CN112833109B - Torque limiter and torsional vibration damper - Google Patents

Abstract

The invention relates to a torque limiter and a torsional vibration damper for breaking a torque flow in a drive train of a motor vehicle and having a first support disk (15), a second support disk (16), a friction disk (50) for transmitting torque in frictional engagement and an output disk (12) for delivering torque, which is connected in a rotationally fixed manner directly or indirectly to the support disks (15, 16) or to the friction disk (50) via a rotationally fixed coupling (27), wherein the output disk (12) has at least one mounting opening (28) for a fastener (49) to pass through, the fastener (49) being used to fix a component coupled on the torque limiter (14) on the input side, wherein the output disk (12) can be moved relative to one another in the axial direction in a rotationally fixed relative position in order to disengage the rotationally fixed coupling (27) and to again establish the rotationally fixed coupling (27). The torsional vibration damper is integrated with the torque limiter.

Description

Torque limiter and torsional vibration damper

Technical Field

The present invention relates to a torque limiter by means of which a torque flow in a drive train of a motor vehicle can be disconnected, thereby protecting components of the drive train from sudden torque shocks. The invention also relates to a torsional vibration damper integrated with the torque limiter. The invention further relates to a method for removing and installing the torsional vibration damper and to a drive train comprising the torsional vibration damper. ,

Background

Torsional vibration damper designed as a dual mass flywheel is used to reduce torsional vibrations in the drive train of a motor vehicle. Torsional vibrations originate from the periodic combustion beats of a reciprocating piston internal combustion engine, which in combination with the firing order create torsional non-uniformities that are introduced from the crankshaft into the drive train. 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. Reducing torsional non-uniformities from the internal combustion engine by the torsional vibration damper improves driving comfort.

DE 10 2012 202 255 A1 shows such a torsional vibration damper which can be used for damping or dampening and which can be used in a drive train between a crankshaft of an internal combustion engine and a disconnect clutch, for example, which is upstream of a transmission. A torsional vibration damper of multistage construction is known from DE 10 2008 032 009 A1, which comprises two radially superposed damper stages arranged in series. The radially outer first damping stage, which is fitted with a curved spring, surrounds the second damping stage, which surrounds the inner helical compression spring. A further design provides that the two damping stages are coupled to one another via a floating intermediate flange.

In the operating state of an internal combustion engine, peak loads, so-called shocks (torque shocks) with high load variations, which can damage the drive train, occur suddenly in the start-up and stop phases of the internal combustion engine or when sudden coupling is caused to stop the engine, in the drive train, in particular in hybrid or CVT applications. In particular, the arcuate springs of the spring damper mechanism are subjected to a large load, and the arcuate springs are temporarily compressed to a limit. In order to avoid the adverse effects of impacts as much as possible and to compensate or isolate the materials compatibly, it is known to equip torsional vibration dampers with torque limiters (DMB) implemented as slip clutches. When the limit torque is exceeded, a slip of one of the co-acting components of the secondary mass part can be achieved by means of a torque limiter integrated in the multi-piece secondary mass part. In this case, the excess energy is dissipated as frictional heat and the component load is reduced. For example, DE 10 2009 033 864 A1, DE 10 2010 025 579 A1 and DE 10 2014 211 603 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 198, 34, 729 A1, in which a primary mass part connected to a drive shaft of a motor vehicle engine is coupled via a curved spring to a secondary mass part which can be rotated relative to the primary mass part. The secondary mass part is coupled to a 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 serve 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 displacement occurs in the primary mass part between the fastening opening for the fastening screw of the torsional vibration damper on the crankshaft and the mounting opening in the component of the secondary mass part. Because of the misalignment, the torsional vibration damper is not detachable or requires high installation costs. There is a constant need to improve the ease of maintenance of torsional vibration dampers having torque dampers.

Disclosure of Invention

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

The above-mentioned problem is solved by a torque limiter for interrupting a torque transmission in a drive train of a motor vehicle, having: a first support plate; the second support disc is arranged beside the first support disc along the axial direction; a friction disk for transmitting torque in a friction engagement manner clamped in a friction engagement manner between the first support disk and the second support disk up to a limit torque; and an output disk for torque output, which is connected directly or indirectly via an anti-rotation coupling to the support disk or to the friction disk in a rotationally fixed manner, wherein the output disk has at least one mounting opening for a fastening element for fastening a component coupled on the input side to the torque limiter, wherein the output disk is axially movable relative to one another in a rotationally fixed relative position in the circumferential direction in order to disengage the anti-rotation coupling and to reestablish the anti-rotation coupling.

