CN107429789B

CN107429789B - Torsional vibration damper

Info

Publication number: CN107429789B
Application number: CN201680019140.0A
Authority: CN
Inventors: A·库伊
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2015-04-09
Filing date: 2016-03-11
Publication date: 2020-03-17
Anticipated expiration: 2036-03-11
Also published as: DE102015206284A1; EP3280928A1; CN107429789A; DE112016001623A5; WO2016162025A1

Abstract

A torsional vibration damper (100), in particular a dual mass flywheel, has an input part (102) and an output part (104) with a common axis of rotation (106), the input element (102) and the output element (104) can be rotated jointly about the axis of rotation and can be rotated in a limited manner relative to one another, and the torsional vibration damper has a spring damper device acting between the input member (102) and the output member (104), the spring damper arrangement has at least one energy store (110) and a friction device (112) for damping a relative rotation between the input part (102) and the output part (104), in the torsional vibration damper, the friction device (112) is not active above the limit rotational speed, in particular due to the action of centrifugal force, in order to structurally and/or functionally improve the torsional vibration damper (100).

Description

Torsional vibration damper

Technical Field

The invention relates to a torsional vibration damper, in particular a dual mass flywheel, having an input part and an output part with a common axis of rotation, which can rotate together about the axis of rotation and can be rotated in a limited manner relative to one another, and having a spring damper arrangement acting between the input part and the output part, which has at least one energy store and a friction device for damping the relative rotation between the input part and the output part.

Background

From DE 19950081 a1, a torsional vibration damper is known, in particular for a motor vehicle clutch, having at least one input part and at least one output part which can be rotated relative to one another and between which at least one damping device having an energy store is arranged, wherein the input part and/or the output part has at least one disk-shaped component. Viewed in the axial direction, a friction control disk is arranged on one side of the disk-shaped member, said friction control disk being fixedly connected in the axial direction to an annular member arranged on the other side of the disk-shaped member. At least one energy store, for example, in particular a disk spring, is tensioned between the friction control disk and the disk-shaped member and/or between the annular member and the disk-shaped member.

DE 102009030984 a1 discloses a dual mass flywheel for a drive train of a motor vehicle, which drive train has an internal combustion engine, which dual mass flywheel has a first flywheel mass which can be assigned to the internal combustion engine, a second flywheel mass which can be rotated relative to the first flywheel mass and is elastically coupled thereto, and a friction device which is assigned to the first and second flywheel masses and is used to prevent a relative rotational movement of the flywheel masses, wherein the friction device has a large number of friction surface contact sections, more than two, in order to provide a dual mass flywheel with an improved friction device. Advantageously, a plurality of friction surface contact portions act as a parallel connection, wherein the friction torque occurring is advantageously increased by a multiple in order to prevent a relative rotational movement of the flywheel masses.

Disclosure of Invention

The invention is based on the following tasks: the torsional vibration damper mentioned in the opening paragraph is structurally and/or functionally improved. In particular, resonance oscillations between the input part and the output part should be suppressed below the idling rotational speed of the internal combustion engine connected to the torsional vibration damper. In particular, damping in the characteristic frequency range should be achieved. In particular, damping should be carried out only in the rotational speed range below the idling rotational speed. The vibration isolation function of the torsional vibration damper should not be hampered by the damping in particular at and above idle operating speeds.

The object is achieved by a torsional vibration damper, in particular a dual mass flywheel, having an input part and an output part with a common axis of rotation about which the input part and the output part can rotate together and can be rotated to a limited extent relative to one another, and having a spring damper arrangement acting between the input part and the output part, which has at least one energy store and a friction device for damping the relative rotation between the input part and the output part, wherein the friction device is inactive above a limit rotational speed, in particular due to the effect of centrifugal forces. Since the friction device does not function above a limit speed, the vibration isolation function of the torsional vibration damper is not impaired by the damping when the rotational speed is above the limit speed. Since the friction means for damping the relative rotation between the input and output members act below the limit rotational speed, the resonance between the input and output members is very effectively damped below the limit rotational speed. The torsional vibration damper may be connected to the internal combustion engine. The limit rotational speed may be less than an idling rotational speed of the internal combustion engine. In the case of operation below the idling speed, for example during a starting process or during a standstill phase of the internal combustion engine, the resonance effect which occurs can be significantly suppressed by the friction device.

