WO2014135143A1

WO2014135143A1 - Friction device for a torsional vibration damper

Info

Publication number: WO2014135143A1
Application number: PCT/DE2014/000090
Authority: WO
Inventors: Ulrich Rohs
Original assignee: Ulrich Rohs
Priority date: 2013-03-05
Filing date: 2014-03-05
Publication date: 2014-09-12
Also published as: CN104508319A; DE102013003628A1; DE112014001174A5

Abstract

The invention relates to a friction device (20) for a torsional vibration damper (10), comprising at least two friction elements (26) which can be moved independently of each other at least in the circumferential direction about a main rotation axis (14) and can be actuated via a primary-side control (28), and complementary secondary-side friction surfaces (30) which can be actuated via a secondary-side control (32) and on which rests in each case a friction element (26) with friction. The invention further relates to torsional vibration dampers and to a method for mounting a friction device of a torsional vibration damper.

Description

REFERENCE DEVICE FOR A TORSION VIBRATION DAMPER

The invention relates to a friction device for a torsional vibration damper and a torsional vibration damper and a method for mounting a friction device and a method for operating a torsional vibration damper.

[02] Torsional vibration dampers are known in a wide variety of concrete embodiments. They have a primary mass or primary side and a secondary mass or secondary side, the secondary side being rotationally movable with respect to the primary side and a spring-damper device acting between the primary side and the secondary side being provided. A central task in the design of torsional vibration dampers is, in particular, to influence the damping properties as a function of the respective operating state, that is to say in particular as a function of the relative rotation between the primary side and the secondary side. So one is usually anxious to provide a comparatively high damping at comparatively large rotational amplitudes between the primary side and secondary side. In particular, at rotational speeds or rotational frequencies at which the respective system - with which the torsional vibration damper is in mechanical operative connection - reaches the resonance region, a comparatively high damping is provided. [03] Known torsional vibration dampers are adapted in only a limited way to provide a damping adapted to the respective operating state. For example, e.g. From EP 1 058 028 A2 a torsional vibration damper with a friction device is known, which comprises a dragging wedge for damping adaptation. From WO 2006/079306 Al a damping device for a dual mass flywheel is known in which a plurality of components are provided which are pressed together with a rotation of the two masses as a result of the provision of mutually slidable wedge surfaces between the masses and in pressed together state a friction between provide the two rotating masses rotating relative to each other. Similarly, the damper part of the known from WO 2005/064198 AI dual mass clutch flywheel is based on components with wedge surfaces. From US 5,503,595 a torsional vibration damper is known in which the friction device is annular.

CONFIRMATION COPY The present invention has for its object to provide an alternative friction device for a torsional vibration damper, with which on the torsional vibration damper in a simple and practical way desired damping properties can be realized.

[05] This object is achieved by a friction device for a torsional vibration damper, by a torsional vibration damper, by a method for mounting a friction device or by a method for operating a torsional vibration damper with the features of the independent claims. Further advantageous embodiments can be found in the subclaims and in the following description.

In this case, in particular the inlet slopes and the design of the primary-side control of the same material as the friction element for the first time allow a correspondingly good decoupling, which then leads to an operation of the torsional vibration damper with correspondingly small hystereses.

[07] The friction device can have at least two friction elements, which can be moved independently of one another about a main rotational axis, at least in the circumferential direction, and which can be actuated via a drive on the outside. Furthermore, complementary secondary-side friction surfaces can be provided, which can be controlled via a secondary-side control and to which a respective friction element is rubbed.

By providing the independently movable friction members and the complementary secondary side friction surfaces, damping properties can be realized and adjusted in a simple and practical manner in cooperation with the primary side drive and the secondary side drive. For this purpose, the primary-side control for driving the friction elements is arranged to transmit torque of the primary side or the primary mass of the torsional vibration damper on the friction elements. The secondary-side drive is provided for driving the secondary-side friction surfaces and in particular configured to transmit torque from the secondary side or the secondary mass to the secondary-side friction surfaces and thus to the friction elements. The friction elements are rubbing against the complementary secondary-side friction surfaces and cause damping by sliding rubbing against the complementary secondary-side friction surfaces, namely in the presence of relative rotation between the primary side and the secondary side, and particularly preferably when they are present or exceeded one of the secondary-side drive for the respective friction element predetermined angle of rotation between the primary side and the secondary side. With the friction device configured in this way, the setting of a defined friction or damping is advantageously possible, wherein in particular the primary-side and secondary-side control to achieve a damping characteristic adapted to the respective application can advantageously be flexibly designed.

[09] Preferably, the friction surfaces and the surface regions of the friction elements resting on the friction surfaces are aligned radially and in the circumferential direction relative to the main axis of rotation. This has the advantage that the frictional forces acting between the secondary-side friction surfaces and the friction elements or the surface regions are independent of the rotational speeds or rotational frequencies of the primary side or secondary side in the first order or first approximation since there are no centrifugal forces in the direction of the corresponding normal force Act.

In a practical embodiment of the friction device according to the invention, the friction surfaces are arranged on a common friction disc. By providing the common friction disc, a compact friction device having a simple structure can be advantageously provided. A simple and compact friction device allows in particular a simple assembly and possibly also a correspondingly easy disassembly of the friction device.

