Torque transmission device, hybrid drive train with this and electric motor for this

Abstract

Torque transmission device (1, 1a) with a torsional vibration damper (2) with an input part (4, 4a) arranged so as to be rotatable about a rotational axis (d) and an output part (5, 5a) which is rotatable to a limited extent about the rotational axis (d) counter to the action of a spring device (9), which contains a friction clutch (3) with a counterpressure plate and a pressure plate (23) which can be axially preloaded relative to the pressure plate by an actuating element (22) and friction linings (25) of a clutch disc (26) which can be clamped between the pressure plates, as well as a flange part (15, 15a) which acts on the spring device (9) on the output side, wherein the flange part (15, 15a) forms the counterpressure plate of the friction clutch (3) and a bearing of the output part (5, 5a) on the input part (4, 4a), and wherein the clutch disc (26) forms an output hub (27) of the torque transmission device (1, 1a) characterized in that a clutch pressure plate (20) of the friction clutch (3) is connected to the flange part (15,15a) which forms a support for the actuating element (22), and wherein the friction linings (25) of the friction clutch (3) are arranged radially inside the spring device (9) and that a clutch cover (21) of the friction clutch (3) is connected to the flange part (15) radially inside the spring device (9) and radially outside the pressure plate (23).

Description

[0001] The invention relates to a torque transmission device, in particular for a hybrid drive train of a motor vehicle and a hybrid drive train having the same, wherein the torque transmission device contains a torsional vibration damper with an input part arranged so as to be rotatable about an axis of rotation and an output part which can be rotated to a limited extent about the axis of rotation against the action of a spring device, wherein the output part contains a friction clutch with a counterpressure plate and a pressure plate which can be axially prestressed relative to the latter by an actuating element and friction linings of a clutch disc which can be clamped between the latter and a flange part which acts on the spring device on the output side.

[0002] Torque transmission devices of this type are used in motor vehicle drivetrains to transmit torque from an internal combustion engine to a downstream transmission. In hybrid drivetrains, these torque transmission devices are used to transmit and distribute the torque of the internal combustion engine and an electric motor to the transmission. Furthermore, embodiments are known in which the electric motor is flanged directly to the internal combustion engine and the torque transmission device is integrated into the electric motor.For example, WO 2015 / 172 784 A2 discloses an electric motor for a hybrid powertrain in which a torsional vibration damper connected to a crankshaft of the internal combustion engine is integrated into the housing of the electric motor. A wet-operated friction clutch is arranged separately from the torsional vibration damper between the rotor of the electric motor and the output part of the torsional vibration damper. The torsional vibration damper and the separately arranged friction clutch form the torque transmission device of the type mentioned.

[0003] DE 10 2004 034 087 A1 discloses a torque transmission device with a torsional vibration damper having an input part rotatable about a rotational axis and an output part that can be rotated to a limited extent about the rotational axis against the action of a spring device. The output part contains a friction clutch with a counterpressure plate and a pressure plate that can be axially preloaded relative to the counterpressure plate by an actuating element. Friction linings of a clutch disc and a flange part that acts on the spring device on the output side are provided between the counterpressure plate and the pressure plate.

[0004] The object of the invention is to further develop a generic torque transmission device, an electric machine with this device and a hybrid drive train.

[0005] The object is solved by the subject matter of claims 1, 6, and 7. The claims dependent on claim 1 represent advantageous embodiments of the subject matter of claim 1.

[0006] The invention provides that a clutch pressure plate of the friction clutch is connected to the flange part, which forms a support for the actuating element. Furthermore, the friction linings of the friction clutch are arranged radially inside the spring device. Furthermore, the invention provides that a clutch cover of the friction clutch is connected to the flange part radially inside the spring device and radially outside the pressure plate.

[0007] The proposed torque transmission device is intended for a drive train of a motor vehicle for transmitting torque from an internal combustion engine to a downstream transmission and for torsional vibration isolation of the torsional vibration-prone torque of the internal combustion engine. In particular, the generic torque transmission device is intended for a hybrid drive train of a motor vehicle for torsional vibration isolation and torque transmission from an internal combustion engine and an electric motor to a downstream transmission, wherein a friction clutch of the torque transmission device is provided for separating the internal combustion engine from the electric motor and the remaining drive train. A second friction clutch, arranged, for example, radially within a rotor of the electric motor, can be provided for separating the internal combustion engine and the electric motor from the remaining drive train.Such a hybrid drive train, commonly referred to as a P2 hybrid, allows, depending on the engagement of the friction clutches, driving with the electric motor and / or the internal combustion engine, starting the internal combustion engine using the electric motor when the rest of the drive train is disconnected, recuperation when the internal combustion engine is disconnected, charging of an electricity storage device when the internal combustion engine is disconnected using the electric motor, and the like.

