Drive arrangement for a hybrid vehicle and drive train with such a drive arrangement

Abstract

Drive arrangement (1) for a hybrid vehicle, wherein the hybrid vehicle has a hybrid drive with an internal combustion engine (7) and an electric machine (6) and a transmission (2) with two transmission input shafts (4, 5) and one output shaft (3), wherein the drive arrangement comprises at least the following, a first planetary gear (PG1) with the elements web (ST1), sun gear (SR1) and ring gear (HR1), wherein a first element of the first planetary gear can be connected to one of the transmission input shafts (5) in a rotationally fixed manner, and wherein a second element of the first planetary gear (PG1) can be connected to the housing; a second planetary gear (PG2) with the elements web (ST2), sun gear (SR2) and ring gear (HR2), wherein a first element of the second planetary gear (PG2) can be connected fixedly to the electric machine (6) in a rotationally fixed manner, and wherein a second element of the second planetary gear (PG2) can be connected to another of the transmission input shafts (4) in a rotationally fixed manner; at least three switching elements (I, J, K), where when a first switching element (J) is closed, a third element of the second planetary gear (PG2) is fixedly connected to the housing; when a second shift element (I) is closed, the third element of the second planetary gear (PG2) is connected in a rotationally fixed manner to the transmission input shaft (5), to which the first element of the first planetary gear (PG1) is also connected in a rotationally fixed manner; when a third switching element (K) is closed, the third element of the second planetary gear (PG2) is connected in a rotationally fixed manner to a third element of the first planetary gear (PG1).

Description

[0001] The invention relates to a drive arrangement for a hybrid vehicle. Furthermore, the invention relates to a drive train with such a drive arrangement.

[0002] Hybrid vehicles with hybrid drives are known from the state of the art.

[0003] Hybrid drives have two or more different power sources, with drivetrains consisting of an internal combustion engine and one or more electric motors, known as parallel hybrids or mixed hybrids, becoming the most popular. These variants feature a substantially parallel arrangement of the internal combustion engine and electric motor in terms of power flow, allowing both superimposition of drive torques and control with a purely internal combustion engine or purely electric motor drive.

[0004] Hybrid vehicles have a transmission in addition to the hybrid drive.

[0005] A transmission refers, in particular, to a multi-speed transmission in which a plurality of gears—i.e., fixed gear ratios between two transmission shafts—can be shifted, preferably automatically, by shifting elements. Such transmissions are primarily used in motor vehicles, especially commercial vehicles, to suitably adapt the speed and torque output characteristics of the drive unit to the vehicle's driving resistance.

[0006] From DE 10 2010 063 582 A1 a drive arrangement for a hybrid vehicle is known, with a planetary gear comprising the elements web, sun gear and ring gear, wherein a first element of these elements of the planetary gear serves for the fixed connection of a first transmission input shaft of a first partial transmission of a transmission, and wherein a second element of these elements of the planetary gear serves for the fixed connection of an electric machine of a hybrid drive.

[0007] The drive arrangement of DE 10 2010 063 582 A1 further comprises a first shifting element, via which a third element of these elements of the planetary gear train can be connected in a first shifting position of the first shifting element to a second transmission input shaft of a second partial transmission of the transmission, to which an internal combustion engine of the hybrid drive can also be coupled, and in a second shifting position of the first shifting element can be connected on the housing side or stator side.

[0008] Furthermore, the drive assembly of DE 10 2010 063 582 A1 has a second shifting element, via which both transmission input shafts of both sub-transmissions can be coupled to one another when the second shifting element is closed, and via which both transmission input shafts of both sub-transmissions can be separated from one another when the second shifting element is open. This enables electrodynamic starting and electrodynamic shifting. Furthermore, the electric machine can be used as a starter generator.

[0009] Based on the state of the art, the object is to create a drive arrangement for a hybrid vehicle which enables reversing in a simple and cost-effective manner, in particular reversing in hybrid operation while also providing drive torque via the combustion engine.

[0010] Furthermore, a drive train for a hybrid vehicle with such a drive arrangement is to be created, in particular with an automated powershift manual transmission, which combines the various advantages of existing manual transmissions and implements them in such a way that a drive train with this transmission is created with low construction costs and high efficiency, which has a spread and gradation specifically for trucks.

