drive system

Abstract

Drive system for a vehicle, including: - a drive system input area (44) to be coupled with a drive unit (14), - a drive system output area (62) to be coupled with a gear arrangement (20), - a start-up assembly (24), wherein the start-up assembly (24) comprises a start-up assembly input area (42) coupled to or providing the drive system input area (44) and a start-up assembly output area (50) coupled to or providing the drive system output area (62), - an electric machine (28) coupled to the start-up assembly output area (50) and / or the drive system output area (62), - a torsional vibration damper arrangement (26) with at least two torsional vibration damper units (68, 70, 72) arranged in series between the drive system input area (44) and the drive system output area (62), characterized in that a rotor arrangement (64) of the electric machine (28) is rigidly coupled to the starting assembly output area (50).

Description

[0001] The present invention relates to a drive system for a vehicle comprising a drive system input area to be coupled to a drive unit and a drive system output area to be coupled to a transmission arrangement and an electric machine.

[0002] Such a drive system is known from US 8,298,105 B2. In this known drive system, a starting assembly is provided in the form of a hydrodynamic torque converter with a pump impeller connectable to a housing by means of a coupling, and a turbine impeller arranged in an interior of the housing and coupled to an output region of the starting assembly. A coupling acting between the pump impeller and the turbine impeller can bridge the hydrodynamic circuit formed by the pump impeller, the turbine impeller, and a stator, thus providing a fixed mechanical torque transmission connection from the housing providing one input region of the starting assembly to the output region of the starting assembly.An electric motor is positioned outside the housing of the starting assembly and is coupled to the pump wheel in order to transmit a drive torque to the output area of ​​the starting assembly and thus also to an output area of ​​the drive system via the pump wheel, the coupling acting between the pump wheel and the turbine wheel and the turbine wheel.

[0003] A comparable drive system is known with DE 10 2009 019 585 A1.

[0004] The object of the present invention is to provide a drive system for a vehicle which avoids excessive stress on a transmission arrangement.

[0005] According to the invention, this problem is solved by a drive system for a vehicle, comprising: - a drive system input area to be coupled with a drive unit, - a drive system output area to be coupled with a gearbox arrangement, - a start-up assembly, wherein the start-up assembly comprises a start-up assembly input area coupled to or providing the drive system input area and a start-up assembly output area coupled to or providing the drive system output area, - an electric machine coupled to the start-up assembly output area and / or the drive system output area, - a torsional vibration damper arrangement with at least two torsional vibration damper units arranged in series between the drive system input area and the drive system output area, wherein a rotor arrangement of the electric machine is rigidly coupled to the start-up assembly output area.

[0006] By providing several series-acting torsional vibration damper units and the intermediate masses formed between them, good vibration decoupling of the gearbox assembly with respect to the drive unit is ensured despite the comparatively large moment of inertia that the drive system, which also includes the electric machine, provides in the torque transmission path between a drive unit and a gearbox arrangement.

[0007] For a compact, stable design, it is proposed that a rotor arrangement of the electric machine be rigidly coupled to the start-up assembly output area.

[0008] In order to provide good vibration decoupling for the gearbox arrangement, particularly in an operating condition in which a drive torque is supplied by both the drive unit and the electric machine, and thus a comparatively large total torque is provided and introduced into a gearbox arrangement, at least one of the torsional vibration damper units can be arranged in the torque transmission path between a rotor arrangement of the electric machine and the drive system output area.

[0009] Furthermore, at least one of the torsional vibration damper units can be arranged in the housing in the torque transmission path between an output area of ​​the lock-up clutch and the start-up assembly output area.

[0010] To further dampen vibration excitations, particularly those occurring at the ignition frequency or multiples thereof, it is proposed that at least one damper unit be provided with a deflection mass carrier and at least one deflection mass mounted on the deflection mass carrier so that it can be deflected from a fixed position against a restoring force. Such damper units can, for example, be designed as fixed-frequency dampers, in which the restoring force is provided by one or more springs with a defined spring constant. In an alternative embodiment, such damper units can be designed as speed-adaptive dampers, in which the restoring force is generated by the centrifugal force acting on the deflection mass during rotation.

