Transmission for a motor vehicle drive train, motor vehicle drive train having a transmission, and method for operating a transmission

Abstract

The invention relates to a transmission (G) for a motor vehicle, comprising an electric motor (EM1), a first input shaft (1), a second input shaft (5), an output shaft (2), three planetary gear sets (11, 12, 13) and at least four shifting elements (SE1, SE2, SE3, SE4), wherein different gears can be shifted by selectively actuating the at least four shifting elements (SE1, SE2, SE3, SE4) and, in addition, different operating modes can be formed when cooperating with the electric motor (EM), and the invention relates to a drive train for a motor vehicle having such a transmission (G) and a method for operating the transmission.

Description

Technical Field

[0001] The present invention relates to a transmission for a motor vehicle drivetrain of a motor vehicle, the transmission comprising an electric motor, a first input shaft, a second input shaft, an output shaft, and a first, second, and third planetary gearsets, wherein each planetary gearset comprises a plurality of elements, wherein a first, second, third, and fourth shifting elements are provided, and the rotor of the electric motor is connected to the second input shaft. The present invention also relates to a motor vehicle drivetrain in which the transmission is used, and a method for operating the transmission. Background Art

[0002] In hybrid vehicles, transmissions are known that, in addition to a gear set, also include one or more electric motors. These transmissions are typically designed with multiple gears. This means that by actuating corresponding shifting elements, a number of different transmission ratios can be switched between the input and output shafts as gears, preferably automatically. Depending on the arrangement of the shifting elements, these shifting elements can be clutches or brakes. The transmission is used to appropriately supply tractive power to the vehicle's drive engine based on various criteria. The transmission gears are often also used in conjunction with the electric motor to enable purely electric driving. Furthermore, the electric motor can typically be connected to the transmission in various ways to create different operating modes.

[0003] DE 10 2014 218 610 A1 discloses a transmission for a hybrid vehicle. The transmission includes, in addition to a first input shaft and an output shaft, three planetary gear sets and an electric motor. Furthermore, in one variant, six shift elements are provided, which enable different power flows from the first input shaft to the output shaft when configuring different gears, and also allow for different engagement of the electric motor. Purely electric driving can also be achieved by solely driving the electric motor.

[0004] DE 10 2012 21 22 57 relates to a planetary transmission for a hybrid drive of a motor vehicle, comprising three coupled planetary gear sets, a plurality of shift elements, and at least one electric motor, which is assigned to a shaft within the transmission. In a first planetary gear set, the ring gear can be connected to a component fixed to the housing, and the planet carrier can be drivingly connected to the ring gear of a second planetary gear set. In a second planetary gear set, the planet carrier is connected to the ring gear of a third planetary gear set, and the sun gear can be driven by the transmission input shaft. In a third planetary gear set, the planet carrier is connected to the transmission output shaft. Furthermore, it is provided that the sun gear of the first planetary gear set is connected to a component fixed to the housing, and the sun gear of the third planetary gear set is connected to a component fixed to the housing and to the ring gear of the first planetary gear set. Summary of the Invention

[0005] The object of the present invention is to provide an alternative design to the transmissions known from the prior art for motor vehicles, with which different operating modes can be configured in a suitable manner within a compact design. In particular, the object is to provide a compact hybrid transmission in the form of a planetary transmission for front transverse installation in a motor vehicle drivetrain.

[0006] According to the present invention, the transmission includes an electric motor, a first input shaft, a second input shaft, an output shaft, and first, second, and third planetary gear sets. Each planetary gear set includes multiple elements, preferably each planetary gear set being equipped with a first, second, and third element. Furthermore, first, second, third, and fourth shifting elements are provided, the selective actuation of which enables different force flow guidance when shifting different gears. Particularly preferably, the transmission ratios enable the formation of exactly four different gears between the first input shaft and the output shaft. Furthermore, the rotor of the electric motor is connected to the second input shaft.

[0007] In the context of the present invention, a "shaft" is understood to be a rotatable component of a transmission, by which relevant components of the transmission are connected to one another in a rotationally fixed manner, or by which such a connection is established when a corresponding shifting element is actuated. A corresponding shaft can connect components to one another axially or radially, or both axially and radially. Thus, a corresponding shaft can also exist as an intermediate element, for example, via which corresponding components are radially connected.

[0008] In the context of the present invention, "axial" refers to the orientation in the direction of the longitudinal center axis along which the planetary gear sets are coaxially arranged with respect to one another. "Radial" is understood to be the orientation in the direction of the diameter of the shaft lying on the longitudinal center axis.

[0009] The output shaft of the transmission preferably has teeth, via which the output shaft is operatively connected in the motor vehicle drivetrain to a differential transmission arranged axially parallel to the output shaft. The teeth are preferably provided at a connection point of the output shaft, wherein this connection point of the output shaft is preferably located axially in the region of one end of the transmission, where the connection point of the first input shaft, which establishes the connection to the upstream drive machine, is also provided. This type of arrangement is particularly suitable for use in motor vehicles having a drivetrain oriented transversely to the direction of travel of the motor vehicle.

[0010] Alternatively, however, the output element of the transmission can also be arranged at the axial end of the transmission opposite the connection point of the first input shaft. In this case, the connection point of the output shaft is designed coaxially with the connection point of the first input shaft at the axial end of the output shaft, so that the drive element and the output element of the transmission are arranged at mutually opposite axial ends of the transmission. A transmission designed in this manner is suitable for use in a motor vehicle having a drive train oriented in the direction of travel of the motor vehicle.

[0011] The planetary gear sets are preferably arranged in the order of the first planetary gear set, the second planetary gear set, and finally the third planetary gear set, following the connection point of the first input shaft in the axial direction. Alternatively, however, a different order of the planetary gear sets can be implemented in the axial direction, provided that the connection of the elements of the planetary gear sets permits this.

