Hybrid drive system for a motor vehicle and motor vehicle

Abstract

Hybrid drive system (16) for a motor vehicle, comprising: - an internal combustion engine (18) which has a first output shaft (24), - an electric machine (28) which has a rotor (32) with a rotor shaft (34) as a second output shaft, and - a transmission (38) comprising a four-shaft first planetary set (40), a second planetary set (44), a first switching element (46a), a second switching element (46b), a third switching element (46c) and a third output shaft (62), wherein: ◯ the four-wave first planetary set (40) has a first wave (42a), a second wave (42b), a third wave (42c) and a fourth wave (42d), ◯ the second planetary set (44) has a first element (48), a second element (50) and a third element (52), ◯ the first shaft (42a), the second shaft (42b), the third shaft (42c) and the fourth shaft (42d) are rotatable relative to each other and can be connected to each other in a rotationally fixed manner by means of the second switching element (46b), ◯ the first output shaft (24) is rotationally fixed to the first shaft (42a) or can be coupled, ◯ the rotor shaft (34) is coupled or can be coupled to the second shaft (42b) in such a way that torques emanating from the rotor shaft (34) can be introduced into the gearbox (38) via the second shaft (42b), and ◯ the third shaft (42c) can be connected to the third output shaft (62) in a rotationally fixed manner by means of the first switching element (46a), wherein the fourth shaft (42d) is connected or can be connected to the first element (48) of the second planetary set (44) in a rotationally fixed manner, characterized in that the first shaft (42a) comprises a first sun gear (76) of the first planetary set (40) and the third shaft (42c) comprises a second sun gear (78) of the first planetary set (40).

Description

[0001] The invention relates to a hybrid drive system for a motor vehicle according to the preamble of claim 1. Furthermore, the invention relates to a motor vehicle with such a hybrid drive system.

[0002] The transmissions for a hybrid drive arrangement are known from DE 10 2019 208 556 A1, DE 10 2007 054 359 A1, and EP 0 787 926 A2.

[0003] Furthermore, US 2009 / 0 275 437 A1 and DE 11 2006 001 124 T5 show hybrid drive systems, each with a gearbox that has a four-shaft first planetary set and a second planetary set designed separately from the four-shaft planetary set.

[0004] The object of the present invention is to create a hybrid drive system for a motor vehicle, in particular for a motor car, and a motor vehicle, so that a particularly space-saving and cost-effective design of the hybrid drive system can be realized.

[0005] This problem is solved by a hybrid drive system with the features of claim 1 and by a motor vehicle with the features of claim 12. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0006] A first aspect of the invention relates to a hybrid drive system for a motor vehicle, in particular for a motor vehicle preferably designed as a passenger car. This means that the motor vehicle, in its fully manufactured state, comprises the hybrid drive system, also referred to as a hybrid drive unit, and can be driven by means of the hybrid drive system. The hybrid drive system comprises an internal combustion engine, also referred to as an internal combustion engine, which has a first output shaft. Preferably, the internal combustion engine is designed as a reciprocating engine, such that the first output shaft is preferably a crankshaft. Via the first output shaft, the internal combustion engine can provide first drive torques, also referred to as first drive torques, for driving the motor vehicle.The hybrid drive system also includes an electric machine with a rotor and a rotor shaft. The rotor shaft is a second output shaft, also referred to as a second output shaft. Via the rotor shaft, the electric machine can provide second torques, also referred to as second drive torques, for propelling the vehicle. For example, the electric machine has a stator by means of which the rotor can be driven. The rotor is rotatable about a machine axis of rotation relative to the stator. The rotor shaft is a second output shaft, also referred to as a second output shaft. Preferably, the electric machine is a high-voltage component whose electrical voltage, in particular its operating or rated voltage, is preferably greater than 50 volts, particularly greater than 60 volts, and most preferably several hundred volts.This allows for particularly high electrical power outputs, especially for purely electric propulsion of the vehicle. Specifically, the electric machine can be operated in motor mode, thus functioning as an electric motor, which can be used to drive the vehicle, particularly in purely electric mode. In its motor mode, the electric machine provides the necessary secondary drive torque for propelling the vehicle.

[0007] The hybrid drive system comprises a transmission with a four-shaft first planetary gear set. The characteristic that the first planetary gear set, also referred to as the first planetary gear set, is a four-shaft planetary gear set means, in particular, that the first planetary gear set has at least, or preferably exactly, four shafts through which a respective torque can be introduced into and / or extracted from the first planetary gear set. The transmission also comprises a second planetary gear set, also referred to as the second planetary gear set, which is provided in addition to the first planetary gear set. Furthermore, the transmission comprises a first shift element, a second shift element, and a third shift element. The transmission also comprises a third output shaft through which torques, also referred to as output torques, can be extracted from the transmission.In other words, the transmission can provide output torques for propelling the vehicle via its third output shaft. For example, the respective output torque results from the respective first input torque and / or the respective second input torque. The shafts of the four-shaft first planetary gear set are also referred to as the first shaft, second shaft, third shaft, and fourth shaft. The second planetary gear set comprises a first element, a second element, and a third element. The elements of the second planetary gear set are also referred to as gear components. In particular, the elements of the second planetary gear set can be a sun gear, a planet carrier (also called a carrier), and a ring gear.The first, second, third, and fourth shafts are rotatable relative to each other and, for example, relative to a housing of the hybrid drive system, particularly about a planetary gear set rotation axis. It is conceivable that the first and / or second planetary gear set are each at least partially located within the housing. The first, second, third, and fourth shafts can be connected to each other in a rotationally fixed manner by means of a locking switching element of the hybrid drive system. It is conceivable that the locking switching element is provided in addition to the aforementioned switching elements and thus constitutes a fourth switching element, or that the locking switching element is formed by one of the aforementioned switching elements. The planetary gear set rotation axis is also simply referred to as the rotation axis.

