TORSIONAL VIBRATION DAMPER WITH ONE ROTATIONAL AXLE FOR A DRIVETRAIN

Description

[0001] The invention relates to a torsional vibration damper according to the preamble of claim 1 with a rotation axis for a drive train, comprising at least the following components: An input side; an output side; one or more intermediate elements in a torque-transmitting connection between the input side and the output side; each intermediate element comprising a first rolling element and a second rolling element, wherein the at least one intermediate element has a transmission track for rolling the rolling elements, the input side and the output side having a counter-track complementary to the respective transmission track; a number of energy storage elements corresponding to the number of intermediate elements, by means of which the intermediate element associated with the respective energy storage element is oscillatively supported. The torsional vibration damper is characterized in particular by the fact that the energy storage element is arranged with a vector component acting in the circumferential direction and / or that, for each intermediate element, only the first rolling element and the second rolling element are provided as rolling elements.

[0002] Various types of torsional vibration dampers are known from the prior art. For example, EP 2 508 771 A1 discloses a torsional vibration damper in which an output side is provided with a (double) cam that acts on a lever-like intermediate element. This intermediate element is tiltably connected to a disk on an input side. The intermediate element is pre-tensioned against the cam of the output side by means of a compression spring and is deflected against the compression spring when the cam geometry passes over it. The compression spring is connected to the input side opposite the intermediate element in a way that transmits a force, thus transferring a torque from the input side to the output side via the compression spring.

[0003] From FR 3 057 321 A1, another variant of a torsional vibration damper is known, in which a lever-like spring element, similar to a (free-form) solid spring, is provided at one output side. This spring element has a ramp-like transmission track on its radial outer side, which is connected to a roller rolling on this track in a torque-transmitting manner. The roller is rotatably mounted on a bolt. When a torsional vibration occurs, a relative movement is caused between the spring element and the corresponding roller. Due to the ramp-like transmission track, the spring element is deflected by the roller in a lever-like manner against its spring force during its rotational relative movement. This dampens the torsional vibration.

[0004] Both the levers from EP 2 508 771 A1 and the spring bodies of FR 3 057 323 A1 are technically difficult to control and / or expensive to manufacture or assemble if low dissipation, i.e., high efficiency, is desired.

[0005] For example, WO 2018 / 215 018 A1 discloses a torsional vibration damper in which two intermediate elements are provided, mounted between an output side and an input side via rolling elements. The rolling elements run on complementary transmission paths such that the intermediate elements are subject to positive guidance. The two intermediate elements are prestressed against each other by means of energy storage elements, so that the functional stiffness of the energy storage elements can be designed independently of torque transmission. For many applications, it is necessary, on the one hand, to reduce the natural frequency of a torque-transmitting system and, on the other hand, to be able to transmit a high torque. From the first requirement, it follows that the functional stiffness must be low. From the second requirement, it follows that the stiffness of the energy storage elements must be high.These conflicting requirements can be resolved using the rolling elements and the transmission tracks. Torque is transmitted between the input and output sides solely via the transmission tracks and the rolling elements arranged between them. The functional stiffness, which thus alters the natural frequency, is translated into a small spring deflection due to the low pitch and large angles of rotation. This cam mechanism results in an (arbitrarily) low functional stiffness. An advantage of this system is that the energy storage elements can be designed independently of the (maximum) transmissible torque. However, the illustrated embodiment, with its large number of separate rolling elements and the high demands placed on the complementary transmission tracks, is complex and expensive to manufacture and assemble. Therefore, this system is not competitive in all areas.

[0006] From DE 10 2015 211 899 A1 a torsional vibration damper is also known which can be read as referring to the preamble of claim 1.

[0007] The present invention is based on the objective of at least partially overcoming the disadvantages known from the prior art.

[0008] This problem is solved according to the invention by a torsional vibration damper according to claim 1. Preferred embodiments are set out in the dependent claims.

[0009] In the following, reference is made to an axis of rotation whenever the axial direction, radial direction, or direction of rotation and corresponding terms are used without explicit indication otherwise. Ordinal numbers used in the description serve solely for unambiguous differentiation, unless explicitly stated otherwise, and do not indicate any order or ranking of the components being described. An ordinal number greater than one does not necessarily imply the presence of another such component.

[0010] The invention relates to a torsional vibration damper with a rotational axis for a drive train, comprising at least the following components: an input side for receiving a torque; an output side for delivering a torque; at least one intermediate element in a torque-transmitting connection between the input side and the output side; each intermediate element having a first rolling element and a second rolling element, wherein the at least one intermediate element has a first transmission track for rolling the first rolling element and a second transmission track for rolling the second rolling element, wherein the input side has a first counter-track complementary to the first transmission track and the output side has a second counter-track complementary to the second transmission track, wherein the first rolling element is guided to roll between the first transmission track and the first counter-track and the second rolling element is guided to roll between the second transmission track and the second counter-track;at least one energy storage element by means of which the intermediate element associated with the energy storage element is oscillatively supported.

[0011] The torsional vibration damper is characterized primarily by the fact that the energy storage element is arranged with a vector component acting on the associated intermediate element in the circumferential direction.