[0012] The present invention now includes the following technical teachings:

[0013] The first element of the first planetary gear set is connected to the second input shaft;

[0014] The second member of the first planetary gear set is connected to the first input shaft;

[0015] The third member of the first planetary gear set is connected to the first member of the third planetary gear set;

[0016] The first element of the second planetary gear set is fixed to the rotationally fixed member;

[0017] The third member of the second planetary gear set is connected to the second member of the third planetary gear set;

[0018] The third element of the third planetary gear set is connected to the output shaft;

[0019] The first shift element is arranged and configured to connect the first input shaft to the second element of the third planetary gear set;

[0020] The second shift element is arranged and configured to connect the first input shaft to the first element of the first planetary gear set;

[0021] The third shift element is arranged and configured to connect the second element of the second planetary gear set to the output shaft;

[0022] The fourth shift element is arranged and configured to connect the third element of the first planetary gear set with the second element of the second planetary gear set.

[0023] Thus, by actuating the first shift element, the first input shaft and the second element of the first planetary gear set are connected to each other in a rotationally fixed manner, while actuating the second shift element results in a rotationally fixed connection between the first input shaft and the first element of the first planetary gear set. In the actuated state, the third shift element connects the second element of the second planetary gear set to the output shaft in a rotationally fixed manner, while actuating the fourth shift element results in a rotationally fixed connection between the third element of the first planetary gear set and the second element of the second planetary gear set.

[0024] The first, second, third and fourth shift elements are preferably present as form-locking shift elements, in particular as dog clutches or claw clutches.

[0025] The corresponding rotationally fixed connection of the rotatable components of the transmission is achieved, in particular, via one or more centrally located shafts, which can also be provided as short intermediate pieces when the components are spatially close together. Specifically, the components permanently connected to one another in a rotationally fixed manner can each be provided either as individual components connected to one another in a rotationally fixed manner or as a single piece. In the second case, the corresponding components and any shafts present are formed by a common component, which is particularly effective when the corresponding components in the transmission are spatially close to one another.

[0026] Even in the case of transmission components that are connected to one another in a rotationally fixed manner only by actuating corresponding shift elements, the connection is preferably effected via one or more intermediate shafts.

[0027] The fixation is achieved in particular by a rotationally fixed connection to a rotationally fixed component of the transmission, which is preferably a permanently stationary component, preferably a housing of the transmission, a part of such a housing or an element rotationally fixedly connected thereto.

[0028] Within the meaning of the present invention, a “connection” of the rotor of the electric machine to the second input shaft of the transmission is understood to mean a connection such that a constant speed dependency exists between the rotor of the electric machine and the second input shaft.

[0029] The term "interlocking" should be understood as the simultaneous connection of two elements of the same planetary gear set. If a planetary gear set is interlocked, the gear ratio is always unity, regardless of the number of teeth. In other words, the planetary gear set operates as a whole, or block.

[0030] Overall, the transmission according to the invention is characterized by a compact design, low component loads, good meshing efficiency, and low losses.

[0031] The first planetary gear set can be interlocked, for example, in the following manner: the second switching element connects the first element of the first planetary gear set with the second element of the first planetary gear set; or connects the second element of the first planetary gear set with the third element of the first planetary gear set; or connects the first element of the first planetary gear set with the third element of the first planetary gear set.

[0032] By means of the transmission, four mechanical gears with different transmission ratios can be realized by selectively actuating at least four shift elements.

[0033] - The first gear is obtained by actuating the second and third shift elements;

[0034] - The second gear is obtained by actuating the first and third shift elements;

[0035] - The third gear is obtained by actuating the first and fourth shift elements;

[0036] - The fourth gear is obtained by actuating the second and fourth shift elements.

[0037] Additional gears can be achieved by actuating the first and second shift elements. Thus, a maximum of five mechanical forward gears can be provided.

[0038] By appropriately selecting the fixed transmission ratios of the planetary gear sets, a range of transmission ratios suitable for use in the automotive industry can be achieved. This allows shifting between gears by only changing the state of one shift element at a time: one of the shift elements participating in the previous gear is opened, and another shift element is actuated to form the next gear. This also allows very rapid shifting between gears.

[0039] The five forward gears can be driven purely by electric power, the internal combustion engine, or a hybrid system. The first electric gear has a ratio equal to the first internal combustion engine gear. The second electric gear has a ratio equal to the second internal combustion engine gear, and so on.

[0040] Starting from electric driving, the internal combustion engine can be engaged in any gear.

[0041] Furthermore, electric drive starting (EDA) can be provided. EDA involves superimposing the speeds of the internal combustion engine, the electric motor, and the output shaft via one or more planetary gear sets. This allows starting from a standstill while the internal combustion engine is running. The electric motor provides torque support.

[0042] Therefore, the first electric power mode is obtained by operating the third shift element; the second electric power mode is obtained by operating the first shift element; and the third electric power mode is obtained by operating the fourth shift element.

[0043] In the first EDA mode, the EDA state is generated on the first planetary gear set by actuating the third shift element. The internal combustion engine drives the second element of the first planetary gear set, while the electric motor simultaneously supports the internal combustion engine's torque on the first element of the first planetary gear set. The third element of the first planetary gear set is connected to the output element via a constant transmission ratio of the second planetary gear set. This allows forward electric power starting. Starting from the first EDA mode, the internal combustion engine can be used in first and second gears, as the third shift element is engaged in each of these gears.

[0044] In the second EDA mode, the EDA state is generated on the first and third planetary gear sets by actuating the first shift element. The internal combustion engine drives the second elements of the first and third planetary gear sets, while the electric motor simultaneously supports the internal combustion engine's torque on the first element of the first planetary gear set. The third element of the third planetary gear set is connected to the output. This allows forward electric starting. Starting from the second EDA mode, the internal combustion engine can be used in the second, third, and fifth gears, as the first shift element is engaged in each of these gears.

[0045] In the third EDA mode, actuating the fourth shift element creates another EDA state on the first planetary gear set. The internal combustion engine drives the second element of the first planetary gear set, while the electric motor simultaneously supports the internal combustion engine's torque on the first element of the first planetary gear set. The third element of the first planetary gear set is connected to the second element of the second planetary gear set. This allows forward electric starting. Starting from the third EDA mode, the internal combustion engine can be used in third and fourth gears, as the fourth shift element is engaged in each of these gears.

[0046] As a further operating mode, charging operation of the electrical energy storage device can also be achieved by closing only the second shift element, thereby establishing a rotationally fixed connection between the first and second input shafts and, consequently, coupling the electric motor to the first input shaft. At the same time, no frictional connection with the output shaft is established, placing the transmission in neutral. In addition to charging operation, this also allows the electric motor to start a connected upstream drive machine. From this state, a shift to first gear can be made by actuating the third shift element.