[0008] The first output shaft is or can be coupled to the first shaft in a rotationally fixed manner. This means, in particular, that the first output shaft is permanently and rotationally fixed to the first shaft, or that the first output shaft can be connected to the first shaft in a rotationally fixed manner.

[0009] Within the scope of the present disclosure, the feature that two components are connected to each other in a rotationally fixed manner is to be understood as meaning that the components are arranged coaxially to each other and are connected to each other in such a way that they rotate together at the same angular velocity about a component rotation axis common to the components.

[0010] The characteristic that the two components are permanently connected to each other in a rotationally fixed manner means that there is no switching element which can be switched between a coupling state that connects the components in a rotationally fixed manner and a decoupling state that releases the components for rotation relative to each other, in particular about the axis of rotation of the components; rather, the components are always permanently connected to each other in a rotationally fixed manner.

[0011] The characteristic that the two components can be connected to each other in a rotationally fixed manner means that the components are assigned a switching element which can be switched between at least one coupled state and at least one decoupling state. In the coupled state, the components are rigidly connected to each other by means of the switching element. In the decoupling state, the components are decoupled from each other, so that in the decoupling state the components can be rotated relative to each other, in particular about the component rotation axis.

[0012] In the hybrid drive system, the rotor shaft is also designed to be coupled or connectable to the second shaft, in particular in a rotationally fixed manner, such that torques originating from or provided by the rotor shaft, such as the second drive torques, can be transmitted to the gearbox via the second shaft. Furthermore, the third shaft is designed to be connected to the third output shaft in a rotationally fixed manner by means of the first switching element. This means, in particular, that the first switching element is switchable between a first coupling state and a first decoupling state. In the first coupling state, the third shaft is connected to the third output shaft in a rotationally fixed manner by means of the first switching element.In the first decoupling state, the first switching element releases the third shaft and the third output shaft such that, in the first decoupling state, the third shaft is rotatable relative to the third output shaft, or vice versa. The first switching element is movable, particularly relative to the housing and / or translationally, between at least one first coupling position and at least one first decoupling position. The first coupling position effects the first coupling state, and the first decoupling position effects the first decoupling state.

[0013] To achieve a particularly space-saving and cost-effective design for the hybrid drive system, the fourth shaft is provided, in a known manner, for being rotationally fixed to the first element of the second planetary gear set. This allows for a particularly compact design, especially in the axial direction of the transmission and thus of the hybrid drive system. Within the context of this disclosure, the term "axial" refers to the axis of rotation of the planetary gear set, so that, particularly when viewed along this axis, a particularly compact, i.e., short, design of the hybrid drive system can be achieved. In other words, a particularly short length of the hybrid drive system along the axial direction of the transmission can be realized.Furthermore, components in the axial direction of the transmission can be arranged particularly close to the internal combustion engine, thus enabling a particularly small installation space requirement for the hybrid drive system. In addition, the costs of the hybrid drive system according to the invention can be kept particularly low. Consequently, the transmission can be advantageously integrated into the vehicle, especially as a hybrid multi-speed transmission. By using the shift elements, the transmission can be designed as a multi-speed transmission. This means that several switchable, and therefore selectable and configurable, gears of the transmission can be created, whose gears differ, for example, in their respective ratios. It is also possible to design at least one, several, or all gears of the transmission to be capable of load shifting.

[0014] Particularly advantageous is the fourth shaft being connected or connectable to the first element of the second planetary set in a rotationally fixed manner, bypassing the first switching element.

[0015] Within the scope of the present disclosure, coaxially arranged rotatable components are understood to be components or elements which are rotatable, in particular, relative to the housing about a respective component rotation axis, wherein the component rotation axes are coaxial to each other or coincide.

[0016] According to the invention, the first shaft comprises a first sun gear of the first planetary gear set, and the third shaft comprises a second sun gear of the first planetary gear set. This allows for a particularly efficient drive system for the motor vehicle in a space-saving, weight-efficient, and cost-effective manner.

[0017] In order to keep the installation space requirement, weight and cost of the hybrid drive system particularly low, an advantageous embodiment of the invention provides that the second planetary set has exactly three elements in the form of the aforementioned elements.

[0018] Another embodiment is characterized in that the four-shafted first planetary gear set has exactly four shafts in the form of the aforementioned shafts. This allows for a particularly space-saving, lightweight, and cost-effective design of the hybrid drive system. Preferably, the first planetary gear set has six gear elements, namely preferably two sun gears, two planet carriers, and two ring gears. A person skilled in the art initially assigns each of these six gear elements to a shaft, resulting in a total of six shafts. Preferably, two of the six elements of the first planetary gear set are rotationally fixed to one another. And preferably, another two of the six elements of the first planetary gear set are rotationally fixed to one another. Thus, the first planetary gear set preferably has four shafts arranged to be rotatable relative to one another.

[0019] In a further, particularly advantageous embodiment of the invention, the second element of the second planetary gear set can be connected to the housing in a rotationally fixed manner by means of the third switching element. Thus, for example, the third switching element can be switched between a second coupling state and a second decoupling state. In the second coupling state, the second element is connected to the housing in a rotationally fixed manner by means of the third switching element, so that relative rotations between the housing and the second element are prevented. In the second decoupling state, the third switching element releases the second element for rotation around the housing, so that in the second decoupling state the second element is rotatable relative to the housing, in particular about an element rotation axis, which is a rotation axis of the second planetary gear set.It is particularly preferred that the planetary gear sets are arranged coaxially to one another, so that the axis of rotation of the planetary gear set, about which the shafts are rotatable, particularly relative to the housing and / or relative to each other, coincides with the axis of rotation of the element of the second planetary gear set. The third switching element, for example, is movable, particularly relative to the housing and / or translationally, between at least one second coupling position that effects the second coupling state and / or at least one second decoupling position that effects the second decoupling state.

