DE3745142C2 - Flywheel with torsional vibration damping - Google Patents

Abstract

The flywheel for a motor vehicle transmission incorporates damping of torsional vibration. Torque from the crankshaft is transmitted by way of a disc (3), and a damping assembly (13) to a disc (41), which drives the second flywheel half (4) and friction clutch. The damper comprises an annular chamber (51) containing a spring (45) and a viscous medium. Rotational effort is applied to the spring (45) by radial projections (41,49) on the input disc (3). The chamber (51) is closed by the projections (49) except for a narrow gap (54).

Description

The invention relates to a torsional vibration damper Power transmission path of a motor vehicle with an internal combustion engine, consisting of at least one input part, which is from the internal combustion engine is drivable, at least one output part, with a gear is connectable, and a torsion spring device between the two parts, including coil springs with a large length / diameter Ratio in guide channels arranged concentrically to the axis of rotation are guided axially and radially and with torque transmission between input and Output part to be compressed.

Such vibration dampers have as a damping means between the Flywheel elements both in the circumferential direction effective energy storage, such as for example coil springs that store energy as well as in the axial direction effective energy stores that work in conjunction with friction or sliding linings a friction, d. H. cause a hysteresis parallel to that in Effective energy stores is switched circumferentially.  

DE 35 20 853 C2 is a device for compensating Rotary impacts have become known with two rotatable ones Inertia masses, between which a power store or Damping device containing energy storage is provided. The the Coil springs forming energy storage are in the Receiving windows of pane parts are insufficiently guided, so that when using such a device in connection with fast rotating Internal combustion engines considerable wear on the window edges or the springs is to be expected, which increases the service life such damper in relation to the life of the motor vehicle or the engine is relatively short.

A vibration damper is known from EP 0 136 825 A2 elongated energy storage formed by helical compression springs, which in installed condition are deformed in an arc, and over guide shoes, which are attached to the coil springs, supported and guided radially are.

The present invention was based on the object of such devices to improve, especially their damping effect, so that an optimal Filtration of the vibrations occurring between the engine and transmission at low as well as at high speeds, at resonance speeds, at  Starting or when parking or the like is achieved. Furthermore, the possibility is to be created, the damping characteristics, d. H. the degree of energy destruction to the different vibration and Noise behavior of a vehicle under different operating conditions and to be able to adapt to other influences. In addition, the The inventive device in a particularly simple and inexpensive Be able to be manufactured. In particular, through constructive measures low manufacturing and assembly costs by using the highest possible Share in non-cutting production are made possible. Wear should also minimized and the service life extended.

According to the invention this is achieved in that in the guide channels provided coil springs in their unassembled condition over their Longitudinal extension are formed pre-curved. Such a configuration has the advantage that in the turns of the coil springs when Compressing the coil springs occurring stresses can be reduced can. Another major advantage is that the assembly of the Vibration damper is significantly simplified since no additional funds are required to install the coil springs in their keep curved installation position. For mounting the vibration damper it is therefore particularly advantageous if the curvature of the pre-curved  Coil springs at least approximately those in the installed state of the Coil springs corresponds.

Between the input part and the output part of the torsional vibration damper can advantageously be arranged several spring stages, wherein it can be useful for some applications if these spring levels are connected to each other in series. For other applications, it can however, it may also be advantageous if such spring stages are parallel to one another are switched, and there may also be applications in which both spring stages connected in series and arranged in parallel are appropriate.

Advantageously, the pre-curved coil springs can be one Be assigned spring level that has a low spring rate. In advantageous Way, the pre-curved coil springs are designed and arranged that they between the input part and the output part of the Torsional vibration damper - starting from a middle position - one Allow relative rotation of at least 25 °.

To a particularly favorable damping behavior of the invention to achieve built-up torsional vibration damper, it can be appropriate be when the pre-curved coil springs are about 70 to 96% of the  Extend angular extent of the device. It can also be an advantage if at least the same diameter, but not more than four Coil springs are arranged.

The design according to the invention ensures that the springs accommodated in channels ensures that these springs can be trained relatively long and thus a large one Angle of rotation is made possible. This allows better damping of the occurring vibrations can be achieved because of the possible large Relative rotations between the input and output part between them effective damping rate over a large or even almost the entire Angle of rotation can be relatively low. The damping rate can the smaller the larger the possible twist angle is.

Due to the design of the device according to the invention, long, one-piece springs with a relatively low stiffness, but with large travel can be used, which is the aforementioned low Allow damping rate. Because of the possible large angle of rotation with a low damping rate, both vibrations can be large Amplitude or large alternating torque peaks as well as vibrations small amplitude or smaller alternating torques damped bez. filtered  become. It is therefore practically in all operating states of the engine perfect damping of the vibrations that occur.

It can be particularly advantageous if the spring rate or the rigidity of the elastic formed by the springs between the input and output part Damper in the order of 2-20 Nm / degree, preferably is between 4-15 Nm / degree. It can be particularly useful if this spring rate or stiffness over at least an angle of rotation of 15 degrees between the entrance and exit part in the direction of pull and / or in Thrust direction is present.

The torsional vibration damper designed according to the invention can in advantageously be part of a damping device or even one form such a damping device, these advantageously can have at least two flywheel elements, one of which with the Internal combustion engine is connectable, and the other z. B. via a Friction clutch with the drive train. The damping device can at least one through components of at least one flywheel element educated, with a viscous medium, such as a pasty agent, at least partially filled ring channel with a practically closed cross-section have, in which at least two provided on the same diameter and supported coil springs are included. The one for support  or loading of the necessary other coil springs Areas can protrude radially into the ring channel Flange body be formed with the other second flywheel element is in rotation.

By compressing and relaxing the long springs and as a result the movement of the areas of the flange body that enter the ring channel protrude, occurring turbulence or displacement of the in the ring channel absorbed viscous medium can be a viscous or hydraulic Damping can be generated depending on the Torque fluctuations or torsional vibrations between the two Flywheel elements occurring angular velocities or accelerations changes. Another advantage is that the through the viscous medium caused damping is changeable depending on the Speed of the motor. So it can depend on the angular velocity between the two flywheel elements and depending on the speed the device the damping ratio or the hysteresis and thus the entire damping characteristics of the device can be changed. By the Viscous medium provided in the ring channel can not only Large amplitude vibrations are dampened by high Torque surges or alternating torques are caused, but also Small amplitude vibrations with correspondingly low hysteresis must be damped and which occur particularly in load operation. This  can be attributed to the fact that the viscous medium building pressure depends on the current speed at which a certain volume of the viscous medium is displaced. That means So that the damping capacity of the at least in the ring channel viscous medium depends on whether between the two Inertia masses or high alternating torques or less Torque fluctuations occur. So it can be practically a self-employed Regulation of the damping effect can be achieved.

The support areas for the springs in the ring channel or in the Guide channels can advantageously through on the flange body molded radial arms are formed, which in the radial areas of the Open the ring channel. The boom can radially outside of the Support areas merge with the springs in the circumferential direction spanning web. The - viewed in the circumferential direction - two radial Crosspieces connecting arms can be in an annular recess are recorded, which adjoins the annular channel radially on the outside.

The webs can - viewed in the radial direction - with respect to the ring channel be designed such that the springs at least when the device is rotating are supported radially on these webs. In particular, this can then be advantageous if at least some of the in the ring channel absorbed energy store come into effect one after the other, i.e. one  form multi-stage torsionally elastic damping, and only after one Starting angle of relative rotation between the two flywheel elements Springs are first positioned over the flange in the circumferential direction, since then during the twist angle at which these springs are not compressed, these rotate with the component, namely the flange on which they are radial support so that an additional friction damping between these springs and the boundary surfaces of the ring channel can be avoided.  

A particularly advantageous construction of the device can be given if the ring channel is formed by two shell-like bodies, with little at least one of these bodies can be a sheet metal part.

It can be particularly useful if the ring channel through two half-scha lenike sheet metal parts is formed, which is part of the with Engine connected flywheel element or even this swing form wheel element. An advantage over such sheet metal parts Parts produced by bracing consist of substantially reduced ferti effort. Furthermore, by punching, drawing and embossing made sheet metal parts a variety of inexpensive designs possible, e.g. B. also channel cross sections manufactured inexpensively that deviate from the rotationally symmetrical shape. They can also Circumferential supports for the springs in the ring channel through impressions or pocket-shaped formations are formed, so that no additional Items are required to ensure this function.

The supports or stops in the ring channel for the end areas of the However, springs can also be easily created by individual elements are formed, which otherwise consistently spanned the scope formed ring channel are used. These elements can be created by blocks or plates, by rivets or by welded Molded parts are formed.  

For the correct loading of the springs in the ring channel it is appropriate if - in the neutral position of the damper or Installation - a pocket-shaped request on both sides of a flange bracket mung or another stop element is provided.

Um - starting from a middle position or a middle range of the two flywheel elements relative to each other - at least in one It can get a multi-stage torsionally elastic damping in the direction of rotation be advantageous if at least one arm of the flange body opposite the supports of the ring channel provided on both sides of this - in Considered circumferential direction - has a smaller extent. Here can the boom and the supports in the mentioned starting position be arranged with respect to each other in such a way that their loading rich are offset relative to each other in both directions of rotation, so that multi-stage torsional elastic damping in both directions results. In the starting position mentioned, the loading can the boom for the energy storage and the supports is also sufficient be flush on one side, so that it is only in one turn tion results in a graduated torsional elastic damping.

The application areas of the boom and the supports can be in with respect to the spring ends, however, also be offset from one another such that around the zero position of the relative rotation between the two flywheel elements There is no suspension over a certain angle, so that then  practically no or only a hydraulic or viscous and / or friction damping can occur. This damping can be very small.

A smaller extension of the boom of the flange body compared to the Supporting the ring channel is particularly advantageous in facilities, where the initially uncompressed spring (s) by the Support of the ring channel in the circumferential direction is or are set.

