and are formed not only so as to serve as actuating plates or deactivating plates for the spring elements of the first plurality of spring elements 230, but also form a spring channel for them at which the spring elements of the first plurality of spring elements can make contact radially outside and radially inside when required.
[0083] Beyond this, the cover plates 440 also serve as control components for the spring elements of the second plurality of spring elements 250 arranged farther radially inside. These spring element of the second plurality of spring elements 250 forms the second stage of the torsional vibration damper 130 and contacts a hub disk 450 to receive the rotational movement transmitted via the second plurality of spring elements 250. The spring element of the second plurality of spring elements 250 accordingly forms the second stage of the torsional vibration damper 130, also designated as second stiffness C2.
[0084] The hub disk 450 is connected via riveting 460 to an output hub 470, also designated as torsion damper hub, so as to be fixed with respect to rotation relative to it. The output hub 470 has an internal toothing via which the transmission input shaft, not shown in
[0085] As will be described more fully referring to
[0086] As was already mentioned referring to
[0087] To couple the torque transmitted via the pump-turbine arrangement 180 to the output hub 470 which can form the output 150 of the torsional vibration damper, for example, the turbine 200 is likewise connected via the riveting 460 to the output hub 470 so as to be fixed with respect to rotation. In other embodiments, however, the turbine 200 can also be connected with a part of the intermediate mass 240 of the torsional vibration damper 130.
[0088] In the example shown here, the intermediate mass 240 comprises, for example, the track plates 440 of the torsional vibration damper 130 and the track plates 530 acting as damper mass carrier structure 420 are likewise connected via riveting 540 to cover plates 440 and, therefore, intermediate mass 240 so as to be fixed with respect to relative rotation. Track plates 530 serve to moveably guide the damper masses 260, which are moveably guided at the damper mass carrier structure 520 via rolling elements, for example, so that the damper masses 260 can perform an oscillation for damping a vibration component of the rotational movement. In the present example of a corresponding speed-adaptive vibration absorber, damper masses 260 are formed of multiple parts and, in this case, include in each instance a plurality of, in the present instance, three, individual damper masses 550 along axis 390.
[0089] In the present example of a torsional vibration damper 130, the damper masses 260, also designated as flyweights, are guided through two track plates, which are spaced apart from one another along axis 390 and collectively form the damper mass carrier structure 520. In other embodiments, it can also be possible to guide the damper mass 260 at both sides of an individual track plate 530 or at both sides of an individual damper mass carrier structure 520. In the example shown here, the torsional vibration damper 130 further comprises a plurality of damper masses 260. In other embodiments, the number of damper masses can also possibly be increased or reduced. Accordingly, it can also be possible, if necessary, to use only one individual damper mass 260 instead of the plurality of damper masses 260 arranged here along the circumferential direction.
[0090] As has already been indicated briefly, the intermediate mass 240 also comprises the damper mass carrier structure 520 in the form of track plates 530, since it is connected via riveting 540 to the cover plates 440 so as to be fixed in respect to rotation relative to it. Riveting 540 also provides for a spacing of the individual track plates 440 along the axis.
[0091] In other configurations, the damper mass carrier 520, i.e., for example, track plates 530, can also be connected directly to the output hub 470, i.e., the output 150 of the torsional vibration damper 130. The turbine 200 can also be connected to the intermediate mass so as to be fixed with respect to rotation relative to it by riveting 540 instead of riveting 460. In this case, the second stage of the torsional vibration damper 130 and possibly also the speed-adaptive vibration absorber with its at least one damper mass 260 could be utilized, depending on its connection, for damping rotational irregularities or torsional vibrations transmitted via the pump-turbine arrangement 180.
[0092]
[0093] The partial elevation in
[0094] In contrast, while the outer springs 480, shown, for example, at the upper right-hand side of
[0095] The torque is transmitted from the first plurality of spring elements 230 via the cover plates 440 to the second plurality of spring elements 250. The torque transmitted via the second plurality of spring elements 250 and the corresponding riveting 460 is then transmitted via the hub disk 450 to the output hub 470, i.e., the output 150 of the torsional vibration damper 130.
[0096] In this case too, however, different spring elements are used in the area of the second plurality of spring elements 250. While the outer springs 480′ are also identical in this case for all of the spring elements of the second plurality of spring elements 250, two inner springs 490″ and 490′ of different lengths are used. The above-mentioned inner springs 490″ have the same length as the corresponding outer springs 480′. In contrast, the shorter inner springs 490″′ which are shown on the lower right-hand side, for example, have a smaller extension along the circumferential direction than the corresponding outer springs 480′ of the second plurality of spring elements 250, for example. Accordingly, through corresponding use of both short and long inner springs 490 in the area of the spring elements of the first plurality of spring elements 230 and second plurality of spring elements 250, a progressive characteristic of the relevant stages of the torsional vibration damper 130 can be implemented, wherein the corresponding transition points, which are knees of the respective characteristics at corresponding twist angles in this case, are spaced apart from one another.
