Crankshaft assembly with centrifugal pendulum attached to crankshaft

Abstract

The invention relates to a crankshaft assembly (1) for a drive train of a motor vehicle, comprising a crankshaft section (2) and a centrifugal pendulum (3) fixed to the crankshaft section, the centrifugal pendulum having a carrier (4) fixed to the crankshaft section and at least one pendulum mass (5) which moves relative to the carrier (4) along a predetermined path, wherein the crankshaft assembly (1) has a breakage suppression device (27) which engages radially externally around the centrifugal pendulum (3) such that components of the centrifugal pendulum (3) which become loose during rotation of the centrifugal pendulum (3) are collected by the breakage suppression device (27).

Description

TECHNICAL FIELD

[0001] The invention relates to a crankshaft assembly for a drive train of a motor vehicle. The crankshaft assembly has a crankshaft section and a centrifugal pendulum attached to the crankshaft section. The centrifugal pendulum has a carrier fixed to the crankshaft section and at least one pendulum mass which moves relative to the carrier along a predetermined orbit. BACKGROUND

[0002] From the prior art it is known to attach a centrifugal pendulum to a crankshaft in order to absorb inherent frequency vibrations of the crankshaft. For example, DE 10 2016 121 397 A1 and DE 10 2017 120 426 A1 each disclose a pendulum assembly which is attached in a radial direction to an outer peripheral surface of the crankshaft.

[0003] However, the prior art still has the disadvantage that the provision of a centrifugal pendulum requires additional installation space and increases the overall weight of the crankshaft, and that the connection of the centrifugal pendulum to the crankshaft weakens the crankshaft.

[0004] It is therefore an object of the invention to avoid or at least reduce the disadvantages of the prior art. In particular, a crankshaft assembly is to be provided in which the centrifugal pendulum can be designed in a space-saving and weight-saving manner and the centrifugal pendulum can be attached to the crankshaft without negatively influencing the function, the strength, the manufacturability and / or the costs. SUMMARY

[0005] This object is achieved by a crankshaft assembly having the features of claim 1. Advantageous further embodiments are claimed in the dependent claims.

[0006] The crankshaft assembly thus has a crankshaft section, i.e. a particular axial section of the crankshaft, and a centrifugal pendulum which is attached directly to the crankshaft section, in particular. The centrifugal pendulum serves to absorb inherent frequency vibrations of the crankshaft. As a result, torsional vibrations / twisting of the crankshaft can be eliminated by the centrifugal pendulum. Preferably, the centrifugal pendulum is tuned to higher orders of vibration; for example to orders of vibration greater than the first order, preferably greater than the second order. For example, the centrifugal pendulum can be tuned to the third order, the fourth order, the fourth and a half order, the sixth order, etc.

[0007] The centrifugal pendulum has a carrier fixed to the crankshaft section and at least one pendulum mass which moves relative to the carrier along a predetermined orbit. In order to meet the resonance condition for compensating torsional vibrations, the raceway preferably has portions in the circumferential direction and in the radial direction.

[0008] In particular, the crankshaft section can have a mass region which is arranged eccentrically (relative to the axis of rotation of the crankshaft / the crankshaft section), by which an imbalance is generated / is forced during operation / rotation of the crankshaft assembly. The mass region is formed, for example, by a connecting rod bearing region of the crankshaft section.

[0009] The crankshaft assembly has a rupture-inhibiting device (catcher) which is particularly fixed to the crankshaft section, which engages radially around the centrifugal pendulum on the outside, so that loose parts of the centrifugal pendulum are caught and / or braked by the rupture-inhibiting device when the centrifugal pendulum is rotating. In other words, the centrifugal pendulum is potted with the rupture-inhibiting device, so that the centrifugal pendulum is radially surrounded / enclosed on the outside. This has the advantage that loose parts, which are loosened as a result of the rotation, cannot be thrown outwards in an uncontrolled manner. The rupture-inhibiting device thus forms a barrier for parts which fly outwards as a result of the centrifugal force, as a result of which damage to other components of the motor vehicle drive train can be prevented.

[0010] According to a preferred embodiment, the rupture-inhibiting device can have a radial section which extends radially outwards on a first axial side of the centrifugal pendulum (opposite the crankshaft section) and an outer axial section which extends radially outwards in the axial direction from the radial section, in particular from a radially outer end of the radial section, to the outside of the centrifugal pendulum with respect to a second (facing the crankshaft section) axial side of the centrifugal pendulum. In other words, the rupture-inhibiting device extends on the radially outer side of the centrifugal pendulum in the direction of the crankshaft section. In particular, the outer axial section extends far enough at least to completely cover the one or more pendulum masses in the axial direction. In particular, the radial section extends radially outwards so far that the radial section extends radially outwards beyond the centrifugal pendulum (pendulum mass). The outer axial section and the radial section are connected, for example, via a deflection / curvature.

