CN112762137B

CN112762137B - Torsional damper and clutch disc

Info

Publication number: CN112762137B
Application number: CN202011131908.8A
Authority: CN
Inventors: E·霍夫曼; L·乔克希尔; M·温克勒; S·奥特; R·韦丁格; B·科布; A·基里安; P·葛斯特; T·辛德勒; A·库比什; D·布尔; K·比迪克
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2019-10-21
Filing date: 2020-10-21
Publication date: 2024-03-01
Anticipated expiration: 2040-10-21
Also published as: CN112762137A; DE102019216146A1

Abstract

The invention relates to a torsional damper (210) and a clutch disk (200) having a torsional damper (210), comprising at least one helical spring (240) and an input element (220) having at least one first window opening (250-1) for receiving the helical spring (240). The first window opening (250-1) has a first stepped portion (232-1) for supporting a coil spring (240) on an outer periphery (252-1) of the first window opening, the first stepped portion extending radially inward. Furthermore, the torsional damper (210) comprises an output member (230) axially spaced from the input member (220), the output member having at least one second window opening (250-2) for receiving a coil spring (240). The second window opening (250-2) has a second stepped portion (232-2) for supporting the coil spring (240) on an outer periphery (252-2) of the second window opening, the second stepped portion extending radially inward.

Description

Torsional damper and clutch disc

Technical Field

The present invention relates to a torsional damper and a clutch disc. In particular, but not exclusively, the invention relates to a torsional vibration damper and a clutch disc for a motor vehicle.

Background

Torsional vibration dampers can be used, for example, in motor vehicle powertrains and in particular in clutch plates of motor vehicles.

In order to damp torsional vibrations caused, for example, by a motor, a torsional vibration damper can have an input element and an output element rotatable relative thereto, which are elastically coupled to one another. The input and output members may be coupled to each other, for example, by means of one or more coil springs that are compressed upon relative rotation of the input and output members. The input and output members may each have a window opening for receiving a coil spring. When the coil springs are compressed, the spring ends of the coil springs on the outer circumference of the window opening may rub against the input element and/or the output element. The frictional work produced in this case can lead to increased wear of the input element, the output element and/or the helical spring and thus to a reduction in the service life of the torsional damper.

It is not known from the prior art to propose a solution for reducing the wear of the helical spring, the input element and/or the output element due to friction work.

Disclosure of Invention

It is therefore conceivable as an object of the invention to reduce the wear of the spiral spring, the input element and/or the output element due to friction work.

This object is achieved according to various aspects of the present disclosure.

According to a first aspect, the invention relates to a torsional damper comprising at least one helical spring, and an input member having at least one first window opening for receiving the helical spring. The first window opening has a first stepped portion for supporting the coil spring on an outer periphery thereof, the first stepped portion extending radially inward. In addition, the torsional damper includes an output member axially spaced from the input member, the output member having at least one second window opening for receiving the coil spring. The second window opening has a second stepped portion for supporting the coil spring on an outer periphery thereof, the second stepped portion extending radially inward.

The first and second window openings can extend through the input member or through the output member in an axial direction such that the coil spring can be disposed in the first and second window openings. The spring ends of the helical springs can each lie against a side face of the window opening in the circumferential direction. Upon a relative rotation of the input element with respect to the output element, the helical spring can be compressed, wherein one of the spring ends is coupled, for example, to the input element and the opposite spring end in the circumferential direction is coupled to the output element.

For support in the radial direction, the coil spring may abut against a first step and a second step, which are arranged on the outer circumference of the first window opening of the input member or the outer circumference of the second window opening of the output member, respectively. By abutting the first and second step portions, the coil spring and/or its spring end may be radially spaced apart from the outer periphery of the first or second window opening that moves relative to the spring end upon relative rotation, for example. In this way, friction-related wear, for example, due to friction of the helical spring on the input element or on the output element, can be avoided.

