FRICTION CLUTCH HAVING A ROTATIONAL AXIS

Abstract

A friction clutch for releasable transmission of a torque between a first drive unit and a second drive unit includes a rotational axis, a friction package for transmitting the torque in a pressed state, a first actuating element, and a second actuating element. The friction package has at least one friction plate and at least one friction disk. The first actuating element is arranged on a first side of the friction package for pressing the friction package in a first axial actuating direction to achieve the pressed state, and the second actuating element is arranged on a second side of the friction package, opposite the first side, for pressing the friction package in a second axial actuating direction, opposite the first axial actuating direction, to achieve the pressed state.

Claims

1.-10. (canceled)

11. A friction clutch for releasable transmission of a torque between a first drive unit and a second drive unit, comprising: a rotational axis; a friction package for transmitting the torque in a pressed state, comprising at least one friction plate; and, at least one friction disk, a one of the at least one friction plate or the at least one friction disk arranged for connection to the first drive unit, and the other of the at least one friction plate or the at least one friction disk arranged for connection to the second drive unit; a first actuating element arranged on a first side of the friction package for pressing the friction package in a first axial actuating direction to achieve the pressed state; and, a second actuating element arranged on a second side of the friction package, opposite the first side, for pressing the friction package in a second axial actuating direction, opposite the first axial actuating direction, to achieve the pressed state.

12. The friction clutch of claim 11 wherein: the first actuating element comprises a pressing spring arranged such that a maximum pressing force of the first actuating element is less than a maximum pressing force of the second actuating element.

13. The friction clutch of claim 11, further comprising a spacing spring, wherein: the at least one friction plate comprises a first friction plate and a second friction plate, adjacent to the first friction plate, and the spacing spring is disposed between the first friction plate and the second friction plate for pushing the first friction plate and the second friction plate axially apart from one another; or, the at least one friction disk comprises a first friction disk and a second friction disk, and the spacing spring is disposed between the first friction disk and the second friction disk for pushing the first friction disk and the second friction disk axially apart.

14. The friction clutch of claim 13 wherein the spacing spring is formed as a corrugated washer.

15. The friction clutch of claim 13 further comprising an outer basket and an inner basket, wherein: the at least one friction plate is hooked in the outer basket and arranged to be fixed rotationally and displaced axially; and, the at least one friction disk is hooked on the inner basket and arranged to be fixed rotationally and displaced axially.

16. The friction clutch of claim 15, further comprising: a ball ramp apparatus comprising: an outer ramp ring; an inner ramp ring; and, an actuating length, adjustable by a relative rotation of the inner ramp ring with respect to the outer ramp ring to achieve a minimum actuating length and a maximum actuating length; and, a freewheel comprising: an input side connected to the inner ramp ring of the ball ramp apparatus; and, an output side connected to the at least one friction disk, wherein the freewheel is arranged to transmit the torque when inner ramp ring is rotated faster than the at least one friction disk, and the freewheel is arranged to be disconnected when the inner ramp ring is rotated slower than the at least one friction disk; wherein: the second actuating element is arranged between the friction package and the outer ramp ring of the ball ramp apparatus; the second actuating element is arranged to be disengaged when the ball ramp apparatus actuating length is at the minimum actuating length; and, the second actuating element is arranged to be engaged when the ball ramp apparatus actuating length is at the maximum actuating length.

17. The friction clutch of claim 16, further comprising an axial bearing on the outer basket, wherein: the freewheel comprises a freewheel pot on the input side; and, the inner ramp ring is indirectly supported on the axial bearing by the freewheel pot.

18. The friction clutch of claim 16, further comprising a pressure pot arranged between the outer ramp ring and the friction package, the pressure pot being hooked in the outer basket and arranged to be fixed rotationally and displaced axially.

19. The friction clutch of claim 16, wherein: the inner basket and the freewheel input side each comprise a through opening; the through openings can be aligned so as to be flush with respect to one another or so as to cover one another; and, when aligned to be flush, the through openings are arranged to guide a screwing instrument so that the friction clutch can be screwed to an output shaft of the first drive unit or the second drive unit.

20. A hybrid module for a drive train, comprising: the friction clutch of claim 11, wherein the first drive unit is an electric motor.

21. The hybrid module of claim 20, further comprising the second drive unit, wherein the first drive unit is arranged to provide the torque to the second drive unit when the friction package is in the pressed state.