In facilities where the only after a relative angle of rotation between the flywheel elements coming into effect It can twist with the flange body via this relative angle of rotation be expedient if at least one arm of the flange body opposite the supports provided on both sides in the ring channel - in um viewed in the direction of capture - has a greater extension. You can the areas of application of the outrigger and the outriggers only in one direction of rotation may be offset from each other or in both directions directions.

For the function of the device, it can be particularly advantageous if at least between some of the arms of the flange body and them facing spring ends intermediate layers are provided, the at least one Have cross-sectional area, at least approximately to the cross section of the annular channel receiving the springs is adapted. By such Design of the intermediate layers act in the ring channel in a relay active rotation between the two flywheel elements such as displacement piston ben for the viscous medium provided in this ring channel. For better  Guiding the spring ends can the intermediate layers on their each End facing the spring side protruding into the interior of the springs Own an extension. To self-thread the extensions into the To allow spring ends, these can have a slightly conical area have to end up in a larger cone angle or a section having a spherical shape merges. This can ensure that if an intermediate layer or a spring bowl in the Operation slips out of a spring end or is pushed out when Relax the spring or when loading the spring bowl of the latter can thread back into the spring without him or him is damaged.

By displacing the intermediate layers or the spring bowls in the ring channel form flask for the viscous medium, these can be advantageous Way to control the attenuation generated by the viscous medium to be pulled. So it is possible in a particularly simple manner via the piston-like intermediate layers the flow rate or the displaced Volume of viscous medium over a certain relative rotation angle to determine or regulate between the two flywheel elements and thus a defined, characteristic damping curve in Ab to achieve dependency on certain operating parameters. The change in twist resistance generated by the viscous medium can in simple Way by changing at least one flow cross-section for the viscous medium. This can be achieved, for example, by that the annular channel at least over partial areas of the length of at least one spring, which at both ends with intermediate layers or spring  wells is not of constant cross-section. At a Relative movement between the ring channel and an intermediate layer can thus the free cross section between the ring channel and the intermediate layer in Change depending on the angle of rotation. It can be useful if at least some of the ones in the end sections of the non-compress Areas of the ring channel located in the spring compared to the rest Areas of this channel are expanded in cross section. Such a cross Cutting extensions can be made over a certain twist angle range progressive or there may also be cross-sectional changes suddenly. To ensure that the intermediate layers and To enable the energy storage device radially on the outside, it is expedient to derar cross-sectional extensions in the area of the inner half of the ring channel.

The one produced by the intermediate layers in connection with the viscous medium Damping can continue by introducing axial cutouts or axial recesses can be changed in these intermediate layers.

For the function of the device, it can be advantageous if the Ausle ger of the flange body have circumferentially pointing lugs, which engage in a recess in the intermediate layers. The nose of the boom are in relation to the respective recess of the Intermediate layers arranged or formed such that the intermediate gene at least the end portions of the springs are kept out of contact with the radially outer areas of the ring channel. The arms of the outrigger can be designed such that when the intermediate layers are applied  the latter are pulled slightly radially inwards through the lugs, and to be lifted off the ring channel wall. This ensures that even at high speed at least some of the end turns of the springs do not come to rest on the bowl-like bodies which form the ringka nal form, and thus can spring freely. It can be advantageous if the recesses in the intermediate layers are circular in cross section are formed and the lugs of the boom at least on the recesses have adjusted areas. The latter can be done, for example, by stamping of the previously punched noses. The recesses of the intermediate layers can - viewed in the axial direction of the springs - be conical or spherical be shaped and form blind holes.

According to a development of the invention can radially within the ring n at least one further spring group of the damping precaution to be seen. For some applications, it can be advantageous if this further spring group with the first spring group provided in the ring channel is arranged in parallel between the flywheel elements. The Arrangement of the individual springs of the first and further spring group can be made in this way between the two flywheel elements that at least individual springs of both groups of springs are gradually this means that the effect is offset and / or at least some Springs of at least one spring group in stages, that is, offset in angle deploy.  

According to a further embodiment of the invention, those in the ring channel provided first spring group and the one arranged radially further inside another spring group between the flywheel elements in series be arranged. Those connected in parallel within these spring groups Springs can also form different levels, the winkelver continues to take effect.

The coupling of the at least two spring groups, which between the Flywheel elements are provided in a simple manner by means of a Flange body take place, the corresponding recordings for the individual Has feathers. These recordings can thereby advantageously be formed that the flange body radially outer, by radial Ausle ger has cutouts separated from one another in the circumferential direction, in which the springs of the first spring group are included, as well as radially further internal windows in which the springs of the other spring group are provided. The cutouts and the windows can be - in um considered direction of catch - be arranged relative to each other such that there is a window radially within a section. Cutouts and windows can be at least approximately the same angular Have extent in the circumferential direction.

By the largest possible twist angle between the two flywheels To allow ment, it can be advantageous if the first and / or the further spring group each has a maximum of four energy stores.  

It can be special for the structure and operation of the facility be advantageous if the housing halves radially within the ring channel or to point the shell-like bodies, such as shaped sheet metal parts, towards one another de have areas that form a passage for the flange body. The Areas facing one another can be annular surfaces define that define an annular passage or gap, the opens into the ring channel. To achieve a very high damping by the viscous medium received in the ring channel can be the passage width correspond at least approximately to the thickness of the flange body. For many Applications, however, can be advantageous if the axial distance between the areas to be pointed towards each other is 0.1 mm to 2 mm larger than the thickness of the areas of the flange body received therein. By part of the gap defined in this way can be accommodated in the ring channel viscous medium in the event of a sudden relative rotation between escape the two flywheel elements radially inwards. By ent speaking dimensioning of the gap can include that in the ring channel tten viscous medium damping effect to the desired level be determined.

Furthermore, it is possible to face the areas of the housing facing one another halves and the areas of the flange body accommodated therein to train each other in such a way that between them one depends of the angle of rotation between the flywheel elements changing There is a gap, the flow cross defined by the gap cut can decrease with increasing angle of twist, whereby the attenuation generated by the viscous medium becomes larger. For this the  Flange body extending on at least one side in the circumferential direction have ramps rising in the axial direction, which correspond with trained counter ramps of the housing facing him on this page rich cooperate so that when the ramps and counter ramps open to be moved towards each other, the flow cross section for the viscous medium gets smaller.

For the construction of the device, it can be particularly advantageous if radially within that between the areas of the Half of the existing passage for the flange body the other Spring group is provided. To accommodate this group of springs, the Halves of the housing or the shell-like body have axial indentations sen. It can be particularly advantageous for the function of the device be when the axial indentations, the passage for the flange body and the ring channel merge. For the perfect management of the Energy storage of the further inner spring group, it can be useful if the indentations at least in the radially outer area to the circumference the cross section of this energy accumulator are adjusted. The between Ring channel and the indentations existing gap or passage for the Flange body can be essentially closed. For this the Flange body have an annular area that at least partially extends radially into this gap. Can advantageously this annular region of the flange body essentially through radially between the outer and inner springs  extending webs can be formed, which the loading areas of the Flange body for the springs, such as radial brackets, interconnect the.

To facilitate assembly of the device, the springs of the white tere spring group pre-curved to at least approximately the diameter be on which they are arranged. This is particularly advantageous holds when the feathers are long. Furthermore, the pre-bend has the springs of the outer and / or the inner spring group have the advantage that they are practical when installed and when the device is not used table are free of bending moments.

It can be advantageous if springs of the further spring group are radial led outside through the areas delimiting the windows of the hub body are so that these springs when rotating device and Beauf mainly against the radially outer contours of the windows of the Support the hub body and practically only in the axial direction the indentations of the housing parts are guided, that means with minimal contact force along the wall delimiting the indentations slide. Advantageously, the outer contours of the windows webs of the flange present between the outer and the inner springs body, which extend in the circumferential direction, be formed. To one Individuals can prevent the spring ends from contacting the housing The window or the webs towards the end are pulled slightly inwards radially  the so that the spring ends acted upon by the flange body of the radially outer areas of the indentations or the annular channel radially be held back.

For some applications, however, it can also be advantageous if the inner springs at least under centrifugal force to which the one Support areas delimiting bores radially. This can occur with springs from Be an advantage only after a certain relative angle of rotation between the two flywheel elements. Furthermore can it will be beneficial for the function of the device if the windows of the Flange body for the inner springs are designed such that they in Form circumferential pointing lugs that directly into the spring ends engage or in a recess of an intermediate layer between a Spring end and the associated area of application of the flange body pers is provided. The lugs can with respect to the spring ends or be formed on the intermediate layers such that they at least the Hold the end areas of the springs radially inwards so that they are in contact with stay out of contact with the radially outer areas of the Indentations and / or the webs of the flange body spanning them. This also results in connection with the on the booms advantages of the flange body molded noses already described.

For the manufacture of the device, it can be particularly advantageous if the indentations for the further spring group are annular, that means to extend over the entire scope of the facility and the Support areas in the circumferential direction for the energy accumulator in the  Indentations introduced stop elements are formed. Such Stop elements can be formed by individual elements, as in Described connection with the stop elements provided in the ring channel were. It can be particularly advantageous if the stop elements are formed by rivets, the application areas for the Lift mechanism are flat or flattened.

For the structure and function of the device, it can be advantageous when the springs of the inner spring group in windows of two washers are taken, which can be connected to the other, to the drive train Flywheel element are in rotary connection and axially between them, coupling the radially outer and the radially inner spring group in series Pick up the flange body.