[0011] According to a preferred embodiment, the outer axial section can extend over a circumferential section of less than 360°, preferably between 90° and 270°. In other words, the outer axial section has a cross section in the shape of a circular arc. In particular, the outer axial section extends only over the circumferential section in which the one or more pendulum masses are arranged. This has the advantage that the rupture-inhibiting device is only formed where it has to fulfil its function, so that material and thus weight can be saved. In particular, the space required by the crankshaft section is not limited by the rupture-inhibiting device.

[0012] According to a preferred embodiment, the crankshaft assembly can have a friction device which is particularly connected to the carrier in a non-rotatable manner and which rests against at least one pendulum mass, so that the friction device exerts a frictional torque on the pendulum mass which impedes the relative movement when the pendulum mass moves relative to the carrier. This has the advantage that the additional friction acting on the relative movement / vibration movement of the centrifugal pendulum, in particular the pendulum masses, improves the isolation of the natural frequency vibrations of the crankshaft and the required pendulum angle can be reduced. In this way, functional parameters such as mass, pendulum angle and friction can be provided to the required extent.

[0013] According to a preferred embodiment, the friction device can have a friction element which rests against the pendulum mass, a receiving disc which is connected to the carrier in a non-rotatable manner, and a spring element which is supported / tensioned axially between the friction element and the receiving disc. A normal force / axial force is exerted on the friction element by the spring element, and the normal force / axial force presses the friction element in the axial direction against the pendulum mass.

[0014] According to a preferred embodiment, the friction device can additionally have a cover disc which is arranged axially between the spring element and the friction element. By providing the cover disc, the contact surface between the spring element and the friction element, i.e. relative to the friction element, can be enlarged, so that the permissible surface pressure of the friction element is not exceeded.

[0015] According to an advantageous refinement, the friction element can be connected to the receiving disc in a non-rotatable manner, in particular in a form-fitting rotational fixed manner. This advantageously defines a friction point between the friction element and the pendulum mass, at which a friction torque is generated which impedes the relative movement between the pendulum mass and the carrier.

[0016] According to a preferred embodiment, the friction device, in particular the receiving disc, can form a rupture inhibition device. This means that the component, in particular the receiving disc, is extended such that it engages radially around the outside of the centrifugal pendulum and can be used as a rupture inhibition device. This has the advantage that no additional components need to be provided to form the rupture inhibition device. The receiving disc can be lengthened in a particularly suitable manner due to its structure without affecting other functions of the receiving disc or the centrifugal pendulum.

[0017] The receiving disc can preferably be designed as a potting sheet metal component. The sheet metal component can be brought into the desired pot shape in a particularly simple manner. Potting in particular means that the receiving disc has a radial section and an outer axial section as well as an inner axial section which extends in the axial direction from a radially inner end of the radial section, in particular towards the second axial side of the centrifugal pendulum. The radial section and the two axial sections thus form a U-shaped longitudinal cross section in which the one or more pendulum masses of the centrifugal pendulum are arranged (so that they are enclosed). The pot-like curvature of the receiving disc increases the stability of the receiving disc.

[0018] In particular, the receiving disc can be formed without cutting; for example, as a shaped component, preferably as a deep-drawn component. The geometry, in particular the U-shape and / or the S-shape, can thus be produced easily.

[0019] According to a preferred embodiment, the friction element can be accommodated in a non-rotatable manner on the axial section / receiving disc of the receiving disc, in particular of the rupture inhibition device, on its radially outer side. The friction element can thus be arranged more outward in the radial direction so that the friction surface is advantageously enlarged.

[0020] According to a preferred embodiment, the friction element can have protrusions protruding radially outward, which engage in corresponding recesses in the receiving disk to prevent rotation. In other words, the anti-rotation means are realized by recesses in the receiving disk and penetrations in the friction element. In this way, the friction element can be attached to the receiving disk in a form-fitting, non-rotatable manner, which is easy to produce.

[0021] According to a preferred embodiment, the receiving disk can alternatively (or additionally) have shaped regions protruding radially inward, for example in the manner of arc spring stops in a dual-mass flywheel, which engage in corresponding recesses in the friction element to prevent rotation. In this way, the friction element can be attached to the receiving disk in a form-fitting, non-rotatable manner, which is easy to produce.

[0022] According to a preferred embodiment, the friction element can rest axially against a radial section of the receiving disk. The fact that the friction element is supported over a large area on both sides advantageously prevents tilting of the friction element.

[0023] According to a preferred embodiment, the friction device can be of an axisymmetric design. In particular, the axis of symmetry of the friction device can correspond to the axis of symmetry of the mass region, for example intersecting orthogonally to the axis of rotation. This configuration has a particularly advantageous effect on the concentricity / unbalance compensation of the crankshaft section.