[0012] The torsional vibration damper proposed here has a small number of separate components and only a small number of rolling elements and complementary transmission tracks, which are referred to here as transmission tracks on the inter-element side and as (complementary) counter-tracks on the input and output sides. The input side is configured to receive torque, although it is not excluded that the input side could also be configured to deliver torque. For example, the input side represents the torque input in a primary state, such as in the drivetrain of a motor vehicle during a so-called traction torque, i.e., the output of torque from a drive motor, such as an internal combustion engine and / or an electric motor, via a transmission to the vehicle wheels for propulsion of the vehicle.The output side is configured to deliver torque, and preferably also to receive torque. In a motor vehicle drivetrain application, for example, the output side acts as the input side for a so-called thrust torque in a secondary state, i.e., when the inertial energy of the moving vehicle during engine braking or recuperation (generating electrical energy from deceleration) provides the input torque.

[0013] To prevent torsional vibrations from being directly transmitted from the input side to the output side or vice versa, at least one intermediate element is provided, preferably at least two. The at least one intermediate element is arranged in a torque-transmitting connection between the input side and the output side. This intermediate element is movable relative to both the input and output sides, allowing torsional vibrations to be induced into the intermediate element and thus onto the energy storage elements with a predetermined (functionally relevant) stiffness. This allows the natural frequency, a function of mass and stiffness, of the system in which the torsional vibration damper is integrated to be modified, preferably reduced.

[0014] The intermediate element is supported by at least one energy storage element, for example, a bow spring, a leaf spring, a gas pressure accumulator, or the like, either against itself or an adjacent intermediate element. The energy storage element is supported by a corresponding, preferably one-piece, connecting element of the associated intermediate element in a force-transmitting or moment-transmitting manner. For example, the connecting element is a contact surface and / or a rivet point.

[0015] The at least one intermediate element is supported at both the input and output sides by means of the series-connected rolling elements. The intermediate element has a transmission track for each of the rolling elements and a complementary counter-track for the same (associated) rolling element at both the input and output sides. The complementary counter-track is formed by the output side and the input side, respectively, preferably integrally with both. A torque is transmitted via the counter-track and transmission track. No torque is transmitted between the input and output sides via the at least one energy storage element.

[0016] For example, if a torque is applied, say from the input side, the rolling elements on the transmission track and the complementary counter-track are rolled upwards from a rest position in the corresponding direction on the ramp-like transmission track due to an existing torque gradient across the torsional vibration damper. "Rolling upwards" here simply illustrates that work is being done. More precisely, due to the geometric relationship, an opposing force from the energy storage element is overcome. "Rolling downwards" therefore means that stored energy is released from the energy storage element in the form of a force on the associated intermediate element. Up and down do not necessarily correspond to a spatial direction, even in a co-rotating coordinate system.

[0017] With this torque-induced movement, the rolling elements force the associated intermediate element into a relative movement with respect to the input and output sides, and the antagonistically acting energy storage element is correspondingly tensioned. If a change in the applied torque occurs, along with a speed difference between the input and output sides, as in the case of torsional vibration, the inertia of the other (torque-receiving) side, here the output side, opposes this, and the rolling elements roll (in a predetermined manner) back and forth on the transmission track and on the complementary counter-track around the position corresponding to the applied torque.In this way, the rolling elements work against the energy storage element, which is tensioned depending on a torque value, so that a natural frequency is changed compared to a rest position or a torque transmission without torsional vibration dampers (but with the same moving flywheel mass).

[0018] The force, in the form of compression, extension, torsion, or other energy storage, is absorbed by the appropriately designed energy storage element and transmitted with a time delay, preferably (almost) without dissipation, to the other side, for example, the output side. The torque input, for example, the input side, including the torsional vibration, is thus modified over time, preferably (almost) without loss, and transmitted to the output side. Furthermore, as explained above, the natural frequency is not constant but, due to the variable position of the intermediate element, depends on the torque gradient and thus on the applied torque.

[0019] In the reverse case, where torque is applied via the output side to the input side, the rolling elements roll in the opposite direction (compared to the previous description of applying torque via the input side) on the transmission track (upwards). This movement of the rolling elements causes a load on the energy storage element in the opposite direction, or, in the case of a paired arrangement, a relief of the load on the energy storage element that was loaded according to the above example (e.g., the first one) and a load on the other (e.g., the second) energy storage element.When two or more intermediate elements are mutually supported by means of a (common) energy storage element in a circular arrangement, all energy storage elements are clamped, for example in the manner of a screw clamp by means of a radial inward displacement of the energy storage elements.

[0020] When the torque changes, as occurs during torsional vibration, at least one energy storage element is deflected by the position corresponding to the applied torque. The stored energy is then transferred in the form of a modified, i.e., time-delayed, motion between the respective transmission path and its complementary opposite path, in this case to the output side, in conjunction with the rolling elements. This changes the natural frequency of the torque-transmitting system in which the torsional vibration damper is integrated.

[0021] In one embodiment, two or more intermediate elements are provided, which are preferably arranged rotationally symmetrically to the axis of rotation, so that the torsional vibration damper is balanced using simple means. For a small number of components and (transmission) tracks, an embodiment with exactly two intermediate elements is advantageous.