According to a development of the invention, it can function and Assembly of the device can be particularly advantageous if one Flywheel element is the one component of an axia with a profile len connector and the other flywheel element the counter profile of the two flywheel elements rotatably coupling connector having. Such a plug connection can be used in particular in a Device should be useful in which the spring groups of the damping Turn in a part with a viscous or pasty medium at least wise fillable chamber are included, which are essentially by the Components of a flywheel element connectable to the engine are formed is and wherein the output part of the damping device is a flange Component is that has profiles that can be brought into engagement  with counter-profiles provided on the other flywheel element, further one of the flywheel elements carries a sealing element that when plugging the two flywheel elements together on one surface of the other of the flywheel elements comes into sealing contact. Such one Construction allows pre-assembly in two modules, namely the one with the Motor connectable on the primary side and via a coupling to the Drive train connectable secondary-side assembly.

It can be advantageous if the flange-like output part of the damper precautionary measures, such as flange bodies, via the profiles of the plug-in binding with the other flywheel element a rotational coupling owns, but is not fixed axially. With such a structure the flange can align itself freely in the axial direction so that it can assembly of the device not between the two flywheel elements is braced, whereby components of the device are impermissibly stressed could become and an already beginning with small twist angles, For example, undesirable, high friction hysteresis when the engine is idling would arise. It can be particularly useful if the flange-like Output part of the damping device, such as flange body, axially floating between the two housing halves or the shell-like bodies of the the engine connectable flywheel element is mounted.

A particularly advantageous embodiment of the device can thereby be made possible by the assembly of the two flywheels ment generated seal at least partially with viscous medium filled chamber seals or closes axially between  the two relatively rotatable flywheel elements lichen annular gap that can be open to the outside. It can be done before be partaking if the counter-profiles on the outer circumference of a ring disc-like component connected to the other flywheel element are provided.

The sealing element sealing the chamber advantageously has at least one washer-like sealing part. It can be useful if the washer-like sealing part is axially resilient, so that after plugging the flywheel elements together for manufacture a perfect seal can be elastically deformed. One of the Like sealing part can be connected to the flywheel connectable to the engine be worn element so that after plugging together the flywheel elements on a contact surface of the other flywheel element with front voltage is present.

To facilitate assembly of the device, it may be appropriate if the inside diameter of the chamber sealing the ring channel Sealing element is larger than the outer diameter of the counter-professional lations of the plug connection. This allows the sealing element when Assembly of the device guided axially over the counter profiles be, which is particularly advantageous if the flange Output part of the damping device has a central recess, whose circumferential contour limits the profiles of the connector and  the ring disk-like that has the counter-profiles on the outer circumference Component on a forehead facing the engine-side flywheel element Surface of the other flywheel element is fixed axially.

A perfect sealing of the chamber and a simple construction of the Device can be achieved in that the sealing element with its radially outer edge region on a radial wall of one Flywheel element is axially supported by the housing half is formed, which on the between the two flywheel elements adjacent radial annular gap. The radially outer edge area of the sealing element on the radial wall axially fixed his. For the function of the sealing element, it may be appropriate if this is clamped axially on the outer edge area. Such Clamping, which can be axially resilient, enables the sealing element to similar to a disc spring to pivot around the clamping area. The provided on the other flywheel element contact surface for the Sealing element can be easily by an annular Component be formed between the face of the other swing wheel element and the component having the counter-profiles axially is clamped and extends radially outwards further than the counterpart profiles. This annular component can radially in Direction away from the component provided with the counter profiles sets or plates.  

For some applications, it can be useful if the between the two flywheel elements effective damping device at least one Includes friction device. This friction device can over the entire Angle of rotation between the two flywheel elements to be effective or but only used in a certain range of this twist angle come. It can be advantageous if the friction device is at least least has a friction disc with at least one in the circumferential direction tion effective energy storage cooperates. The energy store can be designed in such a way that it exerts on the friction disc Moment at least over a portion of its compression path is enough to overcome the frictional torque of the friction disc, so that this is at least partially postponed.

Furthermore, it can be useful if the between the flywheel elements th provided friction device is circumferential with play, this means that between the stops of the friction disc the friction the game and the counterstops assigned to them is. This means the use of the friction device with respect to the insert the lift mechanism is delayed.

To be as constant as possible over the entire life of the unit To achieve friction torque, it may be appropriate to in the friction device the formed by the housing halves or the shell-like body Provide chamber for viscous medium.  

For other applications, however, it can also be advantageous if outside of the space at least partially filled with viscous medium or Ring channel additionally acts between the two flywheel elements same dry friction damping device is arranged.

Although it can be advantageous for some applications if the Friction damping device with the springs of the damping device parallel lel is switched, it can be particularly useful for other applications be moderate if at least one with the flywheel elements friction damping connected in series between these effective springs facility is available. The damping effect of the friction device or Friction damping device can change over the angle of rotation Lich, the damping effect is greater with increasing angle of rotation can be.

For the function and structure of the facility, it can be advantageous if the friction damping acting in parallel with the inner spring group and / or viscous damping is significantly less than that of the outer Spring group of viscous damping and / or friction dampers connected in parallel fung. For this purpose, outer springs can be provided with cups at their ends the outer contour of which is at least approximately the contour of the ring channel corresponds, which creates a great damping through fat displacement. The inner feathers, at least the first stage, are without feather bowls used to at least in the first stage a low fat displacement and thus to achieve low damping. The used with game The springs of the inner spring group can be used to optimize the damping  or be installed without feather bowls. Furthermore, the outer and inner spring group assigned viscous damping by appropriate Determination of the level of viscous medium can be influenced. Advantageous it can be when the outer ring channel is complete and the inner indentations are only partially filled with viscous medium. The high damping effect when the outer springs are compressed, Beaufschla starts immediately start of the springs. The damping assigned to the inner spring group remains low, however, since the feathers are only partially in the viscous medium immerse yourself.

It can be particularly advantageous for the function and structure of the device be liable if the housing half facing the motor or the motor term, shell-like body radially on the inside carries an axial approach, which in Direction of the flywheel element connectable to the drive train is directed and carries a roller bearing that the two flywheel elements stored rotatable relative to each other. Connect that to the drivetrain Bare flywheel element can have an axial recess into which the axial approach protrudes axially. It is advantageous if this Recess forms a seat for receiving the outer ring of the Wälzla gers.

For the assembly of the device, it is particularly advantageous if before the assembly of the two flywheel elements, the rolling bearing is positive is determined on the flywheel connectable to the drive train ment and when assembling this rolling bearing on a seat of the axial to sentence is postponed.  

To a multi-level spring characteristic between the input part and output part of the To obtain torsional vibration damper can at least individual springs a spring group or a damper may be shorter than the circular arc section between the stops interacting with them.

The invention will be explained in more detail with reference to FIGS. 1 to 10.

It shows:

Fig. 1 shows a device according to the invention in section;

Fig. 2 is a view of the device according to arrow II of FIG. 1 with breaks off,

Fig. 3 is a section through another device according to the invention

Fig. 3a shows the detail "X" of Fig. 6 in an enlarged scale,

Fig. 4 is a view of the device according to Fig. 6 in the direction of arrow IV with outbreaks,

Fig. 5 is a half section through an inventive embodiment of a device,

Fig. 6 is a partial section shown along the line VI-VI of Fig. 5,

That can be seen Fig. 7 is a section according to line VII-VII of Fig. 6, whereby components are illustrated only in FIG. 5,

Fig. 8 details of a device according to the invention, which may for example be used in embodiments according to FIGS. 1 to 7,

FIGS. 9 and 10 further sections by gene according to the invention.

The Drehmomentübertragungseinrich shown in Figs. 1 and 2, device 1 for compensating for rotational shocks has a flywheel 2, which is divided into two flywheel elements 3 and 4. The flywheel element 3 is attached to a crankshaft 5 of an internal combustion engine, not shown, via fastening screws 6 . A switchable friction clutch 7 is attached to the flywheel element 4 . Between the pressure plate 8 of the friction clutch 7 and the flywheel element 4 , a clutch disc 9 is provided, which is received on the input shaft 10 of a transmission, not shown. The pressure plate 8 of the friction clutch 7 is struck in the direction of the flywheel element 4 by a plate spring 12 which is pivotally supported on the clutch cover 11 . By actuating the friction clutch 7 , the Schwungradele element 4 and thus also the flywheel 2 and the internal combustion engine of the transmission input shaft 10 can be coupled and uncoupled. Between the flywheel element 3 and the flywheel element 4 , a first, radially outer damper 13 and a second, radially inner damper 14 connected in parallel therewith are provided, which allow a relative rotation between the two flywheel elements 3 and 4 .

The two flywheel elements 3 and 4 are mounted relative to one another via a bearing 15 . The bearing 15 comprises a roller bearing in the form of a single-row ball bearing 16 . The outer bearing ring 17 of the Wälzla gers 16 is in a recess 18 of the flywheel element 4 and the inner bearing ring 19 of the bearing 16 is on a central, axially extending from the crankshaft 5 away and into the recess 18 inra ing cylindrical pin 20 of the flywheel element 3 arranged.

The inner bearing ring 19 is clamped by means of interference fit on the pin 20 and be taken between a shoulder 21 of the pin 20 and the Schwungrade lement 3 and a locking washer 22 which is fixed on the end face of the Zap fens 20th

The bearing 16 is axially secured with respect to the flywheel element 4 by being axially clamped between a shoulder 25 of the flywheel element 4 and an annular disk 27, which is firmly connected to the second flywheel element 4 via rivets 26, with the interposition of two rings 23 , 24 of L-shaped cross section is.

The two rings 23 , 24 form a thermal insulation that interrupts the heat flow from the interacting with the clutch disc 9 friction surface 70 of the flywheel element 4 to the bearing 16 or at least vermin changed.

The radially inward leg 23 a, 24 a of the rings 23 , 24 he partially radially extend over the inner bearing ring 19 and are axially supported on it, thereby serving as a seal for the bearing 16 . In order to ensure proper sealing of the bearing 16 , the radially extending legs 23 a, 24 a are each acted upon axially in the direction of the end faces of the inner bearing ring 19 by a force accumulator in the form of a plate spring 28 , 29 .