[0020] Furthermore, it is preferably provided that the first element is permanently connected or coupled to the fourth shaft in a rotationally fixed manner.

[0021] Furthermore, in this embodiment, it is preferably provided that the third element is permanently and rotationally fixed to the third output shaft. This allows for a particularly compact design of the hybrid drive system.

[0022] To achieve a particularly compact design of the hybrid drive system, especially in the axial direction of the transmission, a further embodiment of the invention provides that the second element is permanently and rotationally fixed to the housing. It has proven particularly advantageous if the first element can be rotationally fixed to the fourth shaft by means of the third switching element. In this embodiment, the first element is thus rotationally fixed to the fourth shaft by means of the third switching element in the second coupled state, and in the second uncoupled state, the third switching element releases the first element and the fourth shaft such that the first element and the fourth shaft can rotate relative to each other, particularly about the planetary gear set axis of rotation or about the element axis of rotation.Furthermore, these embodiments are characterized by the fact that the third element is permanently connected to the third output shaft in a rotationally fixed manner.

[0023] In a further, alternative, and particularly advantageous embodiment of the invention, the second element is permanently connected to the housing in a rotationally fixed manner. The first element is permanently connected to the fourth shaft in a rotationally fixed manner, and the third element can be connected to the third output shaft in a rotationally fixed manner by means of the third switching element. Thus, in this embodiment, it is preferably provided that in the second coupled state, the third element is rotationally fixed to the third output shaft by means of the third switching element, and in the second uncoupled state, the third switching element releases the third element and the third output shaft such that the third element and the third output shaft are rotatable relative to each other, in particular about the planetary gear set's axis of rotation or about the element's axis of rotation.This allows for a particularly short length of the hybrid drive system, especially when viewed in the axial direction of the gearbox.

[0024] To minimize the number of parts and thus the cost, weight, and installation space required for the hybrid drive system, a further embodiment of the invention provides for a total of exactly three switching elements: the first switching element, the second switching element (designed as the interlocking switching element), and the third switching element. In other words, the hybrid drive system comprises exactly three switching elements, with the first switching element being the interlocking switching element. Furthermore, this allows, for example, the aforementioned gears, particularly those capable of power shifting, to be implemented advantageously, enabling the transmission to be designed as a multi-speed transmission with a particularly compact, lightweight, and cost-effective design.

[0025] Another embodiment is characterized in that the electric machine is arranged coaxially, axially overlapping, and radially surrounding the gearbox. This means, in particular, that the electric machine is arranged coaxially with the gearbox, meaning that the axis of rotation of the machine, about which the rotor is rotatable relative to the stator, coincides with the axis of rotation of the first planetary set and thus preferably also with the axis of rotation of the second planetary set.The feature that the electric machine is arranged axially overlapping the gearbox means, in particular, that at least a first longitudinal region of the gearbox, especially at least a first longitudinal region of the first planetary gear set and / or the second planetary gear set, is overlapped or covered in the radial direction of the gearbox, i.e., along a direction perpendicular to the planetary gear set's axis of rotation, by at least a second longitudinal region of the electric machine. Furthermore, the feature that the electric machine is arranged radially surrounding the gearbox means that at least the second longitudinal region of the electric machine completely surrounds at least the first longitudinal region of the gearbox in the circumferential direction of the gearbox's axis of rotation, such that the first longitudinal region is located within the second longitudinal region.This allows for a particularly compact design of the hybrid drive system.

[0026] In a further, particularly advantageous embodiment of the invention, the second shaft comprises a first ring gear of the first planetary gear set and a second ring gear of the first planetary gear set, which is, in particular, permanently and rotationally fixed to the first ring gear. This allows the number of parts, and thus the costs, installation space requirements, and weight of the hybrid drive system, to be kept to a particularly low level.

[0027] In a further, particularly advantageous embodiment of the invention, the fourth shaft comprises a first planet carrier of the first planetary gear set, the first planet carrier of which can be, for example, and in particular permanently, rotationally fixed to the second planet carrier of the second planetary gear set. This allows for a particularly space-saving and advantageous drive system for the motor vehicle.

[0028] Finally, it has proven particularly advantageous if the internal combustion engine, an output pinion (which is, in particular, permanently and rotationally fixed to the third output shaft), the second planetary gear set, and the four-shafted first planetary gear set are arranged in the following order, viewed axially along the transmission and thus along the planetary gear set's axis of rotation: the internal combustion engine – the output pinion – the second planetary gear set – the four-shafted first planetary gear set. In other words, it is preferably provided that, viewed axially along the transmission and thus along the planetary gear set's axis of rotation, the output pinion follows the internal combustion engine, the second planetary gear set follows the output pinion, and the four-shafted first planetary gear set follows the second planetary gear set. This allows the axial length of the hybrid drive system to be kept to a particularly short standard.