22. The hybrid module of claim 20 wherein the at least one friction disk is connected to the first drive unit.

23. A hybrid module for a drive train, comprising: the friction clutch of claim 16, wherein the first drive unit is an electric motor connected to the output side of the freewheel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The above-described embodiments will be explained in detail in the following text against the relevant technical background with reference to the associated drawings which show example refinements. The disclosure is not restricted in any way by the purely diagrammatic drawings; it is to be noted that the drawings are not to scale and are not suitable for defining proportions. In the drawings:

[0052] FIG. 1 shows a sectional view of one exemplary embodiment of the friction clutch, and

[0053] FIG. 2 shows a drive train in a motor vehicle with a friction clutch.

DETAILED DESCRIPTION

[0054] FIG. 1 relates to one exemplary embodiment of an assembly of a dual mass flywheel, a friction clutch 27 for coupling and decoupling an internal combustion engine (second drive unit 30) to and from a drive train of a hybrid vehicle 33, and an electric machine (first drive unit 29), also called an electric motor or electric traction motor. The drive units 29 and 30 are shown in FIG. 2. Features which are not characterized as being essential to the present description are to be understood to be optional. Therefore, the following description also relates to further exemplary embodiments of the drive train, for example of a hybrid vehicle 33, which have part combinations of the features which will be explained in the following text. In particular, the following description relates to exemplary embodiments of the friction clutch 27.

[0055] A primary side 2 of a dual mass flywheel 36 is provided on the input side of the detail (shown in FIG. 1) of a drive train 32 (cf. FIG. 2) of a hybrid vehicle 33 with a fastening 1 for attaching to a crankshaft of an internal combustion engine (not shown) which forms the second drive unit 30. A secondary side 3 of the dual mass flywheel 36 has a centrifugal force pendulum 4. Together with the drive train 32, the friction clutch 27 is mounted rotatably about a rotational axis (D), also called an axis of rotation 28. The secondary side 3 of the dual mass flywheel 36 is connected to an outer basket 5 of the friction clutch 27.

[0056] The friction clutch 27 is configured for coupling and decoupling the internal combustion engine 30 to and from the drive train 32 of the hybrid vehicle 33, and is also called a K0 clutch. Here, the friction clutch 27 is configured as a dry multiple disk clutch and can be engaged by means of an external actuator device (not shown), for example a concentric slave cylinder (CSC), in overrun mode for starting the internal combustion engine 30 or for the utilization of the engine brake. In addition to the outer basket 5, the friction clutch 27 has an inner basket 6 which is arranged within the outer basket 5 in the radial direction 45 (R) of the friction clutch 27, and a friction pairing 10 which is arranged between the outer basket 5 and the inner basket 6. In the engaged state, a torque can be transmitted from the outer basket 5 to the inner basket 6 by way of the friction pairing 10. Furthermore, the friction clutch 27 has a second actuating element (here, a first pressure pot 16), by way of which the friction pairing 10 can be engaged in the axial direction 42 (A) of the friction clutch 27 in a second actuating direction 43 (B1), and a first actuating element (here, a second pressure pot 17), by means of which the friction pairing 10 can be engaged in a first actuating direction 44 (B2) which is directed counter to the second actuating direction 43.

[0057] The first pressure pot 16 is operatively connected to a ball ramp device 19, by way of which part of a torque which prevails on an output side of the friction clutch 27 can be converted into a (second) pressing force which acts in the second actuating direction 43 (B1).

[0058] The second pressure pot 17 can be actuated radially on the inside by way of the abovementioned actuator device (not shown) in the first actuating direction 44 (B2), in order for it to be possible to engage the friction pairing 10 independently of the first pressure pot 16. The first pressure pot 16 is also likewise capable of engaging the friction pairing 10 independently of the second pressure pot 17.

[0059] The ball ramp device 19 is arranged in the radial direction 45 (R) and/or in the axial direction 42 (A) within the friction clutch 27, for example, within the outer basket 5 and/or within the friction pairing 10. Furthermore, the ball ramp device 19 is supported here in the axial direction 42 (A) via an axial bearing 23 such that it can be rotated on the outer basket 5. The ball ramp device 19 has at least one outer ramp ring 21 which is attached on the first pressure pot 16, and at least one inner ramp ring 20 which is supported indirectly or directly on the axial bearing 23. Balls 22 are, for example, arranged between the inner ramp ring 20 and the outer ramp ring 21 in the circumferential direction of the friction clutch 27.