[0011] For example, to efficiently dampen vibration excitations caused by ignition processes, at least one damper unit can be arranged in the torque transmission path between two torsional vibration damper units.

[0012] The start-up assembly input area can include the housing. The start-up assembly output area can include a driven hub located in the housing.

[0013] The invention further relates to a drive train for a vehicle, comprising a drive unit coupled to a transmission arrangement by means of a drive system constructed according to the invention.

[0014] In order to avoid oversizing the stiffness of a torsional vibration damper unit acting between the rotor assembly of the electric machine and the gearbox assembly in such a drive train, where a comparatively large total torque, potentially damaging to a gearbox assembly, can be delivered by the drive unit and the electric machine together in the drive state (i.e., in the traction state), it is proposed that the limit torque of the torsional vibration damper unit, which can be transmitted in the range of elastic effectiveness of the torsional vibration damper unit arranged at least in the torque transmission path between the rotor assembly and the drive system output area, lies in a range of 90% to 130%, preferably 90% to 110%, of a gearbox input limit torque of the gearbox assembly.

[0015] Such a drivetrain can, through suitable motor control, be operated in such a way that the transmission input limit torque is not exceeded, or only briefly exceeded, even in hybrid drive mode where the drive unit and the electric motor operate together. Therefore, the maximum torque that can be transmitted via such a torsional vibration damper unit within its elastic effectiveness range can also be designed to a limit torque in the range of the transmission input limit torque. This ensures that the torques expected or to be transmitted during operation can generally be transmitted within the elastic effectiveness range of such a torsional vibration damper unit. Furthermore, due to the avoidance of excessive stiffness in the elastic elements, such as springs, the torsional vibration damper unit can provide good vibration decoupling across the entire torque range.

[0016] Preferably, the torsional vibration damper unit limit torque can be provided to be below the gearbox input limit torque.

[0017] The present invention is described in detail below with reference to the accompanying figures. These show: Fig. 1 in a schematic representation a vehicle with a drive train comprising a drive unit and a transmission arrangement; Fig. 2. In a circuit diagram-like representation, the vehicle's drive train. Fig. 1; Fig. 3 a partial longitudinal section view of a starting assembly designed as a hydrodynamic torque converter of the drive train of the Fig. 2; Fig. 4 one of the Fig. 3. Corresponding representation of an alternative design type of a start-up assembly; Fig. 5 a diagram showing the torque curve in a drive train versus rotational speed; Fig. 6 a diagram illustrating the design of the stiffness of a torsional vibration damper unit with respect to a gearbox input limit torque of a gearbox arrangement.

[0018] In Fig. Figure 1 is a vehicle generally designated by 10, presented in principle. The vehicle 10 comprises a drive train 12, in which the drive torque provided by a drive unit 14 designed as an internal combustion engine is transmitted to driven wheels 16, 18. The drive train 12 comprises, between the internal combustion engine 14 and a transmission arrangement 20, a drive system generally designated by 22 with a starting assembly 24, a Fig. The diagram shows two torsional vibration damper arrangements 26 and an electric machine 28. The electric machine 28 can provide an additional torque to supplement the drive torque supplied by the drive unit 14, enabling the vehicle 10 to be driven in a hybrid drive mode by both the drive unit 14 and the electric machine 28. Furthermore, the drive unit 14 can be started by means of the electric machine 28.

[0019] The Fig. Figure 2 illustrates in more detail the area of ​​the drive train 12, which is referred to as the drive system 22 within the meaning of the present invention and lies essentially between the drive unit 14 and the transmission arrangement 20.

[0020] The drive system 22 comprises, as its central component, the starting assembly 24, which in the illustrated embodiment is designed as a hydrodynamic torque converter with a hydrodynamic circuit 32 housed in a casing 30. This hydrodynamic circuit 32 consists of a pump impeller 34 coupled to the casing 30 and thus coupled to it for common rotation, a turbine impeller 38 arranged in an interior space 36 of the casing 30, and a guide vane 40 arranged radially inside between the pump impeller 34 and the turbine impeller 38. In the illustrated embodiment, the casing 30 forms a starting assembly input area 42, through which the torque delivered by the drive unit 14 is introduced into the starting assembly 24 and thus into the drive system 22. Therefore, in the illustrated embodiment, the casing 30 can also be considered a drive system input area 44.