The flywheel element 3 forms a housing which delimits an annular chamber 30 in which the dampers 13 , 14 are accommodated. The flywheel element 3 which has the annular chamber 30 essentially consists of two housing parts 31 , 32 which are connected to one another radially on the outside by means of screws 33 . The screws 33 are provided in the radial region of the end faces or abutment surfaces 34 , 35, via which the two housing halves 31 , 32 abut one another. The abutting surfaces 34 , 35 are located radially outside of the first damper 13 . To seal the annular chamber 30 from the outside, a sealing ring 36 is provided, which is arranged axially between the two abutment surfaces 34 , 35 and radially inside the screws 33 . To accommodate the sealing ring 36 , the housing part 31 has an axial annular groove 37 . For the exact positioning of the two housing parts 31 , 32 during assembly, cylindrical pins 38 are also provided, which are received radially outside half of the sealing ring 36 in axially aligned bores of the two housing parts 31 , 32 .

The housing part 31 facing the engine has a school ter 39 on the outer circumference, on which a starter ring gear 40 is shrunk. The two housing parts 31 , 32 can be made of cast iron. If a low moment of inertia of the first flywheel element 3 is desired, at least one of the housing parts 31 , 32 can be made of a light metal alloy such as cast aluminum. Such light metal castings have the advantage that they can be produced by a printing or pressing process and can be used without much rework.

The two dampers 13 , 14 have a common output part in the form of a radial flange 41 which is arranged axially between the two housing halves 31 , 32 . The flange 41 is, as can be seen in particular from FIG. 2, with its radially inner regions via an axial plug-in connection 42 with the annular disk part 27 in a rotationally fixed manner, which on the end face of the axial extension 43 pointing in the direction of the crankshaft 5 of the flywheel element 4 is attached via the rivet 26 . For accurate radial positioning during assembly is between the annular disc member 27 and the axial extension 43 is a centering seat 43 a provided.

The flange 41 has on its outer circumference radial arms 44 which form the application areas for the energy accumulator in the form of helical springs 45 of the outer damper 13 . Radially within the - viewed in the circumferential direction - between the cantilevers 44 existing sections 46 for the coil springs 45 , the flange 41 has arcuate windows 47 in which the energy accumulator in the form of coil springs 48 of the inner damper 14 are received. Radially between the cutouts 46 and the windows 47 , the flange 41 forms webs 49 which run in the circumferential direction and which connect the radial arms 44 or the radial regions 50 of the flange 41 which are present in the circumferential direction between the windows 47 . The radial areas 50 form the supply areas of the flange 41 for the coil springs 48 .

The annular chamber 30 forms an annular channel-like or torus-like receptacle 51 radially on the outside, into which the arms 44 of the flange 41 engage radially.

The ring channel-like receptacle 51 for the energy accumulator 45 is formed in wesent union by extending over the circumference, axial indentations 52 , 53 which are introduced into the radial areas of the housing parts 31 , 32 and in which the projecting on both sides of the flange 41 are rich the energy accumulator 45 immerse axially. The annular channel-like receptacle 51 is closed radially inward by the webs 49 of the flange 41 , apart from a small gap 54 .

As can be seen from FIG. 1, the axial indentations 52 , 53 are designed in cross section in such a way that their arcuate course is at least approximately matched to the circumference of the cross section of the energy accumulator 45 . The outer areas of the indentations 52 , 53 can thus form contact areas or guide areas for the energy stores 45 , on which the energy stores 45 can be supported radially, at least under the action of centrifugal force. By aligning the contact areas formed by the indentations 52 , 53 with the outer circumference of the energy accumulators 45 , the wear, which occurs due to the friction of the windings of the energy accumulators 45 on the radially outer regions of the indentations 52 , 53 , can be substantially reduced, since the support surface between springs 45 and indentations 52 , 53 is enlarged. To act on the energy accumulator 45 on both sides of the arm 44 in the indentations 52 , 53 circumferential strokes 55 , 55 a are introduced, which form support regions for the energy accumulator 45 in the circumferential direction. In the illustrated embodiment, the circumferential stops 55 , 55 a - viewed in the circumferential direction - have the same angular extent as the arms 44 of the flange 41 . The circumferential stops 55 , 55 a are formed by components 56 , 57 which are adapted to the indentations 52 , 53 and are fixedly connected to the housing parts 31 , 32 by means of rivets 58 . The end regions of the circumferential stops 55 , 55 a considered in the circumferential direction are flattened for better loading of the energy accumulator 45 .

Between the arms 44 and the ends of the springs 45 facing them, spring cups 59 are provided (see FIG. 2), the circumference of which is adapted to the cross section of the annular channel-like receptacle 51 .

Radially inside the annular channel-like receptacle 51 , the housing halves 31 , 32 have areas 60 , 61 which face one another and form annular surfaces, between which an annular passage 62 for the flange 41 is present.

In the embodiment of FIGS. 1 and 2, the width of this annular passage 62 is slightly larger than the areas of the flange 41 contained therein, so that a gap 54 is present on at least one side of the flange 41 .

Radially within the annular passage 62 , the housings have seteile or housing halves 31 , 32 further axial indentations 63 , 64 , in which the regions of the inner coil springs 48 projecting on both sides of the flange 41 are at least partially immersed.

As can be seen from Fig. 1, the axial indentations 63 , 64 are formed in cross section such that their arcuate course is at least in the radially outer region to the circumference of the cross section of the helical springs 48 , so that the springs 48 at least in the axial direction are held or guided by the indentations 63 , 64 .

Similar to the outer indentations 52 , 53 , the inner indentations 63 , 64 also extend over the entire circumference of the device. This is advantageous since, for example, the pre-cast indentations 52 , 53 and 63 , 64 can then be machined by a turning operation. To act upon the energy accumulator or coil springs 48 , circumferential stops 65 , 66 are introduced into the indentations 63 , 64 , which form support regions for the coil springs 48 in the circumferential direction. This circumferential stops 65 , 66 are formed by the recesses 63 , 64 aligned components le, which are firmly connected to the housing parts 31 , 32 via rivets 67 . As can be seen from FIG. 2, the stops 65 , 66 provided on both sides of the radial regions 50 of the flange 41 have a smaller angular extent, viewed in the circumferential direction, than these radial regions 50 , which act on the coil springs 48 .

The webs 49 of the flange 41 are dimensioned with respect to the inner indentations 63 , 64 such that the coil springs 48 are supported radially on the webs 49 at least under the influence of centrifugal force.

This is advantageous because the flange can be made of steel, which is at least surface hardened, whereby the wear on the radial support areas for the springs 48 can be reduced. Another advantage of the radial support of the springs 48 on the webs 49 is that until the springs 48 abut against the circumferential stops 65 , 66, the springs 48 can rotate with the flange 41 without substantial friction due to the centrifugal force acting on them to produce on the housing parts 31 , 32 . Such friction is undesirable in many cases because it falsifies the characteristics of the outer damper 13 .

As can be seen from Fig. 2, the device 1 are considered over the circumference, in each case 3 springs 45 and 48 are provided, the radially äuße ren springs 45 each extend over at least approximately 110 degrees. The radially inner springs 48 extend at least approximately at the same angle as the outer springs 45 . In the present case, a spring 48 extends at least approximately over 100 degrees. The outer springs 45 thus extend over approximately 91% of the circumference of the device and the inner springs 48 extend over approximately 83% of the circumference.

In the unassembled state, the springs 45 and / or the springs 48 — viewed in the axial direction — can be straight; this means that during assembly these springs have to be bent in accordance with the shape of the receptacles they have received, or the springs 45 and / or the springs 48 according to the shape of the receptacles they have received can already have a corresponding curvature. By using pre-curved springs 45 , 48 , the stresses occurring in these during compression can be reduced and assembly can be further facilitated.

In the annular chamber 30 , a viscous medium or a lubricant, such as silicone oil or grease, is provided. The level of the viscous medium or the lubricant can - with a rotating device 1 - extend at least to the central region or the axis of the outer springs 45 of the damper 13 . In the embodiment shown, it is advantageous if this level extends at least to the outer regions of the windings of the inner coil springs 48 , so that at least between these windings and the regions that support them radially, in the present case the webs 49 of the flange 1 , there is lubrication to reduce wear. In the device 1 shown, it is advantageous if the filling of viscous medium or lubricant extends approximately up to the axis of the inner coil springs 48 .

By assigning the annular chamber 30 , which contains a viscous medium or a lubricant, to the flywheel element 3 connected to the engine and by the spatial separation of the flywheel element 4 carrying the friction clutch 7 , an influence of the connection with the friction clutch heat generated on the viscous medium or lubricant largely switched off.

Furthermore, between the annular chamber 30 or the housing part 32 and the flywheel element 4, an outwardly open annular channel 68 is provided, which further improves the cooling effect in connection with ventilation channels 69 . The air channels 69 are provided radially within the friction surface 70 of the flywheel element 4 for the clutch disc 9 .

As can be seen in particular from FIG. 2, the flange 41 has a central recess 71 , the contour of which forms radial profiles 72 , which are in engagement with counter profiles 73 , which are provided on the outer circumference of the annular disks 27 connected to the flywheel element 4 . The profiling 72 and counter-profiling 73 forming the axial plug connection 42 enable the flange 41 to be properly aligned between the two housing halves 31 , 32 , so that the gap 54 present between the annular passage 62 and the flange 41 can be made very small. The plug-in connection 42 also makes it possible to expand the axial tolerances between the various contact or support surfaces of the components.

