CN112833109A

CN112833109A - Torque limiter and torsional vibration damper

Info

Publication number: CN112833109A
Application number: CN202010136442.4A
Authority: CN
Inventors: 罗曼·魏森博恩; 帕斯卡·斯特拉瑟
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2019-11-22
Filing date: 2020-03-02
Publication date: 2021-05-25
Anticipated expiration: 2040-03-02
Also published as: CN112833109B

Abstract

The invention relates to a torque limiter and a torsional vibration damper for interrupting the torque flow in a drive train of a motor vehicle, having a first support disk (15), a second support disk (16), a friction disk (50) for transmitting torque in a frictional engagement, and an output disk (12) for dissipating the torque, which is connected in a rotationally fixed manner directly or indirectly via a rotationally fixed coupling (27) to the support disks (15, 16) or to the friction disk (50), wherein the output disk (12) has at least one mounting opening (28) for the passage of a fastening element (49), which fastening element (49) is used to fasten a component coupled to the input side on the torque limiter (14), wherein the output disc (12) can relatively move along the axial direction in the relative position rotating along the circumferential direction, to separate the anti-rotation coupling (27) and to re-establish the anti-rotation coupling (27). The torsional vibration damper is integrated with the above-described torque limiter.

Description

Torque limiter and torsional vibration damper

Technical Field

The invention relates to a torque limiter, by means of which a torque flow in a drive train of a motor vehicle can be interrupted, so that components of the drive train are protected against sudden torque surges. The invention also relates to a torsional vibration damper integrated with the torque limiter. The invention further relates to a method for mounting and dismounting the torsional vibration damper and a drive train comprising the torsional vibration damper. ,

background

Torsional vibration dampers designed as dual mass flywheels are used to reduce torsional vibrations in the drive train of a motor vehicle. The torsional vibrations result from the periodic combustion cycle of the reciprocating-piston internal combustion engine, which, in combination with the ignition sequence, produce torsional irregularities that are introduced into the drive train from the crankshaft. Torsional irregularities transmitted to the drive train of the motor vehicle, which cause vibrations and/or noise in the passenger compartment of the motor vehicle, lead to impaired comfort. The reduction of the torsional irregularities from the internal combustion engine by the torsional vibration damper improves the driving comfort.

DE 102012202255 a1 shows such a torsional vibration damper which can be used for damping or damping vibrations and which can be used in a drive train between a crankshaft of an internal combustion engine and a separating clutch, for example, upstream of a transmission. DE 102008032009 a1 discloses a torsional vibration damper configured in multiple stages, which comprises two damper stages arranged in series radially one above the other. In this case, a radially outer first damping stage, which is equipped with a bow spring, surrounds a second damping stage, which surrounds the inner helical compression spring. Another embodiment provides that the two damping stages are coupled to one another via an intermediate flange of the floating arrangement.

In the operating state of an internal combustion engine, in particular in hybrid or CVT applications, peak loads, so-called shocks (torque shocks) with high load alternation numbers, which can damage the drive train, suddenly occur during the start and stop phases of the internal combustion engine or during the sudden couplings that bring about the stopping of the engine. In particular, the bow spring of the spring absorber is subjected to a great load, and the bow spring is temporarily compressed to the limit. In order to avoid the adverse effects of shocks as far as possible and to compensate for or further isolate them in a material-compatible manner, it is known to equip the torsional vibration damper with a torque limiter (DMB) designed as a slip clutch. When the limit torque is exceeded, a sliding movement of one of the cooperating components of the secondary mass part can be achieved by means of a torque limiter integrated in the multi-part secondary mass part. The excess energy is dissipated as frictional heat and the component load is reduced. For example, DE 102009033864 a1, DE 102010025579 a1 and DE 102014211603 a1 show such torque limiters in the form of slip clutches, which prevent torque peaks from being transmitted into the drive train of the motor vehicle. A dual-mass flywheel is known from DE 19834729 a1, in which a primary mass part connected to the drive shaft of the motor vehicle engine is coupled via a curved spring to a secondary mass part which is rotatable relative to the primary mass part. The secondary mass part is coupled to the counter plate of the friction clutch via a torque limiter designed as a slip clutch, wherein the torque limiter is positioned axially between the secondary mass part and the friction clutch.

In the operating state, when the set limit torque is exceeded and the torque limiter is activated in connection therewith, a relative rotation takes place between the components of the torque limiter which act as a slip clutch. In connection with this, the intermediate element or the secondary mass part of the torque limiter rotates relative to the primary mass part of the torque limiter, as a result of which a misalignment occurs between the fastening opening in the primary mass part for the fastening screw of the torsional vibration damper on the crankshaft and the mounting opening in the component of the secondary mass part. Due to the misalignment, the torsional vibration damper cannot be removed or high installation costs are required. There is a continuing need to improve the ease of maintenance of torsional vibration dampers having torsional vibration dampers.

Disclosure of Invention

The object of the present invention is to provide a torsional vibration damper with a torsional vibration damper that can be easily maintained, in particular a torsional vibration damper with an integrated torque limiter that is structurally and/or functionally improved such that it can be easily removed and/or installed even after the torque limiter has been triggered.