[0097]
[0098] The pluralities of spring elements 230, 250 accordingly form an outer spring set and an inner spring set, wherein the spring elements of the corresponding spring sets are configured in each instance as spring packages with an outer spring and an inner spring. In other examples, however, the arrangements can also be different. For example, instead of a spring package, an individual spring can form a spring element, or more than two springs can form a corresponding spring package or spring element.
[0099] With regard to the mode of functioning of the torsional vibration damper 130 and especially with regard to the speed-adaptive vibration absorber, this is a Sarazin-type absorber. An absorber of this type can be used by itself as torsional vibration decoupling system only with difficulty within the framework of a starting element 100, particularly within the framework of a torque converter 170, since the torsional vibrations introduced into the system through the engine are often too severe for a vibration absorber. On the other hand, if a vibration absorber were configured in such a way that it had a sufficiently high decoupling capacity, it could probably not be utilized in a feasible manner economically or ecologically so that a preliminary decoupling in the form of an upstream decoupling system using spring sets, for example, is always advisable. For example, in case of greater engine torques of 500 Nm or more, for example, a high alternating torque of 1100 Nm or more, for example, can also occur on the order of one half of the quantity of cylinders. With the given installation spaces in current passenger motor vehicles, for example, it is scarcely possible at such high alternating torques to sufficiently decouple the resulting rotational irregularities with only one individual spring set, i.e., an individual plurality of spring elements and one vibration absorber. Therefore, it is advisable to use two pluralities of spring elements (spring sets) in addition to a vibration absorber precisely in torsional vibrations dampers 130 for more powerful internal combustion engines.
[0100] By reason of its basic physical configuration the vibration absorber applies increasing torque with increasing speed. This can also provide a further reason for using a preliminary decoupling system, for example, because this ultimately means that the vibration absorber applies fewer mass damper torques for lower speeds at which there is a greater likelihood based on the system that rotational irregularities will occur. In this speed range, it may be advisable to configure the preliminary decoupling system, i.e., the pluralities of spring elements or the corresponding torsion damper, such that it performs most of the decoupling of rotational irregularities.
[0101] A good decoupling can be carried out, for example, when the system is operated as far as possible from the natural frequency in this supercritical range. This means either that the dimensions should be as large as possible, although this should be valuated rather as critical for ecological and economic reasons, or that the stiffness should be as low as possible. A further restriction as concerns design parameters consists in that only a limited swiveling angle or oscillating angle φ is available because typically only 360 are available for transmitting torque via a corresponding component part (e.g., plate), for further transmitting torque via the spring elements and guiding torque out via another corresponding component part (e.g. plate) for twisting. This means that with a lower spring rate of the spring set, i.e., for example, with values of about C=12 Nm/degrees, the torsional vibration damper 130 reaches its mechanical end stop at a predetermined percentage of the nominal torque (M=φ.Math.C). This is also known as partial load configuration.
[0102] An alternative consists in using a two-step or multi-step characteristic of the spring set, which is progressive. The use of two two-step or multi-step spring sets, including the mounting of the vibration absorber between these spring sets, constitutes a configuration of a torsional vibration damper 130.
[0103] As described in the present case, a two-step configuration of this kind can be realized by short inner springs 490. In this way, rotational irregularities which occur can also be decoupled comparatively well in a lower torque range and, therefore, based on the engine characteristic, also in the lower speed range. The full engine torque can nevertheless be transmitted via the spring elements without the hard mechanical stop being reached, which can lead every time to an impact load and, therefore, to an impact excitation in the overall system.
[0104] There are essentially four parameters in a two-step spring characteristic. This includes the stop torque, the stop angle, the bending torque and the bending angle. The stop torque cannot be selected arbitrarily because the entire engine torque should be transmitted with predetermined reliability when a torsional vibration damper of this type is reliably constructed and configured. The stop angle is frequently design-based, which leaves only the bending torque and the bending angle as free parameters. Therefore, the first section or the first sub-portion of a characteristic of this type can be configured to be softer than the corresponding spring rate without the two-step configuration. In the second section or second sub-portion of the respective characteristic, the behavior can be exactly the opposite. The bending torque with two-step configuration can be configured in such a way that upwards of the speed of the full-load characteristic of the engine associated with this torque, for example, at speeds ranging between 1100 and 1500 revolutions per minute, for example, in the range between 1100 and 1400 revolutions per minute, the vibration absorber can feed back a sufficiently high mass damper torque so that the residual rotational irregularity is sufficiently small.