[0024] In one embodiment, the friction device can be designed to extend around in the circumferential direction. For example, the friction element can have a circular ring shape in cross section, i.e. the friction element can be designed as a friction ring. The rotationally symmetrical design of the friction element means that the friction element can be produced particularly inexpensively and is easy to assemble.

[0025] For example, the receiving disk can be designed as a pot metal sheet part. For example, the receiving disk is produced without cutting, for example as a shaped part, in particular a deep-drawn part. The receiving disk can preferably have two radial sections, which are connected to one another via an axial section, resulting in a longitudinal cross section of approximately S shape. The first (inner) radial section can serve as a fastening section for attachment to the crankshaft section. The second (outer) radial section can serve as a bearing section for axially bearing the spring element and / or the friction element. The receiving disk can be folded over at its radially outer end, i.e. the receiving disk can have an axial protrusion against which the friction element rests in the circumferential direction.

[0026] The spring element can be designed as a disc spring or a wave spring. In particular, the spring element can be attached to the receiving disk in a non-rotatable manner. For example, the spring element can be attached to the receiving disk in a non-rotatable manner by a rivet connection.

[0027] According to a preferred embodiment, the centrifugal pendulum can be dimensioned with respect to its mass and its position on the selected crankshaft section such that during operation, i.e. during rotation of the crankshaft section, the centrifugal pendulum has an unbalance compensation effect on the crankshaft section. This means that the centrifugal pendulum thus forms an unbalance compensation mass for the crankshaft / crankshaft section. Thus, the centrifugal pendulum replaces an unbalance mass (which would otherwise have to be provided, i.e. if the centrifugal pendulum were not present). It can thus be said that the unbalance occurring during rotation of the crankshaft section is mainly or completely compensated by the mass of the centrifugal pendulum and the selection of the fastening position of the centrifugal pendulum on the crankshaft section. This has the advantage that the centrifugal pendulum not only fulfills the actual counteracting function, but also serves as an unbalance compensation. Due to this dual action of the centrifugal pendulum, the total mass / total weight of the crankshaft assembly (or crankshaft) is not increased by the provision of the centrifugal pendulum. Since the centrifugal pendulum replaces the unbalance mass, the individual mass / individual weight of the crankshaft section is reduced due to the unbalance mass being replaced / eliminated by removing material, which in turn corresponds to the individual mass / individual weight of the added centrifugal pendulum. In short, the weight of the crankshaft remains the same with and without the centrifugal pendulum. In other words, the unbalance mass of the crankshaft has the additional function of a centrifugal pendulum.

[0028] According to a preferred embodiment, the crankshaft section can have a front-side recess for accommodating at least a portion of the centrifugal pendulum. This recess can in particular be dimensioned / have such dimensions that the recess has an unbalance compensation effect when the crankshaft section is rotated. This means that in particular so much material / mass is removed for the recess that the recess is again compensated by the provision of an additional component, i.e. the centrifugal pendulum. The recess can then be provided by machining or has already been provided in the blank on the crankshaft section. Thus, manufacturing costs can be saved.

[0029] According to a preferred embodiment, the volume of the recess can be at least partially compensated by the volume of the centrifugal pendulum. In other words, the recess is arranged such that the volume can be used to arrange a component such as the centrifugal pendulum.

[0030] In particular, the recess can be arranged substantially at the same height as the mass region of the crankshaft section in the axial direction. The recess can also be arranged substantially opposite the mass region in the circumferential direction. Furthermore, it can be advantageous to arrange the recess substantially at the same distance from the axis of rotation in the radial direction when the mass region, e.g. the center of gravity of the mass region, is located further away from the axis of rotation in another direction.

[0031] According to an advantageous embodiment, the centrifugal pendulum can have several pendulum masses. In particular, according to the advantageous embodiment, the pendulum masses can be arranged asymmetrically in the circumferential direction. The unbalance behavior of the crankshaft assembly is advantageously influenced by the non-uniform distribution in the circumferential direction. Furthermore, it can also be achieved that the area in which the pendulum masses move does not damage stress-critical regions of the crankshaft section.

[0032] Alternatively or additionally, according to a preferred embodiment, the center of gravity generated by the pendulum mass, particularly one or more pendulum masses, can be arranged in the circumferential direction in a manner substantially opposite to the mass region of the crankshaft section.

[0033] According to a preferred embodiment, a centering region for centrally accommodating a centrifugal pendulum can be formed on the radially outer periphery of the crankshaft section. This centering region can be provided later by machining or already provided in the blank of the crankshaft section. Therefore, manufacturing costs can be saved.

