Transmission for a hybrid vehicle, and drivetrain for a hybrid vehicle

Abstract

Transmission (G) for a hybrid vehicle, wherein the transmission (G) has a drive shaft (GW1), an output shaft (GW2), an electric machine (EM) with a rotationally fixed stator (S) and a rotatable rotor (R), a gear set (RS) with a first and a second planetary gear set (P1, P2), which together have four shafts (W1, W2, W3, W4) designated as first, second, third and fourth shafts in the order of their speed order, and at least one first, second and third shift element (A, B, D), - whereby a plurality of forward gears (G1-G3) can be switched between the input shaft (GW1) and the output shaft (GW2) by selectively closing the switching elements (A, B, D) in pairs, - wherein the drive shaft (GW1) is connectable to the first shaft (W1) via the first switching element (A) and to the third shaft (W3) via the second switching element (B), - the second shaft (W2) is permanently connected to the output shaft (GW2) in a rotationally fixed manner, - wherein the fourth shaft (W4) can be fixed in rotation via the third switching element (D), and wherein the rotor (R) of the electric machine (EM) is constantly operatively connected to the third shaft (W3) via a fixed transmission ratio, characterized in that the first and second planetary gear sets (P1, P2) are designed as minus gear sets, - wherein a sun gear (E11) of the first planetary gear set (P1) and a sun gear (E12) of the second planetary gear set (P2) are components of the first shaft (W1), - wherein a web (E22) of the second planetary gear set (P2) is part of the second shaft (W2), - wherein a carrier (E21) of the first planetary gear set (P1) and a ring gear (E32) of the second planetary gear set (P2) are components of the third shaft (W3), and - wherein a ring gear (E31) of the first planetary gear set (P1) is part of the fourth shaft (W4).

Description

[0001] The invention relates to a transmission for a hybrid vehicle and a drive train for a hybrid vehicle with such a transmission.

[0002] A transmission, in this context, refers specifically to a multi-speed transmission in which a plurality of gears—i.e., fixed gear ratios between an input shaft and an output shaft—can be shifted, preferably automatically, by shifting elements. These shifting elements include, for example, clutches or brakes. Such transmissions are primarily used in motor vehicles to appropriately adapt the speed and torque output characteristics of the drive unit to the vehicle's driving resistance.

[0003] Patent application DE 10 2013 002 587 A1 discloses a hybrid drive system for a motor vehicle comprising an internal combustion engine, an electric motor, and two planetary gear sets. The rotor of the electric motor is permanently connected to an input shaft in a rotationally fixed manner. The internal combustion engine can be connected to the input shaft via a clutch. Two brakes and two clutches allow four gear ratios to be established between the input shaft and an output shaft.

[0004] From DE 10 2012 214 266 A1 a drive train with an input element, an output element, a stationary element and a motor / generator is known.

[0005] To simulate a starting process from an internal combustion engine or hybrid drive system using the hybrid drive system known from the prior art, either the separating clutch or one of the clutches or brakes involved in the starting gear must be operated in a controlled slip state. This is technically complex, as the starting behavior of the vehicle can be negatively affected by unavoidable fluctuations in the friction coefficient and inaccuracies in the control system. In addition, special cooling of the slipping clutch or brake is usually required, which increases the construction complexity of the system.

[0006] It is therefore an object of the invention to provide a transmission for a motor vehicle which enables starting without slipping of the shift elements.

[0007] The problem is solved by the features of patent claim 1. Advantageous embodiments emerge from the subclaims, the description and the figures.

[0008] The transmission comprises an input shaft, an output shaft, an electric motor with a non-rotatable stator and a rotatable rotor, a gear set, and at least three shift elements. The gear set comprises a first and a second planetary gear set, which together comprise a total of four shafts, designated in speed order as the first, second, third, and fourth shafts. The gear set is thus designed as a two-carrier, four-shaft transmission.

[0009] A two-carrier, four-shaft gear train is a planetary gear train consisting of two individual planetary gear sets kinematically coupled to one another via exactly two coupling shafts, and in which four of its elements ("shafts") are freely accessible to other gear train elements. A coupling shaft is defined as a permanent mechanical connection between an element—i.e., a sun gear, carrier, or ring gear—of the first individual planetary gear set and an element—i.e., a sun gear, carrier, or ring gear—of the second individual planetary gear set. The number of individual planetary gear sets and the number of free shafts are not defined by the visual appearance of the gear train, but rather by its kinematics. A speed diagram of the gear train is typically used to graphically represent the kinematics of the gear train, for example, the Kutzbach diagram known from gear train theory.