To seal the annular chamber 30 , a seal 74 between the radially inner region of the housing part 32 and the annular disc 27 and the axial extension 43 of the flywheel element 4 is seen easily. The seal 74 has an annular disk 75 which is supported with its radially inner region on a shoulder 76 formed on the axial extension 43 and with its outer region on a surface 77 which is formed on the radially inner region of the annular housing part 32 . The annular disc 75 is axially deformable like a plate spring. The annular disk 75 is axially pressed against the shoulder 76 and the surface 77 by a plate spring 78 , which is clamped axially between the disk 75 and the flange 41 . The plate spring 78 also presses the flange 41 against the surface 60 , as a result of which a gap 54 is present only on one side of the flange 41 between the annular channel-like receptacle 51 at the regions of the annular chamber 30 lying radially inward. As can be seen from Fig. 1, the seal 74 seals the annular chamber 30 to the existing between the two flywheel elements 3 and 4 ring gap 68 down. The inner diameter of the annular chamber 30 to the annular gap 38 sealing disc 75 is larger than the outer diameter water of the counter profiles 73 of the connector 42nd

The plug-in connection 42 and the seal 74 enable a particularly simple assembly of the torque transmission device 1 , namely by first preassembling the two flywheel elements 3 and 4 and then axially connecting and fastening the securing disk 22 on the end face of the pin 20 are axially connected to one another. For this purpose, the seal 74 is first preassembled on the flywheel element 3 and the roller bearing 16 is positively fixed on the flywheel element 4 . When assembling the two flywheel elements 3 and 4 , the inner roller bearing ring 19 is pushed onto the seat 20 a of the axial projection 20 of the housing part 31 and the counter-profiles 73 are brought into engagement with the profiles 72 . Furthermore comes during together menschiebens the two flywheel Radel elements 3 and 4, the radially inner loading area of the sealing disk 75 for engaging the gebil culminating in the shoulder 76 opposite sealing surface, so that the sealing disk is rotated 75 counter to the force of the plate spring 78 in and with pretension bears against shoulder 76 . The final axial determination of the two swing wheel elements 3 and 4 relative to each other, as already mentioned, is done by fastening the disc 22 to the pin 20th

In order to reduce the wear in the contact area between the turns of the springs 45 and 48 and the indentations 52 , 53 or 63 , 64 assigned to them, the surfaces of the parts 31 , 32 delimiting these indentations can have a greater hardness, at least in these contact areas. This can be done, for example, by induction hardening, case hardening, laser beam hardening or flame hardening these contact areas. In the case of very high loads, however, it can also be expedient if the parts 31 , 32 delimiting the indentations have a coating which reduces abrasion wear, at least in the aforementioned contact areas. Such a coating can be formed, for example, by chemical nickel plating, by chrome plating or by coating with plastic or molybdenum. The applied coating can also be subsequently smoothed in order to obtain a better surface quality of the indentations on which the turns of the springs rub. Such smoothing can be carried out, for example, by a grinding process or turning.

The mode of operation of the device according to FIGS. 1 and 2 will now be described.

When the flywheel element 4 is rotated relative to the flywheel element 3 from the rest position shown in FIG. 2, the flange 41 is driven via the plug connection 42 , so that first the outer springs 45 are compressed between the peripheral stops 55 , 55 a and the radial arms 44 . After passing through the relative angle of rotation 79 in one direction of rotation or 80 in the other direction of rotation, the order stops 65 , 66 on the inner springs 48 come to rest, so that in the event of a further relative rotation between the two flywheel elements 3 and 4 in addition to the springs 45 the springs 48 are compressed. The common compression of the springs 45 and 48 takes place until the inner springs 48 go on block, whereby the relative rotation between the two flywheel elements 3 and 4 is limited. In the exemplary embodiment shown, the maximum angle of rotation, starting from the rest position shown in FIG. 2, is in the order of magnitude of 47 degrees in both directions of rotation. In the event of a relative rotation between the two flywheel elements 3 and 4 , frictional damping is generated by friction of the outer springs 45 on the surfaces of the indentations 52 , 53 and by friction of the flange 41 on the surface 60 . Friction damping also takes place between the radially inner springs 48 and their radial support regions. The friction damping that occurs between the springs 45 , 48 and their radial support regions is speed-dependent, this damping increasing with increasing speed. Furthermore, damping is generated by swirling or displacing the viscous or pasty medium contained in the annular chamber 30 . In particular, the present in the virtually closed ring channel-like seat 51 viscous medium generates a hydraulic or viscous damping, since the Federnäpfe piston 59 are similarly effective in the annular channel-like receptacle. When the outer springs are compressed, the spring cups 59 acted upon by the cantilevers 44 are moved in the direction of the cups which are supported on the circumferential stops 55 , 55 a, so that the viscous medium present in the springs essentially passes through the gap 54 , which is similar to a throttle works, is pushed. Another part of the viscous medium is displaced between the spring cups 59 and the walls of the ring channel-like receptacle 51 . The initially displaced viscous medium ver is distributed evenly over the circumference due to the centrifugal force acting on it. During the relaxation of the outer springs 45 , the viscous medium present on the side of the spring cups 59 facing away from the springs 45 is similarly pressed past the spring cups and displaced through the gap 54 and, due to the centrifugal force acting on them, fills the springs 45 again. The damping generated by the viscous medium depends on the centrifugal force acting on the medium, which means that the damping increases with increasing speeds.

The areas of the radially inner springs 48 immersed in the viscous medium likewise produce a viscous or hydraulic damping by swirling.

By introducing axial recesses or cutouts in at least individual wells and by appropriate dimensioning of the gap 54 or the outer circumference of the wells, the attenuation generated by the viscous medium can be changed or adapted to the particular application. Furthermore, the viscous or hydraulic damping can be adapted in that only some of the springs 45 are provided with cups 59 . Spring cups can also be provided between the spring ends of at least one inner spring 48 and the radial regions 50 of the flange 41 .

The device shown in Fig. 3 and 4 has two flywheel elements 3 and 4 , which are similar to the device according to FIGS. 1 and 2 via a roller bearing 16 rotatably mounted to each other. The axially securing the two flywheel elements washer 122 is fastened on the end face of the axial extension 120 by means of rivets 122 a. The two flywheel elements 3 and 4 are assembled in a similar manner to that described in connection with FIGS. 1 and 2. This means that the bearing 16 is first assembled to the flywheel member 4 and is slid onto the seat 120 during the assembly of the two flywheel elements 3 and 4 a of the axial approach 120th Furthermore, before the assembly of the two flywheel elements 3 and 4, a seal 174 is preassembled on the flywheel element 3 provided on the engine side, and it is between the flange 141 , which forms the output part of the two dampers 13 , 14 connected in parallel, and the disk-like component 127 , which on the flywheel element 4 is fastened via rivets 126 , an axial plug connection 142 is provided. The two, the annular chamber 130 delimiting housing parts 131 , 132 are formed as castings. The housing part 132 has on its periphery an axial cylindrical projection 132 a, over the inner surface 135 of which the housing part 132 is centered on an outer surface 134 of the housing part 131 . The two cast housing parts 131 , 132 are axially secured via radial pins 138 which are introduced in the region of the centering surfaces 134 , 135 . The housing part 132 carries a starter ring gear 140 , which partially overlaps the pins 138 axially, so that they cannot migrate radially.

The axial plug connection 142 is formed by radial brackets 172 formed on the inner circumference of the flange 141 , which engage between radial projections 173 formed on the outer circumference of the ring-like component 127 .

As can be seen in particular from FIG. 3a, the seal 174 provided between the radially inner region of the housing part 132 and the annular disk-like component 127 or the axial extension 143 of the flywheel element 4 has an annular, axially resilient disk 175 , which with its radially inner one Area is supported on an annular component 176 fastened to the axial extension 143 and is axially fixed with its radially outer area to the radially inner area of the housing part 132 . The axially deformable sealing washer 175 bears on its radially outer and inner areas a coating 175 a, 175 b, such as a plastic coating, the z. B. is brought up by spraying. These coatings 175 a, 175 b should have a low coefficient of friction and a certain elastic or plastic deformability. The radially outer edge region of the sealing disk 175 is crimped in a ring-shaped carrier 180 in a sealing manner. The flanging of the outer region of the sealing washer 175 thereby takes place such that the sealing washer 175 may perform a conicity. The areas 180 b of the annular carrier 180 , which encompass the outer circumference of the sealing washer 175 , are received in an axial recess or in an axial recess 177 , which is formed on the radially inner area of the housing part 132 . For the axial fixing of the outer area of the sealing washer 175 , the annular carrier 180 has flanged areas 180 a which radially encompass the inner edge 132 b of the housing part 132 . The ring-shaped carrier 180 forms a deformable sealing disk 175 for the diaphragm spring in an annular pivoting position.

The annular component 176 , which has a sealing surface cooperating with the sealing disc 175 , has a radially inner disc-shaped region 176 a, which is clamped axially between the end face of the axial extension 143 and the disc-like component 127 , and an annular outer region 176 b, on which the sealing washer 175 rests with axial preload.

The radially outer regions 176 b of the annular component 176 are set back in relation to the radially inner regions 176 a in the axial direction by the ring-shaped component having the counter profiles 173 of the plug connection 142 . As can be seen from FIG. 3, the seal 174 seals the annular chamber 130 towards the annular gap 168 between the two flywheel elements 3 and 4 .

In order to enable the two flywheel elements 3 and 4 to be axially plugged together, the inner diameter of the sealing disk 175 is larger than the outer diameter of the radial projections or the counter-profiles 173 . The areas 176 b of the annular component 176 , on which the sealing washer 175 is axially supported, extend radially outward further than the counter-profiles 173 .

When the rolling bearing 16 is pushed onto the seat 120 a, the connector 142 is produced, and the sealing washer 175 is axially braced by contact with the counter-sealing areas 176 b.

To prevent or reduce the wear on the radial support areas from the ring channel-like receptacle 151 for the springs 145 , a high-hardness steel strip 181 is provided which extends over the circumference of the ring channel-like receptacle 151 and surrounds the springs 145 . The steel band 181 is cylindrical and received in a recess 182 , which is formed by a radial recess or a radial recess. When the device 101 rotates, the springs 145 are supported by the windings on the steel belt 181 due to the centrifugal force acting on them.

The circumferential stops 155 , 155 a for the outer springs 145 and the order stops 165 , 166 for the inner springs 148 are formed by molded parts, such as forgings, compression moldings, which have integral rivets 158 , 167 for attachment to the respective housing part 131 , 132 .