[0034] According to a preferred embodiment, a screw-in surface for attachment to the centrifugal pendulum can be formed on the axial end face of the crankshaft section. Due to the axial attachment, the required swing angle of the centrifugal pendulum can be achieved particularly easily. The screw-in surface can be machined later or already provided in the blank on the crankshaft section. Therefore, manufacturing costs can be saved. Preferably, threaded holes can be provided in the region of the screw-in surface of the crankshaft section so that the centrifugal pendulum (carrier) can be easily screwed in.

[0035] Particularly preferred is that if the screw-in surface is arranged radially outside the connection area of ​​the crankshaft segment, the connection area is designed to connect a second adjacent crankshaft segment to the crankshaft segment. This ensures that the crankshaft segment is not unacceptably weakened in its stress-critical region due to the tightening of the centrifugal pendulum. For example, the screw-in surface can be arranged circumferentially in a manner substantially opposite to the mass region of the crankshaft segment.

[0036] A further preferred embodiment is that the friction device and the centrifugal pendulum are attached to the crankshaft section via a common fastening device, for example, to a screw-in surface. This has the advantage that, for example, the number of threaded holes can be reduced, so that the crankshaft section is weakened as little as possible.

[0037] According to a preferred embodiment, the friction device can extend over a circumferential section of less than 360°. This means that the friction device is not designed to be completely circumferential in the circumferential direction. The circumferential direction is specifically defined relative to the axis of rotation of the crankshaft section. This has the advantage that the friction device can only be formed in the area where friction is required. Furthermore, a non-circular friction device has a favorable effect on compensating for imbalances caused by the crankshaft section. The peripheral section can preferably be between 90° and 270°, particularly between 180° and 270°.

[0038] According to a preferred embodiment, the at least one pendulum mass extends over a predetermined circumferential section. The circumferential section over which the friction device extends can in particular correspond to the predetermined circumferential section. The normal force / axial force and the friction element contact are thus provided by the friction device only in the region of the one or more pendulum masses. Furthermore, this has the advantage that the friction device does not require additional contact surfaces in the region in which the one or more pendulum masses are not formed.

[0039] According to an advantageous refinement, the friction device can be segmented, in particular in the form of substantially circular (annular) sectors. It has proven particularly advantageous for use in the crankshaft section to have this shape. The receiving disc can preferably be formed over a circumferential section of less than 360°, for example between 90° and 270°, in particular between 180° and 270°. Alternatively or additionally, the friction element can preferably be formed over a circumferential section of less than 360°, for example between 90° and 270°, in particular between 180° and 270°. Alternatively or additionally, the spring element can preferably be formed over a circumferential section of less than 360°, for example between 90° and 270°, in particular between 180° and 270°. The cover plate can preferably be formed over a circumferential section of less than 360°, for example between 90° and 270°, in particular between 180° and 270°.

[0040] According to a preferred embodiment, the friction device can be arranged in the circumferential direction substantially opposite the mass region of the crankshaft section which generates the unbalance and in particular is arranged eccentrically to the axis of rotation. This has the advantage that the mass of the friction device in the mass region can contribute to compensating the unbalance.

[0041] The friction device can be regarded as part of a centrifugal pendulum. This means that, according to a preferred embodiment, the mass of the centrifugal pendulum and / or the friction device is dimensioned and the position on the crankshaft section is chosen such that during operation, i.e. when the crankshaft section is rotating, the centrifugal pendulum and / or the friction device has an unbalance-compensating effect on the crankshaft section. In other words, the centrifugal pendulum and / or the friction device thus constitutes / forms an unbalance-compensating mass of the crankshaft / crankshaft section.

[0042] According to a preferred embodiment, the carrier of the centrifugal pendulum can extend in the circumferential direction on the side opposite the pendulum mass such that the friction device rests against the carrier. This means that the carrier forms an abutment for the friction device on the side opposite the pendulum mass in the circumferential direction. This has the advantage that one-sided loading and misalignment of the friction device can be avoided or counteracted even if the one or more pendulum masses are assembled asymmetrically in the circumferential direction in an angular range in which the friction device does not abut against the one or more pendulum masses. In other words, the missing abutment is compensated by the special geometry of the carrier of the centrifugal pendulum. Thus, a part of the carrier is provided to hold the one or more pendulum masses and the remaining part is designed such that it provides a contact surface for the friction device.

[0043] In particular, the friction element of the friction device can rest against (or be supported on) the carrier. This means that the friction element rests against the one or more pendulum masses in the first peripheral region and against the carrier in the other, in particular substantially opposite, second peripheral region. A one-sided loading on the friction element is thus avoided.

[0044] The friction device can preferably rest on at least one pendulum mass and on the carrier on the same axial side. This has the advantage that the normal force exerted by the spring element can be supported uniformly and / or over a (larger) area.