[0047] Furthermore, load shifting with traction support can be implemented. In particular, the shifting from the first gear to the second gear, from the second gear to the third gear, and from the third gear to the fourth gear can be performed under load.

[0048] For example, starting with the first gear, the second and third shifting elements are actuated. The drive power of the electric motor and the internal combustion engine is adjusted so that, on the one hand, the desired output torque is provided, and, on the other hand, the second shifting element, which is designed to be unloaded, is unloaded. The second shifting element can now be opened. The drive power of the electric motor and the internal combustion engine is then adjusted so that, on the one hand, the desired output torque is provided, and, on the other hand, the speed of the first input shaft connected to the internal combustion engine is reduced. When the first shifting element to be engaged is synchronized, it is closed. This mechanically shifts the second gear of the internal combustion engine.

[0049] Shifting from second gear to third gear and from third gear to fourth gear occurs in a similar manner.

[0050] Downshift switching is similar to above-mentioned upshift switching and is carried out, just order is reversed.In addition, can realize driving switching, wherein internal combustion engine works under driving operation, because electric machine can support the torque on the planetary gear set with braking.

[0051] According to another embodiment of the present invention, the first input shaft can be rotationally fixedly connected to a connecting shaft via a fifth shift element, which in turn is preferably coupled to an internal combustion engine connected upstream of the transmission within the motor vehicle drivetrain. In principle, the fifth shift element can be designed as a non-positive or positive shift element, but is particularly preferably designed as a dog clutch or claw clutch. Accordingly, the upstream internal combustion engine can also be completely decoupled from the transmission via the fifth shift element, thus enabling purely electric operation without any problems.

[0052] In an extension of the present invention, one or more switching elements are respectively implemented as form-locking switching elements. In this case, the corresponding switching elements are preferably designed as either claw-type switching elements or as locking synchronization devices. The advantage of form-locking switching elements over force-locking switching elements is that lower drag losses occur in the open state, thereby achieving better transmission efficiency. In particular, in the transmission according to the present invention, all switching elements are implemented as form-locking switching elements, thereby achieving the smallest possible drag losses. If possible, the seventh switching element is also preferably designed as a form-locking switching element. However, in principle, one or more switching elements can also be designed as force-locking switching elements, for example, as disc switching elements.

[0053] The planetary gear sets are preferably each present as negative planetary gear sets. In a manner known in principle to a person skilled in the art, the negative planetary gear set consists of the elements sun gear, planet carrier, and ring gear, wherein the planet carrier rotatably guides at least one, but preferably a plurality of planet gears, each of which meshes individually not only with the sun gear but also with the surrounding ring gear.

[0054] According to another embodiment of the present invention, the first and second shifting elements are combined to form a shifting element pair, which is equipped with an actuating element. Starting from the neutral position, the actuating element can actuate both the first shifting element and the second shifting element. This has the advantage that the combination can reduce the number of actuating elements and, therefore, production costs. In this embodiment, the additional fifth gear is omitted.

[0055] As an alternative or supplement to the above-described variant, the third and fourth shifting elements can be combined into a shifting element pair, which is equipped with an actuating element. Starting from the neutral position, the actuating element can actuate both the third shifting element and the fourth shifting element. This reduces production costs by combining the two shifting elements into a shifting element pair, allowing one actuating device to be used for both shifting elements.

[0056] However, all of the above-mentioned two shift element pairs are particularly preferably implemented so that the four shift elements of the transmission can be actuated by two actuating elements. This allows particularly low production costs to be achieved.

[0057] According to one embodiment of the present invention, the rotor of the electric motor is connected to the second input shaft in a rotationally fixed manner. As an alternative to this, one design possibility of the present invention is that the rotor is connected to the second input shaft via at least one gear stage. The electric motor can either be arranged coaxially with the planetary gear set or arranged with an axial offset relative to these planetary gear sets. In the former case, the rotor of the electric motor can either be directly connected to the second input shaft in a rotationally fixed manner or can be coupled to the second input shaft via one or more intermediate gear stages, wherein the latter allows for a more advantageous design of the electric motor with a higher speed and lower torque. The at least one gear stage can be designed as a spur gear stage and / or a planetary gear stage. In the case of a coaxial arrangement of the electric motor, the one or more planetary gear sets can further preferably be arranged axially in the area of ​​the electric motor and radially inwardly relative to the electric motor, thereby shortening the overall axial length of the transmission.

[0058] If, however, the electric motor is arranged with an axial offset relative to the planetary gear set, coupling occurs via one or more intermediate transmission stages and / or a traction means transmission. The transmission stage or stages can also be implemented individually as either spur gear stages or planetary gear stages. The traction means transmission can be either a belt drive or a chain drive.

[0059] Within the scope of the present invention, a starting element can be connected upstream of the transmission, such as a torque converter or a friction clutch. This starting element can also be a component of the transmission and serve to configure the starting process by achieving a slipping speed between the drive machine, particularly an internal combustion engine, and the first input shaft of the transmission. One of the transmission's shifting elements or a possibly present separating clutch can also serve as such a starting element by providing one of the transmission's shifting elements or the separating clutch as a friction shifting element. Furthermore, a freewheel can generally be arranged on each shaft of the transmission, either for the transmission housing or for another shaft.

[0060] The transmission according to the present invention is particularly useful as part of a hybrid or electric vehicle drivetrain and is arranged between a vehicle's drive engine, designed as an internal combustion engine or an electric motor, and another component of the powertrain that follows the vehicle's drive wheels in the direction of power flow. The first input shaft of the transmission can be either permanently coupled to the crankshaft of the internal combustion engine or the rotor shaft of the electric motor in a rotationally fixed manner, or connected to the crankshaft of the internal combustion engine or the rotor shaft of the electric motor via an interposed separating clutch or starting element. A torsional vibration damper can also be provided between the internal combustion engine and the transmission. On the output side, the transmission in the vehicle drivetrain is preferably coupled to a differential gear mechanism for the vehicle's driven axles, but a connection to a longitudinal differential is also possible, through which power is distributed to multiple driven axles of the vehicle. The differential gear mechanism or longitudinal differential can be arranged in a common housing with the gears. Any torsional vibration damper can also be integrated into the housing.