The above object is achieved by a torque limiter for interrupting the transmission of torque in a drive train of a motor vehicle, comprising: a first support tray; the second supporting disk is arranged beside the first supporting disk along the axial direction; a friction disk for transmitting torque in frictional engagement, clamped in frictional engagement between the first support disk and the second support disk up to a limit torque; and an output disk, which is connected to the support disk or to the friction disk directly or indirectly via a rotationally fixed coupling in a rotationally fixed manner, for outputting a torque, wherein the output disk has at least one mounting opening for the passage of a fastening element for fastening a component, which is coupled to the input side on the torque limiter, wherein the output disk is axially displaceable relative to one another in a rotationally fixed relative position in order to disengage the rotationally fixed coupling and to establish the rotationally fixed coupling again.

In the event of a sudden torque shock ("Impact"), unpredictable loads occur in the drive train, which can lead to damage to the components in the drive train that transmit torque. The impact occurs, for example, in the following cases: in the case of an engine stall at the time of starting of the motor vehicle, shifting a gear, quickly engaging the clutch, simultaneously accelerating and downshifting, emergency braking, sudden start (quick start), engine start of the motor vehicle engine. The torque limiter can prevent the transmission of excessively high torques by means of a low-pass filter, which is achieved by the friction disks being able to slip when the torque in the torque limiter is excessively high, whereby the torque transmission can be interrupted at least when a level defined by a limit torque is exceeded. The maximum limit torque that can be transmitted by the torque limiter is related to the friction characteristics, in particular the friction coefficient and the pressing force between the friction disc and the support disc, which are suitably selected to set the desired maximum limit torque. Preferably, the torque limiter is designed as a dry slip clutch. The dry, i.e. unlubricated, frictional contact of the torque limiter limits the change in the friction value which is effective during operation, so that the designed limit torque can be set with high accuracy and low safety margin.

The torque limiter can be integrated in particular in a torsional vibration damper for reducing torsional inhomogeneities in the torque generated by the motor vehicle engine. A torsional vibration damper, which is designed as a dual mass flywheel, for example, can have a primary mass part for introducing a torque from the motor vehicle engine and a secondary mass part, which can be coupled to the primary mass part in a rotationally fixed manner with respect to the primary mass part via an energy storage element, which is designed in particular as an arc spring. The fastening element can be inserted through a mounting opening in the output disk of the torque limiter, by means of which the component connected on the input side to the torque limiter, in particular the primary mass part of the torque limiter designed as a dual-mass flywheel, can be fastened directly or indirectly to the drive shaft of the motor vehicle engine. In the case where the torsional vibration damper needs to be removed for maintenance or repair, a tool may be passed through the mounting opening to remove the fastener and be taken out through the mounting opening. However, when a torque exceeding the limit torque occurs and the friction discs slip, the relative angular position of the output disc changes such that the mounting opening of the output disc can no longer be aligned with an already installed fastener. In fact, the circular arc segment of the output disc completely or partially covers the fastener, thereby hindering accessibility to the fastener and removability of the fastener. However, since the output disk is designed separately and is designed in a rotationally fixed but axially displaceable manner by means of the rotationally fixed coupling, it is possible in this case to move the output disk in the axial direction until the rotationally fixed coupling is disengaged and then to turn it in the circumferential direction until the mounting openings reach a relative angular position in which they can be brought into contact with the fastening elements and can be detached. In this relative angular position, the axial displacement of the output disk can be reversed, so that the rotationally fixed connection of the previously disengaged rotationally fixed coupling is once again established. The torsional vibration damper can then be removed again together with the torque limiter as a whole for maintenance and/or repair and, if necessary, reinstalled. Since the output disk can be rotated in an axially displaced relative position, the accessibility of the fastening means via the mounting opening can be established again if necessary, so that the torsional vibration damper with the torque limiter can be easily serviced.

The friction disk may be clamped via a friction lining between the support disks. Preferably, a pressure spring, in particular designed as a coil spring, is provided, which is supported on one of the support disks and presses a pressure plate, which is axially displaceable between the support disks, against the friction disk. The pressing force and the limit torque can be adjusted via the spring force of the pressing spring. Furthermore, a suitably pretensioned compression spring designed as a disk spring has a gentle spring characteristic curve over the wear region of the friction lining, so that the compression spring can provide a substantially constant or only slightly reduced compression force over the wear region. In particular, it is provided that, in traction mode of the drive train, the torque to be transmitted, and in particular already reduced in torsional vibrations by means of the torsional vibration damper, is introduced into the torque limiter via the friction disk, is transmitted to the support disk and from the support disk to the output disk. However, the opposite configuration is also possible, in which, in traction mode of the drive train, the torque to be transmitted, and in particular already reduced by the torsional vibration damper, is introduced via the support disk into the torque limiter, transmitted to the friction disks and from the friction disks to the output disk. Depending on the type of construction, the rotationally fixed coupling of the output disk is therefore formed in the torque flow between the support disk and the output disk or between the friction disk and the output disk. Furthermore, provision may be made in the torque limiter for the output disk for operation to be held in an axially opposite position of the coupling that achieves the anti-rotation, wherein this holding can be dispensed with for maintenance and/or repair purposes, so that the desired relative angular position of the mounting opening is adjusted by means of the displaceability in the axial direction. For this purpose, the output disk can be fixed in the axial direction, for example detachably, releasably latched and/or mounted elastically in the axial direction with a sufficiently high spring force.

