Drive unit for a hybrid vehicle

Abstract

Drive unit (200) for a powertrain (300) of a hybrid vehicle (100), comprising an input shaft (1) connectable to the combustion engine, an output shaft (2) connectable to the transmission, and a disconnecting clutch (3) by which the input shaft (1) can be brought into operative connection with the output shaft (2), wherein a first clutch component (4) of the disconnecting clutch (3) is rotationally fixed to the input shaft (1) and a second clutch component (5) of the disconnecting clutch (3) is rotationally fixed to the output shaft (2), wherein the drive unit (200) further comprises an electric motor (6) which has a rotor (7) which is radially outside on a rotor carrier (9) belonging to the second clutch component (5), and a motor damper (10), wherein the disconnecting clutch (3) is designed as a conical clutch and the motor damper (10) is at least partially covered radially outside by the rotor carrier (9), characterized in thatthat the motor damper (10) is positioned radially between the rotor carrier (9) and the disconnect coupling (3).

Description

[0001] The invention relates to a drive unit for a powertrain of a hybrid vehicle.

[0002] A hybrid vehicle's powertrain typically comprises a combination of an internal combustion engine and an electric motor, enabling purely electric operation—for example, in urban areas—while simultaneously providing sufficient range and availability for longer journeys. Furthermore, it is possible to use both the internal combustion engine and the electric motor simultaneously in certain operating situations. In a hybrid vehicle, the electric motor usually replaces both the previously standard starter motor for the internal combustion engine and the previously standard alternator, thus reducing the weight increase of the hybrid vehicle compared to vehicles powered solely by internal combustion engines.

[0003] Such drive units are known from the prior art. In particular, DE 10 2017 212 898 A1 discloses, for example, a hybrid drive train in which a disconnect coupling has at least a first coupling part, a second coupling part, and an axially displaceable sliding sleeve for opening and closing the disconnect coupling. Further prior art is known from DE 10 2018 212 575 A1 and AT 507 523 A2.

[0004] As further known from EP 0 773 127 A2, a disconnect clutch can be arranged between the combustion engine and the electric motor to isolate the combustion engine from the electric motor and the rest of the hybrid vehicle's drivetrain. In purely electric mode, the disconnect clutch, also known as a K0 clutch, is then opened and the combustion engine is switched off, so that the drive torque of the hybrid vehicle is provided exclusively by the electric motor.

[0005] Such disconnect clutches are typically operated by a hydraulic actuation system. A hydraulic actuation system usually has a master cylinder that transmits the pressure generated at the master cylinder to a slave cylinder via a hydraulic pressure line. The slave cylinder, by means of an axially displaceable piston and a clutch release bearing, transmits the hydraulic pressure to a lever system, which engages or disengages the frictional connection of the disconnect clutch. Fully hydraulic actuation systems, as are typically used in hybrid modules, can, for example, be equipped with a central release bearing, often also referred to as a "concentric slave cylinder" (CSC).

[0006] Drive units for a hybrid vehicle's powertrain are known from the prior art, which feature a disconnect clutch in the form of a multi-plate clutch. The multi-plate clutch can be installed in a space below a rotor carrier, which supports the rotor of the hybrid vehicle's electric motor. To reduce motor vibrations, such drive units use a motor damper arranged axially next to the clutch. This unit, consisting of the clutch, electric motor, and motor damper, is generally very wide, requiring a considerable amount of installation space in the axial direction. A drive unit according to the preamble of claim 1 is known from DE 10 2016 221 491 A1.

[0007] It is an object of the invention to provide a drive unit for a drive train of a hybrid vehicle which has a small space requirement in the axial direction.

[0008] This problem is solved according to the invention by a drive unit according to claim 1. Furthermore, the invention also relates to a hybrid vehicle according to claim 7, which includes such a drive unit. Preferred embodiments are specified in the dependent claims.

[0009] A drive unit for the powertrain of a hybrid vehicle comprises an input shaft connectable to the combustion engine, an output shaft connectable to the transmission, and a disconnect clutch through which the input shaft can be brought into operative contact with the output shaft. Such a drive unit can be part of the powertrain of a hybrid vehicle, with the disconnect clutch having the fundamental function of establishing a detachable, friction-fit and / or positive-locking connection between a clutch input shaft and a clutch output shaft for the transmission of torque. For this purpose, a first clutch component of the disconnect clutch is rotationally fixed to the input shaft, and a second clutch component of the disconnect clutch is rotationally fixed to the output shaft.

