Friction clutch

Abstract

Friction clutch (2) for a motor vehicle comprising a pressure plate (4), one or more ring(s) (20, 21) bearing against the pressure plate (4), and a disc spring (40) comprising spring tongues (42) bearing against convex areas (22) of at least one ring (20, 21), wherein at least one ring (20, 21) has a first axial projection (24) which projects into a recess (44) of the disc spring (40).

Description

[0001] The invention relates to a friction clutch, in particular for a motor vehicle. The friction clutch comprises, in particular, a pressure plate, a ring resting against the pressure plate, and a disc spring having spring tongues resting against the ring. The invention further relates to a hybrid module comprising the friction clutch.

[0002] For example, friction clutches in the form of tractor double clutches are known, in which one of the partial clutches is essentially formed by a housing, a friction surface on an axially movable pressure plate, and a clutch disc located between them. The pressure plate is subjected to a contact force by a spring-loaded device, such as a diaphragm spring. The direction of the contact force is oriented such that the clutch disc is clamped between the friction surfaces of the pressure plate and the housing for torque transmission.

[0003] To open, i.e., to disengage, the partial clutch, its pressure plate must be moved against the force of the spring-loaded actuator. The disengagement operation is carried out directly on the pressure plate. A lever system is usually used for this. The diaphragm spring, for example, rests against the pressure plate with its inner edge. The axial counterforce of the diaphragm spring can then be supported by the outer edge of the diaphragm spring on a second pressure plate or on the housing. The spring tongues on the inner edge, for example, serve only to transmit the contact force by supporting themselves on the pressure plate.

[0004] It is common practice to provide a spring tongue of the disc spring, which rests against the pressure plate, with at least one slot to secure the disc spring relative to the adjacent pressure plate. At least one fixed pin protrudes from the pressure plate into the slot. This supports or secures the disc spring in the circumferential direction relative to the pressure plate.

[0005] It is known to use a ring for the contact or force transmission between the spring tongues and the pressure plate, which enables locally limited contact for the spring tongues. This can reduce wear on the contact surfaces between the disc spring and the pressure plate and force hysteresis. However, this ring is in design conflict with the aforementioned pin, since the pin must be positioned in the area of ​​the least possible deformation or movement of the spring tongues relative to the pressure plate to ensure permanent fixation. The ring and the pin are thus arranged on a circle of the same diameter, which has not yet been possible with a continuous or circumferentially closed ring.

[0006] Solutions that use an open or discontinuous ring and have only a single pin in the area where the ring is interrupted also provide unsatisfactory fixation of the disc spring to the pressure plate. For example, the disc spring can move translationally relative to the pressure plate due to tolerances and design constraints, which can create imbalance. Increasing the number of pins to further restrict this movement is also unsatisfactory, as it also makes the ring design more complex.

[0007] The object of the present invention is to provide solutions for achieving simple and reliable centering and anti-rotation locking of a disc spring relative to a pressure plate in a friction clutch. In particular, wear on the contact surfaces is to be reduced. Furthermore, potential force hysteresis is to be further reduced. In particular, the disadvantages of the prior art are to be avoided or at least significantly reduced.

[0008] According to the invention, the object is achieved by the features specified in claim 1 and 10, respectively. Advantageous developments of the invention are specified in the subclaims and described in the present application.

[0009] A friction clutch is proposed for a motor vehicle, preferably an agricultural vehicle, in particular a tractor, with a pressure plate, at least one ring resting on the pressure plate, and a disc spring comprising spring tongues resting on convex regions of at least one ring, wherein the ring has a first axial projection which projects into a recess in the disc spring. It is worth mentioning that two or more rings can also be provided. The second or the further rings can also rest on the pressure plate and have the convex regions for resting on the spring tongues and / or the first axial projection projecting into the recess in the disc spring, or several of these. In this case, at least one ring can be provided for transmitting the contact pressure force, and at least one other ring can be provided for fixing the disc spring relative to the pressure plate; ultimately, only one of the rings needs to have the first axial projection orthe first axial projections, while another may be flat annular or free of axial projections.