In particular, a return spring, which is in particular designed as a spiral spring, serves to position the output disk in a defined axial initial position, wherein an axial spring path of the return spring allows the output disk to move axially in order to disengage the rotationally fixed coupling. The return spring can hold the output disk in the initial position in an axially opposite position of the connection secured against rotation by the rotationally fixed coupling. This ensures that the torque transmission takes place via the output disk during operation. In the case of maintenance and repair, the output disk can be moved axially manually against the spring force of the restoring spring until the form-locking of the anti-rotation coupling is released and the output disk can be rotated relative to one another. The axially immovable fixing relative to the output disk can in principle also filter out and/or reduce the axial vibrations acting on the output disk by the axial relative movement of the output disk.

Preferably, the return spring presses the output disk in the axial initial position against an axial stop formed in particular by the first support disk or by the second support disk. This results in an axially defined initial position of the output disk in which a rotationally fixed connection is provided in the rotationally fixed coupling part. Furthermore, the return spring can press the output disk against the axial stop with a high residual contact pressure, so that a sufficiently rotationally fixed connection is maintained even if an axial force suddenly acts on the output disk. In order to form an axial stop, already existing components are used together with the support disk, so that a smaller number of components is maintained.

In particular, the return spring is supported on an axial side remote from the output disk on a retaining surface of the retaining plate spaced apart from the output disk, wherein in particular the retaining plate is fixed, in particular riveted, to a component which forms a rotationally fixed coupling for the output disk. By axially positioning the holding surface of the holding plate relative to the output disk in the initial position, a sufficiently large spring path can be predetermined for the restoring spring, so that the form-locking connection of the output disk in the rotationally fixed coupling can be disengaged. For this purpose, the holding plate can have a curved course in the radial and/or circumferential direction, so that a partial region for forming a holding surface, which is spaced further away from the output disk in the axial direction, and a partial region for fixing the holding plate to the remainder of the torque limiter, which is positioned closer to the output disk in the axial direction, are realized.

In particular, the rotationally fixed coupling is designed as a toothing, wherein in particular the output disk has an external toothing for the toothing. The meshing results in a tangentially acting tooth flank, which can transmit torque. Furthermore, the teeth can be distributed uniformly in the circumferential direction, so that an increased angular offset of the output disk can be achieved in a simple manner when dividing the gear region in which the teeth are formed.

Preferably, an internal toothing of the rotationally fixed coupling designed as a toothing for the first support disk and/or the second support disk or the friction disk is formed. Since the already existing components form the counterpart of the rotationally fixed coupling for the output disk, the number of components and the axial installation space requirement can be kept low. In a preferred embodiment, for example, the output disk can engage with a second support disk located axially closer to the return spring and be pressed by the return spring onto a first support disk located axially further away from the return spring.

In a further embodiment, the internal toothing of the rotationally fixed coupling designed as a toothing is formed for a separate toothing plate connected to the first and second support plates or to the friction disk. The engagement plate can in particular have a greater axial material thickness than the first support plate, the second support plate or the friction plate, so that particularly high torques can be transmitted in the rotationally fixed coupling with low surface pressure.

Particularly preferably, the mounting opening is designed as an elongated hole, in particular curved in the circumferential direction. Thus, sufficient accessibility and detachability of the fastener can be achieved even in the case of very small angular deviations of the mounting opening relative to the fastener. The elongated hole ensures accessibility and detachability of the fastener within increments of a minimum rotation angle, in particular when the output disk is coupled in a rotationally fixed manner in the rotationally fixed coupling within a limited rotational angle increment beyond the minimum rotation angle. The requirement is met when the mounting opening is only extended in the circumferential direction relative to the extension of the fastening element and the extension in the radial direction corresponds in particular to a clearance fit with the fastening element. The radial outer contour, in particular the outer toothing, of the coupling of the output disk for form-locking anti-rotation is thereby not influenced and/or limited by the radial extent of the mounting opening.

In particular, the output disk is connected in a rotationally fixed manner to an output hub for rotationally fixed connection to a shaft which is arranged radially inside the mounting opening. The fastening elements are thereby arranged completely in a common radial region with the output disk. No driving ring is required to be led radially outward from the output disc to ensure sufficient ease of maintenance. A high degree of ease of maintenance is also provided by the radially inner output hub.

The above-mentioned object is also achieved by a torsional vibration damper for reducing torsional vibrations in a drive train of a motor vehicle. The torsional vibration damper is designed as a dual mass flywheel which is fastened to a crankshaft of an internal combustion engine and comprises a primary mass part and a secondary mass part which are jointly rotatable about an axis of rotation and are arranged so as to be rotatable relative to one another and between which a spring damping mechanism is arranged in the torque flow, wherein the secondary mass part designed in multiple parts surrounds a torque limiter designed as a slip clutch and a bearing flange is guided on both sides radially on the inside via friction linings on a second support disk and a first support disk which together form a receptacle and which are connected at least indirectly to an output disk, and the primary mass part is fastened to the crankshaft by means of a fastening element, in particular a screw, which can be inserted through a mounting opening of at least one part of the secondary mass part into a fastening opening of the primary mass part .

The torque limiter is configured according to the principle according to the invention in such a way that the output disk of the secondary mass part is guided axially on the first or on the second support disk and is connected indirectly to the second support disk directly by means of the toothing or via the toothing and an intermediate element, wherein the toothing can be disengaged by an axial displacement of the output disk against the spring force of at least one spiral spring, and the output disk can then be rotated such that the mounting opening of the output disk corresponds to the fastening opening position of the primary mass part.