[0029] A second aspect of the invention relates to a motor vehicle, preferably a passenger car, which has a hybrid drive system according to the first aspect of the invention and can be driven by means of the hybrid drive system. Thus, the motor vehicle is designed as a hybrid vehicle. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa. Since the length of the hybrid drive system extending in the axial direction of the transmission can be kept particularly short, the hybrid drive system can be particularly advantageously installed transversely, i.e., used as a transverse installation.This means that, in the fully manufactured state of the motor vehicle, the axial direction of the transmission and thus of the hybrid drive system as a whole runs transversely or perpendicular to the longitudinal direction of the vehicle (y-direction).

[0030] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combinations, but also in other combinations or on their own, without departing from the scope of the invention.

[0031] The drawing shows in: Fig. 1 a schematic representation of a powertrain for a motor vehicle, with a hybrid drive system according to the invention; Fig. 2 a schematic representation of the hybrid drive system according to a first embodiment; Fig. 3 a schematic representation of the hybrid drive system according to a second embodiment; and Fig. 4. A switching table to explain different operating states of the hybrid drive system.

[0032] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0033] Fig. Figure 1 shows a schematic representation of a drive train 10 for a motor vehicle, preferably a passenger car. In its fully manufactured state, the motor vehicle has at least or exactly two axles arranged one behind the other in the longitudinal direction (x-direction), also referred to as vehicle axles, with the drive train 10 comprising one of the axles. The axle of the drive train 10 is in Fig. 2, denoted by 12. The axle 12 has at least or exactly two wheels 14 opposite each other in the transverse direction (y-direction) of the vehicle, which are also referred to as vehicle wheels and are driven wheels. By driving the wheels 14, the motor vehicle as a whole is driven. The powertrain 10 comprises a hybrid drive system 16 by means of which the wheels 14, and thus the motor vehicle, can be driven. The hybrid drive system 16 has a combustion engine, also referred to as an internal combustion engine.

[0034] Internal combustion engine 18 on. From Fig. Figure 1 shows that the internal combustion engine 18 has an engine block 20 which forms, or in particular directly defines, several cylinders 22. Each cylinder 22 partially defines a combustion chamber in which combustion processes take place during operation of the internal combustion engine 18. The internal combustion engine 18 has a first output shaft 24, which in this case is a crankshaft. The internal combustion engine 18 is designed as a reciprocating piston engine. The crankshaft (first output shaft 24) is rotatable about a crankshaft axis 26 relative to the engine block 20. The internal combustion engine 18 can provide initial drive torques for propelling the motor vehicle via the crankshaft.

[0035] The hybrid drive system 16 also includes a Fig. 1. Particularly schematically represented, electrical machine 28. As from Fig. Figure 2, which shows a first embodiment of the hybrid drive system 16, shows that the electric machine 28 has a stator 30 and a rotor 32, which includes a rotor shaft 34. The rotor 32, and thus the rotor shaft 34, are rotatable about a machine axis of rotation 36 relative to the stator 30 and also relative to the motor block 20. Fig. Figure 2 shows that the electric machine 28 is arranged coaxially to the internal combustion engine 18, so that the machine's axis of rotation 36 coincides with the crankshaft's axis of rotation 26. The rotor 32, or the rotor shaft 34, is a second output shaft via which the electric machine 28, particularly in its motor operation, can provide second drive torques for propelling the motor vehicle or the wheels 14.

[0036] The hybrid drive system 16 also includes a transmission 38. The transmission 38 has a four-shaft first planetary gear set 40, which has at least, or in this case exactly, four shafts 42a-d. The transmission 38 also includes a second planetary gear set 44 and, in particular, exactly three switching elements 46a-c; namely, a first switching element 46a, a second switching element 46b, and a third switching element 46c. The first switching element 46a is also referred to as SB, the second switching element 46b is also referred to as SK, and the third switching element 46c is also referred to as SA. The shaft 42a is also referred to as the first shaft 42a, the shaft 42b is also referred to as the second shaft 42b, the shaft 42c is also referred to as the third shaft 42c, and the shaft 42d is also referred to as the fourth shaft 42d. The second planetary gear set 44 has, in particular, exactly three elements. In the Fig. In the first embodiment shown in Figure 2, a first element of the second planetary gear set 44 is a third sun gear 48 of the second planetary gear set 44, a second element of the planetary gear set 44 is a third ring gear 50 of the second planetary gear set 44, and the third element of the second planetary gear set 44 is a second planet carrier 52 of the second planetary gear set 44. The second planet carrier 52 is also referred to as the second web. The second planetary gear set 44 comprises second planet gears 54 of the second planetary gear set 44, which are rotatably mounted on the second planet carrier 52. The respective second planet gear 54 meshes directly with the sun gear 48 on one side and directly with the ring gear 50 of the second planetary gear set 44 on the other. The shafts 42a-d are oriented relative to each other in Fig. Two housings 56 of the gearbox 38, and thus of the hybrid drive system 16, shown in a particularly schematic way, are rotatable about a planetary set rotation axis 58, also simply referred to as the axis of rotation. Fig. 2 It can be seen that the planetary gear set 40 is arranged coaxially with the electric machine 28 and coaxially with the internal combustion engine 18, such that the planetary gear set's axis of rotation 58 (axis of rotation) coincides with the machine's axis of rotation 36 and with the crankshaft's axis of rotation 26. Furthermore, at least one of the elements of the planetary gear set 44 is rotatable about an element axis of rotation 60 relative to the housing 56 and / or relative to at least one other element of the planetary gear set 44. From Fig. Figure 2 shows that the planning sets 40 and 44 are arranged coaxially to each other, so that the planetary set rotation axis 58 coincides with the element rotation axis 60. Furthermore, the element rotation axis 60 coincides with the machine rotation axis 36 and with the crankshaft rotation axis 26. In addition, the shafts 42a-d can be connected to each other in a rotationally fixed manner by means of a locking element. In the Fig. In the first embodiment shown in Figure 2, the locking switching element is formed by the second switching element 46b, so that the shafts 42a-d can be connected to each other in a rotationally fixed manner by means of the second switching element 46b.