[0022] Preferably, two energy storage elements are provided to act on a (single) intermediate element, wherein the energy storage elements are arranged antagonistically to each other and are preferably balanced with each other according to the embodiment of the transmission tracks and complementary counter-tracks. In an alternative embodiment, at least one positive guidance is provided by means of which a movement is geometrically imposed on at least one of the intermediate elements, for example in the manner of a rail or groove and an encompassing pin or an engaging spring.

[0023] According to this proposal (in contrast to embodiments of the following proposal), the energy storage elements exert a force with a vector component in the circumferential direction on the associated intermediate element. The circumferential direction is defined by a concentric circle to the axis of rotation.

[0024] In one embodiment, the circumferential direction is oriented either constantly via a movement of the associated intermediate element, moving along a constant circle, or constantly or moving along a changing circle. The circle is at least large enough to touch the intermediate element, preferably large enough to intersect a contact point or contact surface where the forces between the energy storage element and the associated intermediate element are transmitted. A circumferential direction is oriented perpendicular to a radius with the axis of rotation as its center. The respective underlying radius intersects the contact point or contact surface of the energy storage element and the intermediate element. This results in a force direction at the intermediate element with a large vector component in the circumferential direction, preferably with a vector component in the circumferential direction that is larger than the vector component in the radial direction.This means that the force on the intermediate element is not purely radial, but rather exclusively (at the point of contact) tangential to the circumferential direction, or with a radial vector component and a tangential vector component (at the point of contact). This results in a force direction that can be transferred to the same intermediate element (from the other side), for example by means of a helical spring, or to the adjacent intermediate element, approximately along the circumferential direction. This allows, for example, for a deflection (or oscillation) of the energy storage element not only in the (radial) transverse direction, but also, or exclusively, in the circumferential direction.In an advantageous embodiment, the intermediate element is supported by the rolling elements in a way that is insufficiently defined, for example, solely radially defined, with the at least one energy storage element defining the movement as a result of the force application direction, for example, solely in the circumferential direction. Alternatively, an additional guide is provided for the intermediate element.

[0025] According to another aspect, a torsional vibration damper with a rotational axis for a drive train is proposed, comprising at least the following components: an input side for receiving a torque; an output side for delivering a torque; at least two intermediate elements in a torque-transmitting connection between the input side and the output side; each intermediate element having a first rolling element and a second rolling element, wherein the intermediate elements each have a first transmission track for rolling the first rolling element and a second transmission track for rolling the second rolling element, wherein the input side has a first counter-track complementary to the first transmission track and the output side has a second counter-track complementary to the second transmission track, wherein the first rolling element is guided to roll between the first transmission track and the first counter-track and the second rolling element is guided to roll between the second transmission track and the second counter-track;a number of energy storage elements corresponding to the number of intermediate elements, by means of which the intermediate element assigned to the energy storage element is oscillatively supported; wherein each of the intermediate elements is supported by means of the associated energy storage elements on at least one adjacent intermediate element.

[0026] The torsional vibration damper is characterized primarily by the fact that only the first rolling element and the second rolling element are provided as rolling bodies for each intermediate element.

[0027] Reference is made to the preceding explanation of the underlying principle, as well as to the definitions and relationships of the input side, the output side, each intermediate element and associated energy storage element, and the rolling elements with their associated transmission tracks and counter-tracks. In contrast to the previous description, at least two intermediate elements and at least one, preferably two, energy storage elements are provided here, wherein the intermediate elements are supported against each other by means of the at least one energy storage element in a force-transmitting manner.

[0028] According to this proposal (in contrast to embodiments of the aforementioned proposal), the at least one energy storage element is supported by the rolling elements in a way that is necessarily insufficiently defined, for example, defined exclusively radially, by providing only two rolling elements for each intermediate element: a single (e.g., first) rolling element on the input side and a single (e.g., second) rolling element on the output side. The at least one energy storage element acting on an intermediate element and supported on at least one (immediately) adjacent intermediate element defines the movement as a result of the force application direction, for example, exclusively in the circumferential direction. For a safe design, for example, a positive guidance is additionally provided by means of which the movement of the respective intermediate element is (geometrically) overdefined.

[0029] It is further proposed that the torsional vibration damper has the features of the aforementioned embodiments.

[0030] In this embodiment, each intermediate element of the plurality of intermediate elements is supported by only two rolling elements, i.e., it is either indeterminately supported or only just determinately supported, provided that the force required to secure the position of the transmission track relative to the complementary counter-track and the intervening rolling element, as well as the intentionally created degree of freedom on the transmission track (e.g., implemented as an indifferent equilibrium position), is disregarded. This force is, for example, supported during operation by the inertial response to the centripetal force (centrifugal force). The intentionally created degree of freedom of the transmission track, for example, as an indifferent equilibrium, is defined and absorbed by the two energy storage elements. For example, the rolling of a rolling element on the transmission track (and complementary counter-track) results in a movement with a radial and / or tangential vector component.Consequently, a path is traversed, which is stored as potential in at least one of the associated energy storage elements. Furthermore, the energy storage elements preferably also apply the necessary force, for example, a purely radial force, to hold the counter-track and the translation track relative to each other in such a way that the associated rolling element can only move between them by rolling motion. Thus, any movement of a rolling element always induces a relative movement between the counter-track and the complementary translation track, and therefore between the intermediate element and the input and output sides. Radial support and / or forced guidance for the intermediate element, for example by means of a larger number of rolling elements, is not necessary.