[0011] This object is achieved by a drive arrangement according to patent claim 1.

[0012] The drive arrangement comprises at least a first planetary gear, a second planetary gear and at least three switching elements.

[0013] The first planetary gear set comprises the elements carrier, sun gear, and ring gear, wherein a first element of the first planetary gear set is rotatably connected to one of the transmission input shafts, and wherein a second element of the first planetary gear set is rotatably connected to the housing. The second planetary gear set also comprises the elements carrier, sun gear, and ring gear, wherein a first element of the second planetary gear set is rotatably connected to the electric machine, and wherein a second element of the second planetary gear set is rotatably connected to another of the transmission input shafts. When a first shifting element is engaged, a third element of the second planetary gear set is fixedly connected to the housing. When a second shifting element is engaged, the third element of the second planetary gear set is rotatably connected to the transmission input shaft, to which the first element of the first planetary gear set is also rotatably connected.Then, when a third switching element is closed, the third element of the second planetary gear is connected in a rotationally fixed manner to a third element of the first planetary gear.

[0014] The drive arrangement according to the invention is inherently independent of the specific gear set of the hybrid vehicle's transmission. The drive arrangement comprises at least the two planetary gears and the three shifting elements. When the first shifting element is engaged, driving is possible purely electrically. When the second shifting element is engaged, driving forward with the involvement of the combustion engine in a so-called EDA operating mode is possible. When the third shifting element is engaged, driving backward with the involvement of the combustion engine is possible, again in EDA operating mode. The invention therefore enables reversing with the involvement of the combustion engine, using the drive arrangement according to the invention, regardless of the specific gear set of the transmission.

[0015] Preferably, the first switching element and the second switching element and the third switching element can be actuated via a common actuator in such a way that only one of these switching elements is closed at any one time.

[0016] This embodiment of the invention is structurally simple, cost-effective, and therefore preferred. A single actuator is sufficient for the three switching elements. Only one of these three switching elements is closed at a time. Furthermore, all three switching elements can also be open, particularly to synchronize switching elements to be engaged via the electric motor.

[0017] According to a first development of the invention, the first switching element and the second switching element and the third switching element are arranged such that the second switching element is arranged between the first switching element and the third switching element.

[0018] According to a second, alternative development, the first switching element and the second switching element and the third switching element are arranged such that the first switching element is arranged between the second switching element and the third switching element.

[0019] The second development of the invention is preferred because, in this second development, the two switching elements that ensure forward driving and reverse driving in the EDA operating mode when the switching position is closed are separated by the switching element that enables purely electric driving when the switching position is closed. When this first switching element is closed, the electric motor has a speed of zero when the vehicle is stationary.When changing from a closed second switching element for forward driving in EDA operating mode to a closed third switching element for reversing in EDA operating mode, the closed switching position of the first switching element must be passed through according to the second further development, in which the electric machine then has a speed of zero when the vehicle is stationary, so that the second switching element can be switched through at the zero crossing of the speed without any synchronization effort for the second switching element.

[0020] The drive train according to the invention is defined in claim 11.

[0021] The drive arrangement is particularly preferably used in a drive train whose transmission comprises a main transmission comprising two partial transmissions connected in parallel with the two transmission input shafts and the output shaft, wherein the main transmission comprises a first gear plane, a second gear plane, a third gear plane, a fourth gear plane and a fifth gear plane, wherein the transmission comprises a first double shift element, a second double shift element, a third double shift element, a fourth double shift element and a fifth double shift element, wherein the transmission comprises a further planetary transmission which is connected to the main transmission as a range group in such a way thatthat the fourth double shift element, when the fourth double shift element is closed, connects the fifth gear plane and a first element of the further planetary gear in a rotationally fixed manner, and when the fourth double shift element is closed, connects the fifth gear plane of the main transmission to a main shaft of the transmission, and that the fifth double shift element couples a second element of the further planetary gear to the output shaft when the fifth double shift element is closed, and locks it fixedly to the housing when the fifth double shift element is closed, with a third element of the further planetary gear being rotationally fixedly coupled to the main shaft of the transmission. A hybrid vehicle that combines the drive arrangement according to the invention with such a transmission is particularly preferred. Various advantages of existing manual transmissions can be combined.In particular, gears are fully powershiftable, whereby a spread and gradation can be ensured with low construction effort and high efficiency, which is particularly suitable for trucks.