[11] In a preferred embodiment of the friction device according to the invention, the primary-side control has a radially inwardly acting centrifugal force compensation for at least one of the friction elements. By providing the radially inwardly acting centrifugal force compensation for at least one of the friction elements, a frictional contact of the friction element with secondary surface areas as a result of centrifugal force can advantageously be avoided or substantially reduced during activation by means of the primary-side activation. Such a frictional contact is particularly disadvantageous or undesirable in radially outer regions, especially at high speeds and at high frequencies to be damped, where damping in contrast to the situation with rotational speeds in the resonance range can lead to an undesirable increase in amplitude, depending on If necessary, the design of the system attached to the torsional vibration damper can also be made larger than in the undamped case. In a further practical embodiment of the friction device according to the invention, the primary-side control comprises a control disk with at least one recess in which a friction element is arranged, wherein the recess is larger in the circumferential direction about the main axis of rotation than the corresponding extent of the friction element arranged in it.

In this further practical embodiment, the control disk as a primary-side control rotatably connected to the primary side or the primary mass or operatively connected to this. By providing a recess which is larger in the circumferential direction about the main axis of rotation than the corresponding extension of the friction element arranged in it, a primary-side drive can be provided, in which only when exceeding or existing for the respective friction element predetermined rotation angle or predetermined minimum rotation angle between the primary side and the secondary side - which depends on the extension of the corresponding recess in the circumferential direction - uses a rubbing or sliding rubbing of the respective friction element on the friction surfaces, that uses a damping caused by the respective friction element. In the presence of the damping caused by the friction element, the friction element is then preferably in contact with a stop surface bounding the respective recess in the circumferential direction or in contact with a stop region delimiting the respective recess in the circumferential direction. Only on contact with this stop surface or the stop area can then transmit the control disk torque of the primary side to the respective friction element to bring about a damping by rubbing the respective friction element on the friction surfaces.

The control disk can also be firmly connected to at least one friction element, so that even at very small non-zero angles of rotation between the primary side and the secondary side rubbing or a frictional movement of the friction element on the friction surfaces occurs. In this way, a basic friction can be provided, which can be advantageous in particular in the operation of the torsional vibration damper in very high speed ranges.

In the above further practical embodiment, preferably at least two recesses may be provided in the control disk, in each of which a friction element is arranged, wherein the difference between the size of the recess in the circumferential direction and the corresponding extension of each arranged in her friction element for the Both recesses is different. Since the predetermined for the respective friction element torsional angle or predetermined minimum angle of rotation between the primary side and the secondary side of the extension of the corresponding recess in the circumferential direction depends (see above), by providing the different or variable difference between the size the recess in the circumferential direction and the corresponding extent of each arranged in their friction element a stepwise reinforcement of the friction or damping are provided. The stepwise reinforcement of the friction or damping is possible because due to the variable difference, the frictional effect or damping effect of the friction elements at different angles of rotation between the primary side and the secondary side begins. By providing the stepwise reinforcement of the friction, it is advantageously possible to provide an attenuation behavior that is individually matched to the respective system.

[17] Preferably, the recess has radially inwardly facing guide surfaces for interaction with associated radially outwardly facing surfaces of the friction element disposed in the recess. In this way can be advantageously very effectively avoided unwanted movement of the friction elements radially outward.

[18] Particularly preferably, the recess and the friction element arranged in it have at least one circumferentially effective inlet bevel. The provision of the inlet slopes allows for a suitable alignment of the inlet slopes an advantageous centrifugal force compensation. Further, by providing the circumferentially effective inlet slopes also advantageously allows a slow shrinkage of the friction element in the respective stop position, ie in the position in which the friction element is in contact with the recess in the circumferential direction limiting stop surface or in contact with a the respective recess is in the circumferential direction limiting stop area (see also above). Due to the slow shrinkage in particular rattling noises or a very rückartiges onset of the corresponding friction can be advantageously minimized.

[19] In a preferred embodiment of the friction device according to the invention, a pressing, which presses the friction elements against the friction surfaces, is provided. A contact pressure as such arises that the friction elements with the corresponding friction surfaces are in a defined frictional contact. A common contact causes on the one hand an advantageous uniform contact pressure of the friction elements, which in turn has the consequence that the friction elements in the axial direction - in contrast to the independent mobility in the circumferential direction - are movable identically in the first approximation. This identical mobility advantageously promotes a uniform frictional movement. By providing the common contact pressure, a simple structure can advantageously also be realized for the friction device according to the invention. A simply constructed friction device allows in particular a simple assembly and disassembly of the same.

Furthermore, a friction device for a torsional vibration damper with at least one friction element, which can be controlled via a primary-side drive, are characterized in that the friction element or an axially acting on the friction element pressure element has an axial projection, and a complementary secondary side friction surface, which can be controlled via a secondary-side control and on which the friction element is pressed by means of a pressing action acting on the axial projection in a frictional manner. By the axial projection in conjunction with the pressure acting on this can be advantageously provided a defined friction by a defined contact force, with a defined friction in turn is advantageously associated with a defined damping of the respective system.

[21] In this case, the axial projection can point away in the direction of the friction element or else also away from the friction element and preferably defines a point of application at which the contact pressure of the contact pressure defines, which then leads accordingly to a defined friction. [22] Preferably, the contact pressure comprises a plate spring. A contact pressure, which includes a plate spring, causes on the one hand an advantageous uniform contact pressure of the friction elements, which in turn has the consequence that the friction elements in the axial direction - in contrast to the independent mobility in the circumferential direction - are movable identically in the first approximation. This identical mobility advantageously promotes a uniform frictional movement. By providing the plate spring can be realized for the friction device according to the invention advantageously also a simple structure. A simple design friction device allows in particular a simple assembly and possibly also a corresponding simple disassembly of the same.