As can be seen from FIG. 4, the stops 155 , 155 a provided on both sides of a boom 144 of the flange 141 have a greater extension in the circumferential direction than the boom 144 , the embodiment shown in the rest position of the device shown in FIG. 4 the arms 144 are arranged centrally in relation to the stops 155 , 155 a, which means that the stops 155 , 155 a project beyond the arms 144 on both sides by the same amount.

The circumferential stops 165 , 166 , which are arranged on both sides of the radial regions 150 of the flange 141 , also have a greater extent in the circumferential direction than the regions 150 , which serve to act on the springs 148 . The arrangement of the stops 165 , 166 with respect to the radial regions 150 is, however, such that the circumferential stops 165 , 166 in the rest position of the device 101 project on one side with respect to the regions 150 , whereas on the other side the stops 165 , 166 and the radial areas 150 can be flush. Furthermore, the offset of the stops 165 , 166 in relation to the radial regions 150 is such that two successive stops 165 and 166 in the circumferential direction are offset in the opposite direction of rotation relative to the radial regions 150 of the flange 141 assigned to them. Due to this structure, the inner springs 148 form two spring groups, namely 148 a and 148 b, which come into effect step by step.

The viscous medium or lubricant, such as silicone oil or grease, which is accommodated in the annular chamber 130 , should at least fill the annular channel-like receptacle 151 when the device 101 rotates. However, it may be advantageous if the level of the viscous medium or lubricant extends at least to the outer regions of the turns of the inner coil springs 148 , it being particularly expedient if the filling of the viscous medium or lubricant extends approximately up to the axis of inner coil springs 148 extends.

Between the arms 144 and the circumferential stops 155 , 155 a and the ends of the springs 145 facing them, spring cups 159 , the circumference of which is adapted to the cross section of the annular channel-like receptacles 151 , can be seen easily. As described in connection with FIGS. 1 and 2, this produces a relatively large damping by displacing the viscous medium present in the annular chamber 130 .

The spring cups 159 have a slightly conical pin 159 a, which projects axially into the springs 145 . The end 159 b of the pin 159 a is tapered in the illustrated embodiment, but could also be dome-shaped. With such a configuration of the spring cups 159 , if a cup slides out of the spring end during operation, the same is self-threaded into the spring when the cup is re-loaded or the spring is released, so that the spring or the cup are not damaged. Spring cups 159 may escape when the outer springs 145 are compressed and the device 101 rotates at a relatively high speed. In this operating state, the friction present between the spring windings of the springs 145 and the radial support regions of the housing halves 131 , 132 for these springs can be so high that the springs 145 cannot at least not fully relax in the event of a sudden load change. Due to the displacement of the viscous medium caused by the radial cantilevers 144 during the load change shock, which is distributed again under centrifugal force, spring cups 159 can be forced out of the ends of the non-relaxing springs 145 .

The mode of operation of the device according to FIGS. 3 and 4 will now be described.

With a rotation of the flywheel element 4 relative to the flywheel element 3 from the rest position shown in Fig. 4, the flange 141 is driven via the plug connection 142 , so that first the inner springs 148 b between the circumferential stops 165 , 166 and the radial loading range 150 compressed become. After driving through the relative angle of rotation 179 in one direction of rotation or 190 in the other direction of rotation, the radial regions 150 of the flange 141 come to rest at the ends of the inner springs 148 a, so that with a further relative rotation between the two flywheel elements 3 and 4 the springs 148 a and 148 b are compressed together. After driving through the relative angle of rotation 179 a in one direction of rotation or 190 a in the other direction of rotation, the outer springs 145 are struck by the radial arms 144 , so that the springs between the circumferential stops 155 , 155 a in a further relative rotation and the radial arms 144 are compressed. In the illustrated embodiment, the angle 179 corresponds to the angle 179 a and the angle 190 to the angle 190 a, so that the springs 148 a and the springs 145 take effect simultaneously. Thus, according to results in the illustrated embodiment of FIGS. 3 and 4 a two-stage spring characteristic. However, the angles 179 , 190 , 179 a, 190 a can also only partially have the same amount or have different values, so that an at least three-stage spring characteristic in both directions of rotation or an at least two-stage spring characteristic in one direction of rotation and an at least three-stage spring characteristic in the other Direction of rotation is possible.

Furthermore, the circumferential stops 165 , 166 , as indicated by a dash-dotted line in FIG. 4 with 165 a, can be set back relative to the spring ends of the springs 148 b retained in the flange, so that the zero position of the relative rotation between the two flywheel elements 3 and 4 there is no suspension over a certain angle, and only hydraulic or viscous damping and / or friction damping occurs.

The height or the characteristic of the hydraulic or viscous damping can be varied, for example, by equipping only some of the outer springs 145 with spring cups 159 , or by not providing a cup 159 at one end of at least one spring 145 . Furthermore, at least one spring 148 a and / or 148 b can be provided with spring cups. Further factors influencing the viscous or hydraulic damping are the radial fill level of the viscous medium and the width of the gap or gaps between the flange 141 and the surfaces 160 , 161 of the housing halves 131 , 132 .

The hydraulic or viscous damping by displacing or swirling the viscous medium takes place in a similar manner to that described in connection with FIGS. 1 and 2.

As can be seen from FIG. 4, four springs 145 and 148 are provided over the circumference of the device 101 , the radially outer springs 145 each extending at least approximately over 78 degrees. The radially inner springs 148 b extend at least approximately over 74 degrees and the springs 148 a at least approximately 68 degrees of the circumference. Thus, the outer springs 145 extend at least approximately 86% of the circumference, whereas the inner springs 148 extend at least approximately 79% of the circumference.

As can be seen in particular from FIG. 4, the component 3 a of the flywheel element 3 has radial arms 186 on the outer circumference, in each of which a threaded bore 187 is provided for fastening a friction clutch. Some of the arms 186 have bores 188 for receiving pins, which ensure an exact positioning of the clutch cover on the component 3 a during assembly.

The radial boom 186 enable a lighter design of the swing wheel element 3 . Furthermore, between the radial cantilevers 186 existing radial recesses 186 a better cooling of the construction part 3 a and the coupling mounted thereon is achieved, since air circulation can take place between the cover and the recesses 186 a. Radially inside the friction surface 4 a of the component 3 a, ventilation channels 169 are provided, which open into the radial gap 168 provided between the two flywheel elements 3 and 4 .

The radial arm 186 permit further, for a given mass, the component 3 a in the area of the friction surface 4 a thicker configure so that overheating can be avoided in this area.

A change in the damping produced by the viscous medium can furthermore be achieved in that the annular channel-like receptacle 151 does not have a constant cross-section at least over partial areas of the length extension of at least one spring 145 , so that in the areas of larger cross-section there is less damping and in the areas with smaller cross-section a higher damping is generated. Although this cross-sectional change of the annular channel-like receptacle 151 can be provided at any location or even at several locations, it is particularly expedient if such cross-sectional changes or cross-sectional expansions are located in the end sections of the uncompressed springs 145 . The cross-sectional changes can be sudden or progressive. It is particularly advantageous if the cross-sectional expansion is provided in the region of the radially inner half of the ring channel-like receptacle 151 . Such an extension is shown in FIG. 4 and identified by 189 . This extension 189 is molded onto the flange 141 , which delimits or closes the annular channel-like receptacle 151 radially inwards. The extensions can, however, also be formed by appropriate shaping of the recesses 152 , 153 delimiting the annular channel-like openings 151 .

The torque transmission device 201 shown in FIGS . 5 and 6 for compensating for rotary shocks has a flywheel 202 which is divided into two flywheel elements 203 , 204 . The two flywheel elements 203 and 204 are mounted relative to one another via a bearing 15 . The flywheel element 203 forms a housing which delimits a ring-shaped chamber 230 , in which a damping device 213 is received.

The flywheel element 203 , which has the annular chamber 230 , consists essentially of two housing parts 231 , 232 which are connected to one another radially on the outside. The two housing parts 231 , 232 are formed by sheet metal parts which are connected to one another on their outer circumference by a weld 238 . This weld 238 simultaneously seals the annular chamber 230 radially outward. For the welding of the two sheet metal parts 231 , 232 , a resistance butt welding or a capacitor surge discharge welding is advantageously suitable, i.e. a welding in which the areas of two components that are in contact and are to be welded by applying an alternating current of high current and low voltage to welding heated to temperature and combined under pressure.

To carry out such a welding have the two shell-like sheet metal parts 231 , 232 end areas or abutting surfaces 234 , 235 , which have a defined area in relation to the amperage used for the welding. In the area of these abutting surfaces 234 , 235 , the housing parts 231 , 232 axially abut one another and are or are welded to one another.

For the precise radial positioning of the two housing parts 231 , 232 during welding, the housing part 231 has an annular projection 231 a radially on the outside, which engages around a centering surface 235 a formed on the outer circumference of the housing part 232 . For precise positioning in the circumferential direction during the welding, axial countersinks 265 , 266 are introduced into the housing parts 231 , 232 . In these countersinks 265 , 266 pins of the welding device can engage, which hold the two housing parts 231 , 232 during the welding in an exact angular position with respect to one another.

Since during the welding of the two sheet metal shells 231 , 232 due to the formation of the weld seam, a certain axial movement takes place between these sheet metal shells, it can be advantageous to provide axial stops between these sheet metal shells, which become effective only during welding. In Fig. 5 such a line, 27330 00070 552 001000280000000200012000285912721900040 0002003745142 00004 27211 on the sheet metal shell 232 molded stop is indicated and marked with 267 . By using such limit stops 267 one is not so dependent on the amperage used for the welding; this means that you can also work with a higher current, since the axial position of the two housing parts 231 , 232 is determined by the stops 267 and not by the current and the welding during the Ver applied to the two housing parts 231 , 232 axial pressure.