Under sudden torque shocks ("Impact"), unpredictable loads are generated in the drive train, which can cause damage to torque-transmitting components in the drive train. The impact occurs, for example, in the following cases: in the event of an engine stall at the start of the motor vehicle, a shift-out, a rapid engagement of the clutch, simultaneous acceleration and downshift, emergency braking, a sudden start (rapid start), an engine start of the motor vehicle engine. By means of the torque limiter, too high a torque can be prevented from being transmitted by means of the low-pass filter, which is achieved by the friction disk being able to slip when the torque in the torque limiter is too high, whereby the torque transmission can be disconnected at least when the level defined by the 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 coefficient of friction 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 type of dry slip clutch. The dry, i.e. non-lubricated, frictional contact points of the torque limiter limit the variation of the friction values that are effective during operation, so that the designed limit torque can be set with high accuracy and low safety margin.

The torque limiter may be integrated in particular in a torsional vibration damper for reducing torsional irregularities in the torque produced by the motor vehicle engine. For example, a torsional vibration damper designed as a dual mass flywheel can have a primary mass part for introducing torque from the motor vehicle engine and a secondary mass part which is coupled to the primary mass part in a rotationally fixed manner via an energy storage element, in particular designed as an arcuate 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 to the torque limiter on the input side, 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 event that disassembly of the torsional vibration damper is required for maintenance or repair, a tool may be passed through the mounting opening to disassemble the fastener and be removed through the mounting opening. However, when a torque exceeding the limit torque occurs and the friction disk slips, the relative angular position of the output disk changes, so that the mounting opening of the output disk can no longer be aligned with the already mounted fastener. In effect, the arcuate segment of the output disc completely or partially covers the fastener, thereby impeding accessibility to the fastener and detachability of the fastener. However, since the output disk is embodied separately and is embodied in a rotationally fixed but axially movable manner by the rotationally fixed coupling, it is possible in this case for the output disk to be moved axially until the rotationally fixed coupling is disengaged and then rotated in the circumferential direction until the mounting opening reaches a relative angular position in which the fastening element is accessible and can be removed. In this relative angular position, the axial displacement of the output disk can take place in opposite directions, so that the previously separated anti-rotation coupling is again connected in an anti-rotation manner. The torsional vibration damper can then be removed again as a whole with the torque limiter for maintenance and/or repair and, if necessary, reinstalled. Since the output disk can be rotated in the axially displaced relative position, the accessibility of the fastening element via the mounting opening can be established again if necessary, so that a torsional vibration damper with a torque limiter can be easily maintained.

The friction discs may be clamped via friction linings between the support discs. Preferably, a compression spring, which is in particular designed as a coil spring, is provided, which is supported on one of the support disks and can press a pressure plate, which can be moved axially between the support disks, onto the friction disk. The pressing force and the limit torque can be adjusted via the spring force of the pressing spring. Furthermore, the compression spring, which is designed as a spiral spring, is suitably preloaded with 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, during traction operation of the drive train, the torque to be transmitted, in particular already reducing the torsional vibrations by means of the torsional vibration damper, is introduced into the torque limiter via the friction disk, transmitted to the support disk and transmitted from the support disk to the output disk. However, the opposite configuration is also possible, in which, during the drive train traction operation, the torque to be transmitted, in particular already reducing the torsional vibrations by means of the torsional vibration damper, is introduced into the torque limiter via the support disk, transmitted to the friction disk and transmitted from the friction disk 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 can be made in the torque limiter for the output disk for operation to be held in an axial relative position of the coupling which effects the rotation resistance, wherein this holding can be omitted for maintenance and/or repair purposes, so that the desired relative angular position of the mounting opening is adjusted by means of the axial displaceability. For this purpose, the output disk can be fixed in the axial direction, for example, detachably, releasably locked and/or elastically supported in the axial direction with a sufficiently high spring force.