Preferably, the plate spring acts directly on the axial projection, along with a very effective and compact construction contact pressure of the friction element to the complementary secondary side friction surface. Also, a friction device for a torsional vibration damper with at least one friction element, characterized in that the friction element can be controlled via a primary-side drive of the same material as the friction element and a complementary secondary side friction surface, which can be controlled via a secondary side drive , rubbing against.

In this friction device, the at least one friction element can be controlled via a primary-side control of the same material as the friction element, along with the advantageous effect that a defined friction between the primary-side drive and the friction element is provided. In particular, even with a suitable design of the friction element and the primary-side activation as a result of the provision of the same material advantageously a significant wear minimization can be provided.

[26] Particularly preferably, the friction element consists of metal, preferably with hardened or rolled contact areas between the friction element and the drive, or of plastic. The formation of the friction element made of metal, preferably with hardened or rolled contact areas between the friction element and the drive, is advantageously associated with a wear-minimizing effect. To provide a formed of plastic friction, has the advantage that rattling and concomitant "rattling noises" can be avoided or significantly minimized.

[27] In a practical embodiment, the primary-side drive in the vicinity of the friction surface in the axial direction is thinner than the friction element. Due to this thinner design of the primary-side control in the vicinity of the friction surface, any friction of the primary-side control is advantageously avoided.

[28] The primary-side drive may in particular be formed in one piece, wherein an integrally formed primary-side control in a simple and practical way z. B. can be produced by injection molding of a sprayable material.

A torsional vibration damper that mates with the friction device may include a primary side and a secondary side or secondary mass rotatable about a main rotational axis of the torsional vibration damper with respect to the primary side, and a spring-damper device having a corresponding friction device acting between the primary side and the secondary side include. By providing the corresponding friction device can in a simple and practical way the torsional vibration damper desired damping properties realized or set, as stated above.

In a practical embodiment of the torsional vibration damper, the primary-side control is positively mounted axially on the primary side. The intended attachability allows easy assembly and disassembly, the positive attachment of the control in any friction of a torsional vibration damper in terms of ease of assembly and disassembly can be beneficial.

[31] Further, in a torsional vibration damper having a primary side and a secondary side rotatable about a main rotational axis of the torsional vibration damper with respect to the primary side and having a spring-damper device acting between the primary side and the secondary side, the spring-damper device can be made viscous Liquid comprising spring means and a sealed against the viscous fluid of the spring means friction device. In this torsional vibration damper, depending on the specific interpretation, the viscous liquid advantageously serve as a lubricant and / or for viscous damping. The sealing of the friction device with respect to the lubricant advantageously ensures the formation of a defined friction for setting desired or adapted damping properties.

[32] Preferably, the friction device is sealed by a non-contact seal. By providing a non-contact seal or by providing a labyrinth seal advantageously undesirable or uncontrolled friction can be avoided.

[33] The friction device is particularly preferably arranged in a fluid path between the spring device and a bearing, preferably a sliding bearing, between the primary side and the secondary side. This has the advantage that the seal provided for the friction device also seals the bearing against the viscous liquid or the lubricant. This is particularly advantageous for bearings in the form of a sliding bearing, which fail when in contact with a lubricant or could not work in the intended manner.

Also, in a method of operating a torsional vibration damper and a torsional vibration damper having a primary side and having a main axis of rotation of the torsional vibration damper with respect to the primary side rotatable secondary side and with an effective between the primary side and the secondary side spring-damper device, the spring Damper device using a spring system have a static characteristic curve which has a hysteresis of less than 15 Nm or less than 10% of the maximum engine torque within 90% of the maximum angle of rotation or within an angle of rotation of less than ± 10 °.

[35] According to the invention, a static characteristic here means a characteristic at very low speed, specifically at a speed at which centrifugal forces are negligible.

The provided within the limits hysteresis less than 15 Nm and less than 10% of the maximum engine torque advantageously allows the formation of a defined friction, which is correspondingly effectively defined especially at high frequencies and independent of the spring system. The angle of rotation is the angle of rotation or angle of rotation between the primary side and the secondary side. The consequence of such a low friction by the spring system of the spring-damper device is that the friction is provided substantially by the friction system of the spring-damper device.

Here, the definition of the hysteresis of the spring system is advantageous because a friction system with a suitable design of the spring-damper device can certainly be removed, shut down or bypassed to perform appropriate measurements, while removing the spring system ultimately to a complete change in the function of the torsional vibration damper and thus lead to non-comparable measurement results.

[38] Preferably, the hysteresis is less than 13 Nm or less than 8% of the maximum engine torque, preferably less than 10 Nm or less than 7% of the maximum engine torque.

[39] Cumulatively, alternatively, in an operation method for a torsional vibration damper and a torsional vibration damper having a primary side and a rotatable about a main axis of rotation of the torsional vibration damper with respect to the primary side movable secondary side and effective between the primary side and the secondary side spring damper Means the spring-damper device comprises a spring system with a dynamic characteristic curve, which within 90% of the maximum rotation angle or within a rotation angle of less than ± 10 °, a hysteresis less than 25 Nm and less than 15% of the maximum engine torque. [40] In this case, a dynamic characteristic curve is understood to mean a characteristic curve at the maximum rotational speed of the respective drive system.