[0010] Four shafts, designated as the first, second, third, and fourth shafts in order of their speed, are characterized by the fact that the speeds of these shafts increase, decrease, or are equal in a linear manner in the order mentioned. In other words, the speed of the first shaft is less than or equal to the speed of the second shaft. The speed of the second shaft is in turn less than or equal to the speed of the third shaft. The speed of the third shaft is less than or equal to the speed of the fourth shaft. This sequence is also reversible, so that the fourth shaft has the lowest speed, while the first shaft assumes a speed that is greater than or equal to the speed of the fourth shaft. There is always a linear relationship between the speeds of all four shafts.

[0011] By selectively engaging the three shift elements in pairs, a plurality of forward gears, i.e. fixed gear ratios between the input shaft and the output shaft, can be engaged. For this purpose, the input shaft can be connected to the first shaft of the gear set via the first shift element and to the third shaft of the gear set via the second shift element. The second shaft of the gear set is permanently connected to the output shaft. The fourth shaft of the gear set can be rotationally fixed via the third shift element by being switchably connected to a housing or another rotationally fixed component of the transmission via the third shift element. The rotor of the electric machine is permanently operatively connected to the third shaft of the gear set via a fixed gear ratio.

[0012] This assignment of the transmission elements enables an electrodynamic starting mode. By closing the first shift element, the input shaft is connected to the first shaft of the gear set. By keeping the other shift elements involved in gear formation open, there is no automatically fixed speed relationship between the four shafts of the gear set. Only when a support torque is applied to the third shaft by the electric machine does a fixed speed relationship between the four gear set shafts arise. By varying the rotor speed and the speed applied to the input shaft, the speed of the output shaft can be continuously changed, thus enabling a starting process. At the same time, the transmission also enables fixed gear ratios between the input shaft and output shaft, as well as between the third shaft and output shaft.This means that the hybrid vehicle also has fixed gears available for both combustion engine driving and purely electric driving.

[0013] The first and second planetary gear sets are designed as negative gear sets. A negative gear set refers to a planetary gear set with a carrier on which the planet gears are rotatably mounted, with a sun gear, and with a ring gear, wherein the teeth of at least one of the planet gears mesh with both the teeth of the sun gear and the teeth of the ring gear, whereby the ring gear and the sun gear rotate in opposite directions when the sun gear rotates with the carrier stationary. A positive gear set differs from the negative planetary gear set just described in that the positive gear set has inner and outer planet gears that are rotatably mounted on the carrier. The teeth of the inner planet gears mesh with the teeth of the sun gear on the one hand, and with the teeth of the outer planet gears on the other. The teeth of the outer planet gears also mesh with the teeth of the ring gear.This means that when the carrier is stationary, the ring gear and the sun gear rotate in the same direction. The first and second planetary gear sets are designed together as a so-called Simpson gear set, i.e. with connected sun gears and a carrier-ring gear coupling. The sun gears of the two planetary gear sets are part of the first shaft of the gear set. The carrier of the second planetary gear set is part of the second shaft of the gear set. The carrier of the first planetary gear set and the ring gear of the second planetary gear set are parts of the third shaft of the gear set. The ring gear of the second planetary gear set is part of the fourth shaft of the gear set. A gear set designed in this way is characterized by its simple construction, good efficiency, and compact external dimensions.

[0014] The fixed gear ratio between the third gear set shaft and the rotor of the electric machine can be formed by a permanent, non-rotatable connection. Alternatively, the fixed gear ratio between the third gear set shaft and the rotor can also be achieved by one or more spur gear stages. The electric machine can be arranged axially parallel to the main axis of the transmission. Preferably, the gear ratio of the at least one spur gear stage is selected such that the speed of the rotor is higher than the speed of the third gear set shaft. This allows the electric machine to operate at a higher speed, allowing it to be designed smaller while maintaining the same target torque.

