Torsional vibration damper comprising a damping system, a damping device and a ground device

A torsional vibration damper (70) with a damping device which has an input (67) and an output (72) which is operatively connected to a driven side (73). The output is connected to a mass damper system (1) and also to a mass arrangement (100). One of the two subassemblies—i.e., mass damper system (1) and mass arrangement (100)—which are connected to the output (72) of the damping device (70) engages at the respective other subassembly comprising mass damper system or mass arrangement which is in turn connected to the output by a connection arrangement (77).

PRIORITY CLAIM

This is a U.S. national stage of application No. PCT/EP2015/055904, filed on Mar. 20, 2015. Priority is claimed on the following application: Country: Germany, Application No.: 10 2014 207 258.1, the content of which is incorporated herein in its entirety by reference.

FIELD OF THE INVENTION

The present invention is directed to a torsional vibration damper with a damping device which has an input and an output which is operatively connected to a driven side, and the output is connected to a mass damper system and also to a mass arrangement.

BACKGROUND OF THE INVENTION

A torsional vibration damper of the type mentioned above can be seen from US20140090514 in FIG. 3. This torsional vibration damper is provided for a hydrodynamic coupling arrangement having a hydrodynamic circuit formed by an impeller, a turbine and a stator. The input of the torsional vibration damper is operatively connected to a drive such as an internal combustion engine via a clutch device serving to bypass the hydrodynamic circuit during predetermined operating states, while the output of the torsional vibration damper is operatively connected to a driven side which is implemented, for example, as a torsion damper hub. Accordingly, the output of the torsional vibration damper is connected not only to a torsion damper hub but also to a mass damper system and to the turbine, and the turbine acts as a mass arrangement associated with the output of the torsional vibration damper.

In torsional vibration dampers having a damping device whose output is connected to a mass damper system as well as to a mass arrangement, there is the advantage of minimal rotational irregularity even under full load at very low speeds, for example, at a speed of 1,000 revolutions per minute. In conflict with this advantage, however, is the fact that there is a significant rise in rotational irregularity at higher speeds, for example, within a speed range of 1,500 to 1,800 revolutions per minute. This rise in rotational irregularity is accompanied by sharply declining deflection angles at the output of the damping device even when torsional vibrations are present at the input of the damping device. This behavior of the damping device, the output of which stays at least approximately in a vibration node, is determined through effects from the transmission arrangement. It is particularly disadvantageous for the output of the damping device to persist in a vibration node because this would dispense with the vibration excitations which are vital for the functioning of damper masses of the mass damper system connected to the output of the damping device. This is especially true with respect to the above-mentioned significant increase in rotational irregularity.

It is an object of the invention to construct a torsional vibration damper with a damping device, whose output is connected to a mass damper system and also to a mass arrangement, such that an increase in rotational irregularity in a determined speed range is at least limited.

SUMMARY OF THE INVENTION

A torsional vibration damper of this type is constructed with a damping device which has an input and an output which is operatively connected to a driven side, and the output is connected to a mass damper system and also to a mass arrangement.

According to a first embodiment, one of the two subassemblies in this torsional vibration damper—i.e., mass damper system or mass arrangement—which are connected to the output of the damping device engages at the respective other subassembly comprising mass damper system or mass arrangement which is in turn connected to the output by a connection arrangement. By separating the two connection points, a compact mode of construction can be achieved in the region of the output particularly in axial direction. In so doing, the mass arrangement preferably engages at the damper mass carrier of the mass damper system by a holder via a connection such as a riveted joint, while this damper mass carrier has a connection to the output by the connection arrangement which can likewise be constructed as a riveted joint.

According to an alternative embodiment, the two subassemblies in this torsional vibration damper—i.e., mass damper system and mass arrangement—which are connected to the output of the damping device engage at the output under axial offset by a common connection arrangement. In this case, the connection arrangement has a plurality of axially multi-stepped rivets which extend not only through the torsion damper hub but at least also through the damper mass carrier. The alternative embodiment is preferable when a connection point is to be dispensed with.

In both of the embodiments mentioned above, the driven side is preferably formed as torsion damper hub having a radial support for the damper mass carrier of the mass damper system and possibly also for a holder of the mass arrangement.

As an alternative to a connection arrangement formed by riveting, a connection arrangement can also be selected in which the radial support at the torsion damper hub has a first toothing and the damper mass carrier has a second toothing in operative connection with the first toothing. In order to secure these two toothings axially, they are held in an axially predetermined position relative to one another by an interference fit.