The torsional vibration damper can be used for arrangement in a drive train of a motor vehicle. The drive train may have an internal combustion engine. The drive train may have a friction clutch arrangement. The friction clutch device may have a double clutch. The drive train may have a transmission. The transmission may be a dual clutch transmission. The drive train may have at least one drivable wheel. A torsional vibration damper may be used for arrangement between the internal combustion engine and the friction clutch device. The torsional vibration damper may be part of a friction clutch arrangement. Torsional vibration dampers can be used to reduce torsional vibrations excited by periodic processes, in particular in internal combustion engines. The torsional vibration damper can be active in the sliding direction and/or in the traction direction. The slip direction is the direction of power flow directed towards the internal combustion engine. The direction of traction is the direction of power flow from the internal combustion engine.

The input element and the output element can be mounted in a mutually rotatable manner by means of bearings. The input element can be used for connection on the drive side, in particular with an internal combustion engine. The output element can be used for connection on the output side, in particular with a friction clutch device. The terms "input" and "output" relate to the direction of power flow from the internal combustion engine.

The input piece may have a flange section. The input piece may have a cover section. The input piece may have a flange section and a cover section. The flange section and the cover section can be fixedly connected to one another, in particular welded. The flange section and the cover section can delimit a toroidal receiving chamber for the at least one first energy store.

The input may have a primary stop. The flange section of the input may have a primary stop. The cap section may have a primary stop. The primary stop may extend into the receiving chamber. The primary stop of the input can be used to support at least one energy store on the input side. The primary stop of the input element can be formed by means of a through-opening (durchtillung) of the flange section and/or of the cover section. The primary stops of the input part can be arranged diametrically opposite one another. The flange member of the output member may have a primary stop. The flange part of the output part can have flange wings which project radially outwards into the receiving chamber. The flange wing may constitute a primary stop for the output member. The primary stop of the output element can be used to support at least one energy store on the output element side. The primary stops of the output part can be arranged diametrically opposite one another. The at least one energy store can be supported on the one hand on a primary stop of the input part and on the other hand on a primary stop of the output part.

The at least one energy storage may have at least one spring. The at least one spring may be a compression spring. The at least one spring may be a coil spring. The at least one spring may be an arcuate spring. The at least one energy store can be active in the slip direction and/or in the traction direction. The at least one energy store can act with an active radius with respect to the axis of rotation. The at least one accumulator may be a high capacity spring.

The torsional vibration damper can have a secondary stop device, wherein the input part and the output part each have a corresponding secondary stop. The secondary stop on the input side and the secondary stop on the output side can abut against one another beyond a predetermined maximum torsion angle between the input and the output. The secondary stop can limit the relative rotation between the input and output in the event of an overload and thus avoid or minimize damage to the components. The secondary stop can ensure, in particular, the driveability of the motor vehicle in the event of a standstill of the energy store.

The output member may have a flange member. The output member may have a flywheel mass. The output member may have a flange member and a flywheel mass member. The flange member and the flywheel mass member may be fixedly connected to each other. The flange part and the flywheel mass part can be connected to one another by means of a plurality of rivets. This can be achieved by means of a so-called main rivet. The flange part of the output part can be arranged axially between the flange section and the cover section of the input part. The flywheel mass of the output part can have an outer diameter which is greater than the radius of action of the at least one energy store.

The friction device may have a bracket. The friction device may have a friction disc. The friction device may have at least one locking element for locking the carrier with the friction disc. The friction device may have at least one locking element for locking the carrier with the friction disc, controlled by centrifugal force. The friction device may have a force store for biasing the locking element in the direction of the locking position.

At least one locking element can be mounted on the support in a pivotable manner. At least one locking element can be mounted on the carrier in a rotatable manner. A rotatably mounted locking element is less prone to warping than a linearly guided locking element. At least one locking element can be mounted on the carrier in a pivotable manner and can interact in a locking manner with a counter-element of the friction disk below a limit rotational speed.

The support may be connected to the output. The bracket may be connected to the flange member of the output member. The friction disc may be rotatably supported on the input member. The friction surfaces of the friction disks can be preloaded against a component of the input element. The friction surfaces of the friction disks can be preloaded against the flange portion of the input element. The friction disks can be elastically prestressed in the axial direction with respect to the input element. The friction disks can be prestressed in the axial direction against the input element by means of disk springs. The disk spring can be supported on the input part in the axial direction. The disk spring can be supported in the axial direction on a support plate of the input part. The support sheet may have a donut-disc shape. The support plate may support the disc spring in the axial direction. The support plate can center the belleville springs. The disc spring may center the friction disc.