[0031] In a further advantageous embodiment of the torsional vibration damper, it is proposed that exactly three intermediate elements and exactly three energy storage elements are provided, wherein the first intermediate element and the second intermediate element are supported against each other by means of the first energy storage element, the second intermediate element and the third intermediate element are supported against each other by means of the second energy storage element, and the first intermediate element and the third intermediate element are supported against each other by means of the third energy storage element.

[0032] In this embodiment, the number of intermediate elements, transmission tracks, counter tracks, rolling elements, and energy storage elements is still small, while the effort required to meet manufacturing tolerances on the transmission tracks and counter tracks is reduced compared to a positive guidance system with more than two rolling elements per intermediate element. Within a design-specific framework, for example, determined by the geometric constraints, a manufacturing-related deviation from the ideal alignment of the intermediate element in its rest position is more tolerable and / or can be compensated for by the energy storage elements during an adjustment process.

[0033] In an advantageous embodiment of the torsional vibration damper, it is further proposed that the at least one intermediate element is supported solely by means of the at least one associated energy storage element and by means of the rolling elements.

[0034] In this embodiment, the intermediate element is brought into a stable equilibrium without additional (forced) guide elements, solely by means of the transmission tracks, the complementary counter-tracks, and the respective rolling elements in conjunction with the associated energy storage elements. A stable equilibrium here means that it cannot be dislodged from its intended position, at least by a design torque deflection and torque oscillations. At least for mobile applications, the equilibrium is so stable that even (design) lateral forces, such as vibrations, cannot dislodge this arrangement from its intended position; for example, the rolling element cannot be lifted from one of its tracks. The vector component of the force of the energy storage elements in the radial direction, or perpendicular to (the adjacent section of) the transmission track and counter-track, is always greater than any lifting (external) force.

[0035] This is ensured if the direction of the applied forces, i.e., the orientation of the force vector along or parallel to a line of action of the energy storage elements, intersects at the moment balance point of the intermediate element with those lines of action of the resultant (counter-)forces over the rolling elements, which run through the rolling center (rolling axis) of the rolling element and are oriented perpendicular to the transmission path and to the complementary counter-running path, regardless of the deflection of the intermediate element. Thus, a moment equilibrium exists at the intermediate element around the moment balance point of the intermediate element. It follows intrinsically that the force component of the force vectors transmitted via the rolling elements corresponds to the force components of the energy storage elements acting on the intermediate element.This means that if the force of the energy storage elements is increased, the resulting force via the rolling elements also increases according to this design rule. The force vectors of two antagonistic energy storage elements thus form a (closed) force polygon, meaning that, according to vector addition rules, the sum of the forces is zero.

[0036] In a further advantageous embodiment of the torsional vibration damper, it is proposed that the two rolling elements are arranged radially apart from each other.

[0037] The advantage of this embodiment is a small required installation space in the circumferential direction, so that, for example, the intermediate elements can be made narrow in the circumferential direction, thus allowing more installation space for the energy storage elements and, for example, a large angle of rotation, and thus a low functional stiffness with simultaneously high stiffness of at least one energy storage element.

[0038] In a further advantageous embodiment of the torsional vibration damper, it is proposed that the two rolling elements are arranged spaced apart from each other in the circumferential direction.

[0039] An advantage of this embodiment is the small radial space required, allowing, for example, the intermediate elements to be arranged on a large circumferential circle. This enables, for instance, a large angle of rotation and thus low functional stiffness while maintaining high stiffness in at least one energy storage element. Alternatively or additionally, torque can be transmitted via identical transmission paths, resulting in the same magnitude.

[0040] In a further advantageous embodiment of the torsional vibration damper, it is proposed that the two rolling elements are arranged radially and circumferentially spaced apart from each other.

[0041] In this embodiment, the advantages of the aforementioned embodiment can be combined with each other or approximated to an ideal with only minor deviations.

[0042] In an advantageous embodiment of the torsional vibration damper, it is further proposed that the transmission tracks and their respective complementary counter-tracks each comprise a tensile torque pairing with a first transmission curve and a shear torque pairing with a second transmission curve, wherein the tensile torque pairing is configured for torque transmission from the input side to the output side, and wherein the shear torque pairing is configured for torque transmission from the output side to the input side, and wherein the first transmission curve and the second transmission curve have at least partially different transmission profiles.

[0043] In a theoretical application, tensile torque and shear torque are fundamentally indistinguishable. The terms are therefore neutral and serve solely to easily differentiate the direction of torque transmission. These terms are derived from the common terminology used in a motor vehicle's drivetrain but are transferable to other applications. The tensile torque pair is present during a tensile torque transmission, for example, from the input side to the output side. As the torque increases, the rolling element on the tensile torque pair rolls against the force of the antagonistic energy storage element (upward). This increases the potential of this antagonistic energy storage element, for example, by stressing it and thus changing its stiffness.Torsional vibrations therefore counteract a greater force from the antagonistic energy storage element with increasing torque, and the natural frequency is thus changed. The same applies to the shear torque pair, whereby the rolling element is forced to roll (highly) on the shear torque pair due to the load on the energy storage element.