[0021] The housing 30, i.e. the start-up assembly input area 42 or the drive system input area 44, can be coupled, for example, by means of a flexible plate or the like, to a drive shaft of the drive unit 14, in particular a crankshaft of the drive unit 14 designed as an internal combustion engine.

[0022] Furthermore, a bypass clutch 46 is arranged in the interior of the housing 36, parallel to the hydrodynamic circuit 32. By means of the bypass clutch 46, a torque can be transmitted parallel to the hydrodynamic circuit 32 to the turbine wheel 38 or to a turbine wheel carrier 48 supporting it, and via this to a starting assembly output area 50. Depending on whether the bypass clutch 46 is engaged or disengaged, a torque is transmitted between the starting assembly input area 42 and the starting assembly output area 50 either via the hydrodynamic circuit 32, thus circulating a fluid present in the interior of the housing 36, generally oil, or the torque is transmitted via the bypass clutch 46, which establishes a mechanical connection.In slip operation of the bridging clutch 46, a portion of the torque introduced into the starting assembly 24 can be transmitted to the starting assembly output area 50 via both torque transmission paths.

[0023] The starting assembly output area 50 can, as described below, for example comprise an output hub connected to a transmission input shaft 60 or an intermediate shaft coupled to it. The intermediate shaft or the transmission input shaft 60 can, for example, provide a drive system output area 62 through which torque can be introduced into the transmission assembly 20.

[0024] The electric machine 28, or a rotor assembly 64 thereof, is rigidly, i.e., permanently, coupled to the starting assembly output area 50 or the drive system output area 62 and thus rigidly connected to it for torque transmission. For example, the rotor assembly 64 of the electric machine 28, whose stator assembly 66 may be supported on a stationary assembly, can be coupled to the gearbox input shaft 60 or to an intermediate shaft that couples the gearbox input shaft 60 to the starting assembly output area 50.

[0025] In the drive train 12 or drive system 22 described above, torque can be transmitted in the drive train 12 to start the drive unit 14, for example by means of the electric machine 28, when the lock-up clutch 46 is engaged. In this state, a clutch 52 or the like associated with or provided in the transmission assembly 20 can be disengaged, i.e., interrupting the torque flow into or within the transmission assembly.

[0026] During driving, drive torque from the drive unit 14 can be transmitted to the drive system output area 62 and thus to the transmission assembly 20. Depending on the driving situation, the lock-up clutch 46 can be engaged, disengaged, or operating in slip mode. In this state, the electric motor 28 can supply a supporting torque to operate the vehicle 10 in a hybrid drive mode. Alternatively, in this state, or in an engine braking state, the electric motor 28 can be operated as a generator to charge a battery located in the vehicle 10.

[0027] In an electric motor drive mode, in which drive torque is supplied solely by the electric motor 28, the rigid, i.e., permanent, coupling of the rotor assembly 64 to the starting assembly output area 50 ensures that torque is transmitted to the drive unit 14 via fluid circulation through the hydrodynamic circuit 32, even when the lock-up clutch 46 is disengaged. To minimize the braking torque generated by the drive unit 14 in this state, the inlet and exhaust valves of the internal combustion engine can be controlled in such a way as to generate the lowest possible braking torque in the drive unit 14, provided the drive unit 14 is configured as an internal combustion engine.

[0028] The in Fig. The identifiable torsional vibration damper arrangement 26 comprises several torsional vibration damper units 68, 70, 72, of which at least two are provided in such a drive train. The torsional vibration damper units 68, 70, 72 act in series with each other in the torque transmission path between the drive unit 14 and the transmission arrangement 20.