[0010] In other words, a friction clutch is proposed which has a pressure plate and at least one annular element (as the ring) which bears against or rests on it, and which has at least one disc spring which bears against or rests on sections of the annular element, for example sections which are round in cross-section, convex or bulbously curved (such sections typically arise with a ring which is round in cross-section). The disc spring usually bears against or on the plate with its spring tongues which typically project radially inwards. The annular element has a projection which extends in the axial direction and projects into the disc spring in order to achieve a positive connection between the projection and the disc spring - in particular in the circumferential direction.

[0011] The invention implements the idea that the disc spring is secured relative to the pressure plate using the ring. It is no longer necessary for the pressure plate (e.g., by means of a pin) to protrude axially into the disc spring itself. Thanks to the invention, movement of the disc spring is coupled, in particular, to movement of the ring, at least to the extent that the first stop in the recess of the disc spring comes into contact or strikes in the direction of movement.

[0012] This advantageously allows for a simpler design of the friction clutch, for example, because attaching the disc spring to the pressure plate requires fewer elements or machining steps. In particular, a friction clutch with reduced wear and reduced hysteresis is created, which is also lighter and more cost-effective to manufacture.

[0013] However, the advantages described here can generally be achieved in all applications in which a friction clutch is used.

[0014] The friction clutch is preferably designed for a motor vehicle, in particular for an agricultural vehicle, in particular its drive train. The friction clutch, i.e., at least the pressure plate, the ring, and the diaphragm spring, is / are assigned a common axis of rotation. The friction clutch is designed, in particular, for torque transmission between an engine and a transmission, as well as for separating the engine and transmission during operation, typically with respect to the aforementioned axis of rotation. The friction clutch can be a dual clutch or tractor dual clutch.

[0015] The pressure plate transmits a contact force in the motor vehicle, preferably to a friction disc, to enable torque transmission. The pressure plate can be designed, in particular, as a cast pressure plate. The pressure plate is preferably designed to be axially movable along the rotation axis. A friction surface and a clutch disc located between or on the friction surface are preferably arranged on one side of the pressure plate, and / or the disc spring is arranged together with the ring on the other side of the pressure plate. In particular, the disc spring, the pressure plate, and the ring are arranged at least substantially parallel to one another.

[0016] The diaphragm spring generates or transmits the contact force, which is then transferred via the pressure plate to transmit torque, for example, to a drive clutch. The diaphragm spring serves primarily as a spring accumulator. To open, i.e., disengage, the friction clutch, the pressure plate is moved against the contact force of the diaphragm spring.

[0017] The disc spring rests on the pressure plate, for example, with its inner edge and / or spring tongues. The axial counterforce of the disc spring can then be supported by the outer edge of the disc spring on a second pressure plate or on the housing.

[0018] A release actuation, in particular, acts directly on the pressure plate and can be carried out, for example, by a lever system. The pressure plate can be moved against the contact force of the disc spring. In particular, during release, the release system does not directly act on the disc spring. Thus, the spring tongues, which are preferably provided, are generally not used as levers for the release actuation. The spring tongues, which are preferably provided on the inner edge of the disc spring, serve only to transmit the contact force, particularly with support on the pressure plate.

[0019] The disc spring is preferably constructed as an at least substantially annular disc. In particular, the spring tongues protrude radially inward and / or radially outward, usually starting from a circumferentially closed disc-shaped section. The disc spring is in particular a sheet metal part and / or a stamped part and / or has parallel, opposite sides. The disc spring typically comprises steel or is made thereof and / or has a friction-reducing coating. The disc spring rests in particular with a radially inner region or inner edge on the pressure plate, preferably only via the ring, preferably indirectly. The spring tongues are particularly preferably provided on the inner region of the disc spring. The inner region of the disc spring serves in particular to transmit the contact pressure to the pressure plate by supporting it on the pressure plate. The contact pressure is in particular directed axially.

[0020] The disc spring has, in particular, a disc spring window between each two adjacent spring tongues. Depending on the orientation, the disc spring window is thus limited radially outwards (the typical case or when the spring tongues point radially inwards) or radially inwards (when the spring tongues point radially outwards). The disc spring window typically forms the recess of the disc spring. Typically, with a plurality of spring tongues, a corresponding plurality of disc spring windows or recesses are provided. However, it is also possible for the recess to be provided separately from the disc spring windows, for example in the manner of the slots described above. In particular, the recess extends axially through the disc spring and / or is U-shaped or V-shaped in axial plan view. In particular, the recess has opposite recess walls in the circumferential direction and a recess base in the radial direction.In any case, the recess is easy to provide, as it can simply be manufactured at the same time.