Insofar as the damping device of the torsional vibration damper has a plurality of damping units, of which the respective damping unit on the drive side is in operative connection with the respective damping unit on the driven side via an intermediate transmission, a selection of a predetermined energy storage combination, a configuration of energy storages for a predetermined load, or a construction of energy storages with a predetermined coil progression can be carried out in at least one damping unit of the damping device. For the selection of a predetermined energy storage combination, it is conceivable, for example, that there is at least one energy storage package in which, in order to achieve a multi-step characteristic, the individual energy storages are either formed with different stiffness and arranged at an offset in circumferential direction or in which the individual energy storages are arranged coaxial to one another and have different length extensions in extension direction. To configure energy storages for a determined load, it can be provided that the energy storages of at least one damping unit are designed for reducing the stiffness at partial load. In this case, however, it is necessary to have ready at least one damping unit with energy storages configured for full load so as to prevent rotational angle stops from taking effect in all of the damping units after predetermined deformation of the energy storages, which would cause the mass damper system to be acted upon directly by excitations present at the input of the torsional vibration damper. Finally, the construction of energy storages with a predetermined coil progression can be provided in that at least a first area with coils having a larger spacing and at least a second area with coils having a smaller spacing are provided, for example, in an energy storage. The stiffness of the energy storage is smaller in the first area than in the second area.

The torsional vibration damper according to the invention is particularly suited for use in a hydrodynamic coupling arrangement. A coupling arrangement of this type preferably has a hydrodynamic circuit formed at least by an impeller and a turbine, and a clutch device for bypassing the hydrodynamic circuit in predetermined operating states. While the mass arrangement of the torsional vibration damper is formed by the turbine, a holder of the mass arrangement for connecting the mass arrangement to the torsion damper hub is in the form of the turbine base of the turbine.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

FIG. 1shows a coupling arrangement56which has a housing54and, since it is constructed as a hydrodynamic torque converter90, a hydrodynamic circuit60with impeller61, turbine62and stator63. Further, a clutch device64is provided which is formed with a clutch piston65and with a friction disk clutch66, wherein radially outer friction disk elements84of the friction disk clutch66are in toothed engagement with an outer wall86of the housing54and radially inner friction disk elements85of the friction disk clutch66are in toothed engagement with a friction disk element carrier87which engages at an input67of a damping device70. Depending on the control of the clutch piston65which is arranged on a piston carrier82so as to be axially displaceable, the clutch device64is movable between an engagement position and a release position. The input67of the damping device70is connected via a first damping unit68to an intermediate transmission74which has two intermediate transmission elements74aand74barranged so as to be spaced apart axially and held at a fixed axial distance by spacer elements81. The intermediate transmission74is connected via a second damping unit69to an output72which cooperates with a torsion damper hub71acting as driven side73. The damping device70serves together with a mass damper system1and a mass arrangement100as torsional vibration damper30, the mass arrangement100being formed in the present case by the turbine62.

As is further shown inFIG. 1, the mass damper system1has a damper mass carrier3with two damper mass carrier elements5aand5barranged so as to be spaced apart axially, damper masses7being received therebetween. Spacer pieces11which serve in each instance to receive an annular component part32(FIGS. 2, 3) as will be described in detail in the following are provided axially between the two damper mass carrier elements5aand5b. In contrast to damper mass carrier element5b, damper mass carrier element5ahas a radially inwardly extending radial lengthening78in order to be connected to the output72of the torsional vibration damper30and, therefore, to the torsion damper hub71forming the driven side73by a connection arrangement77formed as riveted joint. The mass arrangement100also has a radially inwardly extending holder102which is formed by the turbine base92and which is connected by the connection arrangement77to the output72of the torsional vibration damper30and, therefore, to the torsion damper hub71forming the driven side73. In order that the radial lengthening78of the mass damper system1and the holder102of the mass arrangement100can be connected to the output72as well as to the torsion damper hub71, the connection arrangement77has axially multi-stepped rivets76. Not only do these axially multi-stepped rivets76connect all of the above-mentioned component parts to one another axially, but beyond this they also form intermediate riveted joints83such that, for example, the radial lengthening78of the mass damper system1and the holder102of the mass arrangement100are first connected to the output72and to the torsion damper hub71when the connection of the two latter component parts, i.e., output72and torsion damper hub71, has already been produced. Accordingly, a staggered production is possible, which has advantages in the manufacturing process.

The mass damper system1is supported at a radial support97provided at the radial outer side of the torsion damper hub71via the radial lengthening78, and the mass arrangement100is supported at radial support97via the holder102.