This embodiment makes it possible to disengage the toothing by pulling or axially displacing the output disk against the force exerted by the spiral spring, the toothing of the toothing in the operating state snapping in a form-locking manner in the mating toothing of the second support disk of the intermediate element or of the secondary mass part in the torque transmission position. In the position axially offset from the engagement, the output disk can be rotated relative to the second support disk or the intermediate element into a position in which the mounting opening of the output disk and the fastening means are adjusted to a corresponding or identical position or to the same opening configuration, by means of which the torsional vibration damper is screwed onto the crankshaft. By disengaging the engagement, the output disk or the secondary mass part can be moved into a position in which the mounting opening of the output disk is aligned with the fastening opening of the primary mass part after the torque limiter has been triggered or activated, i.e. when a torque exceeding the limit torque occurs and the friction disk slips.

After the axial force has been set and removed, the output disk is automatically moved by the disk spring force into an initial position in which it engages with the second support disk or the intermediate element in the torque-transmitting position. By means of the axial displacement of the adjusted output disk position, the fastening elements, in particular the fastening screws, of the torsional vibration damper can be freely accessible through the mounting opening of the output disk and thus the removal of the torsional vibration damper is simplified and also a simple remounting is enabled.

In contrast to the principle according to the invention, in the secondary mass part screwed down hitherto, the relative rotation of the output disk with respect to the fastening of the torsional vibration damper after triggering or activation of the torque limiter requires high assembly costs. The output disk can usually only be re-entered with the aid of special tools into a position in which it is accessible without hindrance to the fixing screw. In contrast, with the embodiment according to the invention, the output disk can be assigned to the position of the fastening means advantageously by simple measures without the use of special tools.

In towing operation, torque from the motor vehicle engine can be introduced into the primary mass part, while in freewheeling torque from the drive train can be introduced into the secondary mass part. The reverse configuration is also possible, i.e. in traction mode, torque from the motor vehicle engine can be introduced into the secondary mass part, while in freewheeling torque from the drive train can be introduced into the primary mass part. The primary mass part and the secondary mass part, which is coupled to the primary mass part in a rotationally limited manner via the energy storage element, which is in particular designed as a bow spring, can form a mass-spring system, which, in a specific frequency range, can reduce torsional irregularities in terms of rotational speed and torque of the drive power generated by the motor vehicle engine. The moment of inertia of the primary and/or secondary mass part and the spring characteristic of the energy storage element can be selected such that vibrations in the frequency range of the main engine stage of the motor vehicle engine can be reduced. The moment of inertia of the primary mass part and/or the secondary mass part can be influenced in particular by the additional mass mounted. The primary mass part can have a disk-shaped flange element, to which a cover plate can be connected, whereby a substantially annular receiving space for the energy storage element can be limited. The primary mass part can, for example, be stopped tangentially on the energy storage element by means of a profile projecting into the receiving space. The output flange of the secondary mass part can project into the receiving space and can tangentially stop against the opposite end of the energy storage element. If the torsional vibration damper is part of a dual mass flywheel, the primary mass part can have a flywheel disk which can be coupled to a drive shaft of a motor vehicle engine. If the torsional vibration damper is part of a belt pulley assembly as a belt pulley decoupler, the primary mass part can form a belt pulley, on the radially outer side of which a traction means, in particular a wedge belt, can act to transmit a torque, and the belt pulley assembly is used to drive an auxiliary unit of a motor vehicle by means of the traction means. If the torsional vibration damper is used as a disk damper, in particular a clutch disk, of a friction clutch, the primary mass part can be coupled to the disk region carrying the friction linings, and the secondary mass part can be coupled to a transmission input shaft of a motor vehicle transmission.

In particular, the torque limiter is arranged outside the receiving chamber. This prevents lubricant from reaching the torque limiter from the receiving space and affecting the friction behavior. Alternatively, the torque limiter may be operated dry, i.e. without lubricant. Preferably, a sealing means for sealing the receiving space is provided radially between the torque limiter and the receiving space. The sealing means can act, in particular radially outside the support disk of the torque limiter, on the friction disk and the primary mass part and/or the cover plate which project radially inward from the receiving space, so as to seal the receiving space.

Preferably, the extension of the mounting opening in the circumferential direction is greater than the extension of the fastening opening in the circumferential direction, wherein in particular the difference between the extension of the mounting opening in the circumferential direction and the extension of the fastening opening in the circumferential direction is at least twice the minimum relative rotational angular offset permitted by the anti-rotation coupling. In particular, if the output disk can be coupled in a rotationally fixed manner only within the rotationally fixed coupling part, in particular the engagement part, with a limited increased angle value beyond the minimum angle of rotation, the mounting opening ensures accessibility and detachability of the fastening element within an increment of the minimum angle of rotation. It is ensured that always a part of the mounting opening completely coincides with the fastening opening, so that the fastening element reaches the fastening opening.

In a preferred embodiment of the invention, the torsional vibration damper additionally comprises a pre-damper in order to achieve an improved isolation or damping effect of the torsional vibration damper embodied as a dual-mass flywheel. In addition to the spring absorber mechanism, which comprises a curved spring and forms the primary or outer absorber, a pre-absorber, also referred to as an inner absorber, is equipped with a helical compression spring, wherein the energy stores of the two absorbers are arranged in series in the torque flow.