[0021] The ring serves in particular to reduce wear between the contact surface between the disc spring and the pressure plate. The ring serves in particular to reduce force hysteresis. The use of the wire ring can improve the contact between the disc spring and the pressure plate. Typically, the ring has a substantially round shape (in axial view) and / or a round cross-section (sectioned along the axis or axis of rotation). The cross-section can also have any other shape, provided that convex areas or a large convex area are present for the spring tongues. For example, the ring can be convex on one side and flattened on the other side. The ring typically comprises or is made of steel and / or has a friction-reducing coating. The ring is arranged in particular between the pressure plate and the disc spring.The ring preferably has a circular diameter in the region of the inner area of ​​the disc spring. In particular, the ring is formed with a closed, circumferential shape.

[0022] In particular, the ring is made from an annular semi-finished product without axial projections. The annular semi-finished product or the ring itself - in particular with the first axial projection or wide axial projections - typically has a first nominal plane and a second nominal plane. The second nominal plane is located away from the first nominal plane. The second nominal plane is usually directed towards the pressure plate. The first nominal plane is usually directed towards the disc spring. The nominal planes preferably at least substantially delimit the core of the ring, which is intended to rest on the pressure plate at least at the second nominal plane, and from which the axial projection (or several of them) are intended to protrude in the axial direction. Thus, for example, the first axial projection protrudes from the first nominal plane, starting from the area between the nominal planes, pointing towards the disc spring.For example, a second axial projection facing away from the first axial projection also projects from the area between the nominal planes, but on the side facing away from the first axial projection or towards the pressure plate.

[0023] It is possible to provide one or more of the spring tongues with at least one slot (so-called spring centering slot), which points in particular in the radially inner or outer direction and / or is open in that direction. A projection, in particular a pin, extending from the pressure plate and / or pointing axially towards the diaphragm spring can engage in the slot. In particular, the projection is fixed to the pressure plate. This makes it possible to fix the diaphragm spring, in particular to secure it against rotation, and in particular to center it (also: secure the axial position) relative to the pressure plate when using three or more pins and slots distributed around the circumference or arranged in a pattern. This is based on an otherwise known pin centering of a diaphragm spring in a clutch cover.

[0024] The slot or spring centering slot, or several of them, is / are particularly dispensable or not provided in the disc spring. Several of these particularly dispensable spring centering slots are typically evenly distributed in the circumferential direction within some spring tongues and / or extend at most over half the radial extent of a spring tongue and / or over a maximum of 10 mm.

[0025] In particular, the proposal at least eliminates the need for the projection or pin extending from the pressure plate to extend axially into the disc spring or its slots. Thanks to the first axial projection of the ring, it is sufficient, for example, for the projection or pin of the pressure plate to extend axially into the ring to secure it. This also saves material on the pin, and the disc spring does not need to be provided with the slot. Only the first axial projection needs to be provided.

[0026] The invention fundamentally improves the contact between the disc spring and the pressure plate by means of the ring, which has convex areas for supporting the disc spring. Wear on the contacting surfaces of the ring and disc spring, as well as force hysteresis, are reduced. In particular, manufacturing is simplified and made more cost-effective, and the disc spring is reliably secured and positioned relative to the pressure plate.

[0027] The first axial projection can be provided for engagement within the recess of the disc spring and / or against it. The engagement is intended to be in one circumferential direction, in both or opposite circumferential directions, and / or in the radial direction. Therefore, the engagement of the first axial projection can be provided, in particular, against one or both recess walls and / or against the recess base.

[0028] When an axial projection originating from a ring contacts a recess base (e.g., from the disc spring and / or the pressure plate), restoring forces can be provided to prevent imbalance at high speeds. This works particularly well if at least three circumferentially distributed axial projections are provided, each contacting a recess base. This avoids, in particular, the risk of excessive axial misalignment.