In several embodiments of the invention, the first step may extend up to an end of the first window opening defining the first window opening in the first circumferential direction. Further, the second step may extend up to an end of the second window opening defining the second window opening in a second circumferential direction opposite to the first circumferential direction.

In the case of coil springs arranged tangentially to the circumferential direction, the coil springs can come into contact with the input element or with the output element, in particular at their spring ends located on the outer circumference of the first and second window openings. In order to support the helical spring in the radial direction at, for example, spring ends that are opposite in the circumferential direction, the first step and the second step can each extend in opposite circumferential directions, such that one of these steps supports one of the spring ends in the radial direction, respectively.

In several embodiments of the invention, the second circumferential direction may correspond to a direction of rotation of the input member relative to the output member during a traction operation of the torsional damper, and the first circumferential direction may correspond to a direction of rotation of the input member relative to the output member during a coasting operation of the torsional damper.

In particular in torsional dampers for motor vehicles, for example, the drive torque of the motor can be introduced into the torsional damper by way of the input element during a traction operation. In a coasting operation, a reduced torque, which is opposite to the drive torque, for example caused by motor resistance, can be introduced into the torsional damper via the input element. Thus, the rotational direction of the input member relative to the output member during the towing operation is, for example, opposite to the rotational direction during the coasting operation.

The spring end, which is arranged in the first circumferential direction and which abuts against the first step on the outer circumference of the first window opening, is coupled with the input element for compressing the coil spring when the input element is rotated relative to the pulling direction. Furthermore, a spring end, which is arranged in the second circumferential direction and which abuts against the second step on the outer circumference of the second window opening, is coupled to the output element for compressing the helical spring.

By having the spring ends radially supported on the first step or the second step, the spring ends can be kept at a distance from the input member or from the output member rotating relative to these spring ends during the pulling operation. Friction between the spring end and the input and output elements can thereby be avoided at least during traction operations.

In several embodiments of the invention, the first step may extend in the circumferential direction over at least 30% of the extension of the first window opening on its outer periphery, and the second step may extend in the circumferential direction over at least 30% of the extension of the second window opening on its outer periphery.

The first step and the second step may move in the circumferential direction opposite to the spring end when the torsional damper is operated in the coasting operation. The spring end can here for example sweep over a maximum of 30% of the extension of the first or second window opening over its outer circumference in the circumferential direction. In order to avoid seizing of the spring end on a ridge (schweller) defining the first or second step in the circumferential direction, for example in a return movement (oriented opposite to the relative rotation in a coasting operation), the first and second step may thus extend over at least 30% of the extension dimension of the first or second window opening.

In several embodiments of the present invention, the first step may be connected to the input member in a material-fit manner; and the second step may be connected to the output member in a material-fitting manner.

The input element and the output element can each be embodied as one piece, for example as a stamping. The stamping process for producing the input piece and the output piece can be adapted in such a way that the first step is embodied in one piece with the input piece and is therefore connected in a material-fitting manner, or the second step is embodied in one piece with the output piece and is therefore connected in a material-fitting manner.

In this way, cost-effective and simple production of the input and output elements can be achieved.

Alternatively, the first step may be welded or otherwise material-fittingly connected with the input member and the second step may be welded or otherwise material-fittingly connected with the output member.

In several embodiments, the second step may be arranged offset in the axial direction with respect to the spring axis of the helical spring, and the second step may have a bevel in the axial direction.

The second step may be arranged offset in the axial direction with respect to the spring axis, for example, such that the second step abuts the helical spring in an offset manner in the axial direction with respect to the spring axis. Thereby, the coil spring can be supported in the radial direction and at least in the axial direction.

The second step may be inclined in the axial direction so as to provide a planar abutment surface between the coil spring and the second step against the coil spring. The larger the contact surface, the less friction-related wear of the helical spring on the contact surface can be, for example.

The several embodiments further comprise at least one securing element which engages into the helical spring in the circumferential direction and is arranged firmly relative to the input in the axial direction.