[0061] The transmission described above can be a component of an all-wheel drive concept, particularly a combination of an all-wheel drive system and a second, purely electrically driven axle. In such a variant, the transmission can serve as the front-wheel drive, while an additional axle drive with a separate second electric motor is provided on the rear axle. This allows for the following additional functions:

[0062] The aforementioned EDA mode is the E-CVT driving range for power diversion of the internal combustion engine, in which battery-neutral operation (E-CVT function) is also possible.

[0063] Furthermore, serial driving is possible. When the second and fifth shift elements are closed (the transmission is in the "charge neutral" state), the electric machine can generate current for the second electric machine alone.

[0064] When a shift is required in the transmission, the second motor can support the traction force, where the driven member of the gear is unloaded. For example, such a transition is:

[0065] The first electric machine EM1 (and optionally the second electric machine) is used for electric driving, and then the internal combustion engine is started in the neutral state using the first electric machine.

[0066] In this case, firstly a load transfer takes place from the first electric machine to the second electric machine, so that the first electric machine becomes unloaded.

[0067] - The first motor uses the first electric gear,

[0068] - The third switching element can now be turned on,

[0069] The fifth shift element (clutch K0 ) can then be engaged and the internal combustion engine can be started.

[0070] The internal combustion engine is started or driven serially, and then transitions to the first EDA mode:

[0071] Initial state: the second and fifth shift elements are closed.

[0072] - The load on the internal combustion engine and the first electric machine is reduced, so that the second shift element is unloaded. At the same time, the second electric machine briefly takes over the load to maintain the total tractive force.

[0073] - Open the second switching element.

[0074] - Synchronize the third switching element with the speed regulation of the first electric machine. To do this, it may be necessary to rotate EM1 backwards.

[0075] - Close the third shift element.

[0076] -Established the first EDA model.

[0077] From this state, both vehicle axles can be driven even when the vehicle is stationary, even when the energy storage device is empty. This is not possible in serial mode without four-wheel drive.

[0078] For the purposes of the present invention, "connecting" or "coupling" or "connecting" two components of a transmission to one another means that these components are permanently coupled so that they cannot rotate independently of one another. In this context, no shifting elements are provided between these components, which may be elements of a planetary gear set and / or shafts and / or rotationally fixed components of the transmission, but rather the corresponding components are coupled to one another with a constant speed dependency.

[0079] If, on the other hand, a shift element is provided between two components, these components are not permanently coupled to one another, but rather are coupled only by actuating an intermediate shift element. Within the meaning of the present invention, actuating a shift element means that the relevant shift element is switched to the closed state, and as a result, the components directly connected to the relevant shift element are adapted to one another in terms of their rotational movement, if necessary. If the relevant shift element is designed as a positive-locking shift element, the components directly connected to one another in a rotationally fixed manner via the shift element operate at the same speed, while with a non-positive-locking shift element, the same speed difference may exist between the components even after actuation. However, within the scope of the present invention, such desired or undesirable states are still referred to as rotationally fixed connections of the individual components via the shift element. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The advantageous embodiments of the invention explained below are shown in the drawings. In the drawings:

[0081] Figure 1 A schematic diagram showing a motor vehicle having a motor vehicle powertrain;

[0082] Figures 2 to 4 Shown separately for Figure 1 Schematic diagram of a transmission in a motor vehicle powertrain.

[0083] Figures 5 to 7 Shown separately Figures 2 to 4 An exemplary shifting scheme of a transmission;

[0084] Figures 8 to 10 Shown separately can also be used for Figure 1 A schematic diagram of a transmission in a motor vehicle powertrain;

[0085] Figures 11 to 13 Shown separately can also be used for Figure 1 A schematic diagram of a transmission in a motor vehicle powertrain;

[0086] Figure 14 、 Figure 15 Shown separately Figures 11 to 13 An exemplary shifting scheme for a transmission; and

[0087] Figures 16 to 18 Shown separately can also be used for Figure 1 Schematic diagram of a transmission in a motor vehicle powertrain. DETAILED DESCRIPTION

[0088] Figure 1A schematic diagram of a motor vehicle drive train of a hybrid vehicle is shown, wherein in the motor vehicle drive train, an internal combustion engine VM is connected to a transmission G via a torsional vibration damper (not shown) located in between. A differential mechanism (not shown) is connected downstream of the transmission G on the output side, via which the drive power is distributed to the drive wheels DW of the drive axles or drive axles of the motor vehicle. The transmission G and the torsional vibration damper are arranged in a common housing of the transmission G, into which the differential mechanism can also be integrated. As shown in FIG. Figure 1 As can also be seen in FIG, the internal combustion engine VM and the transmission G are oriented transversely to the direction of travel of the motor vehicle. A hybrid vehicle optionally has a drive on the rear axle, which comprises an electric machine and a transmission.

[0089] from Figure 2 A schematic diagram of a transmission G according to a first embodiment of the present invention is shown. As can be seen, transmission G consists of a gear set RS and an electric motor EM, which are arranged together in the housing of transmission G. This gear set includes three planetary gear sets 11, 12, and 13, each of which has a first element 11.1, 12.1, or 13.1, a second element 11.2, 12.2, or 13.2, and a third element 11.3, 12.3, or 13.3. The respective first element is formed by the sun gear of the respective planetary gear set, while the respective second element of the respective planetary gear set is present as a planet carrier, and the respective third element of the respective planetary gear set is present as a ring gear.

[0090] In the present case, the first planetary gear set 11, the second planetary gear set 12, and the third planetary gear set 13 are each present as a negative planetary gear set, whose respective planet carriers rotatably guide at least one planet gear that engages both with the respective radially inner sun gear and with the respective radially surrounding ring gear. However, it is particularly preferred that a plurality of planet gears be provided in each of the first planetary gear set 11, the second planetary gear set 12, and the third planetary gear set 13.

[0091] As in Figure 2 As can be seen in FIG, the transmission G comprises a total of four shift elements in the form of a first shift element SE1, a second shift element SE2, a third shift element SE3, and a fourth shift element SE4. The shift elements SE1, SE2, SE3, and SE4 are each designed as form-locking shift elements and are preferably present as claw shift elements. Furthermore, the shift elements SE1, SE2, SE3, and SE4 are each designed as clutches.