According to a further preferred embodiment of the invention, the force is applied to the output disk by a disk spring which is supported on a curved holding plate which is fixed directly or via an intermediate element position on the second support disk. The holding plate bent in an S-shape forms a side arm directed radially toward the axis of rotation of the torsional vibration damper and spaced apart from the output disk in the axial direction, and the coil spring is supported on the side arm. The axial spacing of the side arms here exceeds the dimensions which ensure an unimpeded axial displacement of the output disk and thus a reliable separation of the engaged components.

According to an advantageous embodiment of the invention, the torsional vibration damper designed as a friction mechanism comprises a disk-shaped friction lining coated with grease or with lubricating oil. The friction linings of the torque limiter, which are assigned to the secondary mass part, are located radially in the direction of the axis of rotation below a receiving chamber of the spring absorber mechanism, which is at least partially filled with a lubricant in order to lubricate the arcuate springs. In the operating state of the torsional vibration damper, the friction surfaces between the friction linings and the components frictionally engaged therewith are lubricated by a lubricant, also referred to as arcuate spring grease, of the spring damping mechanism. The installation of the friction linings in the annular space which is as closed as possible advantageously achieves a low coefficient of friction of the torque limiter over the service life of the torsional vibration damper. Alternatively or additionally to this, the annular space defined by the output disk, the support flange and the further components of the secondary mass part and/or the primary mass part can be filled with lubricant, so that a lubricant reservoir is formed which also lubricates the friction linings.

In a preferred embodiment of the invention, a diaphragm spring is inserted between the holding plate and the second support disk of the secondary mass part, which diaphragm spring is supported in a force-fitting manner in the radial direction on the outer side of the cover plate of the primary mass part. The diaphragm spring serves to seal the receiving space of the spring absorber against the environment and to prevent dirt or water from entering. Furthermore, the diaphragm spring exerts an axial force on the second support disk and on the torque limiter.

According to a further embodiment of the invention, the components of the secondary mass part, i.e. the second support disk, the first support disk and the holding plate, are connected to one another via rivets having a circumferential arrangement on the pitch circle. In addition to this, the diaphragm spring can also be connected to the component of the secondary mass part via a riveted connection.

In a preferred embodiment of the secondary mass part, the meshing that produces the positive connection between the output disk and the intermediate element or the second support disk is arranged offset to the reference circle of the rivet connection. The torque-transmitting elements, the engagement and the riveted connection of the secondary mass part are therefore positioned close to one another in the radial direction, which contributes to the component rigidity.

As a measure for cost-effective production, it is provided that at least the components of the secondary mass part, such as the support flange, the second support disk, the first support disk, the intermediate element and the output disk, are embodied as a profile or a stamping. By means of this method, the components of the primary mass part are also weight-optimized as a supplement to the secondary mass part and are advantageously produced without machining with sufficient component rigidity, which also has a weight advantage over injection-molded parts of similar design.

The above-mentioned object is also achieved by a method by means of which a torsional vibration damper can be removed and installed on a crankshaft of an internal combustion engine. The first method step is to separate the engagement between the two components of the secondary mass part by means of an axial movement. For this purpose, the output disk is first moved relative to the second support disk by pulling with a disk spring force against a spring force. The next method step is to rotate the output disk up to a position in which the fastening screw of the torsional vibration damper coincides or corresponds to the position of the opening in the output disk. Without axial forces, the output disk is automatically displaced in the direction of the output disk, whereby the components are again connected in a rotationally fixed manner via the engagement section. In this position, the clamping screw can be removed by means of a normal tool guided through the opening of the output disk. Furthermore, the output disc enables the torsional vibration damper to be mounted again.

The torsional vibration damper according to the invention, which can be easily removed and installed, comprises a torque limiter and is equipped with a pre-damper if required, is preferably used for hybrid applications. Such torsional vibration dampers, which can also be referred to as hybrid modules, are integrated for this purpose in the drive train of a motor vehicle, which can be driven by an internal combustion engine or an electric motor or simultaneously via two drive sources. Specifically for DHT hybrid transmission applications (dedicated hybrid transmission), torque limiters are provided by the vehicle manufacturer to protect, among other things, the components within the transmission from overloading.

Drawings

Preferred embodiments of the present invention are schematically illustrated in the following with reference to the accompanying drawings. The attached drawings are as follows:

fig. 1 is a half sectional view of a torsional vibration damper according to a first embodiment;

FIG. 2 is a perspective view of the torsional vibration damper shown in FIG. 1;

FIG. 3 is a first cross-sectional view of the secondary mass part of the torsional vibration damper shown in FIG. 1;

FIG. 4 is a second cross-sectional view of the secondary mass part of the torsional vibration damper shown in FIG. 1;

FIG. 5 is a third cross-sectional view of the secondary mass part of the torsional vibration damper shown in FIG. 1;

FIG. 6 is a fourth cross-sectional view of the secondary mass part of the torsional vibration damper shown in FIG. 1;

FIG. 7 is a fifth cross-sectional view of the secondary mass part of the torsional vibration damper shown in FIG. 1;

figure 8 is a schematic cross-sectional view of an alternative secondary mass component for the torsional vibration damper shown in figure 1,

fig. 9 is a half sectional view of a torsional vibration damper according to a second embodiment;

fig. 10 is a half sectional view of a torsional vibration damper according to a third embodiment;