[0029] The in the in Fig. The torsional vibration damper unit 68, which follows the drive unit 14 immediately as shown in Figure 2, comprises a primary side 74 coupled, for example, to the housing 30, and a secondary side 78 coupled to it for torque transmission via a damper element arrangement 76. The secondary side 78 is coupled to an input section 56 of the lock-up clutch 46. An output section 54 of the lock-up clutch 46 is coupled to the turbine wheel carrier 48, which in turn is coupled to a primary side 80 of the torsional vibration damper unit 70 that follows in the torque transmission path. The primary side 80 of the torsional vibration damper unit 70 is coupled to a secondary side 84 of the torsional vibration damper unit 70 via a damper element arrangement 82. The secondary side 84 of the torsional vibration damper unit 70 is coupled to the starting assembly output section 50.

[0030] The turbine wheel 38, coupled via the turbine wheel carrier 48 between the secondary side 78 of the torsional vibration damper unit 68 and the primary side 80 of the torsional vibration damper unit 70, thus forms, together with the turbine wheel carrier 48, the bridging clutch 46 and a damper unit 58, essentially the intermediate mass between the two torsional vibration damper units 68, 70.

[0031] Between the starting assembly output area 50 and the rotor assembly 64 of the electric machine 28, which is rigidly (i.e., permanently) coupled to it, and the drive system output area 62 provided by the transmission input shaft 60, lies the torsional vibration damper unit 70, with its primary side 86 coupled to the starting assembly output area 50 or the rotor assembly 64 and its secondary side 88 coupled to the drive system output area 62 or the transmission input shaft 60. A damper element arrangement 90 of the torsional vibration damper unit 72 acts between the primary side 86 and the secondary side 88 of the torsional vibration damper unit 72.

[0032] The start-up assembly output area 62 together with the rotor arrangement 64 of the electric machine 28 essentially forms the intermediate mass between the secondary side 84 of the torsional vibration damper unit 70 positioned in the housing 30 and the primary side 86 of the torsional vibration damper unit 72 positioned outside the housing 30.

[0033] With regard to the three torsional vibration damper units 68, 70, 72, it should be noted that these can be constructed in a conventional manner. That is, one side of the primary and secondary sides can, for example, comprise two spaced-apart cover plate elements or the like, while the other side of the primary and secondary sides comprises a central plate element engaging between the cover plate elements.The damper element arrangements can each comprise several damper springs, for example helical compression springs, arranged consecutively in the circumferential direction and also nested within one another, which are supported or can be supported circumferentially with respect to the primary and secondary sides in order to permit relative rotation between the primary and secondary sides up to a limit angle of rotation within the elastic effectiveness range of a respective torsional vibration damper unit 68, 70, 72. Upon reaching the limit angle of rotation, the primary and secondary sides of a respective torsional vibration damper unit 68, 70, 72 can no longer be rotated relative to each other.It should be noted that the various torsional vibration damper units 68, 70, 72 can, of course, have fundamentally different designs and, depending on the design of a particular drive train, can also differ in their respective limit torques or the associated limit angles of rotation. This is essential in the case of... Fig. 2 shown structure, that in the torque transmission path between the drive system input area 44 and the drive system output area 62 at least two such serially acting torsional vibration damper units 68, 70, 72 are provided, which each have an intermediate mass between them.

[0034] Another significant contribution to vibration damping can also be made by a [missing information - likely a specific component or feature]. Fig. The damper unit 58 shown in Figure 2 comprises a deflection mass carrier 92 coupled to the turbine wheel carrier 48 in the illustrated example. Several deflection masses 94 are mounted on this carrier, distributed circumferentially, for example, and are deflectable relative to it. The damper unit 58 can be designed as a fixed-frequency damper, in which, when torsional vibrations occur in the drive train 12, the deflection masses 94 are designed to be deflectable relative to the deflection mass carrier 92, for example, circumferentially, against the restoring force generated by one or more restoring springs.Alternatively, the damper unit 58 can be designed as a speed-adaptive damper, in which the force that preloads the deflection masses 94 into their basic relative position with respect to the deflection mass carrier 92 is generated by the centrifugal force acting during rotation, so that with increasing speed the restoring force and thus the natural frequency of such a vibration system also increases.