[0092] The first element 11.1 of the first planetary gear set 11 is permanently connected to the second input shaft 5. The second input shaft 5 is connected in a rotationally fixed manner to the rotor R of the electric motor EM, whose stator S is permanently fixed to the rotationally fixed component GG. The second element 11.2 of the first planetary gear set 11 is connected to the first input shaft 1. The third element 11.3 of the first planetary gear set 10 is connected to the first element 13.1 of the third planetary gear set 13 via shaft 6. The first element 12.1 of the second planetary gear set 12 is permanently fixed to the rotationally fixed component GG via component 0, which is preferably the transmission housing of the transmission G or a part of the transmission housing. In this regard, the first element 12.1 of the second planetary gear set 12 is permanently prevented from rotating. The third element 12.3 of the second planetary gear set 12 is connected to the second element 13.2 of the third planetary gear set 13 via shaft 4. The third element 13.3 of the third planetary gear set 13 is connected to the output shaft 2. The second element 12.2 includes shaft 3.

[0093] The first shifting element (SE1) can connect the first input shaft (1) to the second element (13.2) of the third planetary gear set (13). If the first shifting element is actuated, in other words, the input shaft 1 is connected to the shaft 4.

[0094] The second switching element can interlock the first planetary gear set (11). Figure 2 In the embodiment of , this occurs by connecting the first element 11 . 1 to the second element 11 . 2 of the first planetary gear set 11 . If the second shift element is actuated, in other words, the first input shaft 1 is connected to the second input shaft 5 .

[0095] The third shift element SE3 can connect the second element 12.2 of the second planetary gear set 12 to the output shaft 2. If the third shift element is actuated, in other words, the output shaft 2 is connected to the shaft 3.

[0096] The fourth shift element SE4 can connect the third element 11.3 of the first planetary gear set 11 with the second element 12.2 of the second planetary gear set 12. If the fourth shift element is actuated, in other words, the shaft 3 is connected to the shaft 6.

[0097] Both the first input shaft 1 and the output shaft 2 each have a connection point, wherein the input shaft 1 is Figure 1The connection point in the motor vehicle drivetrain is used for connection to the internal combustion engine VM. The connection point of the output shaft 2 is used for connection to the subsequent differential gear mechanism. The connection point of the first input shaft 1 is designed at the axial end of the transmission G, with the connection point of the output shaft 2 being at the axially opposite end. Furthermore, the first input shaft 1, the second input shaft 5, and the output shaft 2 are arranged coaxially with each other.

[0098] Planetary gear sets 11, 12, 13 are also coaxial with input shafts 1, 5 and output shaft 2, with these being arranged axially following the connection point of first input shaft 1 in the order of first planetary gear set 11, second planetary gear set 12, and third planetary gear set 13. Electric motor EM is also situated coaxially with planetary gear sets 11, 12, and 13, and therefore also with input shafts 1 and 5 and output shaft 2, with electric motor EM being situated axially on the side of first planetary gear set 11 facing away from second planetary gear set 12.

[0099] As from Figure 2 As can also be seen in FIG, the first shifting element SE1 and the second shifting element SE2 are arranged axially between the first planetary gear set P1 and the second planetary gear set P2, wherein the first shifting element SE1 is axially positioned between the second planetary gear set 12 and the second shifting element SE2. The first shifting element SE1 and the second shifting element SE2 are arranged directly or immediately adjacent to each other in the axial direction and are at the same height in the radial direction and are combined to form a shifting element pair SP1. The first shifting element SE1 and the second shifting element SE2 are assigned a common actuating element, by which the first shifting element SE1 can be actuated, starting from the neutral position, on the one hand, and the second shifting element SE2 can be actuated on the other hand.

[0100] The third shifting element SE3 is arranged axially between the first planetary gear set 11 and the second planetary gear set 12. The fourth shifting element SE4 is arranged axially between the second planetary gear set 12 and the third planetary gear set 13. Here, the third shifting element C and the fourth shifting element D are arranged at the same radial height and have a common actuation element, which can be used to actuate the third shifting element SE3 on the one hand and the fourth shifting element SE4 on the other hand, starting from the neutral position. In this respect, the third shifting element SE3 and the fourth shifting element SE4 are combined into a shifting element pair SP2.

[0101] Figure 3 A schematic diagram of a transmission G according to a second design option of the present invention is shown, which can also be implemented in Figure 1 In this case, the design possibility corresponds largely to the Figure 2The preceding embodiment differs in that the second shift element SE2' causes the interlocking of the first planetary gear set 11 by connecting the second element 11.2 and the third element 11.3. Actuation of the second shift element SE2' thus results in a rotationally fixed connection between the second element 11.2 and the third element 11.3 of the first planetary gear set 11. This embodiment is therefore a so-called interlocking variant. In other respects, according to Figure 3 The embodiment corresponds to Figure 2 Implementation methods, reference is therefore made to what has already been described therein.

[0102] Figure 4 A schematic diagram of a transmission G according to a third design option of the present invention is shown, which can also be used in Figure 1 In this case, the design possibility corresponds largely to the Figure 2 The difference is that the second shift element SE2 ″ causes the interlocking of the first planetary gear set 11 by connecting the first element 11.1 and the third element 11.3. The actuation of the second shift element SE2 ″ thus results in a rotationally fixed connection between the first element 11.1 and the third element 11.3 of the first planetary gear set 11. This embodiment is therefore another interlocking variant. In other respects, according to Figure 4 The embodiment corresponds to Figure 2 Implementation methods, reference is therefore made to what has already been described therein.

[0103] exist Figure 5 Shown in table form Figures 2 to 4 1 shows an exemplary shifting scheme for a transmission G in FIG. As can be seen, a total of five gears with different transmission ratios can be realized between the first input shaft 1 and the output shaft 2 , wherein an X in the column of the shifting scheme indicates which of the shift elements SE1 to SE4 is engaged in which of the respective gears.

[0104] The first gear V1 between the first input shaft 1 and the output shaft 2 is shifted by actuating the second shift element SE2 and the third shift element SE3. The second gear V2 between the first input shaft 1 and the output shaft 2 is shifted by actuating the third shift element SE3 and the first shift element SE1. The third gear V3 between the first input shaft 1 and the output shaft 2 is shifted by actuating the fourth shift element SE4 and the first shift element SE1. The fourth gear V4 between the first input shaft 1 and the output shaft 2 is shifted by actuating the fourth shift element SE4 and the second shift element SE2. Furthermore, an additional gear ZV1 can be shifted by actuating the first and second shift elements SE1 and SE2. This additional gear ZV1 is only possible when the first and second shift elements SE1 and SE2 are not combined into the shift element pair SP1.