In contrast,FIG. 4shows a torsional vibration damper30in which the mass arrangement100also has a radially inwardly extending holder102formed by the turbine base92, but this mass arrangement100is not connected directly the output72of the torsional vibration damper30and, therefore, to the driven side73and is merely indirectly connected via the radially inwardly extending radial lengthening78of the damper mass carrier element5a. To this end, a first connection93formed by riveting is provided between the holder102of the mass arrangement100and the radial lengthening78of the damper mass carrier element5a, and a second connection94formed by the connection arrangement77is provided between the radial lengthening78of the damper mass carrier element5aand the output72of the torsional vibration damper30. Owing to the radial and/or axial offset of the connections93,94, the solution according toFIG. 4is appreciably more compact axially than the solution according toFIG. 1in which, however, it is sufficient to form only one individual connection in the form of the connection arrangement77.

As an alternative to the connection of the radial lengthening78of the damper mass carrier element5aand possibly also of the holder102of the mass arrangement100to the output72of the torsional vibration damper30by riveting, it is also conceivable to form this connection by teeth95,96as is shown inFIG. 6, where toothing95is formed as outer toothing in the radial support97at the radial outer side of the torsion damper hub71and toothing96is formed as inner toothing at the radial lengthening78of the damper mass carrier element5aand possibly also at the holder102of the mass arrangement100. The two toothings95,96are axially secured relative to one another by interference fit134.

The damping units68and69are configured as follows: either both damping units68and69are configured for full load so that they are prevented from running against a rotational angle stop within the torque range delivered by a drive such as an internal combustion engine, or, if one of the damping units68,69is to be configured for partial load, it is ensured that the other damping unit68,69is configured for full load in every case. In particular, when one of the damping units68,69is configured for partial load this damping unit is permitted to reach the associated rotational angle stop within the torque range delivered by the drive so that as soon as this happens the respective component provided on the driven side of the damping unit68,69is driven along in the same motion with the respective component provided on the drive side18of the damping unit. Accordingly, in case of damping unit68, the intermediate transmission74is moved with the input67; on the other hand, in case of damping unit69the output72is moved with the intermediate transmission74. However, due to the configuration of the respective other damping unit68or69for full load, there will still be damping for the damper masses7of the damper mass carrier3.

The configuration of one of the damping units68or69for partial load can be advantageous, for example, when a damping unit of low stiffness is required for suppressing certain torsional vibrations.

Alternatively, however, other solutions for forming energy storages of damping unit68and/or damping unit69are also conceivable. Accordingly,FIG. 5ashows the construction of an energy storage98in which the individual coils99—seen in extension direction and with the energy storage relaxed—are provided with varying distances104from one another in different extension zones a to c. Accordingly, multi-stepped characteristic lines can be generated with only one energy storage. Serving the same purpose, i.e., to generate multi-stepped characteristic lines, is the construction of energy storages98aand98bshown inFIG. 5bwhich are arranged coaxial to one another in that energy storage98aencloses energy storage98b. In this case, the length of the two energy storages98a,98bin the extension direction is unequal so that the shorter energy storage98bfirst undergoes deformation when the longer energy storage98ahas been compressed by that amount by which it projected beyond energy storage98bin relaxed state.

The following pertains to the mass damper system1: for the sake of better illustrating the damper masses7received at the damper mass carrier3, the damper mass carrier element5aarranged axially in front of the damper masses7in viewing direction is omitted fromFIGS. 2 and 3and only the damper mass carrier element5barranged axially behind the damper masses7in viewing direction is shown. The damper masses7each have guide paths22formed in pairs for receiving coupling elements20which are formed as rolling elements. The guide paths22are configured in such a way that they allow a radial movement of the damper masses7relative to the coupling elements20. The damper masses7have stop sides43radially inwardly adjoining their circumference sides.

Guide paths13having a curved course are provided at the damper mass carrier elements5aand5b, also in pairs in each instance. Referring to the view inFIG. 2 or 3, the guide paths13each have an initial region14in which the respective guide path13has the greatest radial distance from a central axis15and connection regions17which extend circumferentially opposite one another so as to adjoin both sides of the initial region14. The guide paths22provided at the damper masses7also have a curved course, each with an initial region24in which the respective guide path13has the smallest radial distance from the central axis15and with connection regions25which extend circumferentially opposite one another so as to adjoin both sides of the initial region14. The guide paths22are provided in each instance at both sides of a damper mass center35of the respective damper mass. This damper mass center35is located in a central extension radius36of the damper masses7disposed at a distance R1from the center axis15during driving operation. The state of the damper masses7during driving operation is shown inFIG. 2and exists when the mass damper system1is operated at a speed at which the centrifugal force exceeds the weight force.