[0035] Since at the in Fig. In the structure shown in Figure 2, the damper unit 58 is coupled to the turbine wheel carrier 48, increasing the mass and thus also the moment of inertia of the intermediate mass located between the secondary side 78 of the torsional vibration damper unit 68 and the primary side 80 of the torsional vibration damper unit 70.

[0036] A key function comes into play in the Fig. The structure of the torsional vibration damper unit 72, arranged outside the housing 30 between the rotor assembly 64 and the drive system output area 62, is shown in Figure 2. This unit provides vibration decoupling between the transmission input shaft 60 and the entire mass area of ​​the drive train 12 located between the primary side 86 of the torsional vibration damper unit 72 and the drive unit 14. This vibration decoupling is particularly relevant because this mass area includes not only the various system areas of the starting assembly 24, but also the damper unit 58, which is located in the housing 30 and thus also forms part of the starting assembly 24, and the rotor assembly 64 of the electric machine 28. Undamped transmission of vibration excitations in this area of ​​the drive train 12 to the transmission input shaft 60 could lead to excessive stress on the transmission input shaft 60.This can lead to vibrations in various system areas within the transmission assembly 20 intended for torque transmission. However, the vibration decoupling functionality provided by the torsional vibration damper unit 72 eliminates the risk of excessively strong vibrations being transmitted to the transmission input shaft 60.

[0037] The Fig. Figure 3 shows an embodiment of a drive system 22 with a starting assembly 24 designed as a hydrodynamic torque converter. The turbine wheel 38 is connected to an output hub 96, which in this embodiment also provides the turbine wheel carrier 48, for example by riveting. An intermediate shaft 98 is coupled to the output hub 96, for example by gear meshing, for common rotation about an axis of rotation A. The rotor assembly 64 of the electric machine 28 is rigidly coupled, for example by welding, and thus permanently coupled to the intermediate shaft 98.

[0038] The primary side 76 of the torsional vibration damper unit 68, located inside the housing 36, is rigidly connected to a housing shell 100 of the housing 30. The impeller 34, or a pump impeller shell thereof, is essentially provided by a housing shell 101 of the housing 30, against which the guide wheel 40 is also radially and axially supported internally. The secondary side 78 of the torsional vibration damper unit 68 is coupled to the input area 56 of the lock-up clutch 46, forming, for example, a lamellar carrier for an input-side friction lamella 106 of the lock-up clutch, and is rotatably supported on the output hub 96. The damper unit 58, with its deflection mass carrier 92, is further rigidly connected to the secondary side 78, which is provided by a disc section 99, for example by riveting.

[0039] A disc section 102, essentially providing the output side 54 of the lock-up clutch 46, is radially and internally riveted to the turbine wheel carrier 48 and the output hub 96, respectively, together with the turbine wheel 38. A clutch piston 104 of the lock-up clutch 46 can press the input area 56 of the lock-up clutch 46, essentially provided by the aforementioned friction plate 106, against the disc section 102, which essentially provides the output area 54 of the lock-up clutch 46, in order to engage the lock-up clutch 46 and thus create a direct mechanical coupling of the housing 30 with the output hub 96 and thus with the starting element output area 50, bridging the hydrodynamic circuit 32.

[0040] The torsional vibration damper unit 72, located outside the housing 30, is coupled to the intermediate shaft 98 and thus to the starting element output area 50 via its primary side 86, which, for example, comprises two cover plate elements. In the illustrated example, the primary side 86 is directly connected to the rotor assembly 64, which is rigidly and thus permanently coupled to the intermediate shaft 98 and thus to the starting assembly output area 50. The secondary side 88 of the torsional vibration damper unit 72, which in the illustrated embodiment provides a central disc element, is coupled to the transmission input shaft 60 and thus to the drive system output area 62 of the drive system 22. Thus, in hybrid drive mode, the torsional vibration damper unit 72 transmits all the energy provided by the drive unit 14.The torque introduced into the intermediate shaft 98 from the starting assembly 24, as well as the torque introduced into the intermediate shaft 98 by the electric machine 28, is thereby decoupled by the torsional vibration damper unit 72. This provides vibration decoupling between the transmission assembly 20 or its transmission input shaft 60 and the entire area of ​​the drive system 22 or the drive train 12 located upstream of the torsional vibration damper unit 72 in the torque flow.