In particular, a restoring spring, which is in particular designed as a spiral spring, is used to position the output disk in a defined axial starting position, wherein an axial spring travel of the restoring spring allows an axial displacement of the output disk 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 in which the rotationally fixed connection is achieved by means of the rotationally fixed coupling. In this way, torque transmission via the output disk can be ensured during operation. In the case of maintenance or repair, the output disk can be moved axially manually against the spring force of the return spring until the form-locking of the rotationally fixed coupling is eliminated and the output disk can be rotated relative to one another. The axial vibrations acting on the output disk can in principle also be filtered out and/or reduced by the axial relative movement of the output disk with respect to the axially immovable fixation of the output disk.

The return spring preferably presses the output disk in the axial starting position against an axial stop formed in particular by the first support disk or by the second support disk. An axially defined initial position of the output disk is thereby achieved, in which an anti-rotation fastening is provided in the anti-rotation coupling. Furthermore, the restoring spring can press the output disk against the axial stop with a high residual pressing force, so that a sufficiently rotationally fixed connection is maintained even if an axial force suddenly acts on the output disk. In order to form the axial stop, already existing components are used together with the support disk, so that a low number of components is maintained.

In particular, the restoring spring is supported on a holding surface of the holding plate spaced apart from the output disk on an axial side facing away from the output disk, wherein the holding plate is fastened, in particular riveted, in particular to a component of the rotationally fixed coupling for the output disk. By means of the axial positioning of the holding surface of the holding plate relative to the output disk in the initial position, a sufficiently large spring travel can be predefined for the return spring, so that a positive connection of the output disk in the rotationally fixed coupling can be decoupled. 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 the holding surface, which is axially spaced farther from the output disk, and a partial region for fixing the holding plate to the remainder of the torque limiter, which is located axially closer to the output disk, are achieved.

In particular, the rotationally fixed coupling is embodied as a toothing, wherein in particular the output disk has external toothing for the toothing. The engagement portion obtains a tooth flank acting tangentially, 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 forming the teeth.

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

In a further embodiment, the inner toothing of the anti-rotation coupling part, which is embodied as an engagement part, is embodied for a separate engagement plate connected to the first and second support plate or to the friction plate. 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 bore which is curved in particular in the circumferential direction. Thereby, sufficient accessibility and detachability of the fastener can be achieved even in the case of a very small angular offset of the mounting opening with respect to the fastener. The elongate hole ensures the accessibility and the removability of the fastening element within increments of the minimum rotational angle, in particular if the output disk is coupled in a rotationally fixed manner within the rotationally fixed coupling with a limited increment of rotational angle exceeding the minimum rotational angle. In this case, the requirements are satisfied if the distance of extension of the mounting opening relative to the fastening element is only extended in the circumferential direction and the distance of extension in the radial direction corresponds in particular to the clearance fit with the fastening element. The radially outer contour of the rotationally fixed coupling of the output disk for form-locking, in particular the external toothing, is thus 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 disk hub, which serves to rotationally fix a shaft arranged radially inside the mounting opening. Thereby, the fastener is arranged entirely in a common radial area with the output disc. No drive ring is required which leads radially outward from the output disk to ensure adequate ease of maintenance. A high degree of ease of maintenance is also provided by the output hub being arranged radially inwards.

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 configured as a dual mass flywheel which is fastened to a crankshaft of the internal combustion engine and comprises a primary mass part and a secondary mass part which are arranged rotatably about an axis of rotation and relative to one another, and a spring damper mechanism is arranged in the torque flow between the primary mass part and the secondary mass part, wherein the secondary mass part which is configured as a multi-part surrounds a torque limiter which is embodied as a slip clutch and on both sides radially on the inside is guided via friction linings on a second support disk and a first support disk, which together form a receptacle and the first support disk is connected at least indirectly to the 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 into a fastening opening of the primary mass part through a mounting opening of at least one part of the secondary mass part.

The torque limiter is arranged in accordance with the principles of the present invention such that the output disk of the secondary mass part is guided axially on the first support disk or on the second support disk and is connected to the second support disk directly by means of the engagement part or indirectly via the engagement part and the intermediate element, wherein the engagement part is separable against the spring force of the at least one coil spring by an axial displacement of the output disk, 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.