[0015] According to an alternative embodiment, the fixed transmission ratio between the third shaft of the gear set and the rotor of the electric machine is formed by a third planetary gear set, which has a first, a second, and a third element. The first element is a sun gear of the third planetary gear set. The second element is a carrier of the third planetary gear set, provided this is designed as a minus gear set. If the third planetary gear set is designed as a plus gear set, a ring gear forms the second element of the third planetary gear set. The third element is the ring gear of the third planetary gear set, provided this is designed as a minus gear set. If the third planetary gear set is designed as a plus gear set, the carrier forms the third element of the third planetary gear set. The third gear set shaft is permanently connected to the second element of the third planetary gear set.The rotor is connected to either the first or the third element of the third planetary gear set. The remaining element of the third planetary gear set is permanently fixed in a rotationally fixed manner. This arrangement of the elements of the third planetary gear set ensures that the rotor speed is always higher than the speed of the third gear set shaft, thereby reducing the space required for the electric machine. The three planetary gear sets are preferably arranged in the following axial sequence: first planetary gear set, second planetary gear set, third planetary gear set.

[0016] By selectively operating the three shift elements in pairs, a total of three forward gears can be shifted between the input shaft and the output shaft. The first forward gear is formed by engaging the first shift element and the third shift element. The second forward gear is formed by engaging the first shift element and the second shift element. The third forward gear is formed by engaging the second shift element and the third shift element. By assigning the shift elements to the individual forward gears, a gear ratio that is well suited for use in motor vehicles is achieved with a suitable selection of the stationary gear ratio of the planetary gear sets. In addition, two adjacent gears always have a shift element that is engaged in both of these gears. When shifting into an adjacent gear, therefore only one shift element needs to be opened and one shift element closed.This simplifies the switching process and shortens the switching time.

[0017] In a first electrodynamic operating mode, the first shift element is closed, and all other shift elements involved in gear formation are open. This allows the output speed to be continuously varied at a given input shaft speed and varying the rotor speed. This enables continuously variable transmission operation.

[0018] According to one embodiment, the input shaft can be connected to the fourth shaft of the gear set via a fourth shift element. In a second electrodynamic operating mode, this fourth shift element is closed, and all other shift elements involved in gear formation are open. This allows the output speed to be continuously varied at a predetermined input shaft speed and a variation in the rotor speed. Continuously variable operation of the transmission can thus be achieved. The second electrodynamic operating mode enables a reversal of the direction of rotation between the input shaft and output shaft, giving the transmission an electrodynamic reverse mode. This improves the functionality of the transmission.

[0019] Preferably, a first electric gear is established between the third shaft and the output shaft by engaging the first shifting element and the second shifting element. When the transmission is used in the drive train of a motor vehicle, a purely electric drive of the motor vehicle with a constant gear ratio between the electric motor and the output shaft is thus possible.

[0020] Preferably, a second electric gear is created between the third shaft and the output shaft by closing the third shift element. The second electric gear also enables a purely electric drive of a motor vehicle using the transmission's electric motor. The second electric gear can be provided in addition to or as an alternative to the first electric gear.

[0021] Preferably, the first shift element or the second shift element is also closed in the second electric gear. This facilitates shifting between the first and second electric gears, since during such a shift only one shift element needs to be opened and one shift element needs to be closed. Such a shift can take place under load, provided the shift elements involved are designed as force-locking shift elements with variable torque transmission capacity.

[0022] The transmission preferably has a connecting shaft, which can be designed as an interface to an internal combustion engine. The connecting shaft can also have a torsional vibration damper. The connecting shaft can be connected to the drive shaft via a fifth shifting element. By opening the fifth shifting element, a purely electric drive of the motor vehicle is possible via the electric motor of the transmission, without dragging the drive unit connected to the connecting shaft. The fifth shifting element can be designed as a non-positive or positive shifting element.

[0023] By closing the second switching element and the fifth switching element, an operative connection is established between the connecting shaft and the electric motor without affecting the output shaft. This provides a standby charging mode in which the internal combustion engine can charge an energy storage device while the vehicle is stationary by operating the electric motor as a generator.

[0024] The transmission can have a second electric motor whose rotor is permanently connected to the connecting shaft. This can further enhance the functionality of the transmission, for example, to enable the start of a drive unit connected to the connecting shaft while the fifth switching element is open.