[0008] The torsional vibration damper integrated into the torque transmission device comprises an input part rotatable about a rotational axis and an output part rotatable about the rotational axis to a limited extent against the action of a spring device. A positively opening or positively closing friction clutch is arranged on the output part. It comprises a counterpressure plate and a pressure plate that can be axially preloaded relative to the pressure plate by an actuating element, such as a diaphragm spring or a lever spring. Friction linings of a clutch disc can be clamped between these friction linings.

[0009] The spring device preferably contains arc springs distributed around the circumference. Several arc springs can be nested within one another. The arc springs are loaded in the circumferential direction by means of loading means arranged on the input side and output side, which engage between the end faces of the arc springs arranged adjacently in the circumferential direction. The loading means arranged on the input side can be formed by stamped disc parts forming an annular chamber for the arc springs. The output-side loading means of the spring device are provided on a flange part of the output part. For this purpose, the flange part has arms that extend radially outward in the radial direction.

[0010] To save installation space, especially in a hybrid powertrain, the friction clutch of the torque transmission device is integrated into the torsional vibration damper. In a particularly advantageous manner, the flange part forms the counterpressure plate with a friction surface of the friction clutch and a bearing for the output part on the input part. In particular, the friction clutch is designed as a dry friction clutch.

[0011] In the torque transmission device for a hybrid powertrain, the clutch disc of the friction clutch between the internal combustion engine and the electric motor forms an output hub of the torque transmission device.

[0012] In order to form a particularly radially compact embodiment of the torque transmission device, according to the invention the friction linings of the friction clutch are arranged radially inside the spring device.

[0013] In order to preload the pressure plate against the counterpressure plate while clamping the friction linings of the clutch disc, a clutch cover of the friction clutch can be connected, for example welded or riveted, to the flange part radially outside the friction linings, on which the actuating means is supported and axially preloads the pressure plate, wherein the actuating means, depending on the design of the friction clutch as a forcibly closed or forcibly opened friction clutch, forms a one-armed or two-armed lever which is axially acted upon by a clutch actuator radially inward.

[0014] The output part and the input part are mounted on one another by means of the flange part and a disc part or a component of the input part associated with it, for example by means of a rolling bearing, such as a deep groove ball bearing, angular contact ball bearing or the like, or by means of a plain bearing. For this purpose, the input part contains, for example, in one piece or on a component connected to it, an axially extended bearing surface machined, for example, onto a bearing dome. The bearing surface can be provided radially inside or radially outside of fastening openings provided on the input part for receiving the torque transmission device on a crankshaft of an internal combustion engine or a shaft connected to it in a rotationally locked manner.

[0015] To improve the torsional vibration isolation of the torque transmission device, a centrifugal pendulum absorber can be provided, particularly associated with the output part, as a speed-adaptive torsional vibration damper. The centrifugal pendulum absorber can be arranged on the clutch cover of the friction clutch. A pendulum mass carrier of the centrifugal pendulum absorber can be connected to the clutch cover, for example, riveted or welded, with pendulum masses arranged on both sides of the circumference. Axially opposing pendulum masses are connected to one another to form pendulum mass units by means of center sections that pass through recesses in the pendulum mass carrier. The pendulum mass units are mounted on the pendulum mass carrier in a pendulum-like manner using self-aligning bearings.The self-aligning bearings can be formed between the pendulum mass carrier and the central parts, with a spherical roller, held captively by the pendulum masses, rolling on raceways lying in one plane in the central parts and the pendulum mass carrier. In an alternative embodiment, recesses with raceways are arranged in the pendulum masses of the axially opposite pendulum masses and in the pendulum mass carrier, on which raceways a spherical roller axially penetrating the recesses rolls. Alternatively, the pendulum mass carrier can have two side parts, between which pendulum masses distributed axially over the circumference are accommodated, with the self-aligning bearings each being formed from recesses in the side parts and in the pendulum masses, with raceways on which a spherical roller axially spanning the recesses rolls.The pendulum masses or pendulum mass units of the centrifugal pendulum can be arranged at the radial level of the spring assembly and axially adjacent to it. Radially outside the pendulum masses, for example, a burst protection device designed as a ring part and axially covering the centrifugal pendulum can be arranged to hold back components of the centrifugal pendulum that are accelerated radially outward in the event of a failure of the centrifugal pendulum. The burst protection device can be connected, for example, welded, to a disc part forming the annular chamber.

[0016] The object is further achieved by an electric motor for a hybrid drive train of a motor vehicle. The electric motor comprises a housing with a stator and a rotor rotatable relative to the stator, wherein the proposed torque transmission device is housed in the housing. The housing forms an axial projection for mounting on an engine housing, wherein the torque transmission device can be housed radially within the axial projection.