[0010] Furthermore, the drive unit comprises an electric motor with a rotor mounted radially on the outside of a rotor carrier belonging to the second coupling component, and a motor damper. Thus, the electric motor's rotor is coupled to the output shaft. According to the invention, the disconnect coupling is designed as a conical coupling, and the motor damper is at least partially covered radially on the outside by the rotor carrier. A conical coupling is a friction-fit coupling with a conical clamping hub, through which the frictional connection between the two coupling components of the disconnect coupling is established.

[0011] Since the disconnect coupling is designed as a conical coupling, little installation space is required in the radial direction. In this context, it should be noted that when the terms "radial" and "axial" are used in this description, these directional terms refer to the input shaft as the central axis. The installation space in the radial direction below the rotor carrier that is not required by the disconnect coupling can thus be used to integrate the motor damper into the space between the input shaft and the motor carrier. In other words, in the embodiments of the invention, the disconnect coupling and the motor damper are at least partially covered by the rotor carrier radially outwards. This saves installation space in the axial direction, and the drive unit itself has a narrow profile in the axial direction.

[0012] The drive unit can be designed, in particular, as a hybrid module. In a hybrid module, structural and functional elements of a hybridized powertrain can be spatially and / or structurally combined and preconfigured, so that a hybrid module can be integrated into a motor vehicle's powertrain in a particularly simple manner. Specifically, an electric motor and a clutch system, especially with a disconnect clutch for engaging and / or disengaging the electric motor from the powertrain, can be present in a hybrid module.

[0013] In a drive unit according to the invention, the motor damper is positioned radially between the rotor carrier and the disconnect clutch. This means that the motor carrier is mounted radially above the disconnect clutch. Thus, the disconnect clutch is arranged close to the axis.

[0014] In one embodiment, the motor damper is supported on the output shaft. For this purpose, a support element, one end of which is connected to the motor damper, is preferably guided axially alongside the disconnect clutch on the transmission side, with a second end of the support element being supported on the output shaft.

[0015] To save space, it is advantageous for the engine damper to be designed as a double-row damper. Such a double-row damper has a first and a second damper row, which are arranged side by side in the axial direction. As is known, an engine damper's function is to absorb shocks and jerky movements of the engine. An engine damper thus absorbs energy that could set the engine in motion. If the spring force of such an engine damper can be distributed across two sets, a radially compact damper unit can be achieved. It may also be advantageous to incorporate more than two damper rows.

[0016] Preferably, the first and second rows of dampers are mounted at the same height in the radial direction. In other words, in this configuration, the first and second rows of dampers are mounted side by side at the same height in the axial direction with respect to the radial direction. This enables a uniform damping effect.

[0017] For the sake of simple, space-saving installation, the first and second rows of dampers can be jointly supported on the output shaft. A common support element can be provided for this purpose, which is supported on the output shaft and connected directly or indirectly to each row of dampers.

[0018] The drive unit can include a hydraulic release mechanism for actuating the disconnect clutch, which is at least partially covered radially on the outside by the rotor carrier. In this configuration, the hydraulic release mechanism is thus at least partially housed radially within the rotor carrier. This results in a particularly space-saving design of the drive unit. The hydraulic release mechanism can be, in particular, a central release mechanism, often also referred to as a Concentric Slave Cylinder (CSC). This can consist, in particular, of an annular hydraulic central release piston arranged coaxially to the input shaft and within a central release housing.

[0019] The central release bearing housing serves to contain components of the central release bearing, particularly the movable central release bearing piston, and to protect them from external mechanical or chemical influences. Furthermore, the central release bearing housing facilitates easy installation and securing of the central release bearing within the drivetrain. Preferably, the central release bearing housing can be made of a plastic, a metallic material, and / or a ceramic material. The central release bearing housing can be constructed as a single piece or in multiple pieces.

[0020] As already mentioned, the invention also relates to a hybrid vehicle which has a powertrain which includes a drive unit as described above.

[0021] The invention will now be discussed in more detail with reference to a non-limiting embodiment and the accompanying drawing. The drawing shows: Fig. 1 a cross-sectional view of a drive unit for a powertrain of a hybrid vehicle according to the state of the art; Fig. 2 a cross-sectional view of a drive unit for a powertrain of a hybrid vehicle according to an embodiment of the invention; and Fig. 3 A schematic view of a hybrid vehicle and its powertrain.

[0022] With reference to Fig. 1 will now be a drive unit 200 for a drive train 300 (see Fig. 3) of a hybrid vehicle 100 (see Fig. 3) explained in more detail. The figure shows an input shaft 1 and an output shaft 2, which are coupled to each other via a disconnecting coupling 3. In this prior art, the disconnecting coupling 3 is a multi-plate coupling, which is arranged below an electric motor 6. More precisely, the multi-plate coupling is mounted below a rotor carrier 9, which carries a rotor 7 of the electric motor 6 radially outwards with respect to the input shaft 1.