[0029] In a preferred embodiment, at least three first axial projections are provided. It is also possible to provide only two or more than three, for example four, five or six or more, first axial projections, in particular on one / the ring. The first axial projections preferably protrude, in particular distributed circumferentially, into one / the recess of the disc spring. The first axial projections can be provided to rest in the respective recess of the disc spring. The rest can be provided in an individually oriented manner for one, several or all axial projections (i.e., oriented circumferentially and / or radially as described above). In particular, if three or more first axial projections are present, the fixing of the disc spring, at least relative to the ring, in the form of a centering is advantageously enabled.

[0030] In a preferred embodiment, the ring or at least one of the rings or at least one ring has a second axial projection. According to the proposal, the second axial projection is directed away from at least the first axial projection or all of the first axial projections (in particular this ring). According to the proposal, the second axial projection projects into a recess in the pressure plate that is delimited in the circumferential direction. This recess is designed for abutment or bearing in a basically similar way to the recess of the disc spring and can therefore have recess walls and / or a recess base. The second axial projection is intended in particular for abutment or bearing in the recess of the pressure plate. Insofar as the ring thus has opposing axial projections, the ring can advantageously fix the disc spring relative to the pressure plate, in particular at least in the circumferential direction.

[0031] In a preferred embodiment, at least three second axial projections are provided. It is also possible to provide only two or more than three, for example four, five, six or more, second axial projections, in particular on one or more rings. The second axial projections preferably protrude, in particular distributed circumferentially, into one or more recesses in the pressure plate. The second axial projections can be provided to rest in the respective recess in the pressure plate. In particular, the resting position is provided in the circumferential direction. In particular, if three or more second axial projections are present, the fixing of the disc spring relative to the pressure plate in the form of a centering is advantageously enabled.

[0032] In a preferred embodiment, two rings are provided, in particular exactly two rings. One of the rings is at least substantially radially enlarged compared to the other ring, preferably with only one of the rings having the first axial projection, in particular all of the first axial projections, and / or with only one of the rings having the at least one second axial projection, in particular all of the second axial projections. It is possible for the radially inner ring or the first ring to be provided primarily for supporting the spring tongues and, for this purpose, to have one or the first and / or one or the first second axial projection (or several thereof) so that the ring is fixed relative to the pressure plate or the disc spring. It is furthermore possible for the radially outer ring or the second ring to be provided primarily for fixing in the form of centering the disc spring relative to the pressure plate and, for this purpose, to have one or morethe first axial projection (or several of them) so that the ring is centered relative to the pressure plate or the disc spring. In particular, the first axial projections can be provided to rest against the base of the recess, preferably for resilient or clamping contact. The contact pressure can be distributed across at least two rings and / or the fixing of the disc spring can be functionally assigned to at least one ring so that the other ring can be designed with respect to the contact pressure.

[0033] In a preferred embodiment, the ring is a wire ring. In particular, the ring is made of wire. The ring advantageously has a circumferentially round cross-section. Local deformation allows the axial projections to be easily incorporated into a wire ring.

[0034] In a preferred embodiment, at least one axial projection, i.e. the first and / or the second axial projection, in particular the first and / or the second axial projections, for example one, several or all thereof, is formed by a corrugation of the ring. A corrugation is to be understood in particular as a local curved region of the ring which locally causes a deviation from the actual annular shape of the ring. The curved region is particularly reminiscent of a wave with a rise and a descent if the circumferential course of the annular shape is followed. The corrugation typically has two opposite curved sections which are adjacent to one another or between which there may be an intermediate section, e.g. in the shape of a ring section.The corrugation can easily be produced by forming it into an annular semi-finished product for the ring, for example by locally forming the ring in the axial direction, in particular the axial and radial directions.

[0035] In a preferred embodiment, at least one axial projection is formed by a crimping of the ring and / or by a molding onto the ring. For example, the ring can be crimped in the radial direction to form bulges in the axial direction for the axial projection(s). For example, the axial projection can be attached to a semi-finished product for the ring; e.g., an originally separate part can be welded, soldered, and / or attached in another materially bonded manner.

[0036] In a preferred embodiment, the ring has a recess into which a projection of the pressure plate projects. The projection can be a pin of the pressure plate. The recess can be a passage such as a bore and / or a notch. The recess can also be an interruption in the ring. With the interruption, the ring is not circumferentially closed or has two head ends. These head ends can serve as stop points for a projection or pin of the pressure plate.