[0025] If the transmission has a fifth shift element, the fifth shift element is open in first and second electric gears. This reduces drag losses, as the connecting shaft and the associated drive unit do not need to be dragged in first and second electric gears.

[0026] The transmission can be part of a drive train of a hybrid vehicle. In addition to the transmission, the drive train also has an internal combustion engine, which is connected to the connection shaft of the transmission. The output shaft of the transmission is connected to an axle gear, which is connected to the wheels of the hybrid vehicle. The drive train enables several drive modes of the hybrid vehicle. In electric driving mode, the hybrid vehicle is driven by the electric motor of the transmission, with the fifth shift element open. In combustion engine mode, the hybrid vehicle is driven by the internal combustion engine, with the fifth shift element closed. In hybrid mode, the hybrid vehicle is driven by both the internal combustion engine and the electric motor of the transmission.

[0027] A permanent connection is defined as a connection between two elements that always exists. Such permanently connected elements always rotate with the same dependence between their speeds. A permanent connection between two elements cannot contain a switching element. A permanent connection must therefore be distinguished from a switchable connection.

[0028] Two elements are said to be connectable if there is a rotationally fixed connection between them that can be released by a switching element. If the connection exists, such elements rotate at the same speed.

[0029] Embodiments of the invention are described in detail below with reference to the attached figures. Fig. 1 shows schematically a transmission according to a first embodiment of the invention. Fig. 2 shows a shift diagram of the transmission according to the first embodiment. Fig. 3 shows schematically a transmission according to a second embodiment of the invention. Fig. 4 shows a shift diagram of the transmission according to the second embodiment. Fig. 5 shows a speed diagram of the transmission according to the third embodiment of the invention. Fig. 6 shows schematically a transmission according to a third embodiment of the invention. Fig. 7 schematically shows a transmission according to a fourth embodiment of the invention. Fig. 8 schematically shows a transmission according to a fifth embodiment of the invention. Fig. 9 shows a drive train of a hybrid vehicle.

[0030] Fig. 1 schematically shows a transmission G according to a first embodiment of the invention. The transmission G has a first planetary gear set P1 and a second planetary gear set P2, which together form a gear set RS. The two planetary gear sets P1, P2 are designed as negative gear sets and together form a so-called Simpson gear set. A sun gear E11 of the first planetary gear set P1 is permanently connected to a sun gear E12 of the second planetary gear set P2. A carrier E21 of the first planetary gear set P1 is permanently connected to a ring gear E32 of the second planetary gear set P2. Due to this double coupling of the two planetary gear sets P1, P2, the gear set RS has a total of four shafts, which are designated in their speed order as first shaft W1, second shaft W2, third shaft W3, and fourth shaft W4. The sun gear E11 of the first planetary gear set P1 and the sun gear E12 of the second planetary gear set P2 are components of the first shaft W1.A web E22 of the second planetary gear set P2 is part of the second shaft W2. The web E21 of the first planetary gear set P1 and the ring gear E32 of the second planetary gear set P2 are parts of the third shaft W3. A ring gear E31 of the first planetary gear set P1 is part of the fourth shaft W4. An input shaft GW1 is connectable to the first shaft W1 of the gear set RS via a first switching element A. The input shaft GW1 is connectable to the third shaft W3 of the gear set RS via a second switching element B. The fourth shaft W4 of the gear set RS can be rotationally fixed via a third switching element D by being switchably connected to a housing GG or to another rotationally fixed component of the transmission G. The second shaft W2 of the gear set RS is permanently connected to an output shaft GW2. The transmission G further comprises an electric machine EM with a rotationally fixed stator S and a rotatable rotor R.The rotor R is permanently connected to the third shaft W3 of the gear set RS.