[0060] A freewheel 24 is arranged in the radial direction 45 (R) within the inner basket 6, by which freewheel 24 the torque can be transmitted in a rotational direction to the ball ramp device 19, for example, via a freewheel pot 25, in order to engage the friction pairing 10 in the first actuating direction 43. The inner ramp ring 20 is supported via the freewheel pot 25 on the axial bearing 23. An outer ring (that is to say, the output side) of the freewheel 24 is arranged fixedly in a hub 7 so as to rotate with it, which hub 7 is connected fixedly to the inner basket 6 as to rotate with it or is configured in one piece with the inner basket 6. As an alternative, the inner basket 6 can also be configured in one piece with the hub 7. The hub 7 can be connected to a first output shaft 34 of the first drive unit 29, for example, via a spline toothing system 8.

[0061] The freewheel pot 25 and/or the hub 7 have/has at least one screw opening 26 which extends in the axial direction 42 (A) and is configured to make the screw connection possible of the outer basket 5 or a component which is connected to the outer basket 5, for example the dual mass flywheel 36, that is to say the primary side to of the dual mass flywheel 36, to a second output shaft of a second drive unit 30, for example a crankshaft of an internal combustion engine. Here, that detail of the assembly which is shown can be connected to the second output shaft in a manner which is preassembled in this way.

[0062] The friction pairing 10 can have dry-running outer disks 11 and inner disks 12 which alternate in the axial direction 42. Of the outer disks 11 and the inner disks 12, a first end disk 13 is in contact with the first pressure pot 16, and a second end disk 14 which lies opposite the first end disk 13 in the axial direction 42 is in contact with the second pressure pot 17. The outer disks 11, including the two end disks 13 and 14 in the exemplary embodiment which is shown, are fastened fixedly to the outer basket 5 so as to rotate with it, whereas the inner disks 14 are fastened fixedly to the inner basket 6 so as to rotate with it, in each case spline toothing systems being used, for example. Moreover, the outer disks 11 and/or the inner disks 12 can be moved in the axial direction 42 (A) by way of the pressure pots 16 and 17. The first pressure pot 16 is arranged in the axial direction 42 (A) between the outer basket 5 and the first end disk 13.

[0063] In each case at least one corrugated washer 15 is arranged between adjacent outer disks 11 and/or between adjacent inner disks 12, which corrugated washer 15 has a corresponding prestress, in order to disconnect the disks 11 and 12 in the case of a disengaged friction pairing 10. A securing ring 18 is set up to bear against the second end disk 14 and secures the disks 11 and 12, in particular the outer disks 11 to the open side of the outer basket 5.

[0064] A rotor 9 of an electric machine or an electric motor 29 is connected fixedly to the first output shaft 34 so as to rotate with it, which first output shaft 34 is plugged into the spline toothing system 8 of the hub 7. Therefore, the rotor 9 is connected fixedly to the inner basket 6 so as to rotate with it. Furthermore, the first output shaft 34 can be configured as a transmission input shaft or can be connected to a torque converter or a start-up clutch (single clutch or double clutch).

[0065] The electric machine 29 or the electric motor may be configured as an electric traction motor which can be operated not only in a driving mode, but rather also in a generator mode.

[0066] Although this is not shown, it is advantageous if the friction clutch 27 is received in the radial direction 45 (R) and/or in the axial direction 42 (A) at least partially within the rotor 9, for example by the rotor 9 being of pot-shaped configuration and extending, in relation to FIG. 1, in the radial direction 45 (R) outside the outer basket 5 (to the right in the illustration) in the direction of the dual mass flywheel 36. It is possible as a result to reduce the axial installation space.

[0067] In the case of electric driving, coasting or recuperation, the friction clutch 27 is disengaged and the internal combustion engine 30 is not driven in a coupled manner. In order to reduce the drag torque to a minimum, the multiple disks 11 and 12 are spaced apart uniformly by way of the corrugated washers 15.

[0068] In order to generate an overrun torque (internal combustion engine start/engine brake), the multiple disks 11 and 12 are actuated directly via the second pressure pot 17 by means of an input from the outside and by means of external energy, and are pressed to the left in relation to FIG. 1. Here, the second pressure pot 17 has a certain softness, in order for it to be possible to adjust the pressing force and therefore the torque cleanly.

[0069] When the internal combustion engine is running and catches up with the electric traction motor (the rotational speed of the internal combustion engine and the rotational speed of the electric traction motor are identical), the freewheel 24 engages, by way of which part of the torque is transmitted to the inner ramp 20 of the ball ramp device 19. This results in a relative rotation of the ramp rings 20 and 21 with respect to one another, that is to say twisting of the ball ramp device 19.