The fastening element is arranged, for example, on one of the ends of the first window opening, which define the first window opening in the circumferential direction, and which extends parallel to the spring axis into the helical spring.

In order to fixedly arrange the fastening element in the axial direction relative to the input element, the fastening element comprises, for example, one or more pins which bear axially against the input element on opposite sides. The fastening element can thereby be supported on the input element in the axial direction by means of the pin.

The fixing element prevents or at least reduces axial displacement of the helical spring, which is caused, for example, by axial forces generated when the helical spring is compressed. Thereby, for example, wear of the coil spring caused by axial displacement of this coil spring is reduced.

In several embodiments of the invention, the output member may comprise a first output member and a second output member, which are arranged on opposite sides of the input member in the axial direction.

The first output element and the second output element can be connected to one another, for example, in a rotationally fixed manner. In addition, a second window opening having a second stepped portion may be introduced in the first output member and the second output member so that the coil spring may extend through the first output member and the second output member in the axial direction. The spring ends of the coil springs arranged in the second circumferential direction may be supported on the second stepped portions of the first output member and the second output member in the radial direction with respect to the distance from the outer periphery of the first window opening.

In the case of arranging the helical spring and the first and second output members symmetrically with respect to the input member in the axial direction, it is possible to achieve that the helical spring is subjected to a pressure load symmetrical with respect to the spring axis in the circumferential direction upon compression. This can prevent, for example, the helical spring from deforming in the axial direction when compressed, whereby it is also possible to increase the wear of the torsional damper.

According to a second aspect, the invention relates to a clutch disc comprising a torsional vibration damper according to the above description. Further, the clutch disc includes: a friction lining which is connected in a rotationally fixed manner to an input element of the torsional vibration damper; and a hub which is connected in a rotationally fixed manner to the output element of the torsional vibration damper.

In order to couple the clutch disk to the drive side, pressure may be applied to the friction lining in the axial direction, so that a friction torque is generated between the drive-side component (e.g., flywheel) and the friction lining. The friction torque can be used to introduce, for example, a drive torque or a deceleration torque of the motor into the clutch disk.

The torque introduced into the clutch disk can be transmitted by the friction linings to the input element and by the helical springs of the torsional damper to the output element. The hub may have external teeth to enable coupling with the output member. The hub may have a rotational play in the circumferential direction relative to the output element. After overcoming the rotational play, the output member may transmit torque introduced into the clutch disc to the hub. The hub may have an internal toothing in order to be able to be coupled with a driven shaft, for example for driving a motor vehicle.

During driving operation, centrifugal forces pressing the coil springs radially outwards can act on the clutch disc and the torsional damper. With the above-described embodiment of the torsional vibration damper, friction of the helical spring on the outer circumference of the first window opening or the second window opening can be avoided, for example, when rotating relative to one another in the traction direction.

Thereby, for example, wear of the clutch disc can be reduced, whereby the service life of the clutch disc can be increased.

Drawings

Several examples of embodiments of the present invention will be described in detail below, by way of example only, with reference to the accompanying drawings. In the drawings:

FIG. 1a shows a side view and a cross-sectional illustration of a conventional clutch disc having a conventional torsional damper;

FIG. 1b shows a side view and a cross-sectional illustration of a conventional clutch disc having a conventional torsional damper in the case of relative rotation;

FIG. 2a shows a side view of a clutch disc having a torsional vibration damper in a condition of relative rotation in traction operation;

FIG. 2b shows a side view of a clutch disc having a torsional vibration damper in the case of relative rotation in a coasting operation;

FIG. 3 shows a graph for demonstrating the friction work of a coil spring of a torsional vibration damper;

FIG. 4a shows a first cross-sectional view and a second cross-sectional view of a clutch disc having a stationary element; and

fig. 4b shows an embodiment of a fixation element.