[0037] Various advantageous combinations of features regarding the number and design of the axial projections or rings are also possible in order to achieve synergies.

[0038] For example, two rings can be used as follows: A first ring, e.g., a wire ring, for contact force transmission and with at least three circumferentially evenly distributed first axial projections and with at least three circumferentially evenly distributed second axial projections for centering and anti-rotation. A second ring, e.g., with at least three circumferentially evenly distributed first axial projections resting against the base of the disc spring recess to reinforce or improve centering. The rings typically rest on the pressure plate in a recess each.

[0039] For example, two rings can also be used as follows: A conventional, e.g., smooth wire ring without corrugation can be used to transmit the contact pressure. A standard pin secures the wire ring and the disc spring against rotation. In particular, the ring has no axial projections. A second ring, e.g., a wire ring, with at least three first axial projections evenly distributed around the circumference, resting on the base of the disc spring recess, reinforces or improves centering. The rings typically rest on the pressure plate in a recess each.

[0040] For example, only one ring can be used as follows. The ring, e.g., a wire ring, for contact force transmission has at least three circumferentially evenly distributed first axial projections and at least three circumferentially evenly distributed second axial projections for centering and anti-rotation. Furthermore, at least three of the first axial projections can rest against the recess base of the disc spring to reinforce or improve centering.

[0041] Furthermore, a hybrid module is proposed. The hybrid module is intended for arrangement in a drive train of a motor vehicle, in particular a tractor. The hybrid module comprises, in particular, an electric machine or an electric motor and a clutch unit mechanically coupled to the electric machine for the mechanically separable transmission of torque between the electric machine and an internal combustion engine of the drive train that can be connected to the hybrid module. In particular, the clutch unit for the separable transmission of torque has the friction clutch described here.

[0042] In the context of this disclosure, the abbreviation "bzw." (respectively) is used as a short form for "respectively" and is generally intended to indicate alternative, essentially equivalent, and / or synonymous features or terms in order to convey the idea or meaning of a feature or term. "Respectively" can always be replaced with "and / or."

[0043] The invention is explained below by way of example with reference to the accompanying drawings using preferred embodiments, wherein the features presented below can represent an aspect of the invention both individually and in combination. Where reference numerals are identical in the figures, the description should be applied analogously. They show: Fig. 1A-D: a friction clutch for a tractor with a pressure plate, a disc spring and a ring in a sectional view parallel to a rotation axis (A), only an arrangement of the pressure plate, the disc spring and the ring in the sectional view (B), the arrangement in a partial plan view (C) and only the disc spring in a plan view (D), Fig. 2: another friction clutch in which a ring with first and second axial projections in the form of corrugations is provided, in a schematic sectional view through a rotation axis, Fig. 3: another friction clutch in which a ring with first and second axial projections in the form of pinches is provided, in a schematic sectional view through a rotation axis, Fig. 4: another friction clutch in which a ring with a first axial projection is provided, and in which the ring is fixed by a pin of the pressure plate projecting into a recess of the ring, in a schematic sectional view through a rotation axis, Fig. 5A-B: a ring with first axial projections in a perspective view (A) and in a side view cut parallel to a rotation axis, Fig. 6A-B: a ring with first and second axial projections in a perspective view (A) and in a side view cut parallel to a rotation axis, Fig. 7: a ring with crushing marks in a partial perspective view, Fig. 8: a ring with first axial projections in a perspective view, Fig. 9A-B: another friction clutch with two rings in a perspective view (A) and in a partial plan view (B), Fig. 10A-C: the friction clutch of the Fig. 9B in sectional views through a spring tongue (A) resting on the first ring, through a recess base with a radially adjacent first axial projection of the second ring (B) and through a spring tongue resting on the first ring and on the second ring at a first axial projection, and Fig. 11 a drive train of a motor vehicle, in particular a tractor, with a hybrid module having one of the preceding friction clutches.