FIG. 11 is a first cross-sectional view of the secondary mass part of the torsional vibration damper illustrated in FIG. 10;

FIG. 12 is a second cross-sectional view of the secondary mass part of the torsional vibration damper illustrated in FIG. 10;

FIG. 13 is a front elevational view of the torsional vibration damper illustrated in FIG. 10;

Detailed Description

Fig. 1 and 2 show a first embodiment of a torsional vibration damper 1 according to the invention. The torsional vibration damper 1 of the present embodiment can reduce torsional vibrations in the torque to be transmitted, which are introduced via the drive shaft of the motor vehicle engine in the drive train of the motor vehicle, in particular for DHT hybrid applications. For this purpose, the torsional vibration damper 1 is designed as a dual mass flywheel 53, the dual mass flywheel 53 having a primary mass part 2 and a secondary mass part 3, the primary mass part 2 and the secondary mass part 3 being rotatable jointly about a rotational axis 4 and being rotatable in a limited manner relative to one another. A spring-damper mechanism 5 having energy-accumulating elements embodied as arcuate springs 6 acts between the primary mass part 2 and the secondary mass part 3. The primary mass part 2 comprises a flange element 7, the flange element 7 being connected to a cover plate 8 in one piece radially on the outside, the flange element 7 and the cover plate 8 jointly enclosing a receiving space 9, in which receiving space 9 the bow spring 6 is accommodated in a lubricating manner with grease. The arcuate spring 6 is supported with one spring end on a stop (not shown) of the primary mass part 2 and with the other spring end on a two-part output flange 54 of the multi-part secondary mass part 3. Two-piece output flange 54 reaches through pre-damper 20, which is also received in receiving cavity 9. The predamper comprises six symmetrically positioned helical compression springs 21 distributed circumferentially as shown in figure 2. Predamper 20 may reduce torsional vibrations in a different frequency range than dual mass flywheel 53.

The torque limiter 14 comprises a support flange 10. The torque limiter 14 further comprises a first support disc 15 and a second support disc 16 arranged axially beside the first support disc 15. The bearing flange 10 engages radially on the inside into a U-shaped receptacle 17 which is open in the direction of the spring absorber 5 and is defined axially by oppositely curved sections of the first support disk 15 and the second support disk 16. The support flange 10 is guided on both sides on the first support disk 15 and the second support disk 16 via disk-shaped

friction linings

18, 19. The output-side support flange 10 of the predamper 20 is thus at the same time a friction disk 50 of the torque limiter 14 designed as a dry slip clutch. Since the radially inwardly open receiving space 9 is at least partially filled with lubricant, the

friction linings

18, 19 are lubricated in the operating state of the torsional vibration damper 1. The friction disc 50 is clamped between the first support disc 15 and the second support disc 16 by means of a pressure spring 51 supported on the second support disc 16 or alternatively on the first support disc 15, the pressure spring 51 displacing the pressure disc 52 in the axial direction. Up to a limit torque corresponding to the clamping action, the friction discs 50 can transmit torque to the

support discs

15, 16 in frictional engagement. Above the limit torque, the friction disks 50 may slip and interrupt the torque transmission at least above a level defined by the limit torque. The torque limiter 14 has an output disk 12, which is coupled in a rotationally fixed manner to a sleeve or shaft 13 in order to transmit the resulting reduced torque to the motor vehicle transmission.

The torsional vibration damper 1, in particular the primary mass part 2, can be fastened directly or indirectly to a drive shaft, in particular a crankshaft, by means of at least one fastening element 49, in particular a screw. To achieve this fixing, the output disk 12 has a mounting opening 28 aligned therewith in the region of the fastening element 49 and the radius of the fastening opening 11 for the fastening element 49 in the flange element 7 of the primary mass part 2. However, when slip occurs in the torque limiter 14, the mounting opening 28 may no longer be aligned with the fastening element 49 and the fastening opening 11, so that the fastening element 49 cannot be accessed for the purpose of maintenance and repair in order to disassemble the torsional vibration damper 1.

In the exemplary embodiment shown, a separate engagement plate 22 as an intermediate element is connected to the

support disks

15, 16 and the holding plate 26 via rivet connections 23, the rivets of which are arranged distributed in the circumferential direction in reference circles 24 (shown in fig. 7).

The engagement plate 22 forms, with the output disc 12, an anti-rotation coupling portion 27 configured as an engagement portion. The output disk 12 is connected in the rotationally fixed coupling 27 in a manner that transmits torque in the circumferential direction on the basis of a form fit, so that torque can be transmitted. At the same time, the output disk 12 can be moved axially relative to the engagement plate 22 for dismounting the torsional vibration damper 1 until the form-locking connection in the rotationally fixed coupling 27 is eliminated. Output disc 12 may then be rotated relative to engagement plate 22 until mounting openings 28 of output disc 12 are again in full alignment with fasteners 49, thereby removing fasteners 49. By means of a return spring 25, which is designed in particular as a coil spring, the output disk 12 can be automatically pressed into an initial position in which a form-locking connection of the rotationally fixed coupling 27 is established. The return spring 25 is supported on a retaining surface 48, which is formed by the holding plate 26 riveted to the

support disks

15, 16 and is sufficiently spaced apart from the output disk 12 in the axial direction, so that the return spring 25 is provided with an axial spring path sufficient for disconnecting the rotationally fixed connection in the rotationally fixed coupling 27.