[0031] Fig. 2 shows a shift diagram of the transmission G according to the first exemplary embodiment. The rows of the shift diagram indicate a first electrodynamic operating mode EDA1, three forward gears G1 to G3, a standby charging operating mode GEN, and a first and second electric gear E1, E2. In the columns of the shift diagram, an X indicates which shift elements A, B, D are engaged in which gear or operating mode. In the forward gears G1 to G3, two of the three shift elements A, B, D are engaged. This results in a fixed gear ratio between the input shaft GW1 and the output shaft GW2 in the three forward gears G1, G2, G3. In the first electrodynamic operating mode EDA1, however, only the first shift element A is engaged. As a result, the elements input shaft GW1, output shaft GW2, and rotor R of the electric machine EM are each connected to an element of the second planetary gear set P2.If the electric machine EM does not generate any torque, no power can be transferred from the input shaft GW1 to the output shaft GW2. Only by applying a support torque using the electric machine EM is power transmission via the second planetary gear set P2 possible in the first electrodynamic operating mode EDA1. By varying the rotor speed and the given input shaft speed, a start-up process can thus be achieved. By closing the second switching element B and keeping the other switching elements A, D open in the stand-by charging mode GEN, the input shaft GW1 is connected to the rotor R of the electric machine EM without any power being transferred from the input shaft GW1 to the output shaft GW2. This allows an internal combustion engine connected to the input shaft GW1 to charge an energy storage device through the generator operation of the electric machine EM, without affecting the output.The electrical gears E1, E2 refer to a fixed gear ratio between the third shaft W3 of the gear set RS and the output shaft GW2.

[0032] Fig. Figure 3 shows schematically a transmission G according to a second embodiment of the invention. In contrast to the Fig. 1, the transmission G according to the second embodiment has a fourth shifting element C. By closing the fourth shifting element C, the drive shaft GW1 can be connected to the fourth shaft W4 of the gear set RS.

[0033] Fig. 4 shows a shift diagram of the transmission G according to the second exemplary embodiment. The fourth shift element C is only engaged in a second electrodynamic operating mode EDA2 and is otherwise engaged in all forward gears G1 to G3, or operating modes. In the second electrodynamic operating mode EDA2, none of the remaining shift elements A, B, or D are engaged except for the fourth shift element C. Thus, even in the second electrodynamic operating mode EDA2, power transmission between the input shaft GW1 and output shaft GW2 is only possible if the third shaft W3 of the gear set RS is supported by the electric motor EM.

[0034] Fig. Figure 5 shows a speed diagram of the second embodiment of the transmission G. In the speed diagram, the speeds n of the four shafts W1, W2, W3, W4 of the gear set RS are plotted vertically in relation to the speed of the input shaft GW1. The maximum occurring speed of the input shaft GW1 is normalized to the value one. The distances between the four shafts W1, W2, W3, W4 result from the stationary gear ratios of the first and second planetary gear sets P1, P2. The illustration is for illustrative purposes only and is not to scale. Speed ​​ratios belonging to a specific operating point can be connected by a straight line. The speed ratios available through the two electrodynamic operating modes EDA1, EDA2 are shown hatched.It is clearly visible that the first electrodynamic operating mode EDA1 is useful for starting in the forward direction, while the second electrodynamic operating mode EDA2 is useful for starting in the reverse direction.

[0035] Fig. 6 schematically shows a transmission G according to a third embodiment of the invention. In contrast to the previous embodiments, the rotor R of the electric machine EM is no longer permanently connected to the third shaft W3 of the gear set RS. Instead, the transmission G according to the third embodiment has a third planetary gear set P3, which has a first element E13, a second element E23, and a third element E33. The first element E13 of the third planetary gear set P3 is formed by a sun gear and is permanently fixed in rotation. The second element E23 of the third planetary gear set P3 is formed by a carrier and is permanently connected to the third shaft W3 of the gear set RS. The third element E33 of the third planetary gear set P3 is permanently connected to the rotor R of the electric machine EM.The third planetary gear set P3 adjusts the speed between the third shaft W3 and the rotor R, while still maintaining a fixed gear ratio between the third shaft W3 and the rotor R.

[0036] Fig. Figure 7 schematically shows a transmission G according to a fourth exemplary embodiment of the invention, which is functionally identical to the second exemplary embodiment. Only the relative arrangement of the components of the transmission G to one another has been changed, so that the transmission G according to the fourth exemplary embodiment is suitable for a so-called front-transverse arrangement. Furthermore, the transmission G has a fifth shifting element K0, via which the drive shaft GW1 can be connected to a connecting shaft AN. The fifth shifting element K0 is optional.

[0037] In the same way, connecting shaft AN and fifth switching element K0 could also be used in the previous embodiments.