[0037] The gearbox 38 includes a third output shaft 62, through which output torques can be transmitted from the gearbox 38. The respective output torque results, for example, from the respective first input torque and / or the respective second input torque. The third shaft 42c is rotationally fixed to the third output shaft 62 by means of the first switching element 46a. Fig. 2 It can be seen that the transmission 38 has a gear in the form of an output pinion 64, which is permanently and rotationally fixed to the output shaft 62. From Fig. It can be seen that the hybrid drive system 16 can have a final drive ratio 66, also referred to as a final drive or final drive transmission, which can be single-stage or multi-stage. The final drive ratio 66 includes the output pinion 64. The axle 12 includes a differential gear 68, also simply referred to as a differential, whose function includes, in particular, allowing different rotational speeds of the wheels 14 when the vehicle is cornering, especially such that the outer wheel rotates or can rotate at a higher speed than the inner wheel, particularly while the wheels 14 are driven by the internal combustion engine 18 and / or the electric motor 28 via the differential gear 68.The final gear ratio 66 is located in the torque flow, and is situated between the output shaft 62 and the differential gear 68, i.e. downstream of the output shaft 62 and upstream of the differential gear 68, with respect to a torque flow via which the respective output torque provided by the transmission 38 via the third output shaft 62 can be transmitted from the output shaft 62 to the differential gear 68, and is arranged in the torque flow and therein between the output shaft 62 and the differential gear 68, i.e. downstream of the output shaft 62 and upstream of the differential gear 68, wherein the final gear ratio 66 is the last gear ratio before the differential gear 68 along the torque flow flowing from the output shaft 62 to the differential gear 68.

[0038] The hybrid drive system 16 also includes a disconnect clutch 70, which is also designated K0. The disconnect clutch 70 is preferably a friction clutch. In particular, the disconnect clutch 70 can be a multi-plate clutch. By means of the disconnect clutch 70, the crankshaft (output shaft 24) can be connected to the first shaft 42a in a rotationally fixed manner.

[0039] In order to achieve a particularly space-saving and cost-effective design of the hybrid drive system 16, the fourth shaft 42d is rotationally fixed to, or can be connected to, the first element of the second planetary gear set 44. Thus, in the Fig. In the first embodiment shown in 2, it is provided that the fourth shaft 42d is permanently, and in particular non-rotatably, connected to the sun gear 48 of the planetary set 44.

[0040] Out of Fig. 1 and Fig. 2. It is evident that the hybrid drive system 16 is a vehicle drive system comprising at least the internal combustion engine 18, the electric machine 28, and the planetary gear set 40, which has at least or exactly four shafts. Furthermore, the hybrid drive system 16 comprises a first mechanical section 72 and a second mechanical section 74. The hybrid drive system 16 also includes a node K, to or in which the sections 72 and 74 are connected or connectable, in particular in a rotationally fixed manner. The node K is connected or connectable to the driven axle 12 and thus to the wheels 14. In the first embodiment, the shaft 42a is or can be connected to the crankshaft in a rotationally fixed manner, in particular by means of the disconnecting clutch 70. For example, the shaft 42d is part of the mechanical section 72, which thus comprises the shaft 42d and, in particular, as a further shaft, the second planet carrier 52.Furthermore, the mechanical system 72 includes a sub-gearbox, which in this case is configured as the second planetary gear set 44. The sub-gearbox is connected directly or indirectly to the shaft 42d and the other shaft (planet carrier 52). For example, the shaft 42c is part of the mechanical system 74, which thus includes the shaft 42c and the switching element 46a, as well as the output shaft 62. In this case, for example, node K includes the output pinion 64, so that the shaft 42c can be connected to the output shaft 62 and thus to node K (output pinion 64) in a rotationally fixed manner by means of the switching element 46a. The rotor shaft 34 need not be a separate shaft, so it is conceivable that the rotor 32 can be directly connected to or already connected to the shaft 42b; in other words, the rotor shaft 34 can be the shaft 42b, or vice versa.In other words, the rotor shaft 34 can be formed integrally with the shaft 42b, or vice versa.

[0041] Preferably, the partial transmission, i.e., the planetary gear set 44, has a gear ratio other than 1:1 or a gear stage with a gear ratio other than 1:1. Furthermore, the mechanical section 72 includes the third switching element 46c, also designated SA, by means of which, for example in the second embodiment, the ring gear 50 of the planetary gear set 44 can be connected to the housing 56 in a rotationally fixed manner. Thus, when the switching element SA (third switching element 46c) is closed, a mechanical connection exists between one of the shafts 42a-d of the four-shaft first planetary gear set 40 and the node K, in particular via the mechanical section 72. The switching element SA can be arranged inside or outside the partial transmission.

[0042] It is evident that in the first embodiment, the second planetary gear set 44 comprises exactly three elements in the form of the sun gear 48, the ring gear 50, and the planet carrier 52. Furthermore, it is provided that the four-shafted first planetary gear set 40 comprises exactly four shafts 42-d. In the Fig. In the first embodiment shown in Figure 2, the ring gear 50, which is one or the second element of the planetary set 44, can be connected to the housing 56 in a rotationally fixed manner by means of the third switching element 46c, and the sun gear 48, which is the first element of the planetary set 44, is connected, in particular permanently, in a rotationally fixed manner to the fourth shaft 42d, and the planet carrier 52, which is one or the third element of the planetary set 44, is connected, in particular permanently, in a rotationally fixed manner to the output shaft 62 (third output shaft).