[0044] In this embodiment, the first and second translation curves, each starting from a common point in the equilibrium position, have different translation profiles. The stiffness properties of the torsional vibration damper can therefore be individually adjusted for a tensile moment and a shear moment (differently).

[0045] InIn one embodiment, for example, low stiffness is required for transmitting a tensile torque, which can be achieved with a larger angle of twist (a lower reduction ratio, i.e., a smaller denominator of the transmission ratio) than is desired for a shear torque (a higher reduction ratio). Furthermore, a progressive or degressive stiffness profile may be desired, or even a stiffness profile with multiple variations. For example, a slight increase in stiffness is desired in the near-idle range, a steep increase in stiffness is desired for a main load torque, which then decreases progressively, and a further progressive increase in stiffness is achieved up to the maximum transmissible torque.

[0046] The translation path and the complementary counter-path are designed according to the respective deflection position of the intermediate element, so that the translation curve is superimposed on the movement of the intermediate element. The translation path and the complementary counter-path are preferably designed for a moment equilibrium as described above, preferably so that no additional guide device for the intermediate element is necessary.

[0047] In a further advantageous embodiment of the torsional vibration damper, it is proposed that at least one intermediate element is prestressed by means of two antagonistic energy storage elements.

[0048] In this embodiment, the preload of the energy storage elements against the rolling elements can be reliably and easily controlled via the intermediate element(s). For example, with identical energy storage elements, the dependence on component tolerances, such as the spring characteristic of one energy storage element, is minimal because the tolerances mutually reduce each other. For instance, a lower stiffness than the target stiffness of the first energy storage element is compensated for or reduced by the higher stiffness of the second energy storage element. With the same direction of deviation, the overall preload is reduced or increased compared to the target preload, but is nevertheless balanced due to the antagonistic effect, for example, on both sides of the intermediate element. In one embodiment, only the rest position of the intermediate element is changed.Preferably, the tolerance is so low that the rest position remains within a predetermined tolerance range. In an embodiment with three intermediate elements, the (three) energy storage elements are interconnected in such a way that the first (or second) energy storage element of the first intermediate element is also in an antagonistic operative connection with the second (or first) energy storage element of the second intermediate element, thus achieving a compensating effect on the component tolerance of the energy storage elements. Overall, this reduces the required manufacturing accuracy, assembly effort, adjustment effort, and / or the cost of standard components due to the lower component quality.

[0049] In a further advantageous embodiment of the torsional vibration damper, it is proposed that the first energy storage element exerts a first force and a first force direction on the associated intermediate element, and that the second energy storage element exerts a second force and a second force direction on the associated intermediate element, wherein the first force and the second force differ from each other and / or the first force direction and the second force direction differ from each other in a rest position.

[0050] It should be noted that the energy storage elements do not tilt about a radial axis, or rather, that such a tilt is not conducive to influencing the natural frequency. The force direction described here is therefore defined as a vector lying in the plane of rotation to which the axis of rotation is normal. Furthermore, it should be noted that the force direction of the two antagonistic energy storage elements is always not the same when considered in a global, i.e., common, coordinate system. Here, the force direction is meant in comparison to the reflection of the other force direction, namely the reflection across a rest axis or center line (in the rest position) of the intermediate element and, potentially, the force side, which then differs from the other force direction.The center line of the intermediate element is not related to the geometric or mass-related center, but to the acting forces.

[0051] Here, force refers solely to the magnitude of a force vector, whereby the force vector can be decomposed into the force (magnitude) and the force direction (direction of action).

[0052] Furthermore, it should be noted that the forces and force directions of the two antagonistic energy storage elements differ from each other in a deflected state of the intermediate element in a symmetrical design, and can be the same in a deflected state in a non-symmetrical design, as proposed here.

[0053] In this embodiment, different torque characteristics are provided for the transmission of tensile torque and the transmission of opposing shear torque, so that the influence of the torsional vibration damper on the natural frequency varies depending on the torque direction. Preferably, the intermediate element is brought into equilibrium by means of a corresponding transmission path, as described above.

[0054] In one embodiment, the two antagonistic energy storage elements used are identical (in their uninstalled, i.e., relaxed, state). The differing force is achieved, for example, by means of the different shapes of the tensile torque pairing and the shear torque pairing of the transmission track (see the preceding description). In another embodiment, the differing force is achieved by means of a different installation distance between the force side and the intermediate element.

[0055] The different direction of force is achieved, for example, by different inclinations of the contact surfaces on the intermediate element and / or on the force side for the two antagonistic energy storage elements. In one embodiment, the direction of force is variable via a deflection of the intermediate element, whereby at least one of the two antagonistic energy storage elements tilts about an axis parallel to the axis of rotation. As a result of the different direction of force, the deflection, i.e., the energy absorption at the same deflection of the intermediate element, differs for otherwise identical energy storage elements. Thus, in this installation situation, the stiffness of identical antagonistic energy storage elements differs. Using identical energy storage elements is advantageous with regard to costs, assembly effort, and assembly safety.In the above context, identical energy storage elements are mentioned solely to clarify the relationship, and the application of different force directions is not limited to such a case.