[0023] A stator 8 of the electric motor 6 is radially outside the rotor 7 and rigidly connected to a housing 14. When the disconnect clutch 3 is engaged, the input shaft 1 is coupled to the output shaft 2. A hydraulic release mechanism 13 for actuating the disconnect clutch 3 is arranged laterally to the multi-plate clutch and is operatively connected to it.

[0024] To prevent engine vibrations from being transmitted to the drive train 300, an engine damper 10 is typically used. In the figure, this is located to the right of the disconnect coupling 3 and is bounded by a measuring unit 15. As can be seen, this assembly requires a considerable amount of space in the axial direction.

[0025] With reference to Fig. 2 An embodiment of a drive unit 200 according to the invention is described, wherein identical or corresponding elements as in Fig. 1 are marked with the same reference numerals. In this embodiment, the input shaft 1 is non-rotatably connected to a first coupling component 4, whereas the output shaft 2 is non-rotatably connected to a second coupling component 5. Part of the second coupling component 5 is the rotor carrier 9, which supports the rotor 7 of the electric motor 6. The rotor 7 is mounted radially outwards on the rotor carrier 9, so that it interacts with the field of the stator 8 during rotation. The stator 8 is fixedly anchored to the housing 14.

[0026] Radially within the space defined by the rotor carrier 9, the disconnect clutch 3 is mounted. Unlike the prior art, this is a conical clutch, which is narrow in the radial direction. The conical clutch is actuated by the hydraulic release 13. Due to the small radial space requirement of the conical clutch, it is possible to position the motor damper 10 radially above the disconnect clutch 3, also within the space defined by the rotor carrier 9. In the embodiment shown here, the motor damper 10 is a two-row motor damper 10 with a first damper row 11 and a second damper row 12, which are arranged side by side in the axial direction. Of course, more damper rows can also be used. As can be seen, the damper rows 11 and 12 are at the same height in the radial direction and are jointly supported on the output shaft 2.For this purpose, a common support element 16 is provided, to which both the first damper row 11 and the second damper row 12 are coupled.

[0027] In Fig. Figure 3 shows a schematic view of a hybrid vehicle 100, which is equipped with a powertrain 300, a component of which is a drive unit 200 according to one embodiment of the invention. In addition to the electric motor 6 already described, the hybrid vehicle 100 comprises an internal combustion engine (not shown here), which is also part of the powertrain 300. List of reference symbols 1 Input wave 2 Output shaft 3 Disconnect coupling 4 first clutch component 5 second clutch component 6 electric motor 7 Rotor 8 Stator 9 rotor carriers 10 engine dampers 11 first series of dampers 12 second row of dampers 13 hydraulic release bearings 14 cases 15 Unit of measurement 16 common load-bearing element 100 hybrid vehicles 200 drive unit 300 Powertrain

Claims

[1] Drive unit (200) for a drive train (300) of a hybrid vehicle (100), comprising an input shaft (1) connectable to the internal combustion engine side, an output shaft (2) connectable to the transmission side, and a separating clutch (3) by means of which the input shaft (1) can be brought into operative connection with the output shaft (2), wherein a first clutch component (4) of the separating clutch (3) is connected in a rotationally fixed manner to the input shaft (1) and a second clutch component (5) of the separating clutch (3) is connected in a rotationally fixed manner to the output shaft (2), wherein the drive unit (200) further comprises an electric motor (6) having a rotor (7) which is seated radially outwardly on a rotor carrier (9) associated with the second clutch component (5), and an engine damper (10), wherein the separating clutch (3) is designed as a cone clutch and the engine damper (10) is at least partially covered radially outwardly by the rotor carrier (9), characterized bythat the motor damper (10) is placed in the radial direction between the rotor carrier (9) and the separating clutch (3). [2] Drive unit (200) according to claim 1, characterized by that the engine damper (10) is supported on the output shaft (2). [3] Drive unit (200) according to claim 2, characterized by that the engine damper (10) is designed as a two-row engine damper (10), comprising a first damper row (11) and a second damper row (12) which are placed next to one another in the axial direction. [4] Drive unit (200) according to claim 3, characterized by that the first row of dampers (11) and the second row of dampers (12) are mounted at the same height in the radial direction. [5] Drive unit (200) according to claim 3 or 4, characterized by that the first damper row (11) and the second damper row (12) are supported together on the output shaft (2). [6] Drive unit (200) according to one of the preceding claims, characterized by in that it has a hydraulic releaser (13) for actuating the separating clutch (3), which is at least partially covered radially outwardly by the rotor carrier (9). [7] Hybrid vehicle (100) comprising a drive train (300) which includes a drive unit (200) according to one of the preceding claims.

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