[0041] Thus, torsional vibrations occurring or generated in this system area upstream of the torsional vibration damper 72 cannot be introduced into the gearbox assembly 20, or can only be introduced in a damped manner, so that there is no risk of excessive stress on components of the gearbox assembly 20 due to vibrations arising or transmitted in this system area.

[0042] Unlike in the Fig. The basic structure shown in section 2 is present in the following example. Fig. In the assembly shown in Figure 3, the damper unit 58 is coupled to the intermediate mass located between the secondary side 78 of the torsional vibration damper unit 68 and the primary side 86 of the torsional vibration damper unit 72 in a region upstream of the lock-up clutch 46, i.e., to the input region 56 of the lock-up clutch 46, but nevertheless contributes to the mass or moment of inertia of this intermediate mass. Furthermore, in the assembly shown in Fig. The structure shown in Figure 3 includes the torsional vibration damper unit 70 arranged between the output area 54 of the bridging clutch 46 and the starting element output area 50, in which the following is located: Fig. The structure shown in Figure 3 is not provided for. However, the drive system 22 includes two series-acting torsional vibration damper units, and a damper unit 58 is coupled to a section of the drive system 22 between these two torsional vibration damper units 68, 72.

[0043] An alternative design of such a drive system 22 is shown in Fig. Figure 4 shows this configuration. In this embodiment, the intermediate shaft 98, which is rotationally fixed to the output hub 96 and thus to the starting element output area 50, is rigidly coupled to the transmission input shaft 60 and thus to the drive system output area 62, for example by means of gear meshing. The rotor assembly 64 of the electric machine 28 is likewise rigidly coupled to the intermediate shaft 98. The two torsional vibration damper units 68 and 70 are arranged in series within the housing 36 of the housing 30 of the starting assembly 24. The primary side 74 of the torsional vibration damper unit 68 is coupled to the output area 54 of the lock-up clutch 46, which is provided by a friction plate 108. The input area 56 of the lock-up clutch 46 is essentially provided by the housing shell 100 and the clutch piston 104, which is held rotationally fixed with respect to it.The secondary side 78 of the torsional vibration damper unit 68 is coupled to, or provided by, the deflection mass carrier 92 of the damper unit 58, which also provides the primary side 80 of the torsional vibration damper unit 76 located further radially inwards. The secondary side 84 of the torsional vibration damper unit 70, comprising two cover plate elements, surrounds the deflection mass carrier 92, which provides the primary side 80, in its radially inner region and is firmly connected to the output hub 96, for example by riveting.

[0044] The turbine wheel 38 is connected to one of the cover plate elements of the secondary side 84 of the torsional vibration damper unit 70, for example by riveting, and thus, unlike in the one in Fig. 2. The structure shown does not contribute to increasing the mass or moment of inertia of the intermediate mass formed between the secondary side 78 of the radially outer torsional vibration damper unit 68 and the primary side 80 of the radially inner torsional vibration damper unit 70, which is essentially provided by the damper unit 58.

[0045] The in Fig. The torsional vibration damper unit 72 shown in Figure 2, which provides a torsionally elastic coupling between the rotor arrangement 64 of the electric machine 28 or the intermediate shaft 98 and the gearbox input shaft 60 and thus the drive system output area 62, is located in the Fig. The structure of a drive system 22 shown in section 4 is not provided for.

[0046] The Fig. Figure 5 illustrates different torque curves in a particular case. Fig. 3 shown drive system 22 or drive train 12. The curve M AIn principle, this represents the curve of the torque M delivered by the drive unit 14 as a function of the rotational speed n. The curve M E represents the torque provided by the electric motor 28 and introduced into the drive train 12. The curve M G represents the total torque which is then introduced into the drive train 12 when the drive unit 14 and the electric machine 28 are operated together in hybrid drive mode to deliver a torque.