[0105] The bending torque is calculated from the sum of the product of the stiffness rates (C rates) of the first stage and the swiveling angle of the primary mass or of the input 140 of the torsional vibration damper 130 at a determined speed n1 and the torque at speed n1 from the engine curve.
[0106] There remains the matter of the bending angle. This determines the stiffness or softness of the spring stages. Thus, in principle, it could be considered that the first stage should be as soft as possible in order to ensure optimal decoupling. However, it has been shown that the stiffness of the second stage should not exceed the stiffness of the first stage beyond a factor c.sub.1.2/c.sub.1.1 in a range between 1.6 and 7.
[0107] Thus the bending torque is a torque that is typically in the middle of the typical driving range so that this is often driven through. If the above-mentioned factor c.sub.1.2/c.sub.1.1 is too high, there can be a shock-like excitation of the powertrain every time this point is driven through so that other vibration orders can even be excited. Owing to the high stiffness of the second stage that then exists, this means, in addition, that there is still a small residual angle for this spring set. Accordingly, because of the high alternating torque of the engine, which was described above, the torsional vibration damper can then possibly vibrate in its mechanical end stop. Upwards of a certain amplitude, these effects can have negative consequences for the decoupling behavior and, therefore, for the residual rotational irregularities of the system overall.
[0108] This also applies to the second spring set, i.e., the second stage of the torsional vibration damper 130 and, accordingly, to the second plurality of spring elements 250. It should also be taken into account in this connection that the knees or transition points are configured to the same torque—and a torsional vibration damper 130 not least of all is based on this. These knees or transition points should be spaced apart from one another and should have, for example, a difference of ΔM.sub.knee=20-100 Nm. Otherwise, it may happen that the jump between steps in the overall torsional vibration damper system is again too large. The difference of bending torques accordingly provides for a smoother transition.
[0109] It may also be advisable with regard to the stop torque e of the spring sets, i.e., the stages of the torsional vibration damper 130 and the corresponding pluralities of spring elements 230, 250, not to configure the latter exactly to the same torques. Accordingly, it may be advisable, for example, to configure the second plurality of spring elements 250, i.e., the second stage of the torsional vibration damper 130, to be lower than the stop torque of the first stage of the torsional vibration damper 130 (the first plurality of spring elements 230). A difference with respect to the torques ΔM.sub.stop can be in the range between 10 and 20 Nm, for example.
[0110] A further possibility for generating a smoother transition in the area of the knees is to configure at least one stage of the torsional vibration damper to have three or even more steps. For example, both stages of the torsional vibration damper can be configured in three steps, although it could possibly be beneficial to configure the first stage of the torsional vibration damper 130 in particular in three steps in a corresponding manner. This can be realized, for example, through a further shorter inner spring which can be used in place of the long inner springs 490 or C shown, for example, in
[0111] Referring to
[0112] Accordingly,
[0113] This also applies in principle to characteristic 600-1. The latter also has a plurality of sub-portions 610′-1, 610′-2 and 610′-3 immediately adjoining one another, and the sub-portions 610′ in question extend up to transition points 620′-1 and 620′-2, respectively. Accordingly, in this case the first characteristic 600-1 and the second characteristic 600-2 have a total of three transition points 620, wherein transition point 620 of characteristic 600-2, i.e., the corresponding knee of this stage of the torsional vibration damper 130, lie between the transition points 620′ of the other stage of the torsional vibration damper 130. Here also, the transition points 620 are spaced apart from one another along the torque axis, wherein the distances can be, for example, at least 20 Nm and the distances between two adjacent transition points, regardless of the characteristics 600 to which they belong, can have a maximum spacing of 100 Nm, for example. However, both boundary conditions only represent examples which can be implemented completely independent from one another. Beyond this,
[0114]
[0115]
[0116] A further possibility for generating the corresponding configuration of the characteristics 600, i.e., for example, their two-step configuration, consists in using progressively coiled springs. These may differ along the length of the respective spring, for example, with respect to a diameter of the wire used for the springs, but springs with varying coil spacing can also be used. For example, there can also be two possibilities again for a continuous progressivity and a progressivity by segments. In case of a continuous progressivity, for example, the stiffness can increase continuously. This can eliminate any jump between steps and, therefore, the overall system does not “oscillate against a step.” In the case of a progressivity configured by segment, individual portions of the relevant springs or spring elements can be configured progressively. This can result in a curve similar to that in a two-step or multi-step characteristic with short inner springs. However, it can happen that the relevant characteristics are rounded in the area of the transition points. This can be because the second segment of the spring is co-loaded resulting in a series connection of the two segments of the spring.