The design makes it possible to disengage the engagement part by pulling or axially displacing the output disk against the force exerted by the disk spring, the teeth of the engagement part in the torque transmission position being positively locked in the mating teeth of the second support disk of the intermediate element or of the secondary mass part in the operating state. In a position offset axially from the engagement, the output disk can be rotated relative to the second support disk or the intermediate element to a position in which the mounting opening of the output disk and the fastening element are adjusted to have a corresponding or identical position or to have the same opening structure, the torsional vibration damper being screwed onto the crankshaft by means of the fastening element. By disengaging the engagement, the output disc or the secondary mass part can be moved into a position in which the mounting opening of the output disc is aligned with the fastening opening of the primary mass part after triggering or activating the torque limiter, i.e. when a torque exceeding the limit torque occurs and the friction disc slips.

After the adjustment and withdrawal of the axial force has been completed, the output disk is automatically moved by the coil 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 of the torsional vibration damper, in particular the fastening screws, can be contacted unimpeded via the mounting openings of the output disk, and thus the disassembly of the torsional vibration damper and also the easy reinstallation are simplified.

In contrast to the principle according to the invention, in the secondary mass parts screwed up to now, the relative rotation of the output disk with respect to the fastening element of the torsional vibration damper after the triggering or activation of the torque limiter requires high installation costs. The output disc is usually only re-accessible by means of special tools to the point of unobstructed access to the fixing screw. In contrast, with the embodiment according to the invention, the output disk can be advantageously brought into correspondence with the position of the fastening element by simple measures without the use of special tools.

During traction operation, torque from the motor vehicle engine can be introduced into the primary mass, while during freewheeling torque from the drive train can be introduced into the secondary mass. The opposite can also be made, i.e. in traction operation, 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 fixed manner via an energy storage element, which is in particular designed as a curved spring, can form a mass-spring system which, in a specific frequency range, can reduce torsional irregularities in terms of the 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 installed. The primary mass part may have a disk-shaped flange element, to which the cover plate may be connected, whereby a substantially annular receiving space for the energy storage element may be limited. The primary mass can, for example, be stopped tangentially against the energy storage element by means of a molding which protrudes into the receiving space. The output flange of the secondary mass part can protrude into the receiving space, and the output flange can be stopped tangentially at the opposite end of the energy storage element. If the torsional vibration damper is part of a dual mass flywheel, the primary mass part may have a flywheel disc that can be coupled to a drive shaft of the motor vehicle engine. If the torsional vibration damper is part of a belt pulley assembly as a belt pulley decoupler, the primary mass part may form a belt pulley and a traction element, in particular a wedge belt, may act on the radially outer side of the belt pulley to transmit torque, the belt pulley assembly being used to drive an auxiliary unit of the motor vehicle by means of the traction element. If the torsional vibration damper is used as a disk damper for a friction clutch, in particular for a clutch disk, the primary mass part can be coupled to the disk region carrying the friction linings, while the secondary mass part can be coupled to the transmission input shaft of the motor vehicle transmission.

In particular, the torque limiter is arranged outside the accommodation chamber. Thereby lubricant is prevented from reaching the torque limiter from the accommodation chamber and affecting the friction characteristics. Alternatively, the torque limiter may be operated dry, i.e. without lubricant. Preferably, a sealing means for sealing the receiving space is provided between the torque limiter and the receiving space in the radial direction. 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 protruding radially inwards from the receiving space, so as to seal the receiving space.

Preferably, the mounting opening extends over a greater distance in the circumferential direction than the fastening opening, wherein in particular the difference between the mounting opening and the fastening opening in the circumferential direction is at least twice the minimum relative angular offset allowed by the rotationally fixed coupling. In particular, the mounting opening ensures the accessibility and the removability of the fastening element within the increments of the minimum rotational angle, if the output disk can be coupled in a rotationally fixed manner within the rotationally fixed coupling, in particular the engagement, only with a limited increment of rotational angle beyond the minimum rotational angle. It is ensured that a part of the mounting opening always coincides completely with the fastening opening, so that the fastening member 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 implemented as a dual mass flywheel. In addition to a spring damper mechanism comprising a curved spring, which forms the main damper or the outer damper, the predamper, also referred to as the inner damper, is equipped with a helical compression spring, wherein the accumulators of the two dampers are arranged in series in the torque flow.

According to a further preferred embodiment of the invention, the output disk is acted upon 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 S-shaped curved holding plate forms a side arm which is directed radially toward the rotational axis of the torsional vibration damper and is axially spaced apart from the output disk, on which the disk springs are supported. The axial distance of the side arms exceeds the dimension that ensures unimpeded axial displacement of the output disk and thus reliable separation of the engaged components.