Since the friction surface is prestressed against the input element, a relative rotation between the friction surface and the input element results in suppressed friction. Below the limit speed, the friction disks are locked with the carrier and thus with the output element, so that a relative rotation between the output element and the input element results in a relative rotation between the friction surfaces and the input element. Above the limit speed, the friction disk is decoupled from the carrier and is carried by the input element without relative rotation between the friction surface and the input element.

The locking element may be controlled by centrifugal force. The locking element may be a pawl. The locking element may be a pin. The locking element may be a swing lock. The locking element may be a centrifugal force controlled rotary latch (drehfaile). The locking element can cooperate lockingly with the counter element. The locking element can be supported on the carrier and the counter element can be formed or fastened on the friction disk. The counter element may be a recess in the outer circumference of the friction disk in the radial direction. The counter element may be a slotted recess in the friction disc. The counter element may be a bolt, for example a bolt for co-acting with a rotary latch. The counter element may be a clamping plate, for example a clamping plate for co-acting with a rotary latch.

The locking element can be pretensioned in the direction of interaction with the counter element. The locking element can be pretensioned radially inwards. The locking element can be pretensioned by a force generated by the force accumulator in the direction of interaction with the counter element. The accumulator may be a spring. The accumulator may be a pressure spring. The accumulator may be a helical compression spring. Below the limit speed, the friction disk can be connected to the carrier and thus to the output part by means of a locking element. Above the limit speed, the centrifugal force acting on the at least one locking element exceeds the force of the force store, so that the locking element is released from the counter element. The friction disk is thus no longer carried along by the carrier. The friction discs are then carried into rotation by the input member due to the friction torque between the input member and the friction surfaces of the friction discs, without relative movement between the friction discs and the input member.

At least one locking element can be provided for each direction of rotation of the relative rotation between the input and output. For each direction of rotation of the relative rotation between the input part and the output part, a plurality of locking elements can be provided, which are distributed over the circumference of the friction device. For each direction of rotation of the relative rotation between the input part and the output part, exactly three locking elements can be provided, which are distributed over the circumference of the friction device. For each direction of rotation of the relative rotation between the input part and the output part, more than three locking elements can be provided, which are distributed over the circumference of the friction device and can interact with a corresponding number of counter-elements. Two locking elements for different directions of rotation of the relative rotation between the input and output can be associated and interact with exactly one counter element. Two locking elements for different directions of rotation of the relative rotation between the input part and the output part can be arranged axially next to one another. Two locking elements for different directions of rotation of the relative rotation between the input and output can be arranged axially next to each other and interact with exactly one counter element.

The friction disk may have one metal region or a plurality of metal regions in segments. The friction disks may be produced in sections from sheet metal. The counter element of the friction disk may in particular be formed from a plate material. This makes it possible to form a high-strength counter element on the friction disk. The friction disks may have regions made of plastic in sections. The friction disk may have several regions made of plastic in sections. The friction disk may have a friction region made of plastic. The friction disk may have a friction surface made of plastic. The friction discs may have friction faces made of known materials having a high wear resistance. The friction discs may have friction faces made of known materials having a high coefficient of friction.

In a kinematic opposite of the previously described configuration, the carrier can be connected to the input element and the friction disk can be mounted rotatably on the output element. The friction surfaces of the friction disks can be preloaded against a component of the output element. The principle of action may be as explained before.

The torsional vibration damper may have a centrifugal force pendulum device. Centrifugal pendulum devices can be used to improve the effectiveness of torsional vibration dampers. The centrifugal force pendulum device may be arranged radially inside the at least one energy store. The centrifugal force pendulum device may be arranged axially between the flange section and the cover section of the input part. The centrifugal force pendulum device can be arranged on the output part. The centrifugal force pendulum device may have a pendulum mass carrier part. The flange part of the output part can be used as a pendulum mass support part. The centrifugal pendulum device may have at least one pendulum mass. At least one pendulum mass can be arranged on the pendulum mass carrier part along the pendulum rail in a displaceable manner. At least one pendulum mass can be displaceable into an operating position under the effect of centrifugal force. In the operating position, the at least one pendulum mass can oscillate along the pendulum rail in order to absorb torsional vibrations. At least one pendulum mass can oscillate between two end positions starting from the center position.