Fig. 3 to 7 show in enlarged views the structural details of the torsional vibration damper, which allow the axial displacement of the output disk 12 and the subsequent disengagement of the engagement section 27. The holding plate 26 can be riveted radially on the outside and has on the radially inside a curved region, i.e. a radial edge 29, which forms the retaining surface 48. The restoring spring 25, which is designed as a spiral spring, can thus be supported with a circumferentially continuous force edge on the retaining surface 48 and can support a radially inwardly projecting catch on the output disk 12 in the region of the toothing of the outer toothing of the output disk 12 for the rotationally fixed coupling 27 shown in the example of toothing in fig. 3. The axial distance between the radial edge 29 of the holding plate 26 and the engagement plate 22 is selected such that the output disk 12 can be moved until the engagement 27 is completely disengaged. After completing the axial movement against the coil spring 25 until the output disc 12 is separated or misaligned relative to the engagement plate 22, the output disc 12 may be rotated until the mounting opening 28 (shown in fig. 7) of the output disc 12 corresponds or aligns with the position of the fastening opening 11 (shown in fig. 1) in the primary mass part 2. In the position where the mounting opening 28 of the output disc 12 and the fastening opening 11 of the fastening member 49 for, for example, a fixing screw are aligned with each other, the torsional vibration damper 1 can be simply detached because the fastening member can be detached without a special tool. After the force applied for the axial displacement is removed, the output disk 12 is automatically displaced by the disk spring 25 in the direction of the engagement plate 22 until it snaps into the engagement 27. The torsional vibration damper 1 can also be mounted simply due to the variable positioning of the output disk 12 relative to the engagement plate 22.

FIG. 8 is a schematic cross-sectional view of an alternative secondary mass component for the torsional vibration damper shown in FIG. 1. As shown in fig. 8, the holding plate 26 also has a curved region in the region of its riveted radius to form a retaining surface 48, so that a restoring spring designed as a coil spring 25 can be supported on the holding plate 26 by means of a radially outwardly projecting tongue at a larger radius than in the embodiment shown in fig. 3 to 7.

Fig. 9 is a half sectional view of a torsional vibration damper according to a second embodiment. In contrast to the embodiment of the torsional vibration damper 1 shown in fig. 1, the intermediate element, i.e. the engagement plate 22, is omitted in the embodiment of the torsional vibration damper 1 shown in fig. 9. In this case, a rotationally fixed coupling 27 is formed between the second support disk 16 and the output disk 12. A return spring 25 may press the output disc 12 against the first support disc 16.

Fig. 10 to 13 show a third embodiment of a torsional vibration damper constructed according to the invention, the following description being limited as far as possible to the differences with respect to the first embodiment. The torsional vibration damper 40 shows a component-optimized solution, so that a torque limiter 44 is realized. For this purpose, no intermediate element is required between the output disk 12 and the second support disk 16, and the engagement 47 is provided directly. The receiving space 9 for the arcuate spring 6 of the spring absorber 5 and the torque limiter 44, which at the same time forms a friction mechanism, are sealed by means of the diaphragm spring 41. The radially inner region of the diaphragm spring 41 is clamped between the retaining plate 26 and the second support disk 16 and is positioned via the riveted connection 23. The radially outer region of the diaphragm spring 41 is supported against the inner wall of the cover plate 8 of the primary mass part 2 via a friction ring 42.

List of reference numerals

1 torsional vibration damper

2 primary mass part

3 secondary mass part

4 axis of rotation

5 spring damping mechanism

6 arc spring

7 Flange element

8 cover plate

9 holding cavity

10 support flange

11 fastening opening

12 output tray

13 variator input shaft

14 torque limiter

15 first support disc

16 second support plate

17 accommodating part

18 Friction lining

19 Friction lining

20 pre-damper

21 helical compression spring

22 intermediate members, engaging plates

23 riveted connection

24 reference circle

25 coil spring

26 holding plate

27 a coupling part; engaging part

28 mounting port

29 radial edge

40 torsional vibration damper

41 diaphragm spring

42 friction ring

44 Torque limiter

47 engaging part

48 holding surface

49 fastener

50 friction disk

51 hold down spring

52 pressure plate

53 double-mass flywheel

54 output flange

Claims

1. A torque limiter for interrupting a torque flow in a drive train of a motor vehicle, the torque limiter having:

a first support disc (15);

a second support disc (16) axially arranged beside the first support disc (15);

a friction disc (50) for transmitting torque in frictional engagement, clamped in frictional engagement between the first support disc (15) and the second support disc (16) up to a limit torque;

an output disk (12) for outputting torque, which is connected in a rotationally fixed manner directly or indirectly via a rotationally fixed coupling (27) to the support disks (15, 16) or to the friction disk (50), wherein the output disk (12) has at least one mounting opening (28) for the passage of a fastening element (49), which fastening element (49) is used to fasten a component of the input side coupled to the torque limiter (14),

wherein the output disk (12) is axially relatively movable in a relative position in the circumferential direction in order to disengage the rotationally fixed coupling (27) and to establish the rotationally fixed coupling (27) again.

2. The torque limiter according to claim 1, characterized in that a return spring (25), in particular designed as a coil spring, is provided for positioning the output disc (12) in a defined axial initial position, wherein an axial spring travel of the return spring (25) allows an axial displacement of the output disc (12) for disengaging the anti-rotation coupling (27).