[0105] Although the shift elements SE1 to SE4 are each designed as form-locking shift elements, shifts between the first gear 1 and the second gear, between the second gear and the third gear, and between the third gear and the fourth gear can each be performed under load.

[0106] The reason for this is

[0107] - from the first gear to the second gear, the third shift element SE3 remains closed,

[0108] - From the second gear to the third gear, the first shift element SE1 remains closed, and

[0109] From the third gear to the fourth gear, the fourth shift element SE4 remains closed.

[0110] The switching is done electrically via the motor.

[0111] This should be made clearer by taking the example of the shift from first gear V1 to second gear V2:

[0112] 1. In the output gear V1, the second shift element SE2 and the third shift element SE3 are closed. The first input shaft is connected to the internal combustion engine.

[0113] 2. The torques of the internal combustion engine and the electric machine are set such that, on the one hand, the desired output torque is provided and, on the other hand, the second shift element SE2 to be designed is unloaded.

[0114] 3. Open the second switching element SE2.

[0115] 4. The torques of the internal combustion engine and the electric machine are set so that, on the one hand, the desired output torque is provided and, on the other hand, the speed of the internal combustion engine is reduced.

[0116] 5. If the shift element SE1 to be engaged is synchronized, it is closed, thereby mechanically shifting the second gear V2 of the internal combustion engine.

[0117] 6. The operating principle of the shift V3-V4 is the same as that of the shift V1-V2. Downshifting occurs similarly to upshifting, but in the reverse order.

[0118] For the sake of clarity, only one of the three variants of the second shift element, namely “SE2,” is shown in the shifting scheme. In this context, “SE2” represents all three interlocking variants of the second shift element.

[0119] exist Figure 6 Shown in table form Figures 2 to 4 1 shows an exemplary shifting scheme for the transmission G in FIG. As can be seen, a total of five gears with different transmission ratios can be realized between the second input shaft 5 connected to the electric machine and the output shaft 2, wherein an X in the column of the shifting scheme indicates which of the shift elements SE1 to SE4 is engaged in which of the respective gears.

[0120] The first gear EV1 between the second input shaft 5 and the output shaft 2 is shifted by actuating the second shifting element SE2 and the third shifting element SE3. The second gear EV2 between the second input shaft 5 and the output shaft 2 is shifted by actuating the fourth shifting element SE4 and the first shifting element SE1. The third gear EV3 between the second input shaft 5 and the output shaft 2 is shifted by actuating the third shifting element SE3 and the first shifting element SE1. The fourth gear EV4 between the second input shaft 5 and the output shaft 2 is shifted by actuating the fourth shifting element SE4 and the second shifting element SE2. Furthermore, an additional gear ZEV1 can be shifted by actuating the first and second shifting elements SE1 and SE2. This additional gear ZEV1 is only possible when the first and second shifting elements SE1 and SE2 are not combined into the shifting element pair SP1.

[0121] The five gears mentioned above are achieved purely electrically, and the internal combustion engine can be decoupled.

[0122] Since the motor is not located on the first input shaft, Figure 6 The electric gear always corresponds to Figure 5 The electric gears correspond to the mechanical gears in terms of their transmission ratio only when the second shift element SE2 is closed, i.e., in the first gear, in the fourth gear, and in the additional gear. The second gear V2 is different from the second gear EV2. Furthermore, the third gear V3 is different from the third gear EV3.

[0123] The first gear, the fourth gear and the additional gear can therefore be operated in a hybrid mode, ie with both the internal combustion engine and the electric motor engaged.

[0124] Furthermore, a charging or starting function can be implemented by actuating the second shift element SE2. This is because, in the closed state of the second shift element SE2, the second input shaft 5 is directly and rotationally coupled to the first input shaft 1 and, therefore, also to the internal combustion engine VM. However, there is no frictional connection with the output shaft 2. During generator operation of the electric machine EM1, the internal combustion engine VM can be used to charge the electrical energy storage device, while during motor operation of the electric machine EM, the internal combustion engine VM can be started by the electric machine EM.

[0125] exist Figure 7 The three EDA states are shown in FIG. Thus, actuating the third switching element SE3 results in a first electric power mode EDA1. Actuating the first switching element SE1 results in a second electric power mode EDA2. Actuating the fourth switching element SE4 results in a third electric power mode EDA3. Each of the EDA modes enables starting from a standstill while the internal combustion engine is connected.

[0126] from Figure 8 A schematic diagram of a transmission G according to another embodiment of the present invention is shown in FIG. Figure 1 This embodiment corresponds essentially to the embodiment according to Figure 2 This variant differs in that a speed change mechanism is now provided in the form of a fourth planetary gear set 14. The fourth planetary gear set 14 comprises a first element 14.1, a second element 14.2, and a third element 14.3. The first element 14.1 functions as a sun gear, the second element 14.2 functions as a planetary carrier, and the third element 14.3 functions as a ring gear. The first element 14.1 is fixed to the transmission housing GG. The second element 14.2 is connected to the first element 11.1 of the first planetary gear set 11. The third element 14.3 is connected to the rotor R of the electric motor. The fourth planetary gear set is arranged, in effect, as a speed change mechanism between the electric motor and the first planetary gear set to convert the electric motor's speed. This allows the speed or torque of the electric motor to be better adapted to the transmission.

[0127] The above embodiments each show a transmission G in which the electric motor is arranged coaxially with the input shaft or the output shaft. Figure 9 and 10 An embodiment of the invention is shown having an axis-parallel arrangement according to the invention.

[0128] Therefore, in Figure 9In the embodiment, the electric motor EM is not mounted coaxially with the gear set of the transmission G, but rather with an offset axis. The connection is established via a spur gear stage 15, which consists of a first spur gear 15.1 and a second spur gear 15.2. The first spur gear 15.1 is rotationally fixedly connected to the second input shaft 5. The spur gear 15.1, in turn, engages with the teeth of the spur gear 15.2, which is mounted rotationally fixedly on the input shaft of the electric motor EM. This input shaft establishes a connection within the electric motor EM to the rotor of the electric motor EM1 (not shown further here).