In general and in other words, the invention relates to a dual mass flywheel-hysteresis device, such as a friction device. A fundamental problem of dual mass flywheels, which is determined by the principle, is resonance below the idling speed. A possibility of suppressing such resonances, which is known from the prior art, consists in the use of a friction control disc which is arranged between the primary part (input) and the secondary part (output) of the dual-mass flywheel and prevents possible formation of resonances. Disadvantageously, the high friction required for this prevents the isolating function of the dual mass flywheel during idling. The invention comprises an external (ratchet) carrier, which is optionally mounted on the secondary side (flange part) or on the mirror-symmetrical primary side. It comprises a pawl which is pressed radially inwards by a spring. The spring preload is designed such that it is overcome by the centrifugal force of the pawl at a defined rotational speed (limit speed) (this defined rotational speed is set at the idle operating speed): thereby, the pawls are disengaged from the friction plates. It is expedient if at least three pawls are arranged in the direction of rotation and three pawls are arranged in the opposite direction. Even more pawls achieve an exact insertion as a function of the rotational speed, since the time until engagement is thereby reduced.

By "may" is meant in particular optional features of the invention. There are thus embodiments of the invention having this or these respective features, respectively.

The torsional vibration damper according to the invention suppresses resonance between the input part and the output part below the idling rotational speed of the internal combustion engine connected to the torsional vibration damper. In particular, a vibration damping in the characteristic frequency range is achieved. The damping is carried out in particular only in the rotational speed range below the idling rotational speed. In particular, the vibration isolation function of the torsional vibration damper should not be impeded by the friction device during and above the idling rotational speed.

Drawings

Embodiments of the present invention are described in detail below with reference to the accompanying drawings. Additional features and advantages result from this description. The specific features of this embodiment can illustrate the general features of the invention. Features of the embodiments can also be used to illustrate various features of the invention in combination with other features.

Schematically and exemplarily shown:

FIG. 1 is a partial radial section through a torsional vibration damper according to the invention, and

fig. 2 shows a friction device of a partial torsional vibration damper.

Detailed Description

Fig. 1 shows a torsional vibration damper 100. The torsional vibration damper 100 is used in the drive train of a motor vehicle between an internal combustion engine and a friction clutch device, for example as a dual mass flywheel and a dual clutch damper. Torsional vibration damper 100 has an input member 102 and an output member 104. The torsional vibration damper 100 has a rotational axis 106 about which the input part 102 and the output part 104 can be jointly rotated and can be rotated in a limited manner relative to one another. The directional descriptions used "axial," "radial," and "circumferential" are with respect to the axis of rotation 106.

The input element 102 and the output element 104 are mounted in a rotatable manner in close proximity to one another by means of bearings 108. Between the input member 102 and the output member 104, the arcuate spring 110 functions as an accumulator. Here, the torsional vibration damper 100 has two arc springs 110 of a substantially semicircular arc shape. The arcuate spring 110 stores energy or discharges energy in the event that the input member 102 and the output member 104 twist relative to one another. In addition, a friction device 112 acts between the input member 102 and the output member 104. Thereby, torsional oscillations excited by periodic processes in the internal combustion engine may be reduced. The friction device 112 suppresses a relative rotation, in particular periodically, between the input element 102 and the output element 104, in this case below a limit speed of the internal combustion engine, which is lower than the idle speed of the internal combustion engine.

The input 102 has a flange section 114 and a cover section 116. The cap section 116 has an annular disc shape. The flange section 114 and the cover section 116 are welded to one another. The flange section 114 and the cover section 116 delimit a ring-shaped receiving chamber for the arcuate spring 110.

The input 102 has a primary stop projecting into the receiving chamber for supporting the arcuate spring 110 on the input side. The primary stops of the input part 102 are arranged axially opposite one another on the flange section 114 and on the cover section 116, respectively. The cover section 116 preferably has two primary stops, which are not visible in the drawing. The primary stops are arranged diametrically opposite one another. The primary stops are partial regions of the cover sections 116, which are each formed into the receiving chamber by the material of the cover sections 116 counter to a cross-sectional arch.

The output member 104 has a flange member 118 and a flywheel mass member 120. The flange part 118 has flange wings which project radially outwards into the receiving chamber. The flange wings serve as primary stops for supporting the arcuate springs 110 on the output side. The flange member 118 and the flywheel mass member 120 are connected to each other by means of a plurality of rivets 122.