[0017] The problem is further solved by a hybrid drivetrain comprising an internal combustion engine and an electric motor that can be connected to the internal combustion engine via a friction clutch. The housing of the electric motor is connected to the engine housing of the internal combustion engine, with a torsional vibration damper connected to a crankshaft of the internal combustion engine, and the friction clutch arranged radially within the housing. To save installation space, the friction clutch is integrated into the torsional vibration damper, forming the proposed torque transmission device.

[0018] The invention is based on the Fig. 1 and Fig. 2 are explained in more detail. These show: Fig. 1 the upper part of a torque transmission device arranged so as to be rotatable about a rotation axis in section and Fig. 2 the upper part of a torque transmission device of the Fig. 1 modified torque transmission device in section.

[0019] The Fig. Figure 1 shows a cross-sectional view of the upper part of the torque transmission device 1, which can be rotated about the rotational axis d. The torque transmission device 1 is formed by the torsional vibration damper 2 and the friction clutch 3. The input part 4 of the torque transmission device 1 simultaneously forms the input part of the torsional vibration damper 2, and the output part 5 of the torque transmission device 1 forms the output part of the torsional vibration damper 2.

[0020] The input part 4 contains the two disc parts 6, 7, which radially outwardly form the annular chamber 8, in which the spring device 9, which acts circumferentially between the input part 4 and the output part 5, is housed. The disc part 6 has fastening openings 10 for the fastening screws 11 for attaching the torque transmission device 1 to a crankshaft of an internal combustion engine. The disc part 7 has, radially outwardly, encoder markings 12 for the sensor 13 (only indicated) for controlling the internal combustion engine.

[0021] The spring device 9 is formed from arc springs 14, which are only indicated and distributed over the circumference and which are acted upon on the front side by means of non-visible stampings provided in the disc parts 6, 7 and on the output side by the arms 16 of the flange part 15.

[0022] The flange part 15 is assigned to the output part 5 and accommodates the friction clutch 3. Radially within the fastening openings 10, the output part 5 is mounted on the disc part 6 by means of the flange part 15 about the rotational axis d, with the rolling bearing 19, here a deep groove ball bearing, being arranged between the axial shoulder 17 of the flange part 15 and the bearing dome 18 formed integrally on the disc part 6.

[0023] The clutch pressure plate 20 of the friction clutch 3 contains the clutch cover 21, the actuating element 22 designed as a disc spring and the pressure plate 23.

[0024] The clutch cover 21 is connected, for example, welded, riveted, or screwed, to the flange part 15 radially inside the spring device 9 and radially outside the pressure plate 23. The flange part 15, together with the friction surface 24, forms the counterpressure plate of the friction clutch 3. The friction linings 25 of the clutch disc 26 are arranged between the flange part 15 and the pressure plate 23 and can be preloaded by means of the actuating element 22. The clutch disc 26 forms the output hub 27, which is connected to the shaft journal 28 of a rotor of an electric motor of a hybrid drive train. A further friction clutch can be connected downstream of the shaft journal 28 or the rotor to disconnect the electric motor from the rest of the drive train.

[0025] The friction clutch 3 establishes the switchable connection between the internal combustion engine and the electric machine and, in the exemplary embodiment shown, is designed as a forcibly opened friction clutch 3 which is closed in the non-actuated state and produces torque between the internal combustion engine and the electric machine or the remaining drive train.

[0026] The actuating element 22 is non-rotatably mounted on the clutch cover 21 by means of the shaped bolts 29 and held axially by the preload spring 30. The actuating element 22 is supported as a two-armed lever on the wire ring 31 and preloads the pressure plate 23 against the flange part 15 while clamping the friction linings 25. By appropriately preloading the actuating element 22, the maximum transmittable torque can be set to a limit torque, so that the friction clutch 3 also acts as a torque-limiting device. When the actuating element 22 is subjected to axial loading radially inward by means of an actuator, the preload of the pressure plate 23 is released and the friction clutch 3 is opened. An axially effective friction lining spring can be provided between the friction linings 25 and their receiving elements 32 on the clutch disc 26.

[0027] To improve torsional vibration isolation, the centrifugal pendulum 33 with the pendulum mass carrier 34 and pendulum masses 35, which are merely indicated and distributed over the circumference on both sides of the pendulum mass carrier 34 in the centrifugal force field of the torque transmission device 1 rotating about the rotation axis d, are arranged on the output part 5. The pendulum mass carrier 34 is connected radially inward to the clutch cover 21, for example, welded, riveted, or screwed. Radially outside the pendulum masses 35, the annular burst protection 36, which axially covers the pendulum masses 35, is connected to the disc part 7—here welded.

[0028] The annular chamber 8 is sealed between the input part 4 and the output part 5. For this purpose, the disc spring diaphragm 37 is mounted on the clutch cover 21 and is axially preloaded against the friction ring 38 mounted on the disc part 7, forming a basic friction device upon rotation between the input part 4 and the output part 5. The gap seal 40 is formed radially inward between the reinforcement ring 39 of the input part 4 for the fastening screws 11 and the flange part 15.