[0056] In an advantageous embodiment of the torsional vibration damper, it is further proposed that the at least one energy storage element is a helical compression spring with a straight spring axis.

[0057] A helical compression spring with a straight spring axis, also known as a (purely) cylindrical helical compression spring, is a widely used standard component whose elastic and (low) dissipative properties are well understood and easily controlled. Tolerances in the overall length or the spring characteristic curve over a predetermined installation length can be compensated for with simple means. Furthermore, such helical compression springs do not require additional guides, which would otherwise cause friction and thus reduce efficiency and / or result in damping characteristics that are more difficult to determine due to hysteresis effects. In addition, a helical compression spring allows for a wide range of spring characteristics, which can be adjusted by factors such as the coil pitch, wire diameter, the ratio of the installed length to the relaxed length, and the choice of material.

[0058] Furthermore, helical compression springs with a straight spring axis are break-resistant compared to other types of springs, such as steel springs, and in some embodiments can be loaded to their limit, so that in the event of an overload occurring according to the design on the torsional vibration damper, no additional safety element against breakage of the energy storage element needs to be provided in such a design of the energy storage element that can be brought to its limit.Furthermore, a helical compression spring offers the advantage of a very long possible spring travel combined with high spring stiffness. This allows for the transmission of a large torque via at least one energy storage element and enables suitable gear reduction through the transmission path. As a result, the amplitude of the intermediate element's movement is reduced relative to the amplitude of the torsional vibration, thus resulting in a very small spring travel for the helical compression spring. Consequently, despite its high stiffness, the helical compression spring counteracts torsional vibration with a (suitably) low force.

[0059] The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, although it should be noted that the drawings are not dimensionally accurate and are not suitable for defining size relationships. It is illustrated in Fig. 1: A schematic diagram of a torsional vibration damper in a first embodiment; Fig. 2: A schematic diagram of a torsional vibration damper in a second embodiment; Fig. 3: A diagram of the forces acting on an intermediate element; Fig. 4: A force polygon of the forces acting according to Fig. 3; Fig. 5: a moment-angle-torsion diagram with a first translation curve; Fig. 6: a moment-angle-torsion diagram with a second translation curve; Fig. 7: a moment-angle-torsion diagram with a third translation curve; and Fig. 8: a moment-angle-torsion diagram with a fourth and fifth translation curve.

[0060] Fig. 1 and Fig. 2 Each of the schematic diagrams shows exemplary embodiments of a torsional vibration damper 1, which, for the sake of clarity, are depicted in a largely identical manner, and cross-reference is made to the descriptions of the respective figures for identical components. In this case, an annular disk forms one of the input sides. 4. At the center, at the common axis of rotation 2 is another disc element, for example as the exit side 5 formed. Alternatively, the ring disc is the exit side. 5and the disc element the entrance side 4. The following describes the aforementioned variant, whereby the terms are interchangeable.

[0061] As indicated by the arrows, a tensile moment 45 from the entrance side 4 to the homepage 5 transferable and a thrust moment 46 from the starting side 5 to the homepage 4 transferable. In one embodiment, the direction of the moment is reversed.

[0062] Intermediate between the input side 4 and the exit page 5 are three intermediate elements 6, 7, 8 provided for, whereby the respective intermediate element 6, 7, 8 of paired energy storage elements 15, 16, 17 transmitting force with the respective adjacent intermediate element 6, 7, 8 is connected. By means of a first rolling element. 9 is the respective intermediate element 6, 7, 8on the entrance side 4 supported and by means of a second rolling element 10 is the respective intermediate element 6, 7, 8 on the exit side 5 supported. The first rolling element 9 is transferable on an intermediate-element-side first translation path 11 and a first complementary counter-track 13 on the entrance side 4 The second rolling element is supported in a force-transmitting and thus torque-transmitting manner. 10 is transferable on a second translation path on the side of the intermediate element 12 and a second complementary counter-track 14 on the exit side 5 The rolling elements are supported in a force-transmitting and thus torque-transmitting manner. 9, 10 are thereby by means of the energy storage elements 15, 16, 17 against the translation path 11, 12 and against the opposite lane 13, 14 pre-tensioned and thus guided in a rolling manner. The energy storage elements 15, 16, 17hold the intermediate element 6, 7, 8 acting antagonistically towards each other in a resting position as shown. At the third intermediate element 8 at the first rolling element 9 and the second rolling element 10 (after the designation at the first intermediate element) 6) It has been shown (for the sake of clarity, pars pro toto) that a tensile moment pair exists laterally from the rest position. 21 from the respective complementary ramp portion of the translation path 11, 12 and the opposite track 13, 14 as well as a shear moment pairing 23 on the opposite side from the complementary ramp components of the translation path 11, 12 and the opposite track 13, 14 are formed. Again, solely for the sake of clarity, the tensile moment pairing is represented pars-pro-toto. 21 only on the first rolling element 9 shown and accordingly the shear moment pairing 23 only on the second rolling element 10shown. However, these pairings are present on each of the rolling elements. 9, 10 each from the translation path on the inter-element side 11, 12 and the complementary opposite path 13, 14 formed. Their mode of operation is explained in detail below. In the embodiments shown, the intermediate elements are 6, 7, 8 solely via the respective rolling elements 9, 10 on the entrance side 4 and on the exit side 5 The intermediate elements are supported and aligned with each other. 6, 7, 8 by means of the energy storage elements 15, 16, 17 supported. Additional guidance is preferably not provided.