[0044] Fig. 1A, Fig. 1B and Fig. 1C show part of a friction clutch 2. This is a tractor double clutch. The friction clutch 1 has a housing 12, a clutch disc 18, a pressure plate 4, a diaphragm spring 40, several actuating levers 16, and several pressure levers 17. In the closed state of the friction clutch 2 shown, the diaphragm spring 40 generates a contact pressure on the pressure plate 4 for torque transmission about a rotational axis 10. The diaphragm spring 40 is supported by its inner edge 41 on the pressure plate 4 via a ring 20 designed as a wire ring. The ring 20 is inserted in a radially limited and circumferentially extending groove or recess 7. An axial counterforce of the diaphragm spring 40 is supported by the outer edge 49 or diaphragm spring outer edge on the housing 12. A projection 8 in the form of a pin secures the disc spring 40 against twisting or fixes it relative to the pressure plate 4.Towards the rotation axis 10, the disc spring 40 can also abut with the inner edge 41 formed by spring tongues 42 or disc spring inner edge against radial stops 5 on the pressure plate 4 and is thus substantially centered relative to the pressure plate 4.

[0045] The disc spring 40 rests against convex regions 22 of the ring 20 via its spring tongues 42. Not shown is that the ring 20 has a first axial projection 24 that projects into a recess 44 of the disc spring 40.

[0046] Fig. 1B shows that the ring 20 rests, in particular, with its second nominal plane 27 on the pressure plate 4 or in its recess 7. A first nominal plane 25 serves to support the spring tongues 42. The two nominal planes 25, 27 particularly touch the convex regions 22. The ring 20 is located at least essentially or essentially between the nominal planes 25, 27.

[0047] Fig. 1C and Fig. 1D shows that the spring tongues 42 of the disc spring 40 form recesses 44 in the disc spring 40. The recesses 44 are U-shaped and, for this purpose, have recess walls 45, 46 and a recess base 47. The number of recesses 44 in the disc spring 40 corresponds, in particular, to the number of recesses 6 in the pressure plate. The recesses 6, 44 are aligned with one another. The recesses 44 point in radially inner directions or are open in that direction. Three circumferentially distributed slots 50 in the disc spring 40 or in the spring tongues 42 in the region of the inner edge 41 serve to accommodate the three projections 8.

[0048] In particular, the recess 44 of the disc spring 40 is limited in the circumferential direction U by its opposite recess walls 45, 46 and the recess base 47, e.g. so that a first axial projection 24 (not shown) can strike outwards in the circumferential direction U or in the radial direction.

[0049] Preferably, the recess 6 of the pressure plate 4 is limited in the circumferential direction U by its opposite recess walls 35, 36, e.g. so that a second axial projection 26 (not shown) can abut in the circumferential direction U.

[0050] Fig. Figure 2 shows an embodiment of a friction clutch 2 similar to that shown in Fig. 1A-D and described above. The friction clutch 2 is shown here in a highly simplified manner in order to focus on a function of the ring 20 in the friction clutch 2. In this embodiment, the ring 20 has both first axial projections 24 and second axial projections 26, which are each distributed circumferentially along the ring 20. The first axial projections 24 point towards the plate spring 40 and protrude into a recess 44 in the plate spring 40. The second axial projections 26 point towards the pressure plate 4 and protrude into a recess 6 in the pressure plate 4. With this arrangement, the plate spring 40 is fixed relative to the pressure plate 4, in particular in the circumferential direction U and in the form of a centering. The axial projections 24, 26 strike the recesses 44 and 6, respectively, upon corresponding movement of the disc spring 40 relative to the pressure plate 4, more precisely on the recess walls 35, 36, 45, 46.The axial projections 24, 26 are designed in particular as corrugations.

[0051] In particular, the first axial projections 24 and the second axial projections 26 are arranged alternately with one another in the circumferential direction U of the ring 20. In particular, an equal number of first 24 and second axial projections 26 is provided.

[0052] Fig. 3 shows a further embodiment of a friction clutch 2 similar to that of Fig. 2. The axial projections 24, 26 are designed as pinches.

[0053] The axial projections 24, 26 are arranged in a special pattern. For example, one of the first axial projections 24 faces the recess wall 45, while another of the first axial projections 25 faces the recess wall 46 in another recess 44 of the disc spring 40. For example, one of the second axial projections 26 faces the recess wall 35, while another of the first axial projections 25 faces the recess wall 36 in another recess 6 of the pressure plate 4.