[0038] Fig. Figure 8 schematically shows a transmission G according to a fifth embodiment of the invention. In contrast to the fourth embodiment, the transmission G according to the fifth embodiment has a spur gear set ST, via which the rotor R of the electric motor EM is connected to the third shaft W3 of the gear set RS. The rotational axis of the rotor R is arranged parallel to the main axis of the transmission G.

[0039] Fig.9 shows a drive train of a hybrid vehicle with a transmission G according to the second exemplary embodiment, which includes the fifth shifting element K0. This is to be considered merely an example. The drive train could be implemented with any of the exemplary embodiments of the transmission G mentioned. The drive train has an internal combustion engine VKM, which is connected to the connecting shaft AN of the transmission G via a torsional vibration damper TS. The output shaft GW2 of the transmission G is drive-connected to an axle drive AG. Starting from the axle drive AG, the power applied to the output shaft GW2 is distributed to the wheels DW of the motor vehicle. If the fifth shifting element K0 is engaged, the internal combustion engine VKM drives the input shaft GW1 of the transmission G via the connecting shaft AN. This enables both internal combustion engine operation and hybrid operation of the drive train.If the fifth switching element K0 is open, the electric motor EM of the transmission G can take over the drive. -. Reference symbol G Gearbox GW1 drive shaft GW2 output shaft AN connecting shaft GG case EM Electric Machine S Stator R Rotor n speed RS wheelset W1 First Wave W2 Second Wave W3 Third Wave W4 Fourth Wave P1 First planetary gear set E11 Sun gear of the first planetary gear set E21 web of the first planetary gear set E31 ring gear of the first planetary gear set P2 Second planetary gear set E12 Sun gear of the second planetary gear set E22 Carrier of the second planetary gear set E32 ring gear of the second planetary gear set P3 Third planetary gear set E13 First element of the third planetary gear set E23 Second element of the third planetary gear set E33 Third element of the third planetary gear set A First switching element B Second switching element D Third switching element C Fourth switching element K0 Fifth switching element G1-G3 First to third forward gear EDA1 First electrodynamic operating mode EDA2 Second electrodynamic operating mode E1 First electric gear E2 Second electric gear GEN stand-by charging mode DW Wheels AG axle drive ST spur gear set ICE internal combustion engine TS torsional vibration damper