The output part of the damper 213 is formed by a radial flange 241 which is arranged axially between the two housing parts 231 , 232 . The flange 241 with its radially inner regions is connected via an axial plug connection 242 to the annular disk part 227 , which is fastened on the end face of the axial extension 243 of the flywheel element 204 pointing in the direction of the motor-side housing part 231 via rivets 226 .

The flange 241 has on its outer circumference radial arms 244 , which form the loading areas for the energy accumulators in the form of coil springs 245 of the damper 213 .

The two housing parts 231 , 232 form an annular channel-like or torus-like receptacle 251 on the radially outside, in which the radial arms 244 of the flange 241 engage. The annular channel-like receptacle 251 for the force accumulator 245 is essentially formed by axial indentations or impressions 252 , 253 extending over the circumference, which are introduced into the housing parts 231 , 232 made of sheet metal and into which the regions 241 projecting on both sides immerse the energy accumulator 245 axially. The annular channel-like receptacle 251 is closed radially inward by an annular region 249 of the flange 241 , apart from a small gap 254 .

As can be seen from FIG. 5, the axial indentations 252 , 253 are designed in cross section in such a way that their arcuate course is at least approximately equal to the circumference of the cross section of the energy accumulator 245 . The outer areas of the indentations 252 , 253 can thus form contact areas or guide areas for the force stores 245 , on which the force stores 245 can be supported radially, at least under the action of centrifugal force.

To act upon the energy accumulators 245 , circumferential stops 255 , 255 a are introduced into the recesses 252 , 253 on both sides of the arms 244 . In the illustrated embodiment, the circumferential stops 255 , 255 a - viewed in the circumferential direction - have the same extent as the radial arms 244 of the flange 241 . As can be seen from FIG. 6, intermediate parts in the form of spring cups 259 are provided between the cantilevers 244 and the ends of the springs 245 facing them, the circumference of which is adapted to the cross section of the annular channel-like receptacle 251 .

Radially within the annular channel-like receptacle 251 , the housing halves 231 , 232 have areas 260 , 261 which face each other and form annular surfaces, between which an annular passage 262 for the flange 241 is present.

In the illustrated embodiment of FIGS. 5 and 6, the width of this annular passage 262 is only slightly larger than that so that a very small gap is present in the recorded areas of the flange 241,254.

As can be seen from FIG. 6, four springs 245 are provided over the circumference of the device 201 , each of which extends at least approximately over 82 degrees of the circumference. The springs thus extend over at least approximately 90% of the circumference of the device 201 .

To reduce the stresses occurring in the springs 245 during compression and to facilitate assembly, the springs 245 are at least approximately pre-curved to the radius on which they are arranged.

In the annular chamber 230 , a viscous medium or a lubricant is provided. The viscous medium should - with rotating device 201 - at least fill the annular channel-like receptacle 251 .

As can be seen from Fig. 6, the flange 241 has a central recess 271 , the contour of which forms radial profiles 272 which are in engagement with counter profiles 273 , which are provided on the outer circumference of the ring-shaped disk part 227 connected to the flywheel element 4 . The counter profiles 273 are formed by radial projections which engage in correspondingly adapted cutouts 272 a of the flange 241 . The rivets 226 , which fix the component 227 on the flywheel element 204 , are also provided in the region of the radial projections 273 . The axial connector 242 forming profiles 272 and Gegenpro fillings 273 allow proper alignment of the flange 241 between the two housing halves 231 , 232 , so that the gap 254 between the annular passage 262 and the flange 241 can be made very small.

The plug connection 242 also makes it possible to expand the axial tolerances between the various contact or support surfaces of the components.

To seal the annular chamber 230 , a seal 274 is provided between the radially inner region of the housing part 232 and the flywheel element 204 . The seal 274 differs from the seal 174 described in connection with FIG. 6 essentially in that the circular, axially resilient disc 275 is completely coated and is axially clamped radially on the outside between an annular region 232 a of the housing part 232 and one on Housing part 232 secured by ring rivets 232 b ring washer 280 .

The annular region 232 a of the housing part 232 extends, starting from the outer diameter of the resilient sealing washer 275 radially inward, a radial space 232 c being formed between the annular region 232 a and the sealing washer 275 . In this radial space 232 c, which is open radially inwards, the small amounts of viscous medium which can possibly escape between the inner area of the sealing disk 275 and the counter-sealing areas 276 b can be collected and at higher speeds - due to the centrifugal force - be pressed back into the annular chamber 230 between the annular region 232 a and the sealing washer 275 . The contact zones between the inner regions of the sealing disk 275 and the counter sealing regions 276 b are provided in the axial extension region of the radial space 232 c.

An axial recess or an axial shoulder 291 is formed on the inner region of the housing part 232 , the radially outer lateral surface of which axially engages over the outer regions of the sealing disk 275 .

Which faces the motor housing half 231 carries inside an axial projection 220 on which the the two flywheel elements 203 and 204 relative to each overlapping rolling bearing is in a similar manner as in Fig. 1 taken up 16th The sheet metal part 231 is centered on a seat 220 b of the neck 220 and is supported axially on a radial surface 220 c of the neck 220 provided at the connection to the seat 220 b.

The connection between the sheet metal part or housing part 231 and the axial extension 220 can be made by screwing, riveting, welding or caulking.

The two flywheel elements 203 and 204 are assembled in a similar manner to that described in connection with FIGS. 1 and 2; this means that the roller bearing 16 is first preassembled on the flywheel element 204 and the sealing disc 275 on the flywheel element 203 . When sliding of the roller bearing 16 on the seat 220 a of the projection 220, the connector 242 is produced and the sealing disc clamped b axially through engagement with the flywheel provided on the member 204 counter-sealing areas 276,275. By fastening the locking washer 222 , which radially overlaps the inner bearing ring of the rolling bearing 16 , on the end face of the extension 220 , both flywheel elements 203 and 204 are axially secured to one another. Similar to that shown in FIG. 6, the disk 222 can be attached by riveting. Instead of rivets, screws can also be used.

The hydraulic or viscous damping by displacing or swirling the viscous medium provided in the annular channel-like receptacle 251 takes place in a similar manner to that described in connection with FIGS. 1 and 2.

To prevent the two sheet metal housing parts 231 , 232 from being welded, the components in contact with them - such as in particular the movable components - are partially welded to the housing parts or experience a structural change as a result of partial overheating, is between these components and the sheet metal housing 231 , 232 provided electrical insulation. The components which are endangered during the welding process are in particular the springs 245 present in the annular channel-like receptacle 251 , furthermore the flange 241 and the spring cups 259 .

The insulating coating can be provided on the housing parts 231 , 232 and / or on the components 245 , 241 , 259 , 255 , 255 a that are in contact with them. The insulating coating can only be applied partially, which means that only in the Kontaktbe range between the housing parts and the other components.

The isolation can advantageously be achieved by phosphating individual components. Furthermore, individual components, such as the spring cups 259 and the circumferential stops 255 , 255 a, can be produced from non-conductive material.

It is particularly advantageous if at least the sheet metal parts and / or the flange are phosphated for insulation. The springs 245 are appropriately painted, but can also be phosphated.

In order to isolate the housing parts 231 , 232 from the components in contact with them, ceramic layers, plastic coatings or even grease coatings can also be used. Such coatings can be applied in particular to the housing parts 231 , 232 .

If the sheet metal parts 231 , 232 are completely coated during the insulation treatment, such as phosphating, it is expedient if, in the area of the welding zones and in the contact area for the power supply, the insulating layer previously applied in these areas is removed, for example by mechanical processing, so that there is perfect electrical conductivity in these areas.

When selecting the insulating means, it must always be ensured that they are compatible with the viscous medium introduced into the annular channel-like receptacle 251 .

The use of a phosphate layer as an insulating layer is special advantageous because it has a wear-reducing and self-lubricating effect.

The housing part 231 also has a seat 239 on the outer circumference, on which a starter ring gear 240 is received. The starter ring gear 240 is viewed over the circumference, at least in places connected to the housing part 231 by a weld 240 a. This is advantageous in the sheet metal design of the housing part 231 , because due to the limited wall thickness of the housing part 231, the seat 239 does not extend across the full ring gear width.

As can further be seen from FIG. 5, the motor-side housing part 231 has a greater material thickness than the housing part 232 .

As can be seen from FIG. 7, the circumferential stops 255 , 255 a according to FIG. 5 can be replaced by embossments formed in the sheet metal molded parts 231 , 232 , such as pockets 255 c, 255 d. These pockets 255 c, 255 d can advantageously be used to position the two housing parts 231 , 232 when welding them together. For this purpose, corresponding projections are to be provided on the welding device, which are adapted to the pockets 255 c, 255 d. These projections can form the electrodes which introduce the required welding current into the housing parts 231 , 232 . Through these projections, the axial pressure required for the welding can be applied to the housing parts 231 , 232 who the. It is particularly useful if these projections are provided in the welding device such that they always occupy a predetermined distance during the welding process, which also ensures that the two housing parts 231 , 232 after the welding process have a defined axial position have relative to each other. This is important in relation to the springs 245 provided in the annular channel-like receptacle 251 and, in particular, in relation to the defined distance between the two regions 260 , 261 and the flange 241 provided therebetween, which defines the distance generated by the device hydraulic or Viscous damping is affected.

The detail of a device 301 shown in FIG. 8 shows a flange 341 which has radial arms 344 formed on the outer circumference. As described in connection with the previous figures, force storage means in the form of helical springs 345 , 345 a can be applied via the extension arm 344 . The energy stores 345 , 345 a are received in an annular channel-like receptacle 351 , which is formed by components of the flywheel elements 303 . The spring 345 a is acted upon directly by the radial arm 344 , whereas a spring cup 359 is arranged between the spring 345 and the radial arm 344 .

The boom 344 has circumferential projections in the form of pins or lugs 344 a, 344 b.