[0045] According to an advantageous refinement, the carrier can have a bearing section extending in the radial direction for receiving the at least one pendulum mass and a contact section extending in the radial direction for supporting the friction device. The bearing section and the contact section are preferably arranged spaced apart from one another in the axial direction. Thus, a flat contact surface for the friction device can be provided in an advantageous manner and at the same time the support of the pendulum mass on the carrier can be ensured.

[0046] According to an advantageous refinement, the axial distance between the bearing section and the contact section can substantially correspond to the thickness of the at least one pendulum mass. This has the advantage that the flat friction element can rest axially flush against the pendulum mass and the contact section or can be supported thereon.

[0047] According to an embodiment, the bearing section and the contact section can be connected by a connecting portion of the bracket such that the bracket has a substantially S-shaped shape in the longitudinal cross-section. This ensures sufficient stiffness and strength of the carrier.

[0048] In addition, it has proven advantageous if the contact section is formed by potting the carrier in the direction of the friction device. In this way, the carrier of the desired shape can be manufactured without any effort.

[0049] Furthermore, it is advantageous if the carrier is designed as a shaped sheet metal part. For example, the carrier can be produced without cutting. In particular, the carrier can be produced by stamping and shaping, for example by deep-drawing. Thus, the carrier can be produced inexpensively and in large quantities.

[0050] The cross section of the contact section can preferably have the shape of a circular arc. This has the advantage that the contact section provides a suitable contact surface for a friction element of simple shape.

[0051] In other words, the invention relates to a crankshaft assembly in which a centrifugal pendulum assembly is arranged on an unbalance compensation beam of a crankshaft section. Provided on the crankshaft section is a receptacle for the FKP UZSB, which is machined in the blank or has already been designed such that a centring seat, a screw-in surface and a region in which one or more pendulum masses can vibrate are provided. Arranged on the screw-in surface is a centrifugal pendulum carrier (flange), which is screwed into a threaded hole of the crankshaft section in a non-stress critical region. Additional friction acting on the centrifugal pendulum vibration movement is provided by a friction device, which improves the isolation of the natural frequency vibrations of the crankshaft and reduces the required pendulum angle. The friction device has a pot-encapsulated receptacle disc. On the one hand, a disc spring is supported on the receptacle disc and, on the other hand, a normal force acts on a friction element, which in turn rests on the pendulum mass. If necessary, a cover disc can also be provided between the disc spring and the friction element, such that the permissible surface pressure of the friction element is not exceeded. The friction element is designed so as not to be able to rotate with the receptacle disc, such that the friction point is fixed between the friction element and the pendulum mass. The pendulum masses are arranged asymmetrically in the circumferential direction, such that the pendulum masses serve to compensate for the unbalance in the crankshaft. In particular, a breakage suppression device can also be incorporated into the receptacle disc (support disc / mounting plate), for which purpose the mounting plate extends radially outwards and is pot-encapsulated on the centrifugal pendulum. Anti-twist protection between the mounting plate and the friction element (friction ring) can be achieved by means of recesses in the mounting plate and penetrations in the friction element, or alternatively by means of shaped regions in the mounting plate, which engage in corresponding recesses in the friction element. The friction device can preferably not be circumferential, but rather only designed as a ring section, whereby the normal force and the friction ring contact are provided in the required region of the pendulum mass and there is no exposed region of the friction device that needs to be supported. In this way, the mass in the unneeded region of the friction device is also eliminated, which can compensate for the unbalance caused by the mass of the crankshaft section that has been removed for the centrifugal pendulum. The receptacle disc, spring element, friction element and cover disc can be segmented / non-circumferential and only present in the region of the pendulum mass. Furthermore, in particular in the case of an asymmetric assembly of the pendulum masses in the circumferential direction, the carrier of the centrifugal pendulum can be designed such that it forms an abutment of the friction device. Thus, only a part of the carrier is provided for accommodating the pendulum masses and the remaining region is designed such that it provides a contact surface for the friction device. More preferably, this contact surface can be formed by an annular region that is pot-encapsulated in the direction of the friction device. BRIEF DESCRIPTION OF DRAWINGS

[0052] The invention is explained below with the aid of the drawings. In the drawings:

[0053] Figure 1 and Figure 2 a longitudinal sectional view and a plan view of a crankshaft assembly in a first embodiment are shown,

[0054] Figure 3 and Figure 4 longitudinal sectional view and a plan view of a crankshaft assembly in a second embodiment are shown,

[0055] Figure 5 and Figure 6 longitudinal sectional view and a plan view of a crankshaft assembly in a third embodiment are shown, and

[0056] Figures 7 to 9 longitudinal sectional view and a perspective view of a crankshaft assembly in a fourth embodiment are shown. DETAILED DESCRIPTION

[0057] The drawings are essentially schematic only and are intended to serve only for the purpose of facilitating the understanding of the present application. Identical elements are provided with identical reference signs. Features of the individual embodiments can be interchanged with one another.