[0070] By way of the relative rotation of the ball ramp device 19, its (minimum) actuating length 48 is increased to a (maximum) actuating length 49 and an axial force is generated, by way of which the friction clutch 27 remains permanently closed in the traction mode of the internal combustion engine 30. During this operation, the multiple disks 11 and 12 are moved to the right in relation to FIG. 1, until the second end disk 14 is present at the securing ring 18. The friction clutch 27 is therefore closed without energy in the traction mode.

[0071] If the internal combustion engine 30 is no longer required, the fuel supply is interrupted, for example. As soon as the rotational speed of the internal combustion engine 30 is lower than the rotational speed of the electric traction motor 29, the friction clutch 27 opens automatically, corrugated washers 15 which are arranged between the multiple disks 11 and 12 pressing the individual multiple disks 11 and 12 apart from one another and in the process rotating the ball ramp device 19 back into its relative starting position, with the result that there is again a minimum actuating length 48.

[0072] During electric driving, coasting and recuperation, the K0 clutch is disengaged, in order for it not to be necessary to drive the internal combustion engine in a coupled manner.

[0073] It is an advantage in the case of said arrangement that, during the transition from the overrun mode into the traction mode, the friction clutch 27 does not open, but rather merely a movement of the multiple disks 11 and 12 (from the left to the right in FIG. 1) takes place.

[0074] The preceding exemplary embodiments relate to a K0 clutch which is integrated into the rotor and can be actuated via an actuator device (electrically, hydraulically or pneumatically) in order to generate an overrun torque. In the traction mode, the transmission of torque takes place without energy via the freewheel 24 which is configured as a pilot control element of the ball ramp device 19. The main torque is transmitted via the friction pairing 10.

[0075] FIG. 2 shows a drive train 32 in a hybrid vehicle 33. The drive train has a first drive unit 29, e.g., an electric motor which is set up as a traction motor, and a second drive unit 30, e.g., an internal combustion engine, which drive units can be operated in each case individually or in series. To this end, a friction clutch 27 is arranged between the two drive units 29 and 30, for example, as described above. This entire drive unit is connected in a torque-transmitting manner to a left-hand drive wheel 37 and a right-hand drive wheel 38, the connection being shown diagrammatically here and necessary intermediate elements not being shown. The drive unit is arranged in front of the driver's cab 39 with the motor/engine axis 41 transversely with respect to the longitudinal axis 40.

[0076] Advantageous interaction of an internal combustion engine and an electric motor is ensured mechanically by way of the friction clutch which is proposed here for a hybrid module.

[0077] According to the disclosure, the following embodiments are proposed, furthermore:

[0078] 1. A friction clutch (27) for coupling and decoupling an internal combustion engine to and from a drive train of a hybrid vehicle, having an outer basket (5) and an inner basket (6) which is arranged within the outer basket (5) in the radial direction (R) of the friction clutch (27), and a friction pairing (10) which is arranged between the outer basket (5) and the inner basket (6), and by way of which friction pairing (10) a torque can be transmitted from the outer basket (5) to the inner basket (6) in the engaged state, the friction clutch (27) having a first pressure pot (16), by way of which the friction pairing (10) can be engaged in the axial direction (A) of the friction clutch (27) in a first actuating direction (B1), and the friction clutch (27) having a second pressure pot (17), by way of which the friction pairing (10) can be engaged in a second actuating direction (B2) which is directed counter to the first actuating direction (B1).

[0079] 2. The friction clutch (27) as described in embodiment 1, the first pressure pot (16) being operatively connected to a ball ramp device (19), by way of which a torque which prevails on an output side of the friction clutch (27) can be converted into a force which acts in the first actuating direction (B1).

[0080] 3. The friction clutch (27) as described in embodiment 2, the ball ramp device (19) being arranged in the radial direction (R) and/or in the axial direction (A) within the friction clutch (27), for example, within the outer basket (5) and/or within the friction pairing (10).

[0081] 4. The friction clutch (27) as described in embodiment 2 or 3, the ball ramp device (19) being supported in the axial direction (A) via an axial bearing (23) rotatably on the outer basket (5).

[0082] 5. The friction clutch (27) as described in embodiment 4, the ball ramp device (19) having at least one (possibly annular) outer ramp (21) which is attached on the first pressure pot (16), and at least one (possibly annular) inner ramp (20) which is supported indirectly or directly on the axial bearing (23).

[0083] 6. The friction clutch (27) as described in one of embodiments 2 to 5, a freewheel (24) being arranged in the radial direction (R) within the inner basket (6), via which freewheel (24) the torque can be transmitted in a rotational direction to the ball ramp device (19), for example, via a freewheel pot (25), in order to engage the friction pairing (10) in the first actuating direction (B1).