According to an advantageous embodiment of the invention, the torsional vibration damper configured as a friction mechanism comprises a friction lining which is coated with grease or with lubricating oil and is embodied in the form of a disk. The friction linings of the torque limiter, which are associated with the secondary mass part, are located radially below a receiving space of the spring damper mechanism in the direction of the rotational axis, which receiving space is at least partially filled with a lubricant for lubricating the arcuate spring. 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 called arcuate spring grease, of the spring damper mechanism. The low coefficient of friction of the torque limiter over the service life of the torsional vibration damper is advantageously achieved by the friction lining being mounted in the annular space which is as closed as possible. Alternatively or additionally thereto, the annular space defined by the output disk, the support flange and the secondary mass part and/or other components of the primary mass part may be filled with lubricant, so that a lubricant reservoir is formed which also lubricates the friction lining.

In a preferred embodiment of the invention, a diaphragm spring is inserted between the holding plate and the second support plate of the secondary mass part, the diaphragm spring being supported radially on the outside of the cover plate of the primary mass part in a force-fitting manner. The diaphragm spring serves to seal the receiving chamber of the spring damper mechanism from the environment and prevent dirt or water from entering. Furthermore, the diaphragm spring applies an axial force to the second support disk and to the torque limiter.

According to a further embodiment of the invention, the components of the secondary mass part, namely 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, the diaphragm spring can also be connected to a component of the secondary mass part via a riveted connection.

The preferred embodiment of the secondary mass part also provides that the engagement of the form-locking connection between the output disk and the intermediate element or the second support disk is staggered with respect to the pitch circle of the riveted connection. The torque-transmitting elements, the engagement portions and the rivet connection portions of the secondary mass part are thus positioned radially close to one another, which contributes to the component stiffness.

As a measure for achieving cost-effective production, 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 molded parts or stamped parts. By means of this method, the component of the primary mass part is also optimized in terms of weight as a complement to the secondary mass part and is produced cost-effectively without cutting 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 detached and attached to 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 displacement. For this purpose, the output disk is first moved relative to the second support disk by pulling of the disk spring force against the spring force. The next method step is to rotate the output disk to a position in which the fastening screw of the torsional vibration damper corresponds to the position of the opening in the output disk. The output disk is automatically moved in the direction of the output disk without axial force, whereby the components are again connected in a rotationally positive manner via the engagement. In this position the fastening screw can be removed by means of a normal tool guided through the opening of the output disc. Furthermore, the output disc enables the torsional vibration damper to be mounted again.

Torsional vibration dampers according to the present invention that include a torque limiter and are equipped with a pre-damper when needed that can be easily disassembled and assembled are preferred for hybrid applications. Such torsional vibration dampers, which may 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 via both drive sources. Torque limiters are provided by motor vehicle manufacturers, especially for DHT hybrid applications (dedictated hybrid transmission-specific hybrid transmission), to protect components within the transmission from overload, among other things.

Drawings

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

FIG. 1 is a half cross-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 a secondary mass component of the torsional vibration damper shown in FIG. 1;

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

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

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

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

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

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

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

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

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

FIG. 13 is a front view of the torsional vibration damper shown 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 configured 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 jointly rotatable about the rotational axis 4 and being limitedly rotatable relative to one another. A spring damper 5 with energy storage elements embodied as arcuate springs 6 acts between the primary mass part 2 and the secondary mass part 3. The primary mass 2 comprises a flange element 7, the flange element 7 being connected radially outside to a cover plate 8 in one piece, the flange element 7 and the cover plate 8 jointly enclosing a receiving space 9, in which receiving space 9 the arcuate springs 6 are 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. The two-part outlet flange 54 extends to the pre-damper 20 which is also accommodated in the accommodation space 9. The pre-damper comprises, as shown in fig. 2, six symmetrically positioned helical compression springs 21 distributed circumferentially. Pre-damper 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 support flange 10 engages radially on the inside into a U-shaped receptacle 17 which opens in the direction of the spring damper 5 and is delimited axially by oppositely curved sections of the first support disk 15 and of the second support disk 16. The support flange 10 is guided on both sides via disk-shaped friction linings 18, 19 on the first support disk 15 and the second support disk 16. The output-side support flange 10 of the pre-damper 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 disk 50 can be clamped between the first support disk 15 and the second support disk 16 by means of a compression spring 51 supported on the second support disk 16 or alternatively on the first support disk 15, the compression spring 51 displacing the pressure disk 52 in the axial direction. Up to a limit torque corresponding to the clamping action, the friction disk 50 can transmit torque to the support disks 15, 16 in a frictionally engaged manner. Above the limit torque, the friction disk 50 may slip and interrupt torque transfer 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 reduced torque that is produced 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 designed as a crankshaft, by means of at least one fastening element 49, in particular designed as a screw. In order to achieve this fastening, the output disk 12 has mounting openings 28 aligned with the fastening openings 49 in the fastening elements 49 and in the radial region of the flange element 7 of the primary mass part 2 for the fastening openings 11 of the fastening elements 49. However, when slip occurs in the torque limiter 14, the mounting opening 28 may no longer be aligned with the fastener 49 and the fastening opening 11, thereby making it impossible to access the fastener 49 for maintenance and repair purposes to disassemble the torsional vibration damper 1.