[0058] Figures 1 to 9 Different embodiments of a crankshaft assembly 1 for a motor vehicle drive train are shown. The crankshaft assembly 1 has a crankshaft section 2. The crankshaft section 2 is in particular an axial section of a crankshaft. The crankshaft assembly 1 has a centrifugal pendulum 3 attached to the crankshaft section. The centrifugal pendulum 3 is used to absorb inherent frequency vibrations of the crankshaft or a main exciter command of the motor vehicle drive train.

[0059] The centrifugal pendulum 3 has a carrier 4 fixed to the crankshaft section. The carrier 4 is thus attached to the crankshaft section 2 in a non-rotatable manner. The centrifugal pendulum 3 has at least one pendulum mass 5. The pendulum mass 5 is attached to the carrier 4 such that the pendulum mass can be moved relative to the carrier 4 along a predetermined trajectory. The absorption effect of the centrifugal pendulum 3 is achieved by the relative movement between the pendulum mass 5 and the carrier 4. In the illustrated embodiment, the centrifugal pendulum 3 has a plurality of pendulum masses 5 arranged asymmetrically in the circumferential direction. The circumferential direction is defined relative to the axis of rotation of the crankshaft section 2.

[0060] The mass of the centrifugal pendulum 3 is dimensioned and its position on the crankshaft section 2 is arranged in such a way that the centrifugal pendulum 3 acts on the crankshaft section 2 to compensate for the unbalance during operation, i.e. when the crankshaft section 2 is rotating. The crankshaft section 2 has a mass region 6 which generates an unbalance during operation. The mass region 6 is arranged eccentrically with respect to the axis of rotation. The mass and the position of the centrifugal pendulum 3 are therefore matched to the mass and the position of the mass region 6. The centrifugal pendulum 3, in particular its pendulum mass 5, is arranged opposite the mass region 6 in the circumferential direction. The centrifugal pendulum 3 is arranged at the same height as the mass region 6 in the axial direction (with respect to the axis of rotation). The pendulum mass 5 is spaced apart from the axis of rotation at the same distance as the mass region 6. In other words, the centrifugal pendulum 3 acts as an unbalance compensation element for the mass region 6. This means that the centrifugal pendulum 3 (partially or completely) replaces the unbalance mass of the crankshaft section 2.

[0061] The crankshaft assembly 1 has a friction device 7 which is connected to the carrier 4. The friction device 7 is attached to the carrier 4 and / or to the crankshaft section 2 in a non-rotatable manner. The friction device 7 rests against at least one pendulum mass 5 such that the friction device 7 exerts a friction torque which impedes the relative movement on the pendulum mass 5 when the pendulum mass 5 moves relative to the carrier 4. The friction device 7 has a friction element 8 which rests against the pendulum mass 5. The friction device 7 has a receiving disc 9 which is connected to the carrier 4 in a non-rotatable manner. The friction element 8 is connected to the receiving disc 9 in a non-rotatable manner. The friction device 7 has a spring element 10 which is axially supported, in particular bears, between the friction element 8 and the receiving disc 9. The spring element 10 is designed as a disc spring or a bellows, for example. The spring element 10 exerts a normal force / axial force on the friction element 8 which axially presses the friction element 8 against the pendulum mass 5 such that a friction torque which impedes the relative movement arises when there is a relative movement between the friction element 8 which is fixed to the carrier and the at least one pendulum mass 5.

[0062] The crankshaft section 2 has an unbalance compensation beam 11. The unbalance compensation beam 11 is positioned opposite the mass region 6 in the circumferential direction. The crankshaft section 2 has a front recess 12 (in the unbalance compensation beam 11) for receiving at least a part of the centrifugal pendulum 3, in particular the pendulum mass 5. The recess 12 is dimensioned in such a way that the recess has an unbalance compensation effect when the crankshaft section 2 is rotating. In particular, the mass removed for the recess 12 corresponds to the mass added by the centrifugal pendulum 3.

[0063] The crankshaft section 2 has a connection region 13 which is designed to attach a (axially adjacent) second crankshaft section to the connection region. The connection region 13 is arranged centrally on the crankshaft section 2. The recess 12 is arranged radially outwardly with respect to the connection region 13. The crankshaft section 13 has a centring region 14 on its radially outer periphery for receiving the centrifugal pendulum 3 in a central manner. The crankshaft section 13 has a screw-in region / surface 15 on an axial end face, to which the centrifugal pendulum 3 / carrier 4 is fastened. The screw-in surface 15 is arranged radially outwardly with respect to the connection region 13. The centrifugal pendulum 3 is attached to the screw-in surface 15 axially via fastening means 16, in particular in the form of a plurality of screws. To this end, threaded holes are provided in the screw-in surface 15, into which the fastening means 16 are screwed.