[0029] The Fig. 2 shows in the Fig. 1 shows the torque transmission device 1a modified compared to the torque transmission device 1, in which the bearing arrangement of the input part 4a and the output part 5a around the rotational axis d is modified. The bearing arrangement is effected by means of the plain bearing 19a radially outside the fastening openings 10a in the disc part 6a of the input part 4a or outside the fastening screws 11a. For this purpose, the flange part 15a is arranged opposite the flange part 15 of the Fig. 1 is radially shortened and forms the plain bearing 19a with the axial shoulder 17a and the axial shoulder 18a of the reinforcing ring 39a as well as the sliding bushing 41a arranged therebetween. The thrust ring 42a is arranged between the sliding bushing 41a and the disc part 6a. List of reference symbols 1 torque transmission device 1a Torque transmission device 2 torsional vibration dampers 3 Friction clutch 4 Entrance part 4a Entrance part 5 Output part 5a Output part 6 disc part 6a Disc part 7 Disc part 8 Annular chamber 9 Spring device 10 Mounting hole 10a Mounting opening 11 Fixing screw 11a Fixing screw 12 encoder marking 13 Sensor 14 bow spring 15 Flange part 15a Flange part 16 arms 17 Approach 17a approach 18 Camp Dome 18a approach 19 rolling bearings 19a plain bearing 20 clutch pressure plate 21 Clutch cover 22 Actuating element 23 Pressure plate 24 Friction surface 25 Friction lining 26 Clutch disc 27 Output hub 28 shaft journals 29 form bolts 30 preload spring 31 wire ring 32 receiving element 33 centrifugal pendulum 34 pendulum mass carriers 35 pendulum mass 36 Burst protection 37 Disc spring diaphragm 38 Friction ring 39 Reinforcement ring 39a Reinforcement ring 40 gap seal 41a sliding bushing 42a thrust ring d axis of rotation

Claims

[1] Torque transmission device (1, 1a) with a torsional vibration damper (2) with an input part (4, 4a) arranged so as to be rotatable about an axis of rotation (d) and an output part (5, 5a) which is rotatable to a limited extent about the axis of rotation (d) counter to the action of a spring device (9), which contains a friction clutch (3) with a counterpressure plate and a pressure plate (23) which can be axially prestressed relative to the pressure plate by an actuating element (22) and friction linings (25) of a clutch disc (26) which can be clamped between the pressure plates, as well as a flange part (15, 15a) which acts on the spring device (9) on the output side, wherein the flange part (15, 15a) forms the counterpressure plate of the friction clutch (3) and a bearing of the output part (5, 5a) on the input part (4, 4a), and wherein the clutch disc (26) forms an output hub (27) of the torque transmission device (1, 1a) forms, characterized bythat a clutch pressure plate (20) of the friction clutch (3) is connected to the flange part (15, 15a), which forms a support for the actuating element (22), and wherein the friction linings (25) of the friction clutch (3) are arranged radially inside the spring device (9) and that a clutch cover (21) of the friction clutch (3) is connected to the flange part (15) radially inside the spring device (9) and radially outside the pressure plate (23). [2] Torque transmission device (1) according to claim 1, characterized by that the bearing between the input part (4) and the flange part (15) is provided radially inside fastening openings (10) provided in the input part (4) for receiving the torque transmission device (1) on a crankshaft of an internal combustion engine. [3] Torque transmission device (1a) according to one of claims 1 or 2, characterized bythat the bearing between the input part (4a) and the flange part (15a) is provided radially outside of fastening openings (10a) provided in the input part (4a) for receiving the torque transmission device (1a) on a crankshaft of an internal combustion engine. [4] Torque transmission device (1, 1a) according to one of claims 1 to 3, characterized by that a centrifugal pendulum (33) is arranged on the output part (5, 5a). [5] Torque transmission device (1, 1a) according to one of claims 1 to 4, characterized by that a torque that can be transmitted via the friction clutch (3) is limited to a predetermined limit torque. [6] Electric machine for a hybrid drive train of a motor vehicle with a housing containing a stator and a rotor rotatable relative to the stator, characterized bythat a torque transmission device (1, 1a) according to one of claims 1 to 5 is accommodated in the housing [7] Hybrid drive train with an internal combustion engine and an electric machine which can be connected to the latter by means of a friction clutch (3), the housing of which is connected to an engine housing of the internal combustion engine, wherein a torsional vibration damper (2) is connected to a crankshaft of the internal combustion engine and the friction clutch (3) is arranged radially inside the housing, characterized by that the friction clutch (3) is integrated into the torsional vibration damper (2) to form the torque transmission device (1, 1a) according to one of claims 1 to 6.

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