Detailed Description

Various embodiments will now be described in more detail and with reference to the accompanying drawings in which several embodiments are shown.

While the embodiments may be modified and changed in different ways, embodiments are shown by way of example in the drawings and described in detail herein. It should be understood, however, that there is no intention to limit the embodiments to the forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

Fig. 1a and 1b show a conventional clutch disc 100 with a conventional torsional vibration damper 110 in side view (left side) and in cross-sectional illustration of a section in axial direction (right side), respectively. In fig. 1b, the input member 120 has a relative rotation with respect to the output member 130. In contrast, in fig. 1a, the input member 120 and the output member 130 do not rotate relative to each other.

The output element 130 may, for example (as shown here) comprise two cover plates, which are each arranged on axially opposite sides of the input element.

The input element 120 is connected to the friction lining 102 in a rotationally fixed manner in order to be able to be coupled to a drive-side component (not shown here) and, for example, to introduce a drive torque into the clutch disk 100 and into the torsional damper 110.

In order to elastically couple the input member 120 with the cover plate 130, the conventional torsional vibration damper 110 comprises at least one coil spring 140, of which only the spring end 142 is shown in fig. 1a and 1b, in order and to show the arrangement of the coil springs in the window opening 150-1 of the input member 120 and the window opening 150-2 of the output member 130. Other conventional clutch discs and torsional vibration dampers may have other, e.g., rotationally symmetrically arranged, window openings 150-1 and window openings 150-2 for arranging a plurality of helical springs.

The spring ends 142 of the coil springs are arranged in the circumferential direction such that they can be coupled with the input member 120 and/or the output member at the ends of the window openings 150-1 and 150-2 defined in the circumferential direction.

As can be seen on the right side of fig. 1a, the spiral spring 140 and its spring end 142 can rest against a support section 132 arranged on the periphery of the window opening 150-2. Thereby, the coil spring 140 may be spaced apart from the outer circumference of the window opening 150-1 of the input member 120 in the radial direction.

In case of relative rotation, as can be seen in fig. 1b, the radial distance of the coil spring 140 and its spring end 142 from the outer circumference of the window opening 150-1 decreases. Thus, in the event of relative rotation, friction may be generated between at least one of the spring ends 142 and the support section 132 and/or the outer periphery of the window opening 150-1 against this spring end. Friction may, for example, result in increased wear of the coil spring 140, the spring end 142 of the coil spring, and/or the output member 130 on the support section 132.

It is therefore conceivable as an object of the invention to reduce friction-induced wear of the spiral spring, the input element and/or the output element.

Embodiments of the invention are illustrated by means of fig. 2a and 2 b.

Fig. 2a and 2b show a torsional vibration damper 210, wherein the input element 220 and the output element 230 have opposite relative rotations with respect to each other in fig. 2a and 2 b. During traction operation, there is a relative rotation, for example as illustrated in fig. 2a, if a driving torque, for example generated by a motor, is introduced into the clutch disc 200 and the torsional damper 210. In a coasting operation, if a deceleration torque, for example caused by a motor, is introduced into the clutch disc 200 and the torsional vibration damper 210, there is, for example, a relative rotation as illustrated in fig. 2b, which is opposite to that in a traction operation.

As shown in fig. 2a and 2b, the input 220 of the torsional vibration damper 210 can be embodied, for example, as a entrainer disk (Mitnehmerscheibe), and the output 230 can be embodied, for example, as a cover plate of the clutch disk 200. The cover plate 230 is axially arranged relative to the entraining plate 220. For coupling to the drive-side component, the driving disk 220 can be connected to the friction lining 202 in a rotationally fixed manner. The cover plate 230 can be connected to a hub (not shown here) in a rotationally fixed manner, for example, in order to be able to transmit the torque transmitted by the clutch disk 200 to a component coupled to the hub, for example.