In the exemplary embodiment shown, the individual engagement plates 22 as intermediate elements are connected to the support disks 15, 16 and the holding plate 26 via riveted connections 23, the rivets of which are arranged in a circumferentially distributed manner in the reference circle 24 (shown in fig. 7).

Engagement plate 22 forms an anti-rotation coupling 27 with output disc 12 configured as an engagement. The output disk 12 is connected in a form-fitting manner in the rotationally fixed coupling 27 in a circumferential manner to transmit torque, so that torque can be transmitted. At the same time, for removing the torsional vibration damper 1, the output disk 12 can be moved axially relative to the engagement plate 22 until the form-locking connection in the rotationally fixed coupling 27 is eliminated. The output disc 12 may then be rotated relative to the engagement plate 22 until the mounting port 28 of the output disc 12 is again fully aligned with the fastener 49, thereby removing the fastener 49. By means of a return spring 25, which is in particular designed as a spiral 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 holding surface 48 formed by a holding plate 26 riveted to the support disks 15, 16 and spaced sufficiently from the output disk 12 in the axial direction, so that an axial spring travel is provided for the return spring 25 which is sufficient for separating 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 enables the output disk 12 to be moved axially and subsequently to disengage the engagement 27. The holding plate 26 can be riveted radially on the outside and has a curved region, i.e. a radial edge 29, forming a holding surface 48 on the radially inside. The restoring spring 25 embodied as a coil spring can thus be supported with circumferentially continuous force edges on the holding surface 48 and can be supported on the output disk 12 with radially inwardly projecting catch tongues in the tooth region of the outer toothing of the output disk 12 for the rotationally fixed coupling 27 shown in fig. 3 as an example of a toothing. 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 portion 27 is completely separated. After the axial displacement against the disk spring 25 is completed until the output disk 12 is separated or otherwise misaligned relative to the engagement plate 22, the output disk 12 can be rotated until the mounting opening 28 (shown in fig. 7) of the output disk 12 corresponds to or is aligned with the fastening opening 11 (shown in fig. 1) in the primary mass 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 set 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 removal of the force applied for the axial displacement, 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 simply mounted 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 holding surface 48, so that the restoring spring embodied as a coil spring 25 can be supported on the holding plate 26 by means of a radially outwardly projecting catch 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, in the embodiment of the torsional vibration damper 1 shown in fig. 9, the intermediate element, namely the engagement plate 22, is omitted. The rotationally fixed coupling 27 is formed here between the second support disk 16 and the output disk 12. The 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 in accordance with the invention, the following description being limited as far as possible to the differences with respect to the first embodiment. Torsional vibration damper 40 shows a component-optimized solution, thus realizing a torque limiter 44. For this purpose, the engagement 47 is provided directly between the output disk 12 and the second support disk 16 without intermediate elements. The receiving space 9 of the spring damper 5 for the arcuate spring 6 and the torque limiter 44 which simultaneously forms the friction mechanism are sealed by means of the diaphragm spring 41. The radially inner region of the diaphragm spring 41 is clamped between the holding 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 in a pretensioned manner on 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 component