3. The torque limiter according to claim 2, characterized in that the return spring (25) presses the output disk (12) in an axial initial position against an axial stop, in particular formed by the first support disk (15) or by the second support disk (16).

4. The torque limiter according to claim 2 or 3, characterized in that the return spring (25) is supported on an axial side remote from the output disk (12) on a retaining face (48) of the retaining plate (26) spaced apart from the output disk (12), wherein in particular the retaining plate (26) is fixed, in particular riveted, to a component of a rotationally fixed coupling (27) configured for the output disk (12).

5. The torque limiter according to one of claims 1 to 4, characterized in that the rotationally fixed coupling (27) is embodied as a toothing, wherein in particular the output disk (12) has an external toothing for the toothing.

6. The torque limiter according to claim 5, characterized in that an internal toothing of the anti-rotation coupling (27) designed as a mesh for the first support disk (15) and/or the second support disk (16) or the friction disk (50) is configured.

7. The torque limiter according to claim 5, characterized in that an internal toothing of the anti-rotation coupling (27) designed as a mesh is configured for the separate mesh plate (22) connected to the first support plate (15) and the second support plate (16) or to the friction disk (50).

8. The torque limiter according to one of claims 1 to 7, characterized in that the mounting opening (28) is designed as an elongated hole which is curved, in particular in the circumferential direction.

9. Torsional vibration damper (1, 40) designed as a dual mass flywheel fastened to a crankshaft of an internal combustion engine, comprising a primary mass part (2) and a secondary mass part (3), which primary mass part (2) and secondary mass part (3) are rotatable together about a rotational axis (4) and are arranged so as to be rotatable relative to one another, and a spring damping mechanism (5) is arranged in the torque flow between the primary mass part (2) and the secondary mass part (3), wherein the secondary mass part (3) designed in multiple parts surrounds a torque limiter (14, 44) designed as a slip clutch, and a bearing flange (10) is guided on both sides in the radial direction on the inside via friction linings (18, 19) on a first bearing disk (15) and a second bearing disk (16), which first bearing disk (15) and second bearing disk (16) together axially delimit an accommodation (17) ) And the first support disk (15) is connected at least indirectly to the output disk (12), and the primary mass part (2) is fastened to the crankshaft by means of a fastening element which can be inserted through a mounting opening (28) of at least one component of the secondary mass part (3) into a fastening opening (11) of the primary mass part (2),

characterized in that the output disk (12) is guided axially on the first support disk (15) or the second support disk (16) and is connected directly to the second support disk (16) by means of a toothing (47) or indirectly via a toothing (27) and an intermediate element (22),

wherein the engaging portions (27, 47) can be disengaged against the spring force of at least one coil spring (25) by axial movement of the output disc (12), and then the output disc (12) can be rotated so that the mounting opening (28) of the output disc (12) corresponds in position to the fastening opening (11) of the primary mass part (2).

10. A torsional vibration damper (1, 40) as claimed in claim 9, characterized in that a predamper (20) which is provided for the secondary mass part (3) is positioned between the spring damping mechanism (5) and the torque limiter (14).

11. A torsional vibration damper (1, 40) as claimed in claim 9, characterized in that a force is exerted on the output disc (12) by the disc spring (25), the disc spring (25) being supported on a curved holding plate (26), the holding plate (26) being fixed on the second support disc (16) directly or via the intermediate element (22).

12. Torsional vibration damper (1, 40) as claimed in any of claims 9 to 11, characterized in that the torque limiter (14, 44) surrounds a friction lining (18, 19) which is grease-coated or oil-coated and is embodied in the form of a disc.

13. The torsional vibration damper (1, 40) as claimed in any of claims 9 to 12, characterized in that a diaphragm spring (41) is inserted between the holding plate (26) and the second support disk (16), the diaphragm spring (41) being supported radially on the outside via a friction ring (42) on a cover plate (8) of the primary mass part (2).

14. The torsional vibration damper (1, 40) as claimed in any of claims 9 to 13, characterized in that at least the first support disc (15), the second support disc (16) and the holding plate (26) of the secondary mass part (3) are connected to one another via a riveted connection (23) with rivets arranged around.

15. The torsional vibration damper (1, 40) as claimed in any of claims 9 to 14, characterized in that the meshing sections (27, 47) of the secondary mass part (3) are staggered with reference circles (24) formed by the riveted connection (23).

16. The torsional vibration damper (1, 40) as claimed in any of claims 9 to 15, characterized in that at least components of the secondary mass part (3), such as the bearing flange (10), the first support disk (15), the second support disk (16), the intermediate element (28), the retaining plate (26) and the output disk (12), are embodied as shaped parts or stampings.

17. Method for dismounting and mounting a torsional vibration damper (1, 40) according to any of claims 9 to 16, which is connected to a crankshaft of an internal combustion engine, characterized in that the output disc (12) can be rotated into a position by moving the output disc (12) against the spring force of the disc spring (25), wherein the torsional vibration damper (1, 40) can be dismounted and/or mounted when the mounting opening (28) of the output disc (12) and the fastening opening (11) of the fastening in the primary mass part (2) for the torsional vibration damper (1, 40) correspond in position.

18. Drive train for DHT hybrid applications, which is equipped with an electric motor and an internal combustion engine, characterized in that the drive train has a torsional vibration damper (1, 40) according to at least one of claims 9 to 16, comprising an integrated torque limiter (14, 44).