[0063] In Fig. 1 are the first rolling element 9 and the second rolling element 10 of a respective intermediate element 6, 7, The eight elements are arranged radially spaced apart from each other and, in their rest position, are located on a common radius. Therefore, in their rest position, they have no circumferential spacing. 19up. In Fig. 2 is an alternative embodiment with regard to the arrangement of the two rolling elements 9, 10 of a respective intermediate element 6, 7, 8 pointed towards each other, with the two rolling elements 9, 10 do not have a radial distance, but in the circumferential direction 19 are spaced apart from each other. In the illustrated embodiments, the energy storage elements are spaced apart for better comparability. 15, 16, 17 They are executed in the same manner and arranged in the same way.

[0064] In Fig. 3 is a diagram of the moment equilibrium and in Fig. 4 a force polygon over the first intermediate element 6, second intermediate element 7 or third intermediate element 8 with a first rolling element 9 and the second rolling element 10 according to the embodiment in Fig. 1 shown here is the intermediate element. 6, 7, 8lifted from its rest position and inclined at a deflection angle to the rest position relative to the rest line 35 deflected. The resting line 35 It always passes through the moment balance point. 3 of the intermediate element 6, 7, 8, but only in the rest position through the rolling axes of both rolling elements 9, 10, but always through one of the two rolling axes (here of the second rolling element) 10). At this moment balance point 3 of the intermediate element 6, 7, 8 A moment equilibrium must prevail if it is required that no additional (forced) guidance be provided for the intermediate element. 6, 7, 8 is planned. The resulting force directions 30, 32 via the rolling elements 9, 10, so the first print line 37 of the first rolling element 9 and the second printing line 38 of the second rolling element 10, must lead to the adjacent (theoretically infinitesimal) section of the translation path 11, 12must always be vertically aligned and pass through the moment balance point 3 The course of events must be maintained. To ensure this rule is always followed, a parallel to the first line of action must be established. 33 the first force 25 starting from the first energy storage element 15 with a second parallel line of action spaced at the same distance or proportionally to the force 34 the second force 26 starting from the other (for example, third) energy storage element 16 with the two print lines 37, 38 at the moment balance point 3 Cut so that no (effective) lever arm is created. For suitable contact pressure of the rolling elements. 9, 10 are the first force 25 and the second force 26 (here only at the second force) 26 (represented) into a tangential vector component 18 (functionally effective part) and into a radial vector part 44(Contact factor for the rolling elements) 9, 10) subdivided. The orientation of the tangential vector component 18 results from the tangent at the point of force application to the intermediate element 6, 7, 8 along the circumferential direction 19 on a radius of the circle 36, at which point this force is applied. Furthermore, it is required that the first force 25, the second force 26 and the resulting forces 29, 31 form a self-canceling force triangle, as in Fig. 4 as shown. For this, the first direction of force must be considered. 27, the second direction of force 28 and the resulting directions of forces 30, 32 the two rolling elements 9, 10 as shown. From the position shown, it follows that both the first energy storage element 15 (compare Fig. 1 ) as well as the second energy storage element 16 (compare Fig. 1 )It is tensioned more strongly, resulting in an increased preload force on the intermediate element. 6, 7, 8 The increased tension in this embodiment results from a movement of the intermediate element. 6, 7, 8 radially inwards, so that the energy storage elements 15, 16, 17 with radial inwards and between the adjacent intermediate elements 6, 7, 8 are compressed in the manner of a screw clamp. The intermediate elements 6, 7, 8 They are therefore moved in such a way that the resulting distance along the spring axes 41, 42, 43 the energy storage elements 15, 16, 17 between the intermediate elements 6, 7, 8 is shortened compared to the rest position if increased stiffness is desired at a higher torque (compare Figs. 5 to 8 ). For the correct alignment of the print lines 37, 38 that is, the lines of action of the resultant forces 29, 31 on the rolling elements 9, 10 Is it necessary that the print lines 37, 38,which each define the rolling axis of the associated rolling element 9, 10 and the moment balance point 3 cuts, always perpendicular to the translation path 11, 12 Here is the first translation curve. 22, which the tensile moment 45 is assigned. The respective magnitude of the resulting force. 29, 31 and the resulting direction of force 30, 32 then result intrinsically from the applied first force 25 and second force 26.

[0065] In the Figs. 5 to 8 Moment-angle-moment diagrams are shown, in which the moment axis 39 the ordinate forms and the axis of rotation 40 the abscissa. To the right of the ordinate, in this example, a tensile moment diagram with positively represented moment and angle of twist is shown, and to the left of the ordinate, a shear moment diagram with negatively represented moment and angle of twist.