Claims

[1] Transmission (G) for a hybrid vehicle, wherein the transmission (G) has a drive shaft (GW1), an output shaft (GW2), an electric machine (EM) with a rotationally fixed stator (S) and a rotatable rotor (R), a gear set (RS) with a first and a second planetary gear set (P1, P2), which together have four shafts (W1, W2, W3, W4) designated as first, second, third and fourth shafts in the order of their speed order, and at least one first, second and third shift element (A, B, D), - whereby a plurality of forward gears (G1-G3) can be switched between the input shaft (GW1) and the output shaft (GW2) by selectively closing the switching elements (A, B, D) in pairs, - wherein the drive shaft (GW1) is connectable to the first shaft (W1) via the first switching element (A) and to the third shaft (W3) via the second switching element (B), - the second shaft (W2) is permanently connected to the output shaft (GW2) in a rotationally fixed manner, - wherein the fourth shaft (W4) can be fixed in a rotationally fixed manner via the third switching element (D), and wherein the rotor (R) of the electric machine (EM) is permanently operatively connected to the third shaft (W3) via a fixed transmission ratio, characterized by that the first and second planetary gear sets (P1, P2) are designed as minus gear sets, - wherein a sun gear (E11) of the first planetary gear set (P1) and a sun gear (E12) of the second planetary gear set (P2) are components of the first shaft (W1), - wherein a web (E22) of the second planetary gear set (P2) is part of the second shaft (W2), - wherein a carrier (E21) of the first planetary gear set (P1) and a ring gear (E32) of the second planetary gear set (P2) are components of the third shaft (W3), and - wherein a ring gear (E31) of the first planetary gear set (P1) is part of the fourth shaft (W4). [2] Transmission (G) according to claim 1, characterized by that the fixed transmission of the permanent operative connection between the third shaft (W3) and the rotor (R) of the electrical machine (EM) is formed by a permanently rotationally fixed connection or by at least one spur gear set (ST). [3] Transmission (G) according to claim 1, characterized by that the fixed transmission ratio of the permanent operative connection between the third shaft (W3) and the rotor (R) of the electric machine (EM) is formed by a third planetary gear set (P3) which has a first, second and third element (E13, E23, E33), - wherein the first element (E11) is formed by a sun gear of the third planetary gear set (P3), wherein the second element (E23) is formed by a carrier in the case of a minus gear set and by a ring gear of the third planetary gear set (P3) in the case of a plus gear set, wherein the third element (E33) is formed by the ring gear in the case of a minus gear set and by the carrier of the third planetary gear set (P1P3) in the case of a plus gear set, - wherein the second shaft (W2) is permanently connected to the second element (E23) of the third planetary gear set (P3), - wherein the rotor (R) is permanently connected to either the first or the third element (E13 / E33) of the third planetary gear set (P3), and - whereby the remaining element (E33 / E13) of the third planetary gear set (P3) is permanently fixed against rotation. [4] Transmission (G) according to claim 3, characterized bythat the planetary gear sets (P1, P2, P3) are arranged in the following axial order: first planetary gear set (P1), second planetary gear set (P2), third planetary gear set (P3). [5] Transmission (G) according to one of the preceding claims, characterized by that by selectively closing the three switching elements (A, B, D) in pairs, a total of three forward gears (G1-G3) can be switched between the input shaft (GW1) and the output shaft (GW2), whereby - the first forward gear (G1) by closing the first switching element (A) and the third switching element (D), - the second forward gear (G2) by closing the first switching element (A) and the second switching element (B), and - the third forward gear (G3) is obtained by closing the second switching element (A) and the third switching element (D). [6] Transmission (G) according to one of the preceding claims, characterized byin a first electrodynamic operating mode (EDA1) the first switching element (A) is closed and all other switching elements (B, D) involved in gear formation are open, wherein the speed applied to the output shaft (GW2) is continuously variable at a predetermined speed of the input shaft (GW1) by varying the speed of the rotor (R). [7] Transmission (G) according to one of the preceding claims, characterized by in that the drive shaft (GW1) can be connected to the fourth shaft (W4) via a fourth switching element (C), wherein in a second electrodynamic operating mode (EDA2) the fourth switching element (C) is closed and all other switching elements (A, B, D) involved in gear formation are open, wherein the speed applied to the output shaft (GW2) is continuously variable at a predetermined speed of the drive shaft (GW1) by varying the speed of the rotor (R). [8] Transmission (G) according to one of the preceding claims, characterized by that a first electrical gear (E1) between the third shaft (W3) and the output shaft (GW2) is produced by closing the first switching element (A) and the second switching element (B). [9] Transmission (G) according to one of the preceding claims, characterized by that a second electrical gear (E2) is created between the third shaft (W3) and the output shaft (GW2) by closing the third switching element (D). [10] Transmission (G) according to claim 9, characterized by that in the second electric gear (E2) the first switching element (A) or the second switching element (B) is additionally closed. [11] Transmission (G) according to one of the preceding claims, characterized by that the transmission (G) has a connecting shaft (AN), wherein the connecting shaft can be connected to the drive shaft (GW1) via a fifth switching element (K0). [12] Transmission (G) according to claim 11, characterized by that in a standby charging mode (GEN) the fifth switching element (K0) and the second switching element (B) are closed, and all other switching elements (A, C, D) involved in gear formation are open. [13] Drive train for a hybrid vehicle, wherein the drive train has an internal combustion engine (ICE), a transmission (G) according to claim 12 and an axle transmission (AG) connected to wheels (DW) of the hybrid vehicle, wherein the connecting shaft (AN) of the transmission (G) is torsionally elastically connected to the internal combustion engine (ICE) via a torsional vibration damper (TS) and the output shaft (GW2) of the transmission (G) is drivingly connected to the axle transmission (AG), wherein the hybrid vehicle can be driven by the electric machine (EM) alone in an electric driving mode when the fifth switching element (K0) is open, wherein the hybrid vehicle can be driven by the internal combustion engine (ICE) alone in an internal combustion engine mode when the fifth switching element (K0) is closed and can be driven by the internal combustion engine (ICE) and the electric machine (EM) in a hybrid mode.

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