[0054] Fig. 4 shows a further embodiment of a friction clutch 2 similar to that of Fig. 2. However, no second axial projections 26 are provided here. The ring 20 is secured by a projection 8 in the form of a pin that protrudes axially from the pressure plate 4. The projection 8 engages a recess 28 of the ring 20, where the ring 20 is split.

[0055] Fig. 5A and Fig. 5B show a ring 20 having eight first axial projections 24 in the form of corrugations, which are intended to project into recesses 44 of a disc spring 40 (not shown). The ring 20 has a round, more precisely circular, cross-section. The ring 20 is made of a wire ring. In the figure, the first axial projections 24 protrude from the upper side from a nominal plane designated 25. The lower nominal plane, numbered 27, is free of axial projections. The nominal planes 25, 27 delimit the core of the ring 20. The lower nominal plane 27 in the figure is intended to rest on a pressure plate 4. A disc spring 40 can rest essentially on the first nominal plane 25. However, the ring 20 can also be placed the other way around on a pressure plate 4, which influences the understanding of the first 24 and second axial projections 26.

[0056] In an alternative interpretation of Fig. 5A and Fig. 5B, no first axial projections 24 are provided, but only second axial projections 26. However, the areas between the axial projections 24 and 26 could also be designed as axial projections.

[0057] In particular, the axial projections 24, 26 are essentially characterized by their more localized and circumferentially distributed configuration compared to the rest of the ring 20, 21. In other words, axial projections 24, 26 are typically smaller in relation to the extent in the circumferential direction U compared to the adjacent remainder of a ring 20, 21.

[0058] Fig. 6A and Fig. 6B show a ring 20 having eight first axial projections 24 and eight second axial projections 26 in the form of corrugations, which are intended to project into a recess 44 of a disc spring 40 or into a recess 6 of a pressure plate 4. The ring 20 has a round, more precisely circular, cross-section. The ring 20 is made of a wire ring. In the figure, the first axial projections 24 protrude from the top side of the first nominal plane 25. The second axial projections 26 protrude from the bottom side of the second nominal plane 27. The nominal planes 25, 27 delimit the core of the ring 20. The second nominal plane 27 is intended to rest on a pressure plate 4. A disc spring 40 can rest essentially on the first nominal plane 25.

[0059] Fig. Figure 7 shows a section of a ring 20 with radial crimps. The crimps protrude on both sides in the axial direction. The crimps therefore form both first axial projections 24 and second axial projections 26.

[0060] Fig. 8 shows a ring 20 with axially directed projections, which in this case are provided as first axial projections 24, and in particular without second axial projections 26. By way of example, a total of twelve of the first axial projections 24 are provided, wherein, by way of example, a first and a second form of the axial projections 24 are arranged alternately in a manner distributed in the circumferential direction U. The first form is, by way of example, smaller in the axial direction than the second form. The first form serves, by way of example, for abutment in the circumferential direction U in recesses 44 of a (not shown) disc spring 40, more precisely against the opposite recess walls 45, 46 thereof. The second form serves, by way of example, for abutment in the radial direction in recesses 44 of a disc spring 40, more precisely against the recess base 47. The second form can clamp the disc spring 40 in the radial direction in order to enforce centering.

[0061] Fig. 9A and Fig. Figure 9B shows a friction clutch 2 with two rings 20, 21, more precisely with a first ring 20 and a second ring 21. The first ring 20 is arranged radially inwardly opposite the second ring 21 and has both first 24 and second axial projections 26. The first ring 20 can be, for example, the one shown in Fig. 2 or Fig. 6A and Fig. 6B is ring 20 shown as an example.

[0062] The second ring 21 also has, for example, first 24 and second 26 axial projections, for example, some of the first axial projections 24 in the radial direction causing a clamping of the disc spring 40 for centering, as the sectional view in Fig. 10B with respect to the first axial projection 24 of the second ring 21 in contact with a recess base 47. In particular, the remaining or smaller of these first axial projections 24 of the second ring 21 in the circumferential direction U provide a further stop for the disc spring 40, as the sectional view in Fig. 10C shows. In contrast, the Fig. 10A shows the initial position of the two rings 20, 21, in which the rings 20, 21 rest with their first nominal planes 25 on the pressure plate 4 in a respective recess 7. The respective deflection in the axial projections 24, 26 is shown in relation to the deviation from the nominal planes 25, 27 in Fig. 10B and Fig. 10C.