[0129] Also according to Figure 10 In a variant of the embodiment, the electric motor EM1 is arranged with an axial offset from the corresponding gear set RS of the corresponding transmission G. However, Figure 9 In contrast to the previous variant, the connection here is not via the spur gear stage 15, but rather via a traction means transmission 16. This traction means transmission 16 can be designed as a belt and chain transmission or a chain transmission. The traction means transmission 16 is then connected to the second drive shaft 5 on the gear set side. Here, the coupling to the input shaft of the electric motor EM is established via the traction means transmission 16, which in turn is connected to the rotor of the electric motor within the electric motor EM.

[0130] The traction means transmission 16 can be designed as a belt or chain drive. The traction means transmission 16 is then connected to the second drive shaft 5 via a portion of the gear train. The coupling to the input shaft of the electric motor EM is then established via the traction means transmission 16, which in turn is connected to the rotor of the electric motor within the electric motor EM.

[0131] Figures 11 to 13 Schematic diagrams of transmissions G according to other embodiments of the present invention are shown, as can also be seen in FIG. Figure 1 Used in the powertrain of motor vehicles. Figure 11 The embodiment here corresponds essentially to the embodiment according to Figure 2 According to Figure 12 The embodiment here corresponds essentially to the Figure 3 According to Figure 13 The embodiment here corresponds essentially to the Figure 4 The common difference lies in the fifth switching element SE0, also called clutch K0, which is arranged between the first input shaft 1 and the internal combustion engine (not shown). Therefore, when the fifth switching element SE0 is open, pure electric driving is possible. In addition, when the fifth switching element SE5 is closed, the engine can be started, a so-called momentum start. In other respects, according to Figure 11 、 12 and 13 correspond to the embodiments according to Figure 2or 3 or 4, so reference is made to what has already been described therein.

[0132] exist Figure 14 Shown in table form Figures 11 to 13 An exemplary shifting scheme of the transmission G in FIG. As can be seen, a total of five electric gears with different transmission ratios can be realized between the second input shaft 5 and the output shaft 2, wherein an X in the shifting scheme column indicates which of the shifting elements SE1 to SE4 and SE0 is engaged in which of the respective gears. Figure 6 The switching schemes differ only and exclusively in the fifth switching element SE0, which can decouple the internal combustion engine from the first input shaft. In order to realize the electric gear, the fifth switching element must be open. In other respects, according to Figure 14 The switching diagram corresponds to the Figure 6 , so reference is made to what has already been described therein.

[0133] exist Figure 15 Shown in table form Figures 11 to 13 1 shows an exemplary shifting scenario for the transmission G in FIG. As can be seen, a total of five internal combustion engine gears with different transmission ratios can be realized between the first input shaft 1 and the output shaft 2 , wherein an X in the column of the shifting scenario indicates which of the shift elements SE1 to SE4 and SE0 is engaged in which of the respective gears.

[0134] According to Figure 5 The difference between the switching schemes is only in the fifth switching element SE0, which can decouple the internal combustion engine from the first input shaft. In order to achieve the internal combustion engine gear, the fifth switching element must be closed. In other respects, according to Figure 15 The switching scheme corresponds to the Figure 5 switching scheme, so reference is made to what has already been described therein.

[0135] Figure 16 A schematic diagram of a transmission G according to another embodiment of the present invention is shown, as can also be seen in FIG. Figure 1 Used in the powertrain of motor vehicles. Figure 16 The embodiment here corresponds essentially to the Figure 2 The difference is that the differential is connected downstream of the transmission. The differential is therefore connected to the output shaft 2. Two shafts Ab1 and Ab2 are provided from the differential 16, which drive the wheels of the motor vehicle. If the differential is connected coaxially, one of the two output shafts is preferably guided as a solid shaft through the gear set. In other respects, according to Figure 16 The embodiment corresponds to Figure 2Implementation methods, reference is therefore made to what has already been described therein.

[0136] Figure 17 A schematic diagram of a transmission G according to another embodiment of the present invention is shown, as can also be seen in FIG. Figure 1 Used in the powertrain of motor vehicles. Figure 17 The embodiment here corresponds essentially to the Figure 16 The difference is that a speed change transmission mechanism 17 is provided, which is arranged between the output shaft 2 and the differential D. Therefore, a higher transmission ratio can be provided. The speed change transmission mechanism 17 is implemented in the form of a planetary gear set and includes a first element 17.1 connected to the output shaft 2, a second element 17.2 connected to the differential D, and a third element 17.3 fixed to the transmission housing GG. In other respects, according to Figure 17 The embodiment corresponds to Figure 16 or Figure 2 Implementation methods, reference is therefore made to what has already been described therein.

[0137] at last, Figure 18 A schematic diagram of a motor vehicle drive train is shown as an example. The motor vehicle drive train includes Figure 17 Transmission G, internal combustion engine VM, shock absorber 18, clutch K0 (see Figure 11-13 ) and a traction device transmission 19. This drive system is particularly suitable for front transverse installation.