[0022] Preferred developments emerge from the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail, without being limited thereto, with reference to the drawings. Herein: Fig. 1 a diagram of a first drive arrangement according to the invention; Fig. 2 a diagram of a second drive arrangement according to the invention; Fig. 3 a diagram of a third drive arrangement according to the invention; Fig. 4 the drive arrangement of the Fig. 3 in combination with a preferred gearbox.

[0023] The present invention relates to a drive arrangement for a hybrid vehicle and to a hybrid vehicle with such a drive arrangement and a transmission.

[0024] Fig. Figure 1 shows a first embodiment of a drive arrangement 1 according to the invention together with a transmission 2 shown as a block, wherein an output shaft 3 and two transmission input shafts 4, 5 are shown from the transmission 2. The drive arrangement 1 according to the invention is connected between the transmission 2, namely the transmission input shafts 4, 5 of the transmission 2 and a hybrid drive of a hybrid vehicle, wherein the hybrid drive in Fig. 1 an electric machine 6 and an internal combustion engine 7 are shown. The internal combustion engine 7 is in Fig. 1 is directly coupled in a rotationally fixed manner, i.e., without the interposition of a separating clutch or starting clutch, to one of the transmission input shafts, namely to the transmission input shaft 5. Although such a separating clutch or starting clutch can be dispensed with, it is also possible to connect a separating clutch or starting clutch between the transmission input shaft 5 and the combustion engine 7.

[0025] The drive assembly according to the invention for a hybrid vehicle comprises a first planetary gear PG1 with the elements carrier ST1, sun gear SR1, and ring gear HR1. Furthermore, the drive assembly 1 according to the invention has a second planetary gear PG2, again with the elements carrier ST2, sun gear SR2, and ring gear HR2.

[0026] A first element of the first planetary gear PG1, in Fig. 1, the sun gear SR1, is connected or can be connected in a rotationally fixed manner to one of the transmission input shafts, namely to that transmission input shaft 5 to which the combustion engine 7, namely a drive shaft thereof, is also permanently connected in a rotationally fixed manner without the interposition of a separating clutch. A second element of the first planetary gear PG1, in the embodiment of the Fig. 1 the bridge ST1, is fixed to the housing.

[0027] A first element of the second planetary gear PG2, in Fig. 1 the sun gear SR2, is connected in a rotationally fixed manner to the electrical machine 6, namely to a rotor or runner 8 of the electrical machine 6. A stator or stand 9 of the electrical machine 6 is connected in a housing-fixed manner.

[0028] A second element of the second planetary gear PG2, in the embodiment of the Fig. 1 the web ST2, is permanently and non-rotatably connected to the other transmission input shaft of the transmission 2, namely to the transmission input shaft 4.

[0029] In addition to the two planetary gears PG1 and PG2, the drive arrangement 1 according to the invention comprises at least three switching elements K, I and J.

[0030] Then, when a first switching element J of the drive arrangement 1 is closed, a third element of the second planetary gear PG2, in the embodiment shown the Fig. 1 the ring gear HR2, fixed to the housing.

[0031] Then, however, when a second switching element I of the drive arrangement 1 is closed, the third element of the second planetary gear PG2, in Fig. 1 the ring gear HR2, is connected in a rotationally fixed manner to the transmission input shaft 5 of the transmission 2, to which the first element, in Fig. 1 the sun gear SR1 of the first planetary gear PG1 is connected in a rotationally fixed manner.

[0032] If, however, the third switching element K of the drive arrangement 1 is closed, the third element of the second planetary gear, in Fig. 1 the ring gear HR2, rotationally fixed to a third element of the first planetary gear PG1, in Fig. 1 to the ring gear HR1.

[0033] Then, when the first switching element J is closed, i.e. when Fig. 1 the ring gear HR2 of the second planetary gear PG2 is fixed to the housing, it can be driven in ISG operating mode in a purely electrical manner.