[0063] Fig.11 shows a hybrid module 100 in a motor vehicle. The hybrid module 100 has a clutch unit 102 and an electric motor 104. The clutch unit 102 has a friction clutch 2 according to the invention. The hybrid module 100 is arranged in the schematically sketched drive train 200 of the motor vehicle and can absorb the torque from an internal combustion engine 202 via the friction clutch 2 or transmit it to the transmission and / or wheel drive, in particular supported by the integration of the electric motor 104 in the form of an electric motor. The electric motor can recuperate, assist the internal combustion engine 202, and drive the motor vehicle independently. List of reference symbols 2 friction clutch 4 pressure plate 5 radial stop of the pressure plate 6 Recess of the pressure plate 7 Recess of the pressure plate 8 Projection of the pressure plate 10 Rotation axis 12 housings 16 operating levers 17 pressure lever 18 Clutch disc 20 rings 21 rings 22 convex area 24 first axial projection 25 first nominal level 26 second axial projection 27 second nominal level 28 Return 35 Recess wall of the pressure plate 36 Recess wall of the pressure plate 40 disc spring 41 inner edge 42 spring tongue 44 Recess of the disc spring 45 Recess wall 46 Recess wall 47 Reason for exception 49 Outer edge 50 slot 100 hybrid modules 102 Coupling unit 104 electric machine 200 Powertrain U circumferential direction

Claims

[1] Friction clutch (2) for a motor vehicle with a pressure plate (4), one or more rings (20, 21) resting on the pressure plate (4), and a disc spring (40) comprising spring tongues (42) resting on convex regions (22) of at least one ring (20, 21), wherein at least one ring (20, 21) has a first axial projection (24) which projects into a recess (44) of the disc spring (40). [2] Friction clutch (2) according to claim 1, wherein at least three pieces of the first axial projection (24) are provided, which project circumferentially distributed into a respective recess (44) of the disc spring (40), preferably which are provided for abutting in the respective recess (44) of the disc spring (40). [3] Friction clutch (2) according to one of the preceding claims, wherein at least one ring (20, 21) has a second axial projection (26) which is directed away from at least one first axial projection (24), preferably which projects into a circumferentially limited recess (6) of the pressure plate (4), in particular which is provided for abutting in the recess (6) of the pressure plate (4). [4] Friction clutch (2) according to claim 3, wherein at least three pieces of the second axial projection (26) are provided, preferably which project circumferentially distributed into a respective recess (6) of the pressure plate (4), in particular which bear in the respective recess (6) of the pressure plate (4). [5] Friction clutch (2) according to one of the preceding claims, wherein one of the rings (21) is radially enlarged compared to the other ring (20), preferably wherein only one of the rings (20, 21) has the first axial projection (24), in particular all of the first axial projections (24), and / or wherein only one of the rings (20, 21) has the at least one second axial projection (26), in particular all of the second axial projections (26). [6] Friction clutch (2) according to one of the preceding claims, wherein the ring (20, 21) is a wire ring. [7] Friction clutch (2) according to one of the preceding claims, wherein at least one axial projection (24, 26) is formed by a corrugation of the ring (20, 21). [8] Friction clutch (2) according to one of the preceding claims, wherein at least one axial projection (24, 26) is formed by a pinch of the ring (20, 21) and / or by a molding on the ring (20, 21). [9] Friction clutch (2) according to one of the preceding claims, wherein the ring (20, 21) has a recess (28) into which a projection (8) of the pressure plate (4) projects, in particular wherein the recess (28) is an interruption of the ring (20, 21). [10] Hybrid module (100) for arrangement in a drive train (200) of a motor vehicle, in particular a tractor, comprising an electric machine (104) and a clutch unit (102) mechanically coupled to the electric machine (104) for the mechanically separable transmission of a torque between the electric machine (104) and an internal combustion engine (202) of the drive train (200) connectable to the hybrid module (100), wherein the clutch unit (102) for the separable transmission of the torque has the friction clutch (2) according to one of the preceding claims.

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