[0117] Depending on the type of transmission or internal combustion engine for which a torsional vibration damper 130 is provided, the threshold quotient of the stiffnesses of the respective spring sets, for example, can deviate from the values described above. Depending on the specific embodiment, the configuration can be determined in this case by simulations or trials, for example.
[0118] The characteristics, which are shown by way of example in
[0119]
[0120] Here also, outer springs 480 (A in
[0121] As regards the second plurality of spring elements, i.e. the inner spring set, the corresponding spring elements again have outer springs 480′ (D in
[0122] Accordingly, the spring elements of the first plurality of spring elements 230 are configured as A/B-A/C-A/B-A/B-A/C. Correspondingly, the spring element of the second plurality of spring elements 250 has the configuration D/E-D/E-D/F-D/E-D/F. Here also, the spring elements of the two pluralities 230, 250 of spring elements are again arranged so as to be aligned without an offset, and the first, second, third, fourth and fifth spring elements are arranged in each instance as indicated above on a radial line proceeding from the axis 390, not shown in
[0123]
[0124] As regards the spring elements of the second plurality of spring elements 250, the configuration does not differ from the configuration which was described referring to
[0125]
[0126] Accordingly, a torsional vibration damper can be implemented, for example, with progressive inner springs or exclusively progressive inner springs 490 in the area of the outer spring set, i.e., of the first plurality of spring elements 230. In a further embodiment, not shown, the progressivity can also be brought about, for example, via only one spring type of a corresponding spring set or of a corresponding plurality of spring elements 230, 250. For example, only the respective outer spring or only the inner spring may be configured so as to be continuously progressive. In this respect, it may possibly be advisable to select a variant in which the inner springs are progressive and the outer springs are linear. This can allow the outer springs to transmit a larger torque and thus become the main springs of the corresponding stage of the torsional vibration damper. In contrast, the correspondingly progressively configured inner springs can be utilized merely to transmit the progressive curve. However, the outer springs can also be configured so as to be progressive in a corresponding manner, while the inner springs are linear. For example, it can be possible to dimension and configure the outer springs in such a way that, although they have a progressive characteristic, they nevertheless transmit a majority of the forces or torques.
[0127]
[0128] However, other implementations can also be provided in which, for example, the multi-stepped configuration of the first plurality of spring elements 230 is realized through progressively coiled springs. Accordingly, bending torques can possibly no longer be spoken of but rather transition points as has already been described. As a result of the corresponding coil spacings, the tightly coiled spring turns can contact one another with increasing torque so that the turn-for-turn effect is shut off and a virtually constant progressivity can accordingly be achievable. The transition points accordingly change to a broad transition range or bending torque range. For example, progressively coiled springs 480 can be used as spring elements instead of spring packages within the framework of the spring elements of the outer spring set, i.e., of the first plurality of spring elements or of the first stage of the torsional vibration damper.
[0129]
[0130] Here also, a progressive configuration of the characteristics of the two stages of the torsional vibration damper 130 can again be achieved correspondingly through a corresponding configuration of springs 480, 490, wherein the transition points are again spaced apart from one another.
[0131] Springs 480, 490 of the spring elements are constructed in this case as curved springs but can also be realized as straight springs in other implementations. The spring ends can also be utilized as shown in
[0132] Precisely when using mechanical springs, the use of four or five parallel-connected spring elements in each plurality of spring elements 230, 250 can benefit a compromise with respect to friction, possible twist angles and other parameters. A parallel connection of fewer spring elements can allow a larger twist angle in principle, but can lead to an increase in friction. Correspondingly, an increase in the quantity of parallel-connected spring elements can lead to a decrease in the available twist angle range but can have a favorable effect on wear and friction. Therefore, it can certainly be possible to realize torsional vibration dampers also with more or fewer spring elements than the four or five parallel-connected spring elements shown herein. Also, it is far from compulsory that the first stage and second stage of the torsional vibration damper 130 have the same quantity of parallel-connected spring elements.
[0133] While torque converters have substantially been described in the present case by a vibration absorber and a torsion damper with two or more steps in both spring sets, torsional vibrations dampers can also be used within the framework of other starting elements, for example, wet or dry clutches. Corresponding torsional vibration dampers can also be used in other locations, for example, in a hybrid module or as part of the transmission of a corresponding powertrain.
[0134] The features disclosed in the preceding description, the subsequent claims and the accompanying figures may be of importance and be implemented, both individually and in any combination, for the realization of an embodiment example in their various implementations.
[0135] Thus, while there have been shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.