DE102018132402A1 - Torsional vibration damper - Google Patents

Abstract

A torsional vibration damper (10) for damping torsional vibrations in a drive train of a motor vehicle is provided with a primary mass (12) for introducing a torque, and a secondary mass (16) which is coupled to the primary mass (12) via a energy storage element (14) so as to be relatively rotatable to discharge a Torque and an output hub (26) coupled to the secondary mass (16) via a torque limiter (24) for transmitting the torque to a shaft, the torque limiter (24) having a friction flange (30) projecting radially outwards from the output hub (26). The friction flange (30) is arranged in the axial direction between the secondary mass (16) and a cover (34) fastened to the secondary mass (16), and the torque limiter (24) engages one directly or indirectly via a pressure spring (36) the secondary mass (16) or on the cover (34) supported thrust washer (38) for impressing a frictional force on the Has friction flange (30). By equalizing the surface pressure on the friction flange (30) with the aid of the prestressed thrust washer (38), a transmission of torques in a defined limited torque range is made possible in a drive train of a motor vehicle.

Description

The invention relates to a torsional vibration damper, in particular a dual mass flywheel, with the aid of which torsional vibrations of a drive shaft of a motor vehicle engine can be damped.

Out DE 198 34 729 A1 A dual-mass flywheel is known in which a primary mass connected to a drive shaft of a motor vehicle engine is coupled via an arc spring to a secondary mass that can be rotated relative to the primary mass. The secondary mass is coupled via a torque limiter designed as a slip clutch with a counter plate to a friction clutch, the torque limiter being positioned in the axial direction between the secondary mass and the friction clutch.

There is a constant need in a drive train of a motor vehicle to allow the transmission of torques only in a defined torque range.

It is the object of the invention to show measures which make it possible to transmit torques in a defined, limited torque range in a drive train of a motor vehicle.

The object is achieved according to the invention by means of a torsional vibration damper with the features of claim 1. Preferred embodiments of the invention are specified in the subclaims and the following description, which can each represent an aspect of the invention individually or in combination.

According to the invention, a torsional vibration damper for torsional vibration damping in a drive train of a motor vehicle is provided with a primary mass for introducing a torque, an energy storage element, designed in particular as an arc spring, with the primary mass limitedly rotatably coupled to the secondary mass for diverting a torque and one, in particular as a slip clutch configured, torque limiter coupled to the secondary mass for the transmission of the torque to a shaft, the torque limiter having a radially outwardly projecting friction flange formed by the output hub, the friction flange being arranged in the axial direction between the secondary mass and a cover fastened with the secondary mass, and the torque limiter is a pressure disk, which is supported indirectly or directly on the secondary mass or on the cover by means of a pressure spring, in order to impress a frictional force has on the friction flange.

The torque limiter is designed as a slip clutch, in which the friction flange between the secondary mass and the cover is frictionally clamped with the aid of the pressure disk pretensioned with a spring force, the friction force acting on the friction flange being able to be overcome when the torque exceeds a limit torque and the friction flange then slips can. The pressure disk, which is movably supported by the pressure spring, can automatically align itself with the friction flange when a frictional force is applied to the friction flange. The pressure plate can be floatingly supported by the pressure spring to a certain extent, so that a uniform surface pressure automatically results between the pressure plate and the friction flange. Tolerance-related inclinations, which lead to an uneven surface pressure and increased wear, can thereby be avoided, so that a high dispersion of the static friction and sliding friction moments is avoided, and a limiting torque, in which the torque limiter designed as a slip clutch filters out the transmission of a higher torque, more precisely can be predicted. A thrust washer is particularly preferably provided on both axial sides of the friction flange and is supported in each case by a pressure spring on the secondary mass or on the cover. By equalizing the surface pressure on the friction flange with the aid of the prestressed thrust washer, transmission of torques in a defined, limited torque range is made possible in a drive train of a motor vehicle.

In the event of a sudden torque surge (“impact”), unintended loads can result in the drive train, which can damage torque-transmitting components in the drive train. Impacts arise, for example, when the motor vehicle engine is stalled when the motor vehicle is started, there is a shifting, quick clutch engagement, downshifting with simultaneous accelerating, emergency braking, a bang start ("cavalier start"), engine start of the motor vehicle engine . A transmission of excessive torques can be avoided by the torque limiter in the manner of a low-pass filter, in that the friction flange of the output hub can slip in the torque limiter if the torques are too high. The maximum torque that can still be transmitted by the torque limiter depends on friction properties, in particular the coefficient of friction and contact pressure between the friction flange and the pressure plate are appropriately selected for setting the desired maximum torque.