The cam plate 220 includes at least one first window opening 250-1 and the cover plate 230 includes a second window opening 250-2 for receiving at least one coil spring 240 that can elastically couple the cam plate 220 and the cover plate 230 to each other. In fig. 2a and 2b, only the spring end 242-1 and the spring end 242-2 are shown, respectively, in order to show the arrangement of the spiral spring 240, the coils of which can be arranged, for example, in the circumferential direction between the spring end 242-1 and the spring end 242-2.

In order to fix the helical spring 240 in the axial direction and/or to make the pressure load symmetrical when compressing the helical spring 240, a further cover plate (not shown here) may be arranged on the side of the driver disk 220 axially opposite the cover plate 230.

The coil spring 240 can bear against the first step 232-1 of the driver disk 220 or the second step 232-2 of the cover plate 230 at its spring ends 242-1 and 242-2 in the radial direction. The second step 232-2 of the second window opening may, for example, be inclined in the axial direction and abut the coil spring 240 in a biased manner in the axial direction relative to the spring axis. The spring axis here describes, for example, the connecting line of the center point of the spring coil.

During a pulling operation, the spring end 242-1 and the spring end 242-2 are pressed toward each other in the circumferential direction against the restoring force of the coil spring 240. In the case of a relative rotation during the pulling operation, the spring end 242-1 is in abutment with the driver disk 220 for this purpose at the end of the first window opening 250-1 which is defined in the first circumferential direction. The end of the spring end 242-2 defined in the second circumferential direction at the second window opening 250-2 is in abutment with the cover plate 230. The spring ends 242-1 and 242-2 thus have, for example, negligible wear or ideally no relative movement with respect to the first step 232-1 or the second step 232-2, which respectively bear against the spring ends 242-1 and 242-2. Thus, during a pulling operation, friction-related wear of the cam 220, the cover plate 230, and/or the coil spring 240 and/or the spring ends 242-1 and 242-2 of the coil spring may be negligibly small relative to other wear mechanisms within the torsional damper 210.

By having the spring ends 242-1 and 242-2 abut the first step 232-1 or the second step 232-2, the spring ends are radially spaced from the outer periphery 252-1 and the outer periphery 252-2 of the cover plate 230 or the catch plate 220, respectively, which are movable relative to the spring ends 242-1 and 242-2. In contrast to conventional torsional dampers 110, friction-related wear due to friction on the driving disk 220 movable relative to the spring end 242-1 and the spring end 242-2 or on the cover plate 230 can thereby be avoided during traction operations.

In a sliding operation (as shown in fig. 2 b), the end of the second window opening 250-2 defined in the second circumferential direction forms, for example, a stop for the spring end 242-1 and the cover plate 230, whereby the spring end 242-1 can be moved in the circumferential direction relative to the first step 232-1 in the case of a relative rotation in the sliding operation. Likewise, the end defining the first window opening 250-1 in the first circumferential direction forms, for example, a stop for the spring end 242-2 and the cam plate 220, whereby the spring end 242-2 can move relative to the second step 232-2 in the circumferential direction with relative rotation in the sliding operation.

Thereby, friction work between the spring end 242-1 and the first step 232-1 on the one hand and friction work between the spring end 242-2 and the second step 232-2 on the other hand can be generated during the sliding operation. The consumed frictional work causes the coil spring 240, the cover plate 230 and the driving disk 220 to wear during the sliding operation.

The graph of fig. 3 illustrates, for example, the frictional work that may be dissipated in conventional torsional vibration dampers 110 and 210 depending on the load conditions (coasting operation, traction operation). To this end, frictional work is plotted on the vertical axis 350 against the angle of rotation. The rotation angle is depicted along the horizontal axis 340. The curve of the rotation angle plotted on the horizontal axis 340 describes, for example, the course of the rotation angle with compression and subsequent relaxation of the helical spring 240. The friction work depicted herein relates to the friction work between the coil spring 140 or 240 and components (e.g., the support section 132, the first step 232-1, and/or the second step 232-2) radially abutting the coil spring 140 or 240.