The spring cup 359 has a recess 359 a, in which the nose 344 a engages. The nose 344 a and the recess 359 a are designed and arranged such that at least when the spring 345 is acted upon, the cup 359 and, via this, the end region of the compression spring 345 are retained by the nose 344 a with respect to the radially outer regions of the annular channel-like receptacle 351 or is lifted off. For this purpose, the radially inner region of the nose 344 a forms an inclined ramp 344 c, which interacts with a support region 359 b of the spring cup 359 . Through the ramp 344 c of the nose 344 a, the spring cup 359 is acted upon or pulled radially inward.

The nose 344 b has a bevel 344 d radially on the inside, which cooperates with the end turn of the spring 345 a and strikes or urges it radially inward.

When using a spring cup 359 , it is advantageous if at least the cross section of the ramp 344 c is adapted to the contour of the recess 359 a, so that even when the spring cup 359 is rotated, the same can be properly pressed against the nose 344 a or the boom 344 given is.

Formations or lugs 344 a or 344 b can also be advantageously provided on the radial arms and / or the radial areas of the flanges according to FIGS. 1 to 7.

Such lugs 344 a, 344 b have the advantage that even at higher speeds len at least the end areas, that is, some turns of the coil spring are kept radially out of contact with other components or areas so that these spring turns can spring freely, that means means not to generate friction damping.

Furthermore, can be ensured by such lugs 344 a, 344 b that even in speed ranges in which the normally existing friction between the turns of the springs and their radial support surfaces is so large that the turns can no longer spring, at least the Endbe rich Springs still have elasticity or suspension. This is particularly advantageous in order to dampen the high-frequency vibrations occurring in these speed ranges with a small angular amplitude.

In the embodiment variant of a unit 401 shown schematically in FIG. 9, the flange 441 is riveted in a sealing manner directly to the axial extension 443 of the flywheel element 404 in order to seal the annular chamber 430 which is at least partially filled with a viscous medium, and it is also axially between the flange 441 and the radial side wall 432 of the annular chamber 430 facing the flywheel element 404 is provided with a seal 474 .

Radially within the side wall 432 and axially between the flange 441 and an axially spaced radial area 404 a of the flywheel element 404 , a friction device 490 is provided, which is located outside the at least partially filled with viscous medium, annular chamber 430 . This dry friction device 490 has a friction disk 494 and friction rings 494 a, 494 b provided on both sides thereof, the friction ring 494 b being arranged axially between the friction disk 494 and the flange 441 . On the side of the friction ring 494 b facing away from the friction disc 494 , a pressure disc 493 is arranged, which is acted upon by a plate spring 492 , which is axially clamped between the radial region 404 a and the pressure disc 493 .

The friction disk 494 has radial profiles 495 on its outer circumference, which are in engagement with counter profiles 495 a formed on the radial inner edge of the wall 432 . Depending on the application, the profiles can be designed to be free of play or, in the circumferential direction, allow a certain amount of torsional play between the friction disk 494 and the wall 432 , so that the friction device 490 can then only become effective after the use of at least one of the springs of the damper 413 .

In the unit 501 shown schematically in FIG. 10, a seal 574 , 574 a is provided radially inside the damper 513 and adjacent to the ring channel-like receptacle 551 on both sides of the flange 541 , which seals with corresponding areas of the adjacent parts 532 , 531 , which are the ring channel-like Limit admission 551 , work together as a seal.

Radially inside the seals 574 , 574 a, the flange 541 is clamped axially between two disks 593 , 594 with the interposition of friction rings 594 a, 594 b. The washer 594 is fixedly connected to the flywheel element 504 via spacer bolts 567 . The axially between the flange 541 and the radial region 504 a of the flywheel element 504 arranged on the pressure plate 593 is acted upon by a plate spring 592 which is axially clamped between this pressure plate 593 and the radial region 504 a. Radially inside the plate spring 592 and the pressure plate 593 have cutouts which at least partially encompass the spacer bolts 567 , so that the plate spring 592 and the pressure plate 593 are secured against rotation with respect to the flywheel element 504 .

The pretensioning force of the plate spring 592 determines the moment at which the flange 541 can twist or slip relative to the flywheel element 504 . The components 592 to 594 b thus form a non-positive clutch or slip clutch 590 in connection with the radially inner regions of the flange 541 .

To limit the rotation between the flange 541 and the flywheel element 504 , the flange may have projections on its inner region which, viewed in the circumferential direction, engage radially between the spacer bolts 567 . By abutment of these radial projections of the flange 541 on the spacer bolt 567 , the relative rotation can be limited. For some applications, however, it can also be expedient if there are no such means which limit the relative rotation between flange 541 and flywheel element 504 . In such cases, the non-positive clutch 590 is designed such that the torque that can be transmitted from it is greater than the nominal torque output by the motor.

According to a development of the device shown in FIG. 10, with a limited relative rotation between the flange 541 and the flywheel element 504, additional energy stores in the form of screw springs can be effective between the two disks 593 , 594 and the flange 541 . These springs can be accommodated in corresponding recesses in the two disks 593 , 594 and the flange 541 , wherein these recesses — viewed in the circumferential direction — can be introduced between the spacer bolts 567 . In such a configuration of the device, it is expedient if the springs provided in the area of the non-positive clutch or friction device 590 have a substantially higher spring rate than the springs of the outer damper 513 .

The friction damping generated by the friction device 590 should also be significantly greater than the friction damping present in the torsion angle range of the damper 513 , which is generated, among other things, by the seals 574 , 574 a, which abut the flange 541 .

In the described embodiments, a multi-level spring characteristic line between the corresponding flywheel elements can also be achieved in that at least individual springs of a spring group or a damper are shorter than the angular distance between the stop or loading areas interacting with them. Also, by using springs that are shorter than the annular channel sectors or cutouts or windows that receive them, a torsion angle range that is free of provision, starting from a central position or rest position, can be created between the two flywheel elements. The latter can e.g. B. in an embodiment according to FIGS. 5 and 6 can be achieved in that the springs 245 have a smaller angular extent in the circumferential direction than the angle between the arms 244 or the stops 255 , 255 a.

The invention is not based on the illustrated and described Ausfüh tion examples limited, but also includes variants by combination nation of individuals in connection with the various embodiments described features or elements can be formed.

Claims (19)

1. Torsional vibration damper in the power transmission path of a motor vehicle with an internal combustion engine, consisting of at least one input part that can be driven by the internal combustion engine, at least one output part that can be connected to a transmission, and a torsion spring device between the two parts, including coil springs with a large length. / Diameter ratio, which are guided axially and radially in guide channels arranged concentrically to the axis of rotation and are compressed during torque transmission between the input and output part, characterized in that the helical springs ( 45 ) are pre-curved over their longitudinal extension in the unassembled state. 2. Torsional vibration damper according to claim 1, characterized in that the curvature is at least approximately that of the installed state corresponds.   3. Torsional vibration damper according to one of claims 1, 2, characterized in that the spring ends of the pre-curved coil springs ( 345 , 345 a) are held in the radial direction by holders ( 359 , 344 a, 344 b) such that in the end regions there is no contact with the radially outer guide parts. 4. Torsional vibration damper according to one of claims 1 to 3, which the torsion spring device consists of several spring stages. 5. Torsional vibration damper according to claim 4, characterized in that the curved coil springs ( 45 , 48 ) are associated with a spring step which has a low spring rate. 6. Torsional vibration damper according to one of claims 1 to 5, characterized in that the coil springs ( 45 , 48 ) between the input part ( 3 ) and output part ( 41 ) allow at least a relative rotation of 25 degrees, starting from a central position. 7. Torsional vibration damper according to one of claims 1 to 6, characterized in that the springs ( 45 , 48 ) extend over 70 to 96% of the angular circumference of the device. 8. Torsional vibration damper according to one of claims 1 to 7, characterized in that at least two, but at most four coil springs ( 45 , 48 ) are arranged on the same diameter. 9. Torsional vibration damper according to one of claims 1 to 8, characterized in that a plurality of spring groups ( 13 , 14 ) are provided. 10. Torsional vibration damper according to claim 9, characterized in that the spring groups are connected in series. 11. Torsional vibration damper according to claim 9, characterized in that the spring groups ( 13 , 14 ) are connected in parallel. 12. Torsional vibration damper according to at least one of claims 1 to 11, characterized in that it has at least two flywheel elements ( 3 , 4 ) rotatably mounted relative to one another, one flywheel element ( 3 ) being connectable to the internal combustion engine and the other flywheel element ( 4th ) via a clutch, such as a friction clutch, can be connected to the transmission. 13. Torsional vibration damper according to at least one of claims 1 to 12, characterized in that in the guide channels viscous medium is available. 14. Torsional vibration damper according to at least one of claims 1 to 13, characterized in that to limit the relative movement of the input and output part windings of coil springs ( 45 , 48 ) go on block. 15. Torsional vibration damper according to at least one of claims 1 to 14, characterized in that at least the spring windings provided between the end sections of a helical spring ( 45 , 48 ) are supported radially on the surface delimiting the corresponding guide channel under the action of centrifugal force. 16. Torsional vibration damper according to at least one of claims 1 to 15, characterized in that the coil springs can be supported in the guide channel with the interposition of wear protection ( 181 ). 17. Torsional vibration damper according to one of claims 1 to 16, characterized in that the torsion spring device ( 13 ) at least one formed by components ( 31 , 32 ) of a flywheel element ( 3 ), at least partially filled with viscous medium, such as a pasty agent Channel ( 51 ), in which the coil springs are supported and guided, the channel being closed at least radially outwards and being tight for the viscous medium. 18. Torsional vibration damper according to one of claims 1 to 17, characterized in that the spring-receiving guide channels ( 51 ) are at least externally adapted to the contour of the cross section of the coil springs ( 45 ). 19. Torsional vibration damper according to at least one of claims 16 to 18, characterized in that the wear protection ( 181 ) extends at least approximately over the length of the coil springs.