The coupling elements20received in the guide paths13and22extend in each instance on both sides of the respective guide path22into the guide paths13provided there. In the view according toFIG. 2, the damper masses7tend radially outward owing to the centrifugal force so that the coupling elements20position themselves in the initial region24of the respective guide path22in each instance, i.e., in that region having the smallest radial distance from the center axis15. The coupling elements20are supported in the initial region14of the damper mass carrier elements5aand5b, i.e., in that region having the greatest radial distance from the central axis15.

The damper masses7have in each instance at their radially inner ends a geometric formation28having a first contact area26in the circumferentially central portion, but second contact areas27in the circumferentially outer portions. The first contact area26has an area center37which divides the first contact area26into formation halves23. This geometric formation28cooperates in a manner to be described in the following with stops31which are provided radially inside of the damper masses7and which are gathered at an annular component part32.

In circumferential direction between every two damper masses7, the annular component part32has a holder34which surrounds a spacer piece11so that the holder34serves in each instance as a stop receiver38. Accordingly, the annular component part32is received at the damper mass carrier3so as to be fixed with respect to rotation relative to it. An annular body33extending in circumferential direction acts between every two stop receivers38with a stop profile40. The stop receivers38and stop profiles40form common stops31at the annular component part32.

When the mass damper system1is operated at a speed at which the centrifugal force exceeds the weight force, the damper masses7tend radially outward under the influence of centrifugal force so that the coupling elements20can be positioned in each instance in the initial region24of the respective guide path22of the damper masses7. While torsional vibrations can force deflections of the damper masses7in circumferential direction so that the coupling elements20are deflected from the initial regions14,24of the guide paths13,22into their connection regions17,25, the coupling elements20are always restored to the initial position under the influence of centrifugal force as the torsional vibration decays.

On the other hand, when the centrifugal force drops below the weight force, for example, in creep mode of a motor vehicle or when stopping a drive, e.g., an internal combustion engine, the damper masses7drop radially inward to occupy the relative position, shown inFIG. 3, with respect to one another and with respect to the damper mass carrier3. In an operating state of this kind, the two damper masses7located radially above the central axis15drop radially inward until their stop sides43with the relevant formation half23of the first contact area26for the movement direction come in contact with the associated stop profile40of the stop31at the annular body33of the annular component part32. If the guide paths13,22should permit a further movement of the damper masses7radially downward, this movement will only end when the relevant second circumferential region27of the respective damper mass7for the movement direction arrives at the holder34and, therefore, at the stop receiver38of the annular component part32. The two damper masses7located radially below the central axis15likewise drop radially inward until their stop sides43with the first contact areas26which are formed thereon and which are relevant for the movement direction have come in contact with the associated stop profile40of stop31at annular body33of the annular component part32and until, in addition, the second contact areas27of the respective damper masses7which are relevant for the movement direction have come in contact with the corresponding holders34and, therefore, with the stop receivers38of the annular component part32. In this way, the two damper masses7located radially below the central axis15are prevented from coming in contact with one another by their circumference sides42.

Since the torsional vibration damper30is formed with a damping device70whose output72is connected to a mass damper system1as well as to a mass arrangement100, there is the problem that at certain speeds, for example, within a speed range of between 1,500 and 1,800 revolutions per minute, the deflection angle at the output72of the damping device70drops sharply even when torsional vibrations are present at the input67of the damping device70. Accordingly, since the output72of the damping device70stays at least approximately in a vibration node, the vibration excitations which are urgently required for the functioning of damper masses7of the mass damper system1are very slight. Therefore, it cannot be ruled out that the friction effect existing between the damper mass carrier elements5a,5band the damper masses7is sufficient to prevent a deflection of the damper masses7relative to the damper mass carrier elements5a,5band, therefore, relative to the damper mass carrier3. In order to mitigate this problem, it is provided that a contact device105is associated with the damper mass carrier elements5a,5band, accordingly, with the damper mass carrier3and the at least one damper mass7, which contact device105reduces the hindrances to the deflection of the at least one damper mass relative to the damper mass carrier.

In order to fulfill its purpose, the contact device105(seeFIG. 1 or 4) is provided at one of the two subassemblies—i.e., damper mass carrier elements5a,5band damper mass7—and acts on the respective other subassembly. In a particularly simple configuration, the contact device105is achieved through a surface treatment which is preferably carried out by coating the component parts5a,5bor7of one of the subassemblies or by applying a film to component parts5a,5bor7of one of the two subassemblies, which serves to reduce the dynamic and static friction values between these subassemblies and, therefore, the friction acting upon the latter. The coatings are not limited to friction-reducing plastics such as PTFE (polytetrafluorethylene) or anti-friction paint; on the contrary, constituents such as graphite, sintered metal or molybdenum can also be used.