[0066] In Fig. 5is a first translation curve 22, then belonging to the tensile torque pairing 21, and a second translation curve 24, then belonging to the shear moment pairing 23, shown in a two-part progressive form, so that at low torque values ​​there is a flat curve rise and at high torque values ​​there is a steep curve rise.

[0067] In Fig. 6 Accordingly, a two-part degressive variant is shown, in which there is a steep curve rise at low torque values ​​and a flattened curve rise at high torque values.

[0068] In Fig. 7 One variant is shown in which a progressive and degressive course alternates and in Fig. 8A rigid system with a steep curve, represented by a solid line, is shown in comparison to a system with a flat curve, represented by a dashed line.

[0069] For the embodiment in Fig. 1 and Fig. 2 without additional guidance of the intermediate element 6, 7, 8 is such a translation curve 22, 24 according to the moment equilibrium and force equilibrium as in Fig. 3 and Fig. 4 explained to be adhered to. The illustrated translation curve. 22, 24 is therefore superimposed on the requirement for the translation path 11, 12 according to the description to Fig. 1 (and Fig. 2) ) to be performed. Furthermore, in one embodiment, the force 25 or the stiffness of the first energy storage element 15 compared to the second energy storage element 16 Different in the resting position and not as in Fig. 1 and Fig. 2The design is symmetrically indicated. This is further used for the superposition to achieve the desired translation curve. 22, 24 to be noted.

[0070] The torsional vibration damper proposed here allows for cost-effective and efficient manipulation of the natural frequency using only a few components.

Claims

1. A torsional vibration damper (1) with a rotational axis (2) for a powertrain, comprising at least the following components: - an input side (4) for receiving a torque; - an output side (5) for outputting a torque, - at least two intermediate elements (6, 7, 8) in torque-transmitting connection between the input side (4) and the output side (5); - a first rolling body (9) and a second rolling body (10) for each intermediate element (6, 7, 8), wherein the intermediate elements (6, 7, 8) each comprise a first transmission track (11) for rolling of the first rolling body (9) and a second transmission track (12) for rolling of the second rolling body (10), the input side (4) comprising a first counter-track (13) complementary to the first transmission track (11) and the output side (5) comprising a second counter-track (14) complementary to the second transmission track (12), the first rolling body (9) being guided to roll between the first transmission track (11) and the first counter-track (13) and the second rolling body (10) being guided to roll between the second transmission track (12) and the second counter-track (14); - a number of energy storage elements (15, 16, 17) corresponding to the number of intermediate elements, by means of which the intermediate element (6, 7, 8) associated to the respective energy storage element (15, 16, 17) is supported so as to be oscillatable, each of the intermediate elements (6, 7, 8) being supported by means of the associated energy storage elements (15, 16, 17) on the at least one adjacent intermediate element (7, 8, 6), characterised in that only the first rolling body (9) and the second rolling body (10) are provided as rolling bodies for each intermediate element (6, 7, 8).

2. The torsional vibration damper according to claim 1, wherein the energy storage element (15, 16, 17) is arranged with a vector component (18) acting in the circumferential direction (19) on the associated intermediate element (6, 7, 8), wherein exactly three intermediate elements (6, 7, 8) and exactly three energy storage elements (15, 16, 17) are provided, the first intermediate element (6) and the second intermediate element (7) being supported against one another by means of the first energy storage element (15), the second intermediate element (7) and the third intermediate element (8) being supported against one another by means of the second energy storage element (16), and the first intermediate element (6) and the third intermediate element (8) being supported against one another by means of the third energy storage element (17).

3. The torsional vibration damper (1) according to claim 1 or 2, wherein each of the intermediate elements (6, 7, 8) is mounted solely by means of the at least one associated energy storage element (15, 16, 17) and by means of the rolling bodies (9, 10).

4. The torsional vibration damper (1) according to any one of the preceding claims, wherein the two rolling bodies (9, 10) are arranged radially spaced apart from each other and / or are arranged spaced apart from each other in the circumferential direction (19).

5. The torsional vibration damper (1) according to any one of the preceding claims, wherein the transmission tracks (11, 12) and the complementary counter-tracks (13, 14) each comprise a tensile torque pair (21) having a first transmission curve (22) and a compressive torque pair (23) having a second transmission curve (24), the tensile torque pair (21) being configured for torque transmission from the input side (4) to the output side (5), and the compressive torque pair (23) being configured for torque transmission from the output side (5) to the input side (4), and wherein the first transmission curve (22) and the second transmission curve (24) have at least partially different transmission profiles.

6. The torsional vibration damper (1) according to any one of the preceding claims, wherein the intermediate elements (6, 7, 8) are prestressed by means of two antagonistic energy storage elements (15, 16, 17), wherein preferably the first energy storage element (15) exerts a first force (25) and a first force direction (27) on the associated intermediate element (6, 7) and the second energy storage element (16) exerts a second force (26) and a second force direction (28) on the associated intermediate element (6, 8), and wherein the first force (25) and the second force (26) differ from each other in a rest position and / or the first force direction (27) and the second force direction (28) differ from each other in a rest position.

7. The torsional vibration damper (1) according to any one of the preceding claims, wherein the energy storage elements (15, 16, 17) are helical compression springs which have straight spring axes (41, 42, 43).