[41] The provided within the limits hysteresis less than 25 Nm and less than 15% of the maximum engine torque advantageously allows the formation of a defined friction, which is effectively defined especially at high frequencies, as they occur at high speeds, in particular by the centrifugal force related problems of the spring device does not influence by friction on the damping. Under the angle of rotation is here also the angle of rotation or angle of rotation between the primary side and the secondary side to understand.

[42] Preferably, the hysteresis of the dynamic characteristic, especially in engines with a maximum torque of 200 Nm, less than 50 Nm, preferably less than 40 Nm. Likewise, the hysteresis of the dynamic characteristic, especially in motors with different power, less than 17% of the maximum engine torque, preferably less than 10% of the maximum engine torque, which accordingly leads to a good decoupling especially at high speeds or at high frequencies.

[43] The values for the hysteresis referred to in the present context refer to the vertical extent of the corresponding measurement graph in an angle-torque diagram, so that the corresponding unit must be [Nm].

[44] The abovementioned absolute values refer in particular to motors with low power, in particular with a torque of 200 Nm. The relative values are more general and, in particular, also sufficient for engines with higher power, whereby, of course, the lower absolute values may of course be correspondingly advantageous, since then an even better decoupling is present.

It has been shown that, although a good decoupling is ensured when in the range of idling, ie at very low speeds, high friction is found. At high speeds and therefore at high frequencies, which may be disturbed by the engine and should be filtered out by the torsional vibration damper, however, a friction causes a poorer decoupling, which ultimately can be explained simply by the fact that high frequencies on the friction elements of the friction or of the torsional vibration damper from the engine can get into the rest of the drive train. Are other frictionally effective assemblies, such as resilient assemblies that at high frequencies, especially for example at high speeds, rubbing somewhere abut, before, so there is a coupling of these high frequencies on such assemblies. By the above-described separation between the friction device and the spring device and the design of the spring device with a correspondingly low hysteresis can be ensured that such frictional effects by the spring means to a minimum and the frictional effects are essentially due to the friction device. In this respect, rubbing then takes place only under the conditions to which friction is to take place in the friction device, so that disturbing effects of the spring device are reduced to a minimum and, with a suitable refinement of the friction device, the friction can be deliberately restricted to a minimum required height To decouple frequencies in a targeted manner.

In a preferred embodiment of the above torsional vibration damper with the closer defined hystereses of the spring system, a friction device contributes more than 300 Nm, preferably more than 400 Nm or more than 500 Nm, to the damping, the proportion of the rest of the system, in particular of the Spring system can then turn out correspondingly low.

[47] To mount a friction device, at least one friction element and an associated control of the friction device can first be integrally connected to one another and be separated from one another after the positioning or during the positioning of the friction element. By providing a one-piece connection of the at least one friction element with the associated drive, a very simple assembly can be carried out in the connected state thus provided, which would be much more complicated and cumbersome without the existing connection. Only with or after completion of the assembly, where the friction element is positioned, is the drive, which is preferably connected to the at least one friction element by at least one material web, separated from the at least one friction element. If a connection is preferably provided via the at least one material web, it is severed to separate the actuation from the at least one friction element during positioning or after positioning.

The severing can be done for example by an offset between the friction element and control before assembly, which is then changed by the assembly, or by a first offset during commissioning.

[49] Also, during the assembly of a friction device, a control of the friction device for a friction element of the friction device can be plugged axially onto a primary side of a torsional vibration damper in a form-fitting manner. The attachment of the control on the Primary side can be carried out in a simple and practical way and therefore allows easy assembly and disassembly of the friction device. The positive axial attachment also creates a secure rotationally fixed connection between the control and the primary side.

[50] It is understood that the features of the solutions described above or in the claims can optionally also be combined in order to be able to implement the advantages in a cumulative manner.

[51] Further advantages, objects and features of the present invention will be explained with reference to the following description of exemplary embodiments, which are particularly illustrated in attached drawings. In the drawing show:

1 is a sectional view (radial section) of a first embodiment of a torsional vibration damper according to the invention,

2A and B are each a plan view of the friction device of the torsional vibration damper shown in Fig. 1,

3 is a plan view of a second embodiment of a torsional vibration damper according to the invention, which differs from that shown in FIG. 1 in that four springs and four flyer rings are provided instead of three springs and three flyer rings in this embodiment.

4 is an enlarged view of a detail of Fig. 2A,

5 is an enlarged view of a detail of Fig. 1,

6 is a sectional view (radial section) of a third embodiment of a torsional vibration damper according to the invention,

7 is a sectional view (radial section) of a portion of a fourth embodiment of a torsional vibration damper according to the invention,

8 is a plan view of an alternative friction device for a torsional vibration damper,

9 is a sectional view (radial section) of the friction device of FIG. 8

10A to 10D are each a perspective view, a plan view and sectional views (radial sections) of primary-side drives, which consist of the same material as the friction elements also shown,

1 1A to 1 IC are each a plan view, sectional views (radial sections) and a detailed representation (radial section) of a primary-side control with unilaterally open recesses, together with friction elements and a secondary-side friction disc, 12 shows a plan view of a primary-side activation together with friction elements, which differs from that shown in FIG. 11, in particular in that, in this activation, no receptacle is provided for the positive axial attachment to the primary side,

13A and 13B are a plan view and a sectional view (radial section) of a friction device together with the springs of the spring-damper device of the torsional vibration damper,

14 is a static characteristic of an exemplary spring system,

FIG. 15 shows a static characteristic of an overall system from the spring system with the characteristic curve according to FIG. 14 and an exemplary friction system, and FIG

16 shows a quasi-static characteristic of the arrangement with the characteristics according to FIGS. 14 and 15.