The friction device 112 is arranged spatially and functionally between a flange section 114 of the input part 102 and a flange part 118 of the output part 104. The friction device 112 has a carrier 124 connected to the output element 104, a friction disk 126 rotatably mounted on the input element 102, and six locking elements 128 for locking the carrier 124 with the friction disk 126 below a limit rotational speed. Fig. 2 shows one of the six locking elements 128. Three of the six locking elements 128 act in the first direction of rotation. Three of the six locking elements 128 act in a second rotational direction opposite to the first rotational direction.

The friction disc 126 has the basic shape of a ring disc. Six counter elements 130 are arranged radially on the outer periphery of the friction disc 126. Each of the counter elements 130 is a radially inwardly formed, slotted recess in the radially outer circumferential direction of the friction disc 126. In the region of the counter element 130, the friction disk 126 is formed from sheet metal and has a U-shaped cross section. A groove-like depression is produced in the circumferential direction by this partially U-shaped cross section. On the side of the friction disk 126 facing the flange section 114 of the input part 102, the friction disk 126 has a friction surface 132 made of plastic, which bears against the flange section 114.

The friction disk 126 is prestressed in the axial direction against the flange section 114 by means of a disk spring 134, so that a friction torque counteracts a possible relative rotation between the friction disk 126 and the flange section 114. The belleville springs 134 are supported in the axial direction on a support plate 136. The support plate 136 has a doughnut-type shape. The radially inner region of the support sheet 136 is riveted to the flange section 114. The radially outer region of the support sheet 136, which is bent in the axial direction relative to the radially inner region, supports the disk spring 134 in the axial direction and, in addition, centers the disk spring 134 in the radial direction. A disc spring 134 centers the friction disc 126.

The bracket 124 has a ring-disk-shaped base body having a U-shaped basic cross section. On the side of the U-shaped base body facing the flange part 118 of the output part 104, a disk-shaped fastening flange projects radially outward. The fastening flange of the carrier 124 is connected to the flange part 118 of the output part 104 by means of a plurality of rivets 138 distributed over the circumference. The carrier 124 is disposed radially outwardly of the friction disc 126. The carrier 124 and the friction disk 126 overlap in the axial direction.

The locking elements 128 are respectively oblong pawls. The locking elements 128 are pawls that are each controlled by centrifugal force. The first end region of each of all the locking elements 128 is articulated in a manner pivotable in a limited manner about a pivot axis 140 on the carrier 124. The pivot axes 140 are each arranged eccentrically with respect to the mass center of gravity of the locking element 128, so that the centrifugal force acting on the locking element 128 with rotational speed exerts an opening torque on the locking element 128 about the pivot axes 140.

The principle of action of one of the six locking elements 128 is explained below. The functional principle of the remaining locking elements 128 is relevant. The locking element 128 is prestressed by means of a force accumulator 142, which is designed as a compression spring, in such a way that the second end region of the locking element 128 is tensioned radially inward and thus in the direction of the counter element 130 of the friction disk 126. Below the limit rotational speed, the second end region of the locking element 128 is thereby pivoted into a groove-like recess in the radially outer circumference of the friction disk 126, which recess acts as a counter element 130. The pivoting-in (Einschwenken) of the second end region of the locking element 128 is delimited by the contour of the counter element 130. In the pivoted-in state, the locking elements 128 are arranged at an acute angle to the circumferential direction and lock the carrier 124 with the friction disk 126 in the rotational direction upon receiving a pressure force. Above the limit rotational speed of the internal combustion engine, the centrifugal force acting radially outward on the locking element 128 exceeds the force acting radially inward of the force store 142, so that the locking element 128 is released from the counter element 130, i.e. the locking element 128 pivots about the pivot axis 140 and pivots out of a groove-like recess in the radially outer circumferential direction of the friction disk 126.

For each direction of rotation of the relative rotation between the input part 102 and the output part 104, three locking elements 128 are provided, which are arranged distributed over the circumference of the friction device 112 and can interact with a corresponding number of counter-elements 130.