[0064] The receiving disc 9 of the friction device 7 is designed as a pot-encapsulated sheet metal part. The receiving disc 9 has a (inner) first radial section 17 which serves as a fastening section. The radial section 17 is firmly attached to the carrier 4 and to the crankshaft section 2 via fastening means. An axial section 18 extends from the radially outer end of the first radial section 17 in the axial direction away from the crankshaft section 2 / screw-in surface 15. The axial section 18 extends radially on the inner side of the pendulum mass 5. An (outer) second radial section 19 extends outwardly in the radial direction from the axially distal end of the axial section 18. The receiving disc 9 thus has at least partially an S-shape. The spring element 10 and / or the friction element 8 are axially supported on the receiving disc 9 in the region of the second radial section 19. An axial protrusion 20 extends in the axial direction from the radially outer end of the second radial section 19 towards the pendulum mass 5. The spring element 10 and / or the friction element 8 are supported on the axial protrusion 20 in the circumferential direction.

[0065] In the embodiment shown, the centrifugal pendulum 3 has a plurality of pendulum mass packages. Each pendulum mass package has two pendulum masses 5 which are held axially parallel spaced apart by one or more spacer elements 21. The two pendulum masses 5 are connected to one another, for example by a rivet 22.

[0066] Figure 1 and Figure 2 A first embodiment of the crankshaft assembly 1 is shown. Figure 1A plan view is shown without the friction device 7. The carrier 4 has a central through-hole 23 via which the carrier 4 is centered on the centering region 14. In the first embodiment, the friction element 8 is designed as a friction ring which extends in the circumferential direction. The friction element 8 has a form-fit element 24 on its radially inner side which engages in a corresponding recess 25 in the receiving disc 9 in a form-fit manner for anti-twist protection. The friction element 8 is thus fastened radially on the inner side. The receiving disc 9 is designed to surround and extend in the circumferential direction. The second radial section 19 and / or the axial protrusion 20 has a rotationally symmetrical design.

[0067] Figure 3 and Figure 4 A second embodiment of the crankshaft assembly 1 is shown. Only the differences to the first embodiment are explained in the following. The friction device 7 has an additional cover disc 26 which is arranged in the axial direction between the spring element 10 and the friction element 8. The crankshaft assembly 1 has a breakage suppression device 27. The breakage suppression device 27 engages radially on the outside around the centrifugal pendulum 3. Thus, when the centrifugal pendulum 3 is rotated, loose parts are captured by the breakage suppression device 27. The breakage suppression device 27 is formed by the receiving disc 9. The second radial section 19 extends radially outwards such that it protrudes radially outwards beyond the pendulum mass 5. From the radially outer end of the second radial section 19, an outer axial section 28 extends in the axial direction towards the crankshaft section 2. The outer axial section 28 extends axially beyond the pendulum mass 5. This means that the axial protrusion 20 is lengthened in the axial direction at least in the peripheral region of the pendulum mass 5 in order to form the outer axial section 28. The pendulum mass 5 is accordingly potted by the receiving disc 9. In order to form the breakage suppression device 27, the receiving disc 9 has a U-shaped shape which axially engages around the pendulum mass 5 in a potting manner. The friction element 8 is fastened radially on the outside of the receiving disc 9 against rotation. For example, the friction element 8 and the receiving disc 9 engage with one another. The friction element 8 is supported in the radially inner region on the cover disc 26 and in the radially outer region on the receiving disc 9. The carrier 4 extends approximately in the shape of a crescent in the region of the pendulum mass 5.

[0068] Figure 5 and Figure 6A third embodiment of the crankshaft assembly 1 is shown. Only differences to the first or second embodiment are explained in the following. In the third embodiment, the friction device 7, in particular the receiving disk 9, the friction element 8, the spring element 10 and / or the cover disk 26, extends over a circumferential section which is less than 360°. This means that the friction device 7 is not designed to be completely circumferential in the circumferential direction. The peripheral section is between 90° and 270°, in particular between 180° and 270°. The peripheral section essentially corresponds to the predetermined peripheral section over which the pendulum mass 5 extends. The friction device 7 is segmented, in this embodiment shown in the form of a circular (ring) sector. The friction device 7 can be regarded as part of the centrifugal pendulum 3, so that the design, size and positioning of the friction device 7 also has an unbalance compensation effect on the crankshaft section 2 during operation.