FIG. 1 shows a radial section of a first exemplary embodiment of a torsional vibration damper 10. The torsional vibration damper 10 comprises a primary side 12 or primary mass 12, a secondary side 16 or secondary mass 16 which is rotatable about a main rotational axis 14 of the torsional vibration damper 10 with respect to the primary side 12 and an effective between the primary side 12 and the secondary side 16 spring-damper device 18 with a friction device 20 according to the invention as a torsional vibration damper 10, which is intended for use in a motor vehicle, the secondary side 16 is provided for contact with a clutch of the motor vehicle , and the primary side 12 has bores 22 for producing a screw connection with the crankshaft of the motor vehicle. Further, a starter ring gear 13 is provided on the primary side 12.

The friction device 20 comprises eight (see also FIGS. 2A and B) in the circumferential direction about the main rotation axis 14 (see FIG. 1) independently movable friction elements 26, which comprise a primary-side drive 28, which comprises a control disk 28, can be controlled, and complementary secondary-side friction surfaces 30, which can be controlled via a secondary-side drive 32 and to each of which a friction element 26 rubbing. The control disk 28 is thinner in the axial direction than the friction elements 26 in the vicinity of the friction surfaces 30.

The secondary-side drive 32 comprises, on the one hand, a housing 38 composed of two sheet metal parts 34, 36 made of a sheet metal material, wherein a first housing part 34 is designed in the form of a common friction disk 34, on which the friction elements 26 are arranged. Furthermore, the secondary-side drive 32 comprises a contact pressure in the form of a plate spring 40 and a rotationally fixed connection to the secondary side 16.

In this exemplary embodiment, two complementary secondary-side friction surfaces 30 are provided, wherein one of the friction surfaces 30 is provided on the friction disk 34 and the other friction surface 30 on the disk spring 40. On both friction surfaces 30, the friction elements 26 rub against. The friction surfaces 30 and the frictionally abutting the friction surfaces 30 surface portions 42 of the friction elements 26 are aligned radially and circumferentially to the main axis of rotation 14. The plate spring 40 is provided as a common contact pressure to press all the friction elements 26 against the provided on the friction plate 34 friction surface 30, as shown in particular in FIG. 5, which shows an enlarged view of a corresponding detail of FIG. The enlarged view is best seen that the friction elements 26 have an axial projection 44 on which the plate spring 40 acts directly.

[56] FIGS. 2A and 2B each show a plan view of the friction device 20 of the torsional vibration damper 10 shown in FIG. 1. The structure of the control disk 28 is particularly apparent from these figures. The control disk 28, which is rotatably connected to the primary side 12, has eight recesses 46, wherein in each recess 46, a single friction element 26 (see FIG. 4) is arranged. Each of the recesses 46 is larger in the circumferential direction about the main axis of rotation 14 than the corresponding extent of the friction element 26 arranged in it.

[57] For non-rotatable connection to the primary side 12, the control disk 28 has a recess 48 in the form of a hexagon 48. On the primary side 12, a center piece 50 designed to be complementary to this recess 48 is provided, which can be inserted axially into the recess 48 in a positive-locking manner so that the control disk 28 is mounted in a form-fitting manner axially on the primary side 12 or the center piece 50 (cf. Fig. 1).

[58] By providing the recesses 46 which are larger in the circumferential direction about the main axis of rotation 14 than the corresponding extent of the friction element 26 arranged in it, a primary-side drive 28 can be provided, in which only for the respective friction element is exceeded or present 26 predefined angle of rotation or predetermined minimum angle of rotation between the primary side 12 and the secondary side 16 - the angle of rotation depends on the extent of the corresponding recess 46 in the circumferential direction - a rubbing or sliding Rubbing of the respective friction element 26 on the friction surfaces 30 sets, so uses a caused by the respective friction element 26 damping. In the presence of the damping caused by the respective friction element 26, the friction element 26 is in contact with a stop surface 52 delimiting the respective recess 46 in the circumferential direction. Only upon contact with this stop surface 52 can the control disk 28 "take along" the respective friction element or torque the primary side 12 transmitted to the respective friction element 26 in order to bring about a damping by rubbing the respective friction element 26 on the friction surfaces 30.

FIG. 2B illustrates the situation where a damping effect due to the existing contact of the friction member 26 with the stopper surface 52 is caused by the uppermost and lowermost friction member 26 in FIG. 2B. For the remaining six friction elements 26, the angle of rotation or the minimum angle of rotation is not or not yet reached, so that no rubbing of the friction elements 26 takes place on the friction surfaces 30 and these friction elements 26 therefore do not contribute to the damping. This is a consequence of the fact that the difference between the size of the recess 46 in the circumferential direction and the corresponding extent of the respective friction element 26 arranged in it is not the same for all the recesses 46 in order to advantageously provide a stepwise reinforcement of the friction or damping. FIG. 2A illustrates the situation in which for none of the friction elements 26 is the angle of rotation or the minimum angle of rotation achieved, so that there is still no damping effect due to friction element friction.