The arc spring 110 is supported on the one hand on a primary stop 114 of the input part 102 and on the other hand on a primary stop of the output part 104. In the event that the input member 102 and the output member 104 twist relative to one another, the arcuate springs 110 are compressed or relaxed. In the normal operation of torsional vibration damper 100, that is to say at a rotational speed of the internal combustion engine and thus of torsional vibration damper 100 which is equal to or greater than the idling rotational speed of the internal combustion engine, bow spring 110 is actuated within its elastic range. In the case of operation below the idling rotational speed, for example during a starting process or during a standstill phase of the internal combustion engine, a resonance effect occurs as a result of the low characteristic frequency of the torsional vibration damper 100, which is significantly suppressed by the friction device 112 acting in this rotational speed range. As a result, the bow spring 110 is also not overloaded below the idling rotational speed and undesirable stop noise is avoided.

List of reference numerals

100 torsional vibration damper

102 input member

104 output element

106 axis of rotation

108 bearing

110 energy accumulator, arc spring

112 friction device

114 flange segment

116 cover section

118 flange

120 flywheel mass part

122 rivet

124 support

126 friction disk

128 locking element

130 corresponding element

132 friction surface

134 disc spring

136 support plate

138 rivet

140 axis of oscillation

142 power storage device

Claims

1. Torsional vibration damper (100) having an input part (102) and an output part (104) with a common axis of rotation (106), around which the input part (102) and the output part (104) can be rotated jointly and can be rotated to a limited extent relative to one another, and having a spring damper arrangement which acts between the input part (102) and the output part (104) and which has at least one energy store (110) and a friction arrangement (112) for damping a relative rotation between the input part (102) and the output part (104), characterized in that the friction arrangement (112) does not act above a limit rotational speed, the friction arrangement (112) having a carrier (124), a friction disk (126) and at least one locking element (128) for locking the carrier (124) to the friction disk (126), the carrier (124) being connected to the output element (104), the friction disk (126) being rotatably mounted on the input element (102),

-below the limit speed, the friction disc (126) is connected to the carrier (124) and thus to the output element (104) by means of the locking element (128);

-above said limit speed, said locking element (128) is released from said friction disc (126), whereby said friction disc (126) is no longer carried by said carrier (124), said friction disc (126) being carried in rotation by said input member (102) due to a friction torque between friction surfaces of said friction disc (126) and said input member.

2. The torsional vibration damper (100) of claim 1, characterized in that the locking elements are controlled by centrifugal force.

3. The torsional vibration damper (100) of claim 1 or 2, characterized in that the locking element is a centrifugally controlled pawl (128).

4. The torsional vibration damper (100) of claim 1 or 2, characterized in that the friction surface (132) of the friction disk (126) is preloaded against a component of the input member (102).

5. The torsional vibration damper (100) according to claim 1 or 2, characterized in that the at least one locking element (128) is mounted on the carrier (124) in a pivotable manner and interacts in a locking manner with a counter element (130) of the friction disk (126) below the limit rotational speed.

6. Torsional vibration damper (100) according to claim 5, characterized in that the locking element (128) is pretensioned by means of a force generated by a force store (142) in a direction co-acting with the counter element (130), and above the limit rotational speed the centrifugal force acting on the at least one locking element (128) acts beyond the force of the force store (142), so that the locking element (128) is released from the counter element (130).

7. The torsional vibration damper (100) according to claim 1 or 2, characterized in that for each direction of rotation of the relative rotation between the input part (102) and the output part (104) there are provided at least three locking elements (128) which are arranged distributed over the circumference of the friction device (112) and can interact with a corresponding number of counter-elements (130).

8. Torsional vibration damper (100) according to claim 1 or 2, characterized in that two respective locking elements (128) are associated with each other for different directions of rotation and can interact with exactly one counter-element (130).

9. The torsional vibration damper (100) of claim 1 or 2, characterized in that the friction disc (126) has a metal region with a counter element (130) and a friction region made of plastic with a friction face (132).

10. The torsional vibration damper (100) according to claim 1 or 2, characterized in that the torsional vibration damper (100) is connectable to an internal combustion engine and the limit rotational speed is smaller than an idling rotational speed of the internal combustion engine.

11. The torsional vibration damper (100) of claim 1, characterized in that the torsional vibration damper (100) is a dual mass flywheel.

12. Torsional vibration damper (100) according to claim 1, characterized in that the friction means (112) are inoperative above a limit rotational speed due to the effect of centrifugal forces.

13. The torsional vibration damper (100) of claim 4, characterized in that the friction surfaces (132) of the friction disks (126) are preloaded against the flange section (114) of the input member (102).

14. The torsional vibration damper (100) of claim 9, characterized in that the metal region is made of sheet material.