[0069] Figures 7 to 9 A fourth embodiment of the crankshaft assembly 1 is shown. Only differences to the first, second or third embodiment are explained in the following. In the fourth embodiment, the carrier 4 of the centrifugal pendulum 3 extends in the circumferential direction on the side opposite the pendulum mass 5, so that the friction device 7 rests against the carrier 4. The carrier 4 thus extends in the radial direction and in the circumferential direction up to the mass region 6. The carrier 4 has a connecting section in the form of an axial potting 29 which connects a first radial section 30 adjacent to the pendulum mass 5 in the circumferential direction to a second radial section 31 adjacent to the mass region 6 in the circumferential direction. The second radial section 31 is potting towards the friction device 7. The first radial section 30 is arranged axially spaced apart from and parallel to the second radial section 31. The first radial section 30 serves as a bearing section for receiving the pendulum mass 5. The second radial section 31 serves as a contact section against which the friction device 7 rests. In particular, the friction element 8 rests against the second radial section 31 in one circumferential section on the same axial side and against the pendulum mass 5 in another circumferential section. The carrier 4 has a through-hole 32. The through-hole 32 is formed eccentrically. In the region adjacent to the pendulum mass 5 in the circumferential direction, the radially inner side / inner surface of the carrier 4 rests against the centering region 14. The through-hole 32 further extends radially outwards in the region adjacent to the mass region 6 in the circumferential direction, so that the carrier 4 rests against the crankshaft section 2 only over a circumferential section which is less than 360°.

[0070] Legend of the figures

[0071] 1 crankshaft assembly

[0072] 2 crankshaft section

[0073] 3 centrifugal pendulum

[0074] 4 carrier

[0075] 5 pendulum mass

[0076] 6 mass region

[0077] 7 friction device

[0078] 8 friction element

[0079] 9 receiving disc

[0080] 10 spring element

[0081] 11 unbalance compensation beam

[0082] 12 recess

[0083] 13 connecting region

[0084] 14 centering region

[0085] 15 screw-in surface

[0086] 16 fastening device

[0087] 17 first radial section

[0088] 18 axial section

[0089] 19 second radial section

[0090] 20 axial protrusion

[0091] 21 spacer element

[0092] 22 rivet

[0093] 23 through-hole

[0094] 24 form-fit element

[0095] 25 recess

[0096] 26 cover disc

[0097] 27 fracture-inhibiting device

[0098] 28 axial section

[0099] 29 potting

[0100] 30 first radial section

[0101] 31 second radial section

[0102] 32 through-hole

Claims

1. A crankshaft assembly (1) for a motor vehicle transmission system, the crankshaft assembly comprising a crankshaft section (2) and a centrifugal pendulum (3) fixed to the crankshaft section, the centrifugal pendulum having a carrier (4) fixed to the crankshaft section and at least one pendulum mass (5) movable relative to the carrier (4) along a predetermined track, characterized in that, The crankshaft assembly (1) has a fracture suppression device (27) that is radially engaged externally around the centrifugal pendulum (3) such that any loosened parts of the centrifugal pendulum (3) during rotation of the centrifugal pendulum (3) are collected by the fracture suppression device (27). The crankshaft assembly (1) has a friction device (7) that is connected to the support member (4) and rests against at least one of the pendulum masses (5) such that the friction device (7) applies a frictional torque to the pendulum mass (5) to impede relative motion as the pendulum mass (5) moves relative to the support member (4). The friction device (7) has a friction element (8) resting against the pendulum mass (5), a receiving disc (9) connected to the support member (4), and a spring element (10) axially supported between the friction element (8) and the receiving disc (9), wherein the receiving disc (10) forms the fracture suppression device (27).

2. The crankshaft assembly (1) according to claim 1, characterized in that, The rupture suppression device (27) has a radial section (19) extending radially outward on a first axial side of the centrifugal pendulum (3) and an axial section (28) extending axially from the radial section (19) to a second axial side of the centrifugal pendulum (3) on the radial outside of the centrifugal pendulum (3).

3. The crankshaft assembly (1) according to claim 1, characterized in that, The receiving plate (9) is designed as a potted metal plate component.

4. The crankshaft assembly (1) according to claim 1, characterized in that, The friction element (8) is received in the receiving disk (9) in a non-rotatable manner on the radially outer side of the friction element.

5. The crankshaft assembly (1) according to claim 4, characterized in that, The friction element (8) has a radially outward protrusion (24) that engages in a corresponding recess (25) in the receiving disc (9) to prevent rotation.

6. The crankshaft assembly (1) according to claim 1, characterized in that, The receiving disc (9) has a shaped area that protrudes radially inward and engages in a corresponding recess in the friction element (8) to prevent rotation.

7. The crankshaft assembly (1) according to claim 2, characterized in that, The friction element (8) is axially resting on the radial section (19) of the receiving disc (9).

8. The crankshaft assembly (1) according to claim 2, characterized in that, The axial section (28) extends over a circumferential section of less than 360°.

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