3. Secondary mass component

4. Axis of rotation

5. Spring vibration damping mechanism

6. Arc spring

7. Flange element

8. Cover plate

9. Accommodating chamber

10. Support flange

11. Fastening opening

12. Output disc

13. Transmission input shaft

14. Torque limiter

15. First supporting plate

16. Second supporting disk

17. Housing part

18. Friction lining

19. Friction lining

20. Pre-vibration damper

21. Helical compression spring

22. Intermediate element, engagement plate

23. Riveted joint

24. Reference circle

25. Coil spring

26. Holding plate

27. A coupling section; engagement portion

28. Mounting opening

29. Radial edge

40. Torsional vibration damper

41. Diaphragm spring

42. Friction ring

44. Torque limiter

47. Engagement portion

48. Holding surface

49. Fastening piece

50. Friction disk

51. Compression spring

52. Pressure plate

53. Dual mass flywheel

54. Output flange

Claims (18)

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

a first support plate (15);

a second support plate (16) disposed axially beside the first support plate (15);

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

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

wherein the output disc (12) is axially movable relative to each other in a relative position of circumferential rotation to disengage the anti-rotation coupling (27) and reestablish the anti-rotation coupling (27).

2. Torque limiter according to claim 1, characterized in that a return spring (25) 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. Torque limiter according to claim 2, characterized in that the return spring (25) presses the output disc (12) in an axial initial position against an axial stop formed by the first support disc (15) or by the second support disc (16).

4. A torque limiter according to claim 3, characterized in that the return spring (25) is supported on an axial side remote from the output disc (12) on a holding surface (48) of a holding plate (26) spaced apart from the output disc (12), wherein the holding plate (26) is fixed with a member configured for an anti-rotation coupling (27) of the output disc (12).

5. Torque limiter according to claim 4, characterized in that the anti-rotation coupling (27) is embodied as a toothing, wherein the output disk (12) has external toothing for the toothing.

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

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

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

9. Torsional vibration damper (1, 40) configured 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), the primary mass part (2) and the secondary mass part (3) being jointly rotatable about a rotational axis (4) and being arranged rotatably relative to one another, and a spring damper mechanism (5) being arranged in the torque flow between the primary mass part (2) and the secondary mass part (3), wherein the secondary mass part (3) configured as a multi-piece surrounds a torque limiter (14, 44) embodied as a slip clutch and a support flange (10) is guided on both sides on the radial side via friction linings (18, 19) on a first support disk (15) and a second support disk (16), the first support disk (15) and the second support disk (16) jointly defining a receptacle (17) in the axial direction and being connected at least indirectly to an output disk (12) and the primary mass part (2) being fastened to at least one fastening element (28) which can be fastened to the primary mass part (2) by means of the fastening element (28) being fastened to 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 engagement parts (27, 47) can be separated 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. Torsional vibration damper (1, 40) according to claim 9, characterized in that a pre-damper (20) provided for the secondary mass part (3) is positioned between the spring damper mechanism (5) and the torque limiter (14).

11. Torsional vibration damper (1, 40) according to 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) according to claim 11, characterized in that the torque limiter (14, 44) encloses a friction lining (18, 19) coated with grease or with lubricating oil, which is embodied in the form of a disk.

13. Torsional vibration damper (1, 40) according to claim 11, characterized in that a diaphragm spring (41) is inserted between the holding plate (26) and the second support plate (16), the diaphragm spring (41) being supported radially on the outside via a friction ring (42) on the cover plate (8) of the primary mass part (2).

14. Torsional vibration damper (1, 40) according to claim 11, characterized in that at least the first support disk (15), the second support disk (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. Torsional vibration damper (1, 40) according to claim 14, characterized in that the engagement portions (27, 47) of the secondary mass part (3) are staggered with respect to the reference circle (24) formed by the riveted joint (23).

16. Torsional vibration damper (1, 40) according to claim 11, characterized in that at least the bearing flange (10), the first support disk (15), the second support disk (16), the intermediate element (22), the holding plate (26) and the output disk (12) of the secondary mass part (3) are embodied as a molding or stamping.

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 position by moving the output disc (12) against the spring force of the spiral spring (25), wherein the torsional vibration damper (1, 40) can be dismounted and/or mounted in a position corresponding to the mounting opening (28) of the output disc (12) and the fastening opening (11) of the primary mass part (2) for the fastening of the torsional vibration damper (1, 40).

18. Drive train for DHT hybrid applications, 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).