[0043] Fig. Figure 3 shows a second embodiment of the hybrid drive system 16. In the second embodiment, the ring gear 50 (second element) is, in particular, permanently, rotationally fixed to the housing 56, and the sun gear 48 (first element) is, in particular, permanently, rotationally fixed to the fourth shaft 42d, and the planet carrier 52 (third element) can be connected to the third output shaft 62 and thus to the output pinion 64 and the node K by means of the third switching element 46c in a rotationally fixed manner.

[0044] In a third embodiment not shown in the figures, the second element (ring gear 50) is connected, in particular permanently, to the housing 56 in a rotationally fixed manner, and the first element (sun gear 48) can be connected, in particular permanently, to the fourth shaft 42d by means of the third switching element 46c, and the third element (planet carrier 52) is connected, in particular permanently, to the third output shaft 62 in a rotationally fixed manner.

[0045] In a further embodiment, it is conceivable that the second element (ring gear 50) can be connected to the housing 56 in a rotationally fixed manner by means of the switching element 46c, and that the first element (ring gear 48) is connected, in particular permanently, in a rotationally fixed manner to the fourth shaft 42d, and that the third element (planet carrier 52) can be connected to the third shaft 42c in a rotationally fixed manner by means of the second switching element 46b.

[0046] In principle, it is conceivable that the output pinion 64 meshes directly with the differential gear 68, i.e., with an input gear of the differential gear 66 designed, for example, as a ring gear, or an intermediate gear can be provided such that the output pinion 64 meshes directly with the intermediate gear without meshing directly with the input gear, which meshes directly with the intermediate gear.

[0047] Preferably, the four-shaft first planetary gear set 40 is configured such that the first shaft 42a forms a single, or sum, shaft with respect to the fourth shaft 42d and the third output shaft 62, particularly as soon as a gear stage in the sub-transmission is actively engaged and the switching element SB (first switching element 46a) is closed, and the electric machine 28 does not provide significant torque, and that the fourth shaft 42d forms a single, or sum, shaft with respect to the rotor shaft 34 and the first shaft 42a as soon as a gear stage in the sub-transmission is actively engaged and the switching element SB is open, and the electric machine 28 provides significant torque. In the embodiment shown in the figures, the sub-transmission is configured as a planetary gear set and thus forms the second planetary gear set 44. The planetary gear set 44 is preferably configured as a three-shaft planetary gear set, and more precisely, as such.In at least one switching state of the switching element SA (third switching element 46c), a mechanical connection exists, particularly via the partial transmission, between the four-shaft first planetary gear set 40 and the node K, preferably with a gear ratio other than 1, i.e., not 1:1. Alternatively or additionally, it can preferably be provided that the mechanical path 74 between the planetary gear set 40 and the node K does not contain a separate gear ratio stage such as a gear pair, a planetary gear set, or the like, so that preferably the mechanical path 74 between the four-shaft first planetary gear set 40 and the node K is directly geared or has a gear ratio of 1 (1:1).

[0048] The four-shaft first planetary gear set 40 can preferably be locked together by means of a locking switching element, also referred to as SK. In the embodiments shown in the figures, the second switching element 46b is used as the locking switching element SK. By locking the four-shaft first planetary gear set 40, its four shafts 42a-d rotate as a unit and thus at an identical speed, in particular about the planetary gear set's axis of rotation 58 and relative to the housing 56. It is preferably provided that the switching element SK (locking switching element or second switching element 46b), in its closed or switched state, couples or connects at least any two of the shafts 42a-d of the four-shaft first planetary gear set 40 to each other in a rotationally fixed manner.

[0049] The switching element SK (second switching element 46b) can be designed as a friction-fit connection. The switching element SK can be designed as a positive-fit connection. The switching element SK can be designed as a positive-fit connection but not synchronized.

[0050] The switching element SB (first switching element 46a) can be designed to be positively locked, particularly within the mechanical path 74. The switching element SB can be designed to be positively locked but not synchronized, particularly within the mechanical path 74. The switching element SB can be frictionally locked, particularly within the mechanical path 74.

[0051] The internal combustion engine (internal combustion engine 18), or rather its crankshaft, can be decoupled from the rest of the drive train 10, also referred to as the powertrain, by means of the disconnecting clutch 70. The disconnecting clutch, also designated K0, can be friction-fit. The disconnecting clutch K0 can be positive-locking. The disconnecting clutch K0 can be positive-locking and not synchronized.

[0052] The sub-gearbox and the four-shaft first planetary gear set 40 can be connected to each other, in particular in a rotationally fixed manner, via a shaft, such as the fourth shaft 42d in this case. Alternatively or additionally, the sub-gearbox can be switchable.

[0053] The switching element SA (third switching element 46c), particularly within the mechanical path 72, can be positively engaged. The switching element SA, particularly within the mechanical path 72, can be positively engaged but not synchronized. The switching element SA, particularly within the mechanical path 72, can be frictionally engaged. In its switched or closed state, the switching element SA connects one of the shafts 42a-d of the planetary gear set 44 to the housing 56 in a rotationally fixed manner.