Each of the recesses 46 and the friction element 26 arranged in it have two inlet diameters 54 which are effective in the circumferential direction (cf., for example, FIG. 2A, right and FIG. 4). The provision of the inlet slopes 54 allows for an advantageous centrifugal force compensation for the friction elements 26. Femer is also provided by providing the circumferentially effective inlet slopes 54 a slow running of the friction element 26 in the respective stop position, ie in the position in which the friction element 26 is in contact with the recess 46 in the circumferential direction limiting stop surface 52 is located. By providing the radially inwardly acting centrifugal force compensation for the friction elements 26 by the inlet bevels 54, a frictional contact of the friction elements 26 with secondary-side regions or secondary-side surface regions as a result of centrifugal force can advantageously be avoided or substantially reduced when driving by means of the primary-side control 28 the secondary-side surface areas in the embodiment shown here around the circumferentially extending surface 56 of the second housing part 36 of the housing 38 of the secondary-side drive 32 (see also Fig. 1, and in particular also Fig. 4, which shows an enlarged view of an area in the vicinity of a friction element 26 from Fig. 2A).

[61] The spring-damper device 18 (see Fig. 1) comprises a spring device 60, which has a viscous liquid or a lubricant, wherein the friction device 20 is sealed against the lubricant of the spring device 60. The friction device 20 is in this case arranged in a fluid path between the spring device 60 and a slide bearing 62, via which the secondary side 16 is rotatably mounted on the primary side 12. The friction device 20 is sealed by a non-contact seal 64 in the manner of a labyrinth seal, which is in the form of an integrally formed on the friction plate 34 projection 64 which extends from the friction disc 34 radially inward and thereby penetration of the lubricant in the friction device 20 avoids which can be pressed radially outward due to the centrifugal force.

[62] To mount the torsional vibration damper 10, among other things, first the slide bearing 62 is received on the secondary side 16. Subsequently, the friction device 20 is rotatably connected to the secondary side 16 for providing the secondary-side drive 32. Finally, the primary side 12 is rotatably connected via the recess 48 or positively connected to the friction device 20.

Fig. 3 shows a top view of a second embodiment of a torsional vibration damper 10, which differs from that shown in Fig. 1 in that instead of three springs 66 and three flyer rings 68 in this embodiment, four springs 66 and four flyer rings 68 are provided are. The flyer rings 68 serve to hold down the springs 66 of the spring-damper device 18 in order to compensate for or counteract the centrifugal forces.

FIG. 6 shows a radial section of a third embodiment of a torsional vibration damper 10. The torsional vibration damper 10 shown here differs from that shown in FIG. 1, inter alia, in that a rivet connection 70 is provided for the rotationally fixed connection of the control disk 28 to the primary side 12 is. Further, the axial projection 44 on the friction elements 26 in the axial direction is larger or more clearly formed than in the friction device 20 of the torsional vibration damper 10 shown in FIG. 1. The two housing parts 34, 36 of the housing 38 of the friction device 20 are formed radially inwardly extended , in analogy to the Embodiment of FIG. 1 form a non-contact seal in the manner of a labyrinth seal for sealing the friction device 20 against the lubricant of the spring device 60.

FIG. 7 shows a radial section of a partial region of a fourth exemplary embodiment of a torsional vibration damper 10, the partial region illustrating the friction device 20 of this fourth exemplary embodiment in more detail. In the friction device 20 shown here, an axially acting on the friction elements 26 pressure element 72 is provided with an axial projection 44. The friction elements 26 abut against a complementary secondary-side friction surface 30 of the friction disk 34, wherein the friction elements 26 abut on the axial projection 44 acting pressing in the form of a plate spring rubbing frictionally.

[66] FIG. 8 shows a plan view of an alternative friction device 20 for a torsional vibration damper. In contrast to the friction devices 20 described above, lenticular frictional elements 26 are provided here, which are each arranged in a recess 46 of a control disk 28 which is open on one side, each of the recesses 46 being open towards a secondary-side annular region 74. In the case of this friction device 20, in the case of a relative movement between the primary side and the secondary side, the friction elements 26 are rubbed against secondary-side inner surfaces 78 of the annular region 74 as a result of centrifugal force and run into the slopes of the inlet slopes. Even a damping provided in this way may be advantageous in certain applications.

FIG. 9 shows a radial section of the friction device 20 of FIG. 8. Analogous to the situation of the friction device 20 of the exemplary embodiment of FIG. 7, a pressure element 72 acting axially on the friction elements 26 is also provided with an axial projection 44. The friction elements 26 abut against a complementary secondary-side friction surface 30, wherein the friction elements 26 abut on the pressure acting on the axial projection 44 in the form of a plate spring 40 rubbing frictionally.

FIGS. 10A to 10D each show a perspective view, a plan view and radial sections of two further primary-side actuators 28, which each comprise a control disk 28, which consist of the same material as the friction elements 26 likewise shown. For positive axial attachment to the primary side, each control disk 28 has a recess 48 or receptacle 48, which is of a circumferential wavy boundary 80 is limited. The differences between the control disks 28 which can not be seen in FIGS. 10A and 10B can be seen from the radial sections (see FIGS. 10C and 10D), which show that, with the exception of one friction element 26, all friction elements 26 on both control disks 28 Material webs 82 are connected to the control discs 28. Furthermore, it can be seen from FIG. 10D that the friction elements 26 connected to the control disk 28 according to FIG. 10D are offset axially in contrast to the situation with the control disk 28 according to FIG. 10C. Due to this difference, the control disks 28 according to FIG. 10C and 10D are suitable for different embodiments of the method according to the invention for mounting a friction device.