[0034] Then, when the second shift element I is closed, i.e. when the ring gear HR2 of the second planetary gear PG2 is connected to the transmission input shaft 5, forward travel is possible with the participation of the combustion engine 7, in particular in a so-called EDA operating mode.

[0035] Then, when the third switching element K is closed, i.e. when the two ring gears HR1 and HR2 of the two planetary gears PG1 and PG2 are connected, it is possible to drive backwards, particularly in the EDA operating mode, with the participation of the combustion engine 7.

[0036] The first planetary gear PG1 therefore serves as a reversing stage, in which the sun gear SR1 is driven by the combustion engine 7, in which the web ST1 is fixed to the housing, and in which the ring gear HR1 rotates backwards.

[0037] In the Fig. In the embodiment of the drive arrangement 1 shown in Figure 1, the three switching elements J, I, and K can be actuated via a common actuator 10; the three switching elements J, I, and K are thus combined to form a triple switching element S6. In this preferred embodiment, only one of the three switching elements J, I, and K can be closed at any one time; however, it is also possible for all three switching elements J, I, and K to be open.

[0038] In Fig. 1, the three switching elements J, I and K of the drive arrangement 1 are arranged such that the second switching element I is arranged between the first switching element J and the third switching element K. Starting from a closed switching element position of the first switching element J, a closed switching element position of the second switching element I must therefore first be passed through before a closed switching element position of the third switching element K can be assumed. In this case, a neutral switching element position or neutral position is implemented on the one hand between the closed switching element position of the first switching element J and the closed switching element position of the second switching element I and on the other hand between the closed switching element position I and the closed switching element position K.

[0039] The neutral position between the switching elements I and J as well as the neutral position between the switching elements I and K is required in order to synchronize a rotational speed at a switching element of the three switching elements J, I and K to be engaged, in particular via the electric machine 6.

[0040] In Fig. 1, there are therefore five switching element positions for the switching elements K, I and J combined to form the triple switching element S6, namely three closed switching element positions and two neutral positions.

[0041] Fig. 2 shows a second drive arrangement 1 according to the invention, which differs from the one shown in Fig. 1 shown drive arrangement 1 by the relative position of the three switching elements I, J and K. Regarding the remaining details, the drive arrangement of the Fig. 1 with the drive arrangement of the Fig. 2, so that to avoid unnecessary repetition, the same reference numbers are used for the same components and with regard to the embodiment of the Fig. 2 to the explanations of the embodiment of the Fig. 1 is referred to.

[0042] In the embodiment of the Fig. 2, the three switching elements I, J and K are arranged such that the first switching element J is positioned between the second switching element I and the third switching element K, so that accordingly, starting from a closed switching element position of the second switching element I, a closed switching element position of the first switching element J must first be passed through before a closed switching element position of the third switching element K can be assumed. This has the advantage that when changing between forward travel and reverse travel with the involvement of the combustion engine in the so-called EDA operating mode, which is provided by the closed switching element positions of the second switching element I and the third switching element K, the closed switching element position of the first switching element J must always be passed through.

[0043] When the switching element position of the second switching element J is closed when the vehicle is stationary, the electric machine has a speed of zero anyway, so that when changing between forward travel with the second switching element I closed and reverse travel with the third switching element K closed, the corresponding switching can be carried out without additional synchronization effort for the first switching element J.

[0044] Both variants of the Fig. 1 and Fig. 2 have in common that when the vehicle is stationary, the electric machine 6 has a speed of zero, and thus also the transmission input shaft 4, whereas the combustion engine 7 is idling. The ring gear HR1 of the first planetary gear PG1 then rotates continuously in reverse at a relatively low speed. Then, if the third switching element K is closed in this situation, the ring gear HR2 of the second planetary gear PG2 also rotates relatively slowly in reverse, with the electric machine 6 then rotating forward to compensate. Then, if, however, the first switching element J is closed in this situation, the electric machine 6 is stationary due to the housing-fixed connection of the ring gear HR2 of the planetary gear PG2. If, however, the second switching element I is closed in this situation, the ring gear HR2 of the second planetary gear PG2 rotates forward, with the electric machine 6 then rotating backward to compensate.When switching between the closed switching element positions of switching elements I, J, and K, a differential speed at the switching element to be engaged can be actively synchronized with the help of the electric machine 6. The switching always occurs with traction interrupted. The variant of the . Fig. 2, however, to switch between the closed switching element positions of the switching elements I and K, the first switching element J can be switched through at zero crossing without any synchronization effort.