[0138] Reference Signs List

[0139] G transmission

[0140] GG anti-rotation structural element

[0141] 1First input shaft

[0142] 2 output shaft

[0143] 3-axis

[0144] 4-axis

[0145] 5 Second input shaft

[0146] 6-axis

[0147] 11First planetary gear set

[0148] 11.1 First element of the first planetary gear set

[0149] 11.2 Second element of the first planetary gear set

[0150] 11.3 The third element of the first planetary gear set

[0151] 12 Second planetary gear set

[0152] 12.1 First element of the second planetary gear set

[0153] 12.2 Second element of the second planetary gear set

[0154] 12.3 The third element of the second planetary gear set

[0155] 13Third planetary gear set

[0156] 13.1 First element of the third planetary gear set

[0157] 13.2 Second element of the third planetary gear set

[0158] 13.3 The third element of the third planetary gear set

[0159] 14 Fourth planetary gear set

[0160] 14.1 First element of the fourth planetary gear set

[0161] 14.2 Second element of the fourth planetary gear set

[0162] 14.3 The third element of the fourth planetary gear set

[0163] 15 spur gear stages

[0164] 15.1 Spur gears

[0165] 15.2 Spur Gears

[0166] 16 Traction device transmission

[0167] 17Fifth planetary gear set

[0168] 17.1 First element of the fifth planetary gear set

[0169] 17.2 Second element of the fifth planetary gear set

[0170] 17.3 The third element of the fifth planetary gear set

[0171] 18 Torsional vibration damper

[0172] 19 Traction device transmission

[0173] SE1 first switching element

[0174] SE2 / 2' / 2'' second switching element

[0175] SE3 third switching element

[0176] SE4 fourth switching element

[0177] SE5 fifth switching element, K0

[0178] SP1 switching element pair

[0179] SP2 switching element pair

[0180] V1 first gear

[0181] V2 second gear

[0182] V3 third gear

[0183] V4 fourth gear

[0184] ZV1's additional fifth gear

[0185] E1 first gear

[0186] E2 second gear

[0187] E3 third gear

[0188] E4 fourth gear

[0189] ZEV1 additional fifth gear

[0190] EM motor

[0191] S stator

[0192] R rotor

[0193] SRS spur gear stage

[0194] SR1 spur gear

[0195] SR2 spur gear

[0196] D Differential transmission mechanism

[0197] DW drive wheel

[0198] VM internal combustion engine

Claims

1. A transmission (G) for a motor vehicle powertrain of a motor vehicle, the transmission comprising an electric motor (EM1), a first input shaft (1), a second input shaft (5), an output shaft (2), and a first planetary gear set (11), a second planetary gear set (12), and a third planetary gear set (13), wherein: Each planetary gear set includes a plurality of elements, wherein a first switching element (SE1), a second switching element (SE2, SE2', SE2''), a third switching element (SE3) and a fourth switching element (SE4) are provided, and a rotor (R1) of an electric motor (EM1) is connected to a second input shaft (5), wherein: - the first element (11.1) of the first planetary gear set (11) is connected to the second input shaft (5); - the second element (11.2) of the first planetary gear set (11) is connected to the first input shaft (1); - the third element (11.3) of the first planetary gear set (11) is connected to the first element (13.1) of the third planetary gear set (13); - the first element (12.1) of the second planetary gear set (12) is fixed to a rotationally fixed component (GG); - the third element (12.3) of the second planetary gear set (12) is connected to the second element (13.2) of the third planetary gear set (13); - the third element (13.3) of the third planetary gear set (13) is connected to the output shaft (2); - a first shifting element (SE1) is arranged and configured to connect the first input shaft (1) to the second element (13.2) of the third planetary gear set (13); - the second shift element (SE2, SE2', SE2'') is arranged and configured to interlock the first planetary gear set (11); - a third shift element (SE3) arranged and configured to connect the second element (12.2) of the second planetary gear set (12) to the output shaft (2); - a fourth shifting element (SE4) arranged and configured to connect the third element (11.3) of the first planetary gear set (11) to the second element (12.2) of the second planetary gear set (12); - obtaining a first electric power mode (EDA1) by operating a third switching element (SE3); - obtaining a second electric power mode (EDA2) by operating the first switching element (SE1); - obtaining a third electric power mode (EDA3) by operating the fourth switching element (SE4); and / or The respective planetary gear set is present as a negative planetary gear set, wherein the respective first element is the respective sun gear, the respective second element is the respective planet carrier, and the respective third element is the respective ring gear.

2. The transmission (G) according to claim 1, wherein: - the second shifting element is arranged to connect the first element (11.1) of the first planetary gear set (11) with the second element (11.2) of the first planetary gear set (11); or - the second shifting element is arranged to connect the second element (11.2) of the first planetary gear set (11) to the third element (11.3) of the first planetary gear set (11); or The second shift element is provided for connecting the first element (11.1) of the first planetary gear set (11) to the third element (11.3) of the first planetary gear set (11).

3. The transmission (G) according to claim 1 or 2, wherein: By selectively operating four switching elements, the first input shaft (1) and the output shaft (2) are switched between - obtaining the first gear by operating the second shift element and the third shift element (SE3); - obtaining the second gear by operating the first shift element (SE1) and the third shift element (SE3); - obtaining the third gear by actuating the first shift element (SE1) and the fourth shift element (SE4), The fourth gear is obtained by actuating the second shift element and the fourth shift element ( SE4 ).

4. The transmission (G) according to claim 1 or 2, wherein: By selectively operating four switching elements, the second input shaft (5) and the output shaft (2) are switched between - A first gear is obtained by actuating the second shift element (SE2, SE2', SE2") and the third shift element (SE3); - obtaining the second gear by operating the first shift element (SE1) and the fourth shift element (SE4); - obtaining the third gear by actuating the first shift element (SE1) and the third shift element (SE3), The fourth gear is obtained by actuating the second shift element (SE2, SE2', SE2") and the fourth shift element (SE4).

5. The transmission (G) according to claim 1 or 2, wherein: The fifth shift element (SE0) is arranged and configured to connect the first input shaft (1) to an internal combustion engine of a motor vehicle drive train.

6. The transmission (G) according to claim 1 or 2, wherein: One or more of the shift elements are each designed as a form-locking shift element.

7. The transmission (G) according to claim 1 or 2, wherein: A first shift element (SE1) and a second shift element are combined to form a shift element pair (SP1) to which an actuating element is assigned, wherein, starting from a neutral position, the actuating element can actuate the first shift element (SE1) on the one hand and the second shift element on the other hand.

8. The transmission (G) according to claim 1 or 2, wherein: A third shift element (SE3) and a fourth shift element (SE4) are combined to form a shift element pair (SP1) to which an actuating element is assigned, wherein, starting from a neutral position, the actuating element can actuate the third shift element (SE3) on the one hand and the fourth shift element (SE4) on the other hand.

9. The transmission (G) according to claim 1 or 2, wherein: The rotor (R1) of the electric motor (EM1) is connected to the second input shaft (5) in a rotationally fixed manner or is connected to the second input shaft (5) via at least one gear stage.

10. A motor vehicle drive train for a hybrid vehicle or an electric vehicle, comprising a transmission (G) according to any one of claims 1 to 9.

11. Method for operating a transmission (G) according to claim 1, wherein: To establish a charging operation or a starting operation, only the second shift element is closed.

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