[0047] Line G G represents a gearbox input limit torque of the gearbox arrangement 20. This gearbox input limit torque G G should not be exceeded during operation, or only for short periods, in order to avoid damage in the area of ​​the gearbox assembly 20, especially also in the area of ​​the gearbox input shaft 60.

[0048] The Fig. Figure 5 clearly shows that in hybrid drive mode a state could fundamentally occur in which the total torque M G this gearbox input limit torque G G could exceed. Suitable engine power control ensures that, in a vehicle equipped with such a powertrain 12, the total torque M is not exceeded even in hybrid drive mode. G the gearbox input limit torque G G does not exceed or only exceeds it briefly.

[0049] This creates a permanent situation in which the total torque M introduced into the gear arrangement 20 G the gearbox input limit torque G G exceeding, practically excluded, it is possible to find the in the Fig. 2 and Fig. 3 torsional vibration damper unit 72 shown with regard to the limit torque G that can be transmitted by this torsional vibration damper unit in the range of elastic effectivenessT not to the maximum possible total torque M G , but rather on the transmission input limit torque G G to interpret. Fig. Figure 6 illustrates the characteristic curves of the torsional vibration damper unit 72 using curves K1 and K2 (curve K1 for the case of a single-stage or linear design, curve K2 for the case of a two-stage or multi-stage design).

[0050] It can be seen that the primary side 86 of the torsional vibration damper unit 72 and the secondary side 88 of the torsional vibration damper unit 72 are in the range of elastic effectiveness of the torsional vibration damper unit 72 when a limit rotation angle G is reached. E a torsional vibration damper unit limit torque G T transferred. The design of the torsional vibration damper unit 72 such that, upon reaching the limit rotation angle G, E transmitted torsional vibration damper unit limit torque G Tin the area of ​​the gearbox input limit torque G G between a lower torque threshold S U in the range of 80% of the transmission input limit torque G G and an upper torque threshold S O in the range of 150% of the gearbox input limit torque G G On the one hand, this ensures that the transmission input limit torque G is maintained due to the motor control described above. G The torques to be transmitted, which do not exceed the limit, can be transmitted entirely within the elastic effectiveness range of the torsional vibration damper unit 72, i.e., in a range in which the primary side 86 and the secondary side 88 are not yet locked against rotation relative to each other. For example, the torsional vibration damper unit limit torque G is... T below the gearbox input limit torque G G. This design ensures that the damper element arrangement 90 of the torsional vibration damper unit 72 does not need to be provided with excessively high stiffness, i.e., spring constant, so that the torsional vibration damper unit 72 can provide vibration decoupling for the gearbox arrangement 20 in an optimized manner.

[0051] It should be noted that the foregoing refers to the Fig. 2, Fig. 3 to Fig. The drive system described in section 4 can be varied in different ways. For example, as an alternative or in addition to the damper unit 58 provided in the starting assembly 24, one or more damper units could also be provided outside the starting assembly 24. For example, in the Fig. In the structure shown in Figure 3, a damper unit together with the primary side 86 of the torsional vibration damper unit 72 may be coupled to the rotor arrangement 64 of the electric machine or could be directly coupled to the intermediate shaft 98.

[0052] It should also be noted that, in particular, those involved in the Fig. The protective function for the gearbox arrangement 20 introduced by the torsional vibration damper unit 72 in the torque transmission path between the rotor arrangement 64 of the electric machine 28 and the drive system output area 62 in the embodiment shown in Figure 3 can also be achieved if no further torsional vibration damper unit is provided further upstream in the torque flow, for example in the starting assembly 24.