[0045] A further embodiment of a drive arrangement 1 according to the invention shows Fig. 3, wherein the drive arrangement 1 of the Fig. 3 a further development of the drive arrangement 1 of the Fig. 2. Therefore, the same reference numbers are used below for the same components and, to avoid unnecessary repetition, the drive arrangement of the Fig. 3 on the explanations of the drive arrangement of the Fig. 2 and thus also the Fig. 1.

[0046] The drive arrangement 1 of the Fig. 3, in addition to the two planetary gears PG1 and PG2 and in addition to the three shift elements J, I, and K, has a further shift element C, which is designed as a coupling shift element. When this fourth shift element C is closed, the two transmission input shafts 4 and 5 of the transmission 2 are coupled to one another in a rotationally fixed manner, whereas when this shift element C is open, the two transmission input shafts 4 and 5 are not coupled to one another in a rotationally fixed manner. By means of the fourth shift element C, the combustion engine 7 can also use those gears of the transmission 2 that are assigned to the transmission input shaft 4, in order to provide mechanical forward gears.

[0047] In Fig. 3, the fourth shifting element C is shown within the transmission 2, i.e., designed as an internal shifting element. However, it is also possible for this fourth shifting element C to be positioned outside the transmission 2, i.e., designed as an external shifting element.

[0048] As already mentioned in connection with Fig. 1, a separating clutch or starting clutch can be connected between the internal combustion engine 7 and the transmission input shaft 5 interacting with the internal combustion engine 7. However, such a separating clutch or starting clutch is advantageously omitted to reduce the number of components.

[0049] Although the Fig. While the interconnection of the three elements of each of the two planetary gears PG1, PG2 with the transmission input shafts 4, 5 and the shifting elements J, I, and K shown in Figures 1 to 3 is preferred, a different connection of the planetary gears is also possible. Thus, in the second planetary gear PG2, the electric motor 6 can also engage the ring gear HR2, and the sun gear SR2 can be shiftable via the shifting elements J, I, and K.

[0050] Furthermore, a plus gear set can be used for the planetary gears PG1 and PG2 to reduce other gear ratios.

[0051] Furthermore, a different coupling of the three elements of the planetary gear PG1 can be used, for example in conjunction with a plus planetary gear set for the planetary gear PG1, in which the ring gear HR1 is then fixed to the housing, the sun SR1 is connected to the transmission input shaft 5 and the web SR1 can be switched via the switching elements K, I and J.

[0052] In the drive arrangements according to the invention, an additional brake can be provided as a conventional starting element for starting in forward and reverse travel on the transmission input shaft 4, which interacts with the electric motor 6. Such a starting element can support or replace dynamic torque support by the electric motor 6, both for forward travel with the second shift element I engaged and for reverse travel with the third shift element K engaged.

[0053] Furthermore, it is possible to assign an additional shifting element to the second planetary gear set PG2, via which the second planetary gear set PG2 can be locked so that it operates in block rotation when the speeds of the sun gear SR2, carrier ST2, and ring gear HR2 are the same. This allows mechanical reverse gears to be provided without the need for torque support from the electric motor. Such a lock-up clutch can be designed as a friction clutch and serve as a conventional starting element for starting in forward and reverse travel.

[0054] As stated above, the decision taken with reference to Fig. 1 to 3, the drive arrangement 1 according to the invention is independent of the specific gear set of the transmission 2.

[0055] However, it is particularly preferred with the Fig. 4 is used to provide a gear ratio spread and stepping specifically for trucks with automated powershift gears in the gearbox 2 with low construction effort and high efficiency.