In particular, the output hub can be moved relatively to the secondary mass in the axial direction. For example, the output hub can be coupled to a shaft in a rotationally fixed but axially displaceable manner via a spline. This enables the thrust washer to press the friction flange against another friction partner on the axial side facing away from the thrust washer. The further friction partner can be, for example, the secondary mass, the cover or a further pressure disk biased by a further pressure spring. This can significantly increase the effective friction surface of the torque limiter.

Friction linings are preferably provided on both axial sides of the friction flange, in particular fastened with the friction flange. The pressure spring can be compressed and relaxed by a certain amount of travel. As a result, the pressure spring is able to press the thrust washer over a correspondingly larger axial path if the friction linings become thinner due to wear. A noise-intensive steel-to-steel friction contact is thereby avoided, so that oiling of the torque limiter can also be omitted if necessary. The torque limiter can thereby be designed as a dry slip clutch. In addition, an effective coefficient of friction can be set more precisely with the help of the friction linings, as a result of which the limit torque can be set with greater accuracy.

The contact spring is particularly preferably designed as a plate spring. The contact spring can thus provide a significant contact force with a very small amount of space in the axial direction over a sufficiently large spring travel.

In particular, the pressure spring is supported radially outside the friction flange on the cover or on the secondary mass. The pressure spring can thereby achieve a particularly soft and long characteristic curve, whereby in particular a wear-related axial offset of the pressure disk to the friction flange caused by the friction linings provided can be compensated for.

The pressure spring is preferably coupled in a rotationally fixed manner to the cover and the secondary mass via a rotation lock, the rotation lock in particular having a shoulder inserted into an opening. This can ensure that the thrust washer only has a slip which is subject to friction between the thrust washer and the friction flange. Frictional contact with another friction partner that cannot be predicted with sufficient accuracy is avoided, so that the limit torque can be predicted and set with a higher accuracy. In particular, the thrust washer is coupled in a rotationally fixed manner to the pressure spring, so that no slip with friction can occur between the thrust washer and the pressure spring. For this purpose, interlocking locking wings are provided, for example, which can strike against each other tangentially in order to block a relative rotation.

The cover particularly preferably has a cranked fastening tab for indirect or direct fastening with the secondary mass, the fastening tab passing through a recess of the pressure spring, which is designed in particular as a plate spring and is open radially outwards. The fastening tab can in particular be riveted to the secondary mass or to a component fastened, in particular riveted, to the secondary mass. Due to the skimmed course of the fastening tab, the pressure spring with its edges delimiting the recess can strike tangentially on the fastening tab, so that with the aid of the fastening tab provided anyway, a rotation lock of the pressure spring is formed on the cover. For example, the pressure spring designed as a plate spring has a radially inward indentation or radially outwardly projecting fingers spaced apart in the circumferential direction in order to form the recess of the pressure spring provided for the fastening tab.

In particular, the secondary mass has an output flange that can be tangentially attached to the energy storage element, wherein the output flange or an intermediate plate fastened to the output flange can be pressed against the friction flange. If the output flange forms a friction partner for the friction flange, a space-saving and compact construction can result, in which a small number of components is reached. Due to the washer attached with the output flange, the torque limiter can be positioned outside a fat space of the torsional vibration damper provided for the energy storage element, so that the risk that a lubricant reaches the friction flange and influences the friction conditions of the torque limiter is avoided.

The torque limiter is preferably arranged at least partially in a common radius area with the energy storage element or radially inside the energy storage element. If the torque limiter is arranged in a common radius area with the energy storage element, the torque limiter is positioned radially on the outside in such a way that particularly large friction contact surfaces are realized to let. If the torque limiter is arranged radially inside the energy storage element, the axial installation space requirement and / or the material used to form the torque limiter can be reduced.

The torque limiter is particularly preferably arranged at least partially axially offset in a common axial region with the energy storage element or with the energy storage element. If the torque limiter and the energy storage element are arranged in a common axial area, the nesting achieved in this way results in less axial space requirement. If the torque limiter is positioned axially offset from the energy storage element, it is possible for the torsional vibration damper with the torque limiter to be able to grip around a subsequently connected unit radially on the outside, as a result of which free installation space can be better utilized.