[0054] The electric machine 28 and the four-shaft first planetary gear set 40 are preferably arranged coaxially with each other. Furthermore, in the embodiments shown in the figures, the electric machine 28 is arranged coaxially, axially overlapping and radially surrounding the transmission 38, in particular such that the electric machine 28 is arranged coaxially, axially overlapping and radially surrounding the four-shaft first planetary gear set 40 and / or the second planetary gear set 44. Alternatively or additionally, the electric machine 28 and the second planetary gear set 40 are arranged coaxially with each other. Therefore, it is preferably provided that the partial transmission, i.e., the second planetary gear set 44, is arranged in the axial direction of the transmission 38 and thus along the planetary gear set rotation axis 58, between the four-shaft first planetary gear set 40 and the internal combustion engine 18.Alternatively or additionally, the partial transmission, i.e., the second planetary gear set 44, can be arranged axially within the transmission 38 between the four-shaft first planetary gear set 40 and the internal combustion engine 18. Alternatively or additionally, it is preferably provided that the output pinion 64, also referred to as the final drive pinion or final reduction pinion, is arranged axially within the transmission 38 between the partial transmission or the second planetary gear set 44 and the internal combustion engine 18.

[0055] The switching element SB can be arranged axially within the transmission 38 at least substantially between the four-shafted first planetary gear set 40 and the sub-transmission or the second planetary gear set 44. Furthermore, it is conceivable that the switching element SB is arranged axially within the transmission 38 between the output pinion 64 and the internal combustion engine 18. It is also conceivable that the switching element SB is enclosed by a hollow shaft. This is the case with the Fig. The second embodiment shown in Figure 3 is provided. The hollow shaft in question is in particular the planet carrier 52, so that the switching element SB (first switching element 46a) is preferably arranged in the hollow shaft.

[0056] Finally, it shows Fig. 4. A switching table with different states EVT 1, gear 1, gear 2, gear 3, EVT 2, E1, E2 and E3 of the hybrid drive system 16. The aforementioned states are entered in a column SP1 of the switching table. In a row Z1 of the switching table, the disconnect clutch K0 and the switching elements SK, SA and SB are entered. In the Fig. In the switching table shown in Figure 4, a filled dot indicates that the disconnect clutch K0, or the respective switching element SK, SA, and SB under which the filled dot is entered, is closed or engaged. If no filled dot is entered under the disconnect clutch K0, or under the switching element SK, SB, or SA, then the disconnect clutch K0, or the respective switching element SK, SB, or SA, is open. The state EVT 1 is therefore activated when the disconnect clutch K0 and the switching element SA are closed, while the switching elements SK and SB are open. The state Gear 1 is activated when the disconnect clutch K0 and the switching elements SK and SA are closed, while the switching element SB is open.Accordingly, state 2 is activated when the disconnect clutch K0 and the switching elements SA and SB are closed, while the switching element SK is open. State 3 is activated when the disconnect clutch K0 and the switching elements SK and SB are closed, while the switching element SA is open. State EVT 2 is activated when the disconnect clutch K0 and the switching element SB are closed, while the switching elements SK and SA are open. State E1 is activated when the switching elements SA and SB are closed, while the disconnect clutch K0 and the switching element SK are open. State E2 is activated when the switching elements SK and SA are closed, while the disconnect clutch K0 and the switching element SB are open.The state E3 is activated when the switching elements SK and SB are closed simultaneously, while the disconnecting coupling K0 and the switching element SA are open.

[0057] In other words, the hybrid drive system 16, also referred to as the drive unit, can be operated in the first EVT mode, state EVT 1. Here, the speeds and torques of the internal combustion engine 18 and the electric machine 28 are superimposed on the four-shaft, first planetary gear set 40. The first EVT mode serves, among other things, to start the vehicle in a hybrid mode in which both the internal combustion engine 18 and the electric machine 28 are involved. The first EVT mode can also be used for active gear ratio adjustment and speed synchronization, particularly within the shift element SB, when shifting from gear 1 to gear 2. The electric machine 28 can be operated as a generator in the first EVT mode. The electric machine 28 can also be operated as a motor in the first EVT mode.The electric machine 28 can be operated as a generator and as a motor in the first EVT mode.

[0058] The drive unit can be operated in a second EVT mode, which is state EVT 2. In this mode, the speeds and torques of the internal combustion engine 18 and the electric motor 28 are superimposed on the planetary gear set 40. The second EVT mode serves, among other things, as an overdrive mode with a long gear ratio. The second EVT mode can also be used for active gear ratio adjustment and speed synchronization, particularly within the shift element SK, especially when shifting from gear 2 to gear 3. The second EVT mode can also be used for active gear ratio adjustment and speed synchronization, particularly within the shift element SA, especially when shifting from gear 3 to gear 2. The electric motor 28 can be operated as a generator in the second EVT mode. The electric motor 28 can be operated as a motor in the second EVT mode.The electric machine 28 can be operated as a generator and as a motor in the second EVT mode.