Fig. 3 schematically illustrates friction work 310 that may be consumed during a towing operation of a conventional torsional vibration damper 110. Due to the symmetrical design of window openings 150-1 and 150-2, it may be assumed that the friction work of conventional torsional vibration damper 110 in coasting operation is equal to friction work 310 in traction operation.

According to the graph of fig. 3, the friction work 320 of the torsional vibration damper 210 in coasting operation exceeds the friction work 310 of the conventional torsional vibration damper 110 in traction operation.

Furthermore, the graph illustrated in fig. 3 gives the friction work 330 that may be consumed in the traction operation of the torsional vibration damper 210, for example. The friction work 330 is here significantly smaller than the friction work 310 and the friction work 320.

Thus, the sum of the friction works 320 and 330 may be less than the sum of the friction works of the conventional torsional vibration damper 110 during both the coasting operation and the traction operation. Thus, the torsional damper 210 or the clutch disc 200 may have less friction-related wear relative to the conventional torsional damper 110 or the conventional clutch disc 100.

Especially commercial vehicles (NKW) operate in traction operations more frequently than in coasting operations, for example. For this reason, friction-related wear of the torsional damper 210 or the clutch disc 200 may be smaller, for example, in particular in NKW, than friction-related wear of the conventional torsional damper 110 or the conventional clutch disc 200.

Fig. 4a shows an embodiment of the clutch disc 200 in a first cross-sectional illustration (upper) in a cross-section along section line G-G and in a second cross-sectional illustration (lower) in a cross-section along section line F-F.

The clutch plate 200 includes, for example, a driver plate 220 having a plurality of first window openings 250-1 for receiving the same number of coil springs 240. On axially opposite sides of the driver disk 220, one of the cover plates 230 is arranged, which has a corresponding number of second window openings 250-2 for receiving the coil springs 240.

The second step 232-2 of the second window opening 250-2 is correspondingly biased axially against the outer periphery of the coil spring 240 with respect to the spring axis. The spring end 242-2 of the spiral spring 240 is thus arranged firmly with respect to the cover plate 230 and the driver disk 220, for example, in the axial direction, or is fastened in the axial direction.

On the opposite spring end 242-1, the first step 232-1 of the first window opening 250-1 correspondingly abuts the helical spring 240 radially with respect to the spring axis on the outer circumference. Thus, for example, axial fixation of the spring end 242-1 is not ensured, so that the spring end 242-1 can have an axial displacement when compressed.

For axially fixing the spring end 242-1, a fixing element 260 can be used, for example. An embodiment for such a fixing element 260 is shown in fig. 4 b. Fig. 4b shows the fixing element in a perspective view in the circumferential direction (upper left side), in a perspective view in the axial direction (upper right side) and in a perspective view in the radial direction (lower right side) and in an oblique view (lower left side).

The fixing element 260 has, for example, a cylindrical holding section 262, the outer diameter of which is smaller than the inner diameter of the coil spring 240. The holding sections 262 are arranged such that they each engage into the helical spring 240 in the circumferential direction.

Further, the fixing member 260 has a plurality of pin portions 264. The pins 264 are arranged such that they abut the driver disk 220 on axially opposite sides.

Thus, by means of the fixing element 260, the helical spring 240 can be fastened in particular in the axial direction, so that an axial displacement of the helical spring 240 is prevented or at least limited. In this way, wear of the helical spring 240 and, for example, of the entraining disk 220 due to friction during axial displacement of the spring end 242-1 can be reduced.

The securing element 260 can be released from the driving disk 220, for example, in the radial direction, so that the helical spring 240 can be controlled by the cover plate 230 or by the driving disk 220 by means of the securing element 260, depending on whether the clutch disk 200 is operated in a traction or coasting operation.