[0053] The electric motor 28 can also be arranged parallel to the axis of rotation of the transmission input shaft 60 and coupled to it, for example, by means of a belt drive, a spur gear drive, or a chain drive, wherein preferably a speed reduction is achieved by such a coupling, so that the transmission input shaft 60 rotates at a lower speed. When a torsional vibration damper unit 72 is used, the electric motor 28 is preferably rotationally fixed to its primary side 86. Reference sign 10 vehicles 12 Powertrain 14 Drive unit 16 drive wheel 18 drive wheel 20 Gear arrangement 22 Drive system 24 Starting assembly 26 Torsional vibration damper arrangement 28 Electric machine 30 cases 32 hydrodynamic cycle 34 Pump wheel 36 Housing interior 38 Turbine wheel 40 Guide wheel 42 Starting assembly - entrance area 44 Drive system input area 46 Jumper coupling 48 turbine wheel carriers 50 Starting assembly - output area 52 Clutch 54 Output area of ​​the jump-start clutch 56 Input area of ​​the jump-start coupling 58 damper units 60 Gearbox input shaft 62 Drive system output area 64 Rotor arrangement 66 Stator arrangement 68 Torsional vibration damper unit 70 Torsional vibration damper unit 72 Torsional vibration damper unit 74 Primary page 76 damper element arrangement 78 Secondary page 80 Primary page 82 damper element arrangement 84 Secondary page 86 Primary page 88 Secondary page 90 damper element arrangement 92 Deflection mass carriers 94 deflection mass 96 Output hub 98 Intermediate shaft 99 disc part 100 housing shells 101 Housing shell 102 disc part 104 clutch pistons 106 friction plate 108 friction plate M torque n rotational speed M A Torque of the drive unit M E torque of the electric machine M G Total torque G G Gearbox input limit torque G T Torsional vibration damper unit - limit torque W Relative rotation angle K1 characteristic curve K2 characteristic curve G E Limiting rotation angle S U lower torque threshold Thus, the upper torque threshold A axis of rotation

Claims

Drive system for a vehicle, comprising: - a drive system input area (44) to be coupled to a drive unit (14), - a drive system output area (62) to be coupled to a transmission arrangement (20), - a starting assembly (24), wherein the starting assembly (24) comprises a starting assembly input area (42) coupled to or providing the drive system input area (44) and a starting assembly output area (50) coupled to or providing the drive system output area (62), - an electric machine (28) coupled to the starting assembly output area (50) and / or the drive system output area (62), - a torsional vibration damper arrangement (26) with at least two torsional vibration damper units (68, 70) arranged in series between the drive system input area (44) and the drive system output area (62). 72), characterized thereby,that a rotor arrangement (64) of the electric machine (28) is rigidly coupled to the starting assembly output area (50). Drive system according to claim 1, characterized in that at least one of the torsional vibration damper units (68, 70, 72) is arranged in the torque transmission path between a rotor arrangement (64) of the electric machine (28) and the drive system output area (60). Drive system according to one of the preceding claims, characterized in that at least one damper unit (58) is provided with a deflection mass carrier (92) and at least one deflection mass (94) which is mounted on the deflection mass carrier (92) so as to be deflected from a basic relative position against a restoring force. Drive system according to claim 3, characterized in that at least one damper unit (58) is arranged in the torque transmission path between two torsional vibration damper units (68, 70, 72). Drive system according to claim 3 or 4, characterized in that the start-up assembly input area (42) comprises the housing (30), and / or that the start-up assembly output area (50) comprises an output hub (68) arranged in the housing (30). Powertrain for a vehicle comprising a drive unit (14) coupled to a transmission arrangement (20) by means of a drive system (22) according to one of the preceding claims. Drive train according to claim 6, insofar as it refers back to claim 2, characterized in that a torsional vibration damper unit limit torque (GT) transmissible in the area of ​​elastic effectiveness of the torsional vibration damper unit arranged at least in the torque transmission path between the rotor arrangement (64) of the electric machine (28) and the drive system output area (62) lies in a range of 80 % to 150 % of a gearbox input limit torque (GG) of the gearbox arrangement (20). Drive train according to claim 6, insofar as it refers back to claim 2 or 6, characterized in that a torsional vibration damper unit limit torque (GT) transmissible in the area of ​​elastic effectiveness of the torsional vibration damper unit arranged at least in the torque transmission path between the rotor arrangement (64) of the electric machine (28) and the drive system output area (62) lies in a range of 90% to 110% of a gearbox input limit torque (GG) of the gearbox arrangement (20). Drive train according to claim 7 or 8, characterized in that the torsional vibration damper unit limit torque (GT) is below the transmission input limit torque (GG).

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