In particular, the secondary mass, in particular the washer, and / or the cover has an additional mass, in particular projecting radially outward, to increase the moment of inertia. The additional mass is a part of the secondary mass or the cover which is no longer required for fastening the cover to the secondary mass and which extends from a fastening means provided for fastening the cover to the secondary mass beyond the required radial material thickness for receiving the fastening means. The additional mass preferably has a region bent over in two layers. The washer and / or the cover can be bent through 180 °, so that there is twice the material thickness in this area. The additional mass of the secondary mass particularly preferably forms an accommodating pocket which is open in the axial direction, the additional mass of the cover, preferably with its double-layer region, at least partially immersed in the accommodating pocket. In particular, the additional mass of the secondary mass can largely, preferably completely, cover the additional mass of the cover when viewed in the radial direction. Alternatively, the additional mass of the lid forms an accommodating pocket which is open in the axial direction, the additional mass of the secondary mass, preferably with its double-layer region, being at least partially immersed in the accommodating pocket. In particular, the additional mass of the cover can largely, preferably completely, cover the additional mass of the secondary mass when viewed in the radial direction. In particular, if the torque limiter is axially offset from the energy storage element and is arranged radially inside, the installation space radially outside the torque limiter can be used to provide an additional damping mass moment of inertia.

• 1: eine schematische Schnittansicht einer ersten Ausführungsform eines Drehschwingungsdämpfers,
• 2: eine schematische Schnittansicht einer zweiten Ausführungsform eines Drehschwingungsdämpfers,
• 3: eine schematische Schnittansicht einer dritten Ausführungsform eines Drehschwingungsdämpfers,
• 4: eine schematische Schnittansicht einer vierten Ausführungsform eines Drehschwingungsdämpfers,
• 5: eine schematische Schnittansicht einer fünften Ausführungsform eines Drehschwingungsdämpfers und
• 6: eine schematische Schnittansicht einer sechsten Ausführungsform eines Drehschwingungsdämpfers.

In the following, the invention is explained by way of example with reference to the attached drawings using preferred exemplary embodiments, the features shown below being able to represent an aspect of the invention both individually and in combination. Show it:

• 1 1 shows a schematic sectional view of a first embodiment of a torsional vibration damper,
• 2nd 1 shows a schematic sectional view of a second embodiment of a torsional vibration damper,
• 3rd 1 shows a schematic sectional view of a third embodiment of a torsional vibration damper,
• 4th 1 shows a schematic sectional view of a fourth embodiment of a torsional vibration damper,
• 5 : A schematic sectional view of a fifth embodiment of a torsional vibration damper and
• 6 : A schematic sectional view of a sixth embodiment of a torsional vibration damper.

The in 1 torsional vibration damper shown 10th can be used in a drive train of a motor vehicle to dampen torsional vibrations generated by a motor vehicle engine. The torsional vibration damper 10th has a primary mass which can be connected directly or indirectly to a drive shaft of the motor vehicle engine 12 to which via an energy storage element designed as an arc spring 14 a secondary mass 16 can be twisted to a limited extent. The secondary mass 16 has one in one of the primary mass 12 partially limited recording space 18th protruding output flange 20th on that at the in the recording room 18th recorded energy storage element 14 can strike tangentially to transmit a torque. In the recording room 18th a lubricant, in particular lubricating grease, can be filled in around the energy storage element 14 to lubricate.

In the illustrated embodiment, the secondary mass 12 one with the output flange 20th riveted washer 22 on that is axially spaced from the energy storage element 14 via a torque limiter designed as a slip clutch 24th with an output hub 26 is coupled. The output hub 26 can have an internal toothing 28 axially slidably coupled to a shaft. The wave can For example, an intermediate shaft to which an electrical machine and / or a clutch is coupled and / or a transmission input shaft of a motor vehicle transmission.

The output hub 26 has a radially projecting friction flange 30th on, which is also part of the torque limiter 24th is. The friction flange 30th has friction linings glued and riveted on both axial sides 32 on that in the axial direction between the washer 22 the secondary mass 16 and one with the washer 22 riveted lid 34 are arranged. For example, only on the lid 34 is a pressure spring designed as a plate spring 36 supported which is a thrust washer 38 against the friction flange 30th presses so that on both friction linings 32 on the one hand from the thrust washer 38 and on the other hand from the washer 22 a frictional force can be applied. The lid 34 is over a cranked fastening tab 40 with the washer 22 riveted, the fastening tab 40 through a recess in the pressure spring 36 runs through to a rotation lock for the pressure spring 36 to train. It is also possible to use the output flange 20th , on the washer 22 and / or on the friction flange 30th a centrifugal pendulum, not shown 30th or to provide other torsional vibration dampers.

At the in 2nd illustrated embodiment of the torsional vibration damper 10th is compared to that in 1 illustrated embodiment of the torsional vibration damper 10th the torque limiter 24th positioned so far radially that the energy storage element 14 and the torque limiter 24th are arranged in a common radius area and can at least partially overlap when viewed in the axial direction. This allows the friction contact surfaces of the torque limiter 24th be enlarged and a softer characteristic of the pressure spring 36 can be achieved.