Since the fastening element 260 is supported in the axial direction on the carrier plate 220, rather than on the cover plate 230 as is also conceivable, it is possible to dispense with the insertion and removal process (Ein-und) of the coupling of the carrier plate 220 to the fastening element 260 during the damping of torsional vibrations during the towing operation)。

In order to fasten the inner springs 270 within the coil springs 240, the fixing elements 260 additionally each have a further holding section 263 which engages into the respective inner spring 270 in the circumferential direction.

List of reference numerals

100. Conventional clutch disc

102. Friction lining

110. Conventional torsional damper

120. Input piece

130. Output piece

132. Support section

140. Spiral spring

142. Spring end of helical spring

150-1 Window opening

150-2 Window opening

200. Clutch disc

202. Friction lining

210. Torsional vibration damper

220. Driving disk

230. Cover plate

232-1 first step

232-2 second step

240. Spiral spring

242-1 spring end

242-2 spring end

250-1 first window opening

250-2 second window opening

252-1 outer periphery of the first window opening

252-2 second window opening periphery

260. Fixing element

262. Holding section

263. Additional holding section

264. Pin part

270. Inner spring

310. Friction work of conventional torsional damper in traction operation

320. Friction work of torsional damper in coasting operation

330. Friction work of torsional damper in traction operation

Claims

1. A torsional damper (210), comprising:

at least one coil spring (240);

-an input member (220) having at least one first window opening (250-1) for receiving the coil spring (240), wherein the first window opening (250-1) has a first step (232-1) for supporting the coil spring (240) on an outer periphery (252-1) of the first window opening, the first step extending radially inwards;

an output member (230) axially spaced from the input member (220), the output member having at least one second window opening (250-2) for receiving the coil spring (240), wherein the second window opening (250-2) has a second step (232-2) for supporting the coil spring (240) on an outer periphery (252-2) of the second window opening, the second step extending radially inward,

it is characterized in that the method comprises the steps of,

the first step (232-1) extends up to an end of the first window opening (250-1) defining the first window opening (250-1) in a first circumferential direction; and is also provided with

The second step (232-2) extends up to an end of the second window opening (250-2) defining the second window opening (250-2) in a second circumferential direction opposite to the first circumferential direction.

2. The torsional damper (210) of claim 1, wherein the second circumferential direction corresponds to a rotational direction of the input member (220) relative to the output member (230) during a traction operation of the torsional damper and the first circumferential direction corresponds to a rotational direction of the input member (220) relative to the output member (230) during a coasting operation of the torsional damper (210).

3. Torsional damper (210) according to one of the preceding claims,

wherein the first step (232-1) extends in a circumferential direction over at least 30% of an extension of the first window opening (250-1) at its outer periphery (252-1); and is also provided with

Wherein the second step (232-2) extends over at least 30% of the extension of the second window opening (250-2) at its outer periphery (252-2) in the circumferential direction.

4. The torsional damper (210) of claim 1,

wherein the first step (232-1) is connected to the input element (220) in a material-fitting manner; and is also provided with

Wherein the second step (232-2) is connected to the output element (230) in a material-fitting manner.

5. The torsional damper (210) of claim 1, wherein the second step (232-2) is arranged offset from a spring axis of the helical spring (240) in an axial direction, and the second step has a bevel in the axial direction.

6. The torsional damper (210) of claim 1, further comprising at least one fixation element (260), wherein the fixation element (260) engages into the helical spring (240) in a circumferential direction, and wherein the fixation element (260) is fixedly arranged relative to the input (220) in an axial direction.

7. The torsional damper (210) of claim 1, wherein the output member (230) includes a first output member and a second output member, the first output member and the second output member being axially disposed on opposite sides of the input member (220).

8. A clutch disc (200), comprising:

the torsional damper (210) of any one of claims 1 to 7;

-a friction lining (202) connected in a rotationally fixed manner to an input element (220) of the torsional vibration damper (210);

a hub, which is connected to an output element (230) of the torsional vibration damper in a rotationally fixed manner.