[0059] Out of Fig. 2 and Fig.Figure 3 shows that the first shaft 42a comprises a first sun gear 76 of the planetary gear set 40. The third shaft 42c comprises a second sun gear 78 of the planetary gear set 40. The fourth shaft 42d comprises a first planet carrier 80 of the planetary gear set 40, the first planet carrier 80 of which can be permanently connected to the ring gear 48 in a rotationally fixed manner. The second shaft 42b comprises a first ring gear 82 and a second ring gear 84 of the planetary gear set 40, wherein the ring gears 82 and 84 are permanently connected to each other in a rotationally fixed manner. The ring gears 82 and 84 differ in their number of teeth. In other words, the ring gear 82 has a first number of teeth and the ring gear 84 has a second number of teeth that differs from the first number of teeth. The first planet gears 86 of the planet set 40 are assigned to the ring gear 82, and the second planet gears 88 of the planet set 44 are assigned to the ring gear 84.Each planet gear 86 meshes directly with the ring gear 82 on one side and directly with the sun gear 76 on the other, and each planet gear 88 meshes directly with the sun gear 78 on one side and directly with the ring gear 84 on the other. Both the planet gears 86 and the planet gears 88 are rotatably mounted on the planet carrier 80 (shaft 42d) of the planetary gear set 40, which is common to both planet gears 86 and 88. The planet carrier 80 is also referred to as the first web. Reference symbol list 10 Powertrain 12-axis 14-inch wheel 16 Hybrid drive system 18 Internal combustion engine 20 Engine block 22 cylinders 24 first output shaft 26 Crankshaft axis 28 electric machine 30 Stator 32 Rotor 34 Rotor shaft 36 Machine rotary axis 38 gearboxes 40 four-wave first planetary set 42a-d wave 44 second planetary set 46a-c switching element 48 Sun wheel 50 ring gear 52 planetary carriers 54 planetary gear 56 cases 58 Planetary set rotation axis 60 Element rotation axis 62 third output shaft 64 output pinions 66 Final translation 68 Differential gears 70 Disconnect coupling 72 mechanical track 74 mechanical track 76 Sun wheel 78 Sun wheel 80 planetary carriers 82 Ring gear 84 Ring gear 86 planetary gear 88 planetary gear K nodes

Claims

[1] Hybrid drive system (16) for a motor vehicle, comprising: - an internal combustion engine (18) having a first output shaft (24), - an electric machine (28) having a rotor (32) with a rotor shaft (34) as a second output shaft, and - a transmission (38) comprising a four-shaft first planetary gear set (40), a second planetary gear set (44), a first shifting element (46a), a second shifting element (46b), a third shifting element (46c) and a third output shaft (62), wherein: ◯ the four-shaft, first planetary gear set (40) has a first shaft (42a), a second shaft (42b), a third shaft (42c) and a fourth shaft (42d), ◯ the second planetary gear set (44) comprises a first element (48), a second element (50) and a third element (52), ◯ the first shaft (42a), the second shaft (42b), the third shaft (42c) and the fourth shaft (42d) are rotatable relative to one another and can be connected to one another in a rotationally fixed manner by means of the second switching element (46b), ◯ the first output shaft (24) is or can be coupled in a rotationally fixed manner to the first shaft (42a), ◯ the rotor shaft (34) is coupled or can be coupled to the second shaft (42b) in such a way that torques emanating from the rotor shaft (34) can be introduced into the gear (38) via the second shaft (42b), and ◯ the third shaft (42c) is rotatably connected to the third output shaft (62) by means of the first switching element (46a), wherein the fourth shaft (42d) is or can be rotatably connected to the first element (48) of the second planetary gear set (44), characterized bythat the first shaft (42a) comprises a first sun gear (76) of the first planetary gear set (40) and the third shaft (42c) comprises a second sun gear (78) of the first planetary gear set (40). [2] Hybrid drive system (16) according to claim 1, characterized by that the second planetary gear set (44) has exactly three elements (48, 50, 52), namely the first element (48), the second element (50) and the third element (52). [3] Hybrid drive system (16) according to claim 1 or 2, characterized by that the four-shaft, first planetary gear set (40) has exactly four shafts (42a-d). [4] Hybrid drive system (16) according to one of the preceding claims, characterized by , that: - the second element (50) can be connected in a rotationally fixed manner to a housing (56) of the hybrid drive system (16) by means of the third switching element (46c), - the first element (48) is connected to the fourth shaft (42d) in a rotationally fixed manner, and - the third element (52) is connected in a rotationally fixed manner to the third output shaft (62). [5] Hybrid drive system (16) according to one of claims 1 to 3, characterized by , that: - the second element (50) is connected in a rotationally fixed manner to a housing (56) of the hybrid drive system (16), - the first element (48) is rotatably connected to the fourth shaft (42d) by means of the third switching element (46c), and - the third element (52) is connected in a rotationally fixed manner to the third output shaft (62). [6] Hybrid drive system (16) according to one of claims 1 to 3, characterized by , that: - second element (50) is connected in a rotationally fixed manner to a housing (56) of the hybrid drive system (16), - the first element (48) is connected to the fourth shaft (42d) in a rotationally fixed manner, and - the third element (52) can be connected to the third output shaft (62) in a rotationally fixed manner by means of the third switching element (46c). [7] Hybrid drive system (16) according to one of claims 4 to 6, characterized by that a total of exactly three switching elements (46a-c) are provided in the form of the first switching element (46a), the second switching element (46b) designed as the blocking switching element (46b) and the third switching element (46c). [8] Hybrid drive system (16) according to one of the preceding claims, characterized by that the electric machine (28) is arranged coaxially, axially overlapping and radially surrounding the transmission (38). [9] Hybrid drive system (16) according to one of the preceding claims, characterized by that the second shaft (42b) comprises a first ring gear (82) of the first planetary gear set (40) and a second ring gear (84) of the first planetary gear set (40) which is connected in a rotationally fixed manner to the first ring gear (82). [10] Hybrid drive system (16) according to one of the preceding claims, characterized bythat the fourth shaft (42d) comprises a first planet carrier (80) of the first planetary gear set (40). [11] Hybrid drive system (16) according to one of the preceding claims, characterized by that the internal combustion engine (18), an output pinion (64) which is connected in a rotationally fixed manner to the third output shaft (62), the second planetary gear set (44) and the four-shaft, first planetary gear set (40) are arranged in the axial direction of the transmission (38) in the following order: the internal combustion engine (18) - the output pinion (64) - the second planetary gear set (44) - the four-shaft, first planetary gear set (40). [12] Motor vehicle, comprising a hybrid drive system (16) according to one of the preceding claims.

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