At the in 3rd illustrated embodiment of the torsional vibration damper 10th is compared to that in 1 illustrated embodiment of the torsional vibration damper 10th the torque limiter 24th positioned slightly radially inward so that the torque limiter 24th somewhat closer to the energy storage element in the axial direction 14 can be arranged. This allows for the torsional vibration damper 10th achieve a smaller space requirement in the radial direction and / or in the axial direction.

At the in 4th illustrated embodiment of the torsional vibration damper 10th is compared to that in 3rd illustrated embodiment of the torsional vibration damper 10th the torque limiter 24th in a common axial area with the energy storage element 14 positioned. This allows the axial space requirement of the torsional vibration damper 10th be minimized. It is also possible that the recording room 18th delimiting cover element 42 also the torque limiter 24th can at least partially cover and protect against environmental influences. In particular, the washer 22 saved, so that the output flange, which in particular is bent, is already saved 20th as part of the torque limiter 24th a friction contact surface for the friction flange 30th can provide.

At the in 5 illustrated embodiment of the torsional vibration damper 10th exhibit compared to that in 3rd illustrated embodiment of the torsional vibration damper 10th the washer 22 the secondary mass 16 and the lid 34 one additional mass protruding radially outwards 44 on, which is designed at least in a partial area double-layer. The additional mass 44 the washer 22 forms a receiving pocket open in the axial direction and radially inward 46 into which the additional mass 44 of the lid 34 is completely submerged. At the in 6 illustrated embodiment of the torsional vibration damper 10th is compared to that in 5 illustrated embodiment of the torsional vibration damper 10th the pocket 46 from the additional mass 44 of the lid 34 trained, the additional mass 44 the washer 22 in the pocket 46 is completely submerged.

Reference symbol list

10th

Torsional vibration damper

12

Primary mass

14

Energy storage element

16

Secondary mass

18th

Recording room

20th

Output flange

22

Washer

24th

Torque limiter

26

Output hub

28

Internal teeth

30th

Friction flange

32

Friction lining

34

cover

36

Pressure spring

38

Thrust washer

40

Mounting bracket

42

Cover element

44

Additional mass

46

Pocket

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 19834729 A1 [0002]

Claims (10)

Torsional vibration damper for torsional vibration damping in a drive train of a motor vehicle, with a primary mass (12) for introducing a torque, a secondary mass (16), which is coupled to the primary mass (12) and is limitedly rotatable to a certain extent, in particular in the form of an arc spring, for diverting a torque and an output hub (26) coupled to the secondary mass (16) via a torque limiter (24), in particular in the form of a slip clutch, for transmitting the torque to a shaft, wherein the torque limiter (24) has a radially outwardly projecting friction flange (30) formed by the output hub (26), the friction flange (30) in the axial direction between the secondary mass (16) and a cover (16) fastened to the secondary mass (16) 34) is arranged, and the torque limiter (24) has a pressure disc (38), which is supported directly or indirectly on the secondary mass (16) or on the cover (34) via a pressure spring (36), for impressing a frictional force on the friction flange (30). Torsional vibration damper after Claim 1 characterized in that the output hub (26) relative to the secondary mass (16) is relatively displaceable in the axial direction. Torsional vibration damper after Claim 1 or 2nd characterized in that friction linings (32) are provided on both axial sides of the friction flange (30), in particular fastened with the friction flange (30). Torsional vibration damper according to one of the Claims 1 to 3rd characterized in that the pressure spring (36) is designed as a plate spring. Torsional vibration damper after Claim 4 characterized in that the pressure spring (36) is supported radially outside the friction flange (30) on the cover (34) or on the secondary mass (16). Torsional vibration damper according to one of the Claims 1 to 5 characterized in that the pressure spring (36) is coupled in a rotationally fixed manner to the cover (34) and the secondary mass (16) via a rotation lock, the rotation lock in particular having a shoulder inserted into an opening. Torsional vibration damper according to one of the Claims 1 to 6 characterized in that the cover (34) has an angled fastening tab (40) for indirect or direct attachment to the secondary mass (16), the attachment tab (40) being provided by a recess of the pressure spring (in particular a plate spring) 36) runs through. Torsional vibration damper according to one of the Claims 1 to 7 characterized in that the secondary mass (16) has an output flange (20) which can be tangentially attached to the energy storage element (14), the output flange (20) or an intermediate disk (22) fastened to the output flange (20) being able to be pressed against the friction flange (30) is. Torsional vibration damper according to one of the Claims 1 to 8th characterized in that the torque limiter (24) is arranged at least partially in a common radius area with the energy storage element (14) or radially inside to the energy storage element (14). Torsional vibration damper according to one of the Claims 1 to 9 characterized in that the torque limiter (24) is at least partially arranged axially offset in a common axial area with the energy storage element (14) or with the energy storage element (14).

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