[0084] 7. The friction clutch (27) as described in embodiments 5 and 6, the inner ramp (20) being supported via the freewheel pot (25) on the axial bearing (23).

[0085] 8. The friction clutch (27) as described in embodiment 6 or 7, an outer ring of the freewheel (24) being arranged fixedly in a hub (7) so as to rotate with it, which hub (7) is connected fixedly to the inner basket (6) so as to rotate with it or is configured in one piece with the inner basket (6), or being configured in one piece with the hub (7), and it being possible for the hub (7) to be connected to an output shaft.

[0086] 9. The friction clutch (27) as described in one of embodiment 6 to 8, the freewheel pot (25) and/or the hub (7) having at least one screw opening (26) which extends in the axial direction (A) and is configured to make the screw connection possible of the outer basket (5) or a component which is connected to the outer basket (5), for example a dual mass flywheel, to a crankshaft of the internal combustion engine.

[0087] 10. The friction clutch (27) as described in one of embodiments 1 to 9, the friction pairing (10) having, for example, dry-running outer disks (11) and inner disks (12) which alternate in the axial direction (A) and of which a first end disk (13) is in contact with the first pressure pot (16), and of which a second end disk (14) which lies opposite the first end disk (13) in the axial direction (A) is in contact with the second pressure pot (17), and the outer disks (11), for example, being fastened fixedly to the outer basket (5) so as to rotate with it, and the inner disks (14) being fastened fixedly to the inner basket (6) so as to rotate with it.

[0088] 11. The friction clutch (27) as described in embodiment 10, in each case at least one corrugated washer (15) being arranged between adjacent outer disks (11) and/or between adjacent inner disks (12), which corrugated washer (15) is configured to disconnect the multiple disks (11, 12) in the case of a disengaged friction pairing (10).

[0089] 12. The friction clutch (27) as described in embodiment 10 or 11, the first pressure pot (16) being arranged in the axial direction (A) between the outer basket (5) and the first end disk (13).

[0090] 13. An assembly of a friction clutch (27) as described in one of embodiments 1 to 12 and an electric machine which may be configured as an electric traction motor which, in particular, can, for example, be operated not only in a traction mode, but rather also in a generator mode, the electric machine having a rotor (9) which is connected fixedly to the inner basket (6) so as to rotate with it, and the friction clutch (27), for example, being received in the radial direction (R) and/or in the axial direction (A) at least partially within the rotor (9).

LIST OF REFERENCE NUMERALS

[0091] 1 Fastening for crankshaft of an internal combustion engine

[0092] 2 Primary side of the dual mass flywheel

[0093] 3 Secondary side of the dual mass flywheel

[0094] 4 Centrifugal force pendulum

[0095] 5 Outer basket of the K0 clutch

[0096] 6 Inner basket of the K0 clutch

[0097] 7 Hub

[0098] 8 Spline toothing system for a first output shaft

[0099] 9 Rotor of an electric traction motor

[0100] 10 Friction pairing

[0101] 11 Friction plate or outer disk

[0102] 12 Friction plate or inner disk

[0103] 13 Ramp-side or first end disk

[0104] 14 Actuation-side or second end disk

[0105] 15 Corrugated washer

[0106] 16 Second actuating element or first pressure pot

[0107] 17 First actuating element or second pressure pot

[0108] 18 Securing ring

[0109] 19 Ball ramp device

[0110] 20 Inner ramp ring

[0111] 21 Outer ramp ring

[0112] 22 Ball

[0113] 23 Axial bearing

[0114] 24 Freewheel

[0115] 25 Output side or freewheel pot

[0116] 26 Through opening

[0117] 27 Friction clutch

[0118] 28 Rotational axis or rotary axis (D)

[0119] 29 First drive unit (electric motor)

[0120] 30 Second drive unit (internal combustion engine)

[0121] 31 Hybrid module

[0122] 32 Drive train

[0123] 33 Hybrid vehicle

[0124] 34 First output shaft

[0125] 36 Dual mass flywheel

[0126] 37 Left hand drive wheel

[0127] 38 Right hand drive wheel

[0128] 39 Driver's cab

[0129] 40 Longitudinal axis

[0130] 41 Engine axis

[0131] 42 Axial direction (A)

[0132] 43 Second actuating direction, ball ramp device (B1)

[0133] 44 First actuating direction, actuator device (B2)

[0134] 45 Radial direction (R)

[0135] 46 Input side of the freewheel

[0136] 47 Output side of the freewheel

[0137] 48 Minimum actuating length of the ball ramp device

[0138] 49 Maximum actuating length of the ball ramp device