[69] In one of the embodiments, the friction members 26 and the control disk 28 are first integrally connected with each other as shown in FIG. 10C, and after the friction members 26 are positioned, the control disk 28 and the friction members 26 are separated from each other during running operation a relative rotation between the primary side and the secondary side, in which the material webs 82 tear. In the other embodiment, the separation of control disc 28 and friction elements 26 already takes place during positioning, since during positioning the material webs 82 tear as a result of the axial offset.

It can also be seen from FIGS. 10A and 10B that a friction element 26 (in the figures, the right outer one) is integral with the respective control disk 28 and is thus firmly connected to it in order to provide a basic friction in very high speed ranges and at to provide very small rotational amplitudes. A radially inwardly acting centrifugal force compensation for the friction elements 26 is provided in that for each recess 46, a radially outer boundary 84 is provided, which extends in the circumferential direction. In contrast to the situation according to FIGS. 2A and 2B, a possibly disadvantageous circumferential rubbing of the friction element 26 at the boundary 84 may take place in the case of the centrifugal force compensation provided here, in particular during return movements or reverse rotations.

[71] FIGS. 1A to 1C each show a plan view, radial sections and a detailed representation in the form of a radial section of a primary-side control 28, which comprises a control disk 28 with recesses 46 open on one side, together with friction elements 26 and a secondary-side friction disk 34. The control disk 28 shown here also has a recess 48 or receptacle 48 for positive axial attachment to the primary side, which recess is delimited by a circumferential wavy boundary 80, wherein the friction elements 26 each have a recess 46 open on one side the control disk 28 are arranged and also as an assembly aid a one-piece connection Uber material webs 82 is provided. Further, here too, a friction member 26 (see far right) for providing a base friction is integral with the control disk 28. In the radial cuts (see Fig. 11B and 1 IC), the friction members 26 are not illustrated, however, to be taken from the radial cuts is that the primary-side control disc 28 and the secondary-side friction plate 34 are also integrally connected to provide a mounting aid material webs 86 which can tear during assembly or after assembly in the presence of relative rotation between the primary side and secondary side.

FIG. 12 shows a plan view of a primary-side drive 28, which comprises a control disk 28, together with friction elements 26, wherein the control disk 28 differs from that shown in FIG. 11 inter alia in that no control disk 28 is provided Recording is provided for positive axial attachment to the primary side. FIG. 12 also shows six primary bores 22 (analogous to FIG. 3) for producing a screw connection with the crankshaft of the respective motor vehicle.

[73] Figs. 13A and 13B show a plan view and a radial section of a friction device 20 together with the springs 66 of the spring-damper mechanism of the corresponding torsional vibration damper. In contrast to the embodiments described above, the springs 66 of the spring-damper device of the torsional vibration damper are arranged radially inwardly relative to the friction elements 26 here.

[74] In the arrangements described above, it is advantageous if the spring device 60 contributes as little as possible to the friction and the friction is mainly caused by the friction device 20. A correspondingly advantageous design of the spring device 60 is shown by way of example in FIGS. 14 to 16, wherein the friction device 60 according to FIG. 14 has a hysteresis of less than 20 Nm in the range of 90% of the maximum deflection and, by the way, an even lower hysteresis.

[75] Accordingly, as can be seen from the static characteristic curve of the overall system in FIG. 15, the hysteresis can be determined by the friction device 20 and kept exactly in defined paths. In this case, the quasi-static state of FIG. 16, in which twist angles are traversed very slowly in small oscillations, shows that the characteristic also corresponds essentially to the static characteristic curve, even with small movements. [76] At higher, not shown speeds, the corresponding applies, in which case correspondingly high excitation frequencies must be checked, since in such a state large deflection angle with correspondingly low frequencies simply no longer occur.

LIST OF REFERENCE NUMBERS

10 torsional vibration damper 48 recess

12 primary side 50 center piece

13 starter sprocket 52 stop surface

5 14 Main axis of rotation 25 54 Infeed slope

16 Secondary side 56 Second housing part surface

18 spring-damper device 60 spring device

20 friction device 62 slide bearing

22 bore 64 Non-contact seal

10 26 Friction element 30 66 Spring

28 primary-side control, 68 flyer ring

Control disc 70 Rivet connection

30 friction surface 72 pressure element

32 secondary-side drive 74 annular area

1 ₅ 34 Housing part, friction disc 3 ₅ 78 Secondary inner surface

36 housing part 80 wavy boundary

38 Housing 82 Material web

40 plate spring 84 radially outer boundary

42 Surface area 86 Material web

₂₀ 44 axial projection 40th

46 recess

Claims

claims:

1. Friction device (20) for a torsional vibration damper (10), wherein the friction device (20) at least two circumferentially about a Haupttrotationsachse (14) independently movable friction elements (26), which can be controlled via a primary-side drive (28), and complementary secondary-side friction surfaces (30), which can be actuated via a secondary-side drive (32) and on each of which a friction element (26) frictionally abuts, and wherein the primary-side drive (28) comprises a control disk (28) with at least one recess (28). 46), in which a friction element (26) is arranged, wherein the recess (46) in the circumferential direction about the main axis of rotation (14) is greater than the corresponding extension of the friction element (26) arranged in it, characterized in that the recess (46) and the friction element (26) arranged in it comprise at least one circumferentially effective inlet bevel (54) isen.

Second friction device (20) according to claim 1, characterized in that the friction surfaces (30) and the friction surfaces (30) frictionally abutting surface regions (42) of the friction elements (26) are aligned radially and circumferentially to the main axis of rotation (14).

3. friction device (20) according to claim 1 or 2, characterized in that the friction surfaces (30) on a common friction disc (34) are arranged.

4. Reibreinrichtung (20) according to any one of the preceding claims, characterized in that the primary-side control (28) has a radially inwardly acting centrifugal force compensation for at least one of the friction elements (26).

5. friction device (20) according to any one of the preceding claims, characterized by at least two recesses (46) in the control disc (28), in each of which a friction element (26) is arranged, wherein the difference between the size of the recess (46) in Circumferential direction and the corresponding extent of the respectively arranged in her friction elements (26) for the two recesses (46) is different.

Friction device (20) according to one of the preceding claims, characterized in that the recess (46) has radially inwardly facing guide surfaces (54) for interaction with associated radially outwardly facing surfaces (54) of the recess (46) arranged in the friction element (26 ) having.

Friction device (20) according to one of the preceding claims, characterized by a friction elements (26) against the friction surfaces (30) oppressive, preferably common, contact pressure (40).

Friction device (20) according to one of the preceding claims, characterized in that the friction element (26) or an axially acting on the friction element pressure element (72) has an axial projection (44) and that on the complementary secondary side friction surface (30) the friction element ( 26) via a on the axial projection (44) acting contact pressure (40) pressed frictionally rests.

Friction device (20) according to claim 8, characterized in that the contact pressure (40) comprises a disc spring (40).

Friction device (20) according to claim 9, characterized in that the disc spring (40) acts directly on the axial projection (44).

Friction device (20) for a torsional vibration damper (10), characterized by at least one friction element (26), which can be controlled via a primary-side drive (28) made of the same material as the friction element (26), and by a complementary secondary-side friction surface (30) , which can be controlled via a secondary-side control (32) and on which the friction element (26) rubbing.

Friction device (20) according to one of the preceding claims, characterized in that the friction element (26) made of metal, preferably with hardened or rolled contact areas between friction element (26) and control (28, 32), or plastic.

Friction device (20) according to one of the preceding claims, characterized in that the primary-side drive (28) in the vicinity of the friction surface (30) in the axial direction is thinner than the friction element (26).

Friction device (20) according to one of the preceding claims, characterized in that the primary-side drive (28) is integrally formed.

Torsional vibration damper (10) having a primary side (12) and a secondary side (16) rotatable about a main axis of rotation (14) of the torsional vibration damper (10) with respect to the primary side (12) and with one between the primary side (12) and the secondary side (16 ) effective spring-damper device (18) with a friction device (20) according to any one of the preceding claims.

Torsional vibration damper (10) according to claim 15, characterized in that the primary-side control (28) is positively mounted axially on the primary side (12).

Torsional vibration damper (10) having a primary side (12) and a secondary side (16) rotatable about a main axis of rotation (14) of the torsional vibration damper (10) with respect to the primary side (12) and one between the primary side (12) and the secondary side (16). effective spring-damper device (18), characterized in that the spring-damper device (18) comprises a viscous fluid having spring means (60) and against the viscous fluid of the spring means (60) sealed friction means (20).

Torsional vibration damper (10) according to claim 17, characterized in that the friction device (20) via a non-contact seal (64) is sealed.

Torsional vibration damper (10) according to claim 17 or 18, characterized in that the friction device (20) in a fluid path between the spring means (30) and a bearing (62) between the primary side (12) and secondary side (16) is arranged. Method for operating a torsional vibration damper (10) having a primary side (12) and a secondary side (16) which is rotatable about a main axis of rotation (14) of the torsional vibration damper (10) with respect to the primary side (12) and between the primary side (12) and the Secondary side (16) effective spring damper device (18), characterized in that the spring-damper device (18) has a spring system with a static characteristic which is within 90% of the maximum angle of rotation or within a rotation angle smaller + 10 ° has a hysteresis less than 15 Nm or less than 10% of the maximum engine torque.

Operating method according to claim 20, characterized in that the hysteresis is less than 13 Nm or less than 8% of the maximum engine torque, preferably less than 10 Nm or less than 7% of the maximum engine torque.

Method for operating a torsional vibration damper (10) having a primary side (12) and a secondary side (16) which is rotatable about a main axis of rotation (14) of the torsional vibration damper (10) with respect to the primary side (12) and between the primary side (12) and the Secondary side (16) effective spring damper device (18), characterized in that the spring-damper device (18) comprises a spring system with a dynamic characteristic curve, within 90% of the maximum angle of rotation or within a rotation angle smaller + 10 ° has a hysteresis less than 25 Nm or less than 15% of the maximum engine torque.

Operating method (10) according to claim 22, characterized in that the hysteresis is less than 20 Nm or less than 17% of the maximum engine torque, preferably less than 15 Nm or less than 10% of the maximum engine torque.

Torsional vibration damper (10) according to any one of claims 20 to 23, characterized in that a friction device (20) contributes more than 300 Nm, preferably more than 400 Nm or more than 500 Nm, for damping.

Method for assembling a friction device (20), characterized in that at least one friction element (26) and an associated drive (28) of the Frictional device (20) are first integrally connected to each other and after the positioning or during the positioning of the friction element (26), the control (28) and the friction element (26) are separated from each other.

Method for assembling a friction device (20), characterized in that a control (28) of the friction device (20) for a friction element (26) of the friction device (20) is positively plugged axially onto a primary side (12) of a torsional vibration damper (10).