[0056] This shows Fig. 4 shows the preferred embodiment of the transmission 2 together with the drive arrangement 1 according to the invention. The transmission 2 comprises a 5-speed main transmission HG, which has two sub-transmissions, and a further planetary transmission PG3 with the elements carrier ST3, sun gear SR3 and ring gear HR3. The further planetary transmission PG3 is used as a range group and connects to the main group HG. The first transmission input shaft 4 is designed as a hollow shaft and is assigned to a first sub-transmission of the main transmission HG. A second transmission input shaft 5 is designed as a solid shaft and is assigned to the second sub-transmission of the main transmission HG.

[0057] The main transmission HG comprises a first gear plane R1, a second gear plane R2, a third gear plane R3, a fourth gear plane R4 and a fifth gear plane R5 as well as a first double shifting element S1 with the shifting elements A and B, a second double shifting element S2 with the shifting elements C and D, a third double shifting element S3 with the shifting elements E and F and a fourth double shifting element S4 with the shifting elements G and H.

[0058] The fifth gear plane R5 forms the output constant of the main gearbox HG.

[0059] All double switching elements S1 to S4 of the main gearbox HG can connect two different elements of gearbox 1 to a shaft or a gearbox component.

[0060] The first gear plane R1 is formed by a first loose gear of the first transmission input shaft 4 with a first fixed gear of a countershaft VW. The second gear plane R2 is formed by a loose gear of the first transmission input shaft 4 with a second fixed gear of the countershaft VW. The third gear plane R3 is formed by a third loose gear on the second transmission input shaft and a third fixed gear of the countershaft VW. The fourth gear plane R4 is formed by a fourth loose gear on the second transmission input shaft 5 and a fourth fixed gear on the countershaft VW. The fifth gear plane R5 is formed by a fifth loose gear on a main shaft 11 and a fifth fixed gear on the countershaft VW.

[0061] The main shaft 11 runs coaxially to the transmission input shafts 4, 5 and the output shaft 3 and is located between the second transmission input shaft 5 and the countershaft VW and runs parallel to the axis of the transmission input shafts 4, 5, the main shaft 11 and the output shaft 3. The first double shift element S1 can connect the first gear plane R1 with the first transmission input shaft 4 when the shift element A is closed, or the second gear plane R2 with the first transmission input shaft 4 when the shift element B is closed. The second double shift element S2 can connect the first transmission input shaft 4 with the first transmission input shaft 4, or the third gear plane R3 with the second transmission input shaft 5 when the shift element D is closed. The second double shift element S2 therefore serves to couple the partial transmission when the shift element C is closed.The third double shift element S3 can couple the fourth gear plane R4 with the second transmission input shaft 5 when the shift element E is closed, or the main shaft 11 with the second transmission input shaft 5 when the shift element F is closed. When the shift element F is closed, a direct gear can be engaged, whereby torque is transmitted from the second transmission input shaft 5 via the main shaft 11 and the planetary gear PG3 to the output shaft 3. The fourth double shift element S4 can connect the main shaft 11 with the fifth gear plane R5 when the shift element G is closed, or the carrier ST3 of the further planetary gear PG3 with the shift element H is closed. The output constant, i.e. the fifth gear plane R5 of the main transmission HG, can thus be coupled via the fourth double shift element S4 either to the sun gear SR3 or to the carrier ST3 of the further planetary gear PG3, since the main shaft 11 is directly connected to the sun gear SR3 of the planetary gear PG3.By coupling the electric motor 2 via the output constant to the carrier ST3 of the planetary gear PG3, the fifth double shift element S5 is load-free and can be shifted. The electric motor 6 therefore supports the tractive force via the countershaft VW, so that the range group PG3 can be shifted with traction support. A further advantage of coupling the electric motor 2 to the carrier ST3 is that the speed of the countershaft VW can be reduced when driving in direct gear in order to reduce drag losses on the bearings and seals. Each of the double shift elements S1 to S4 can also be switched to neutral, so that it does not connect any of the aforementioned elements with each other.

[0062] The transmission 1 comprises the range group in the form of the planetary gear PG3. The range group PG3 serves to double the number of gears of the main transmission HG. For this purpose, the fifth double shift element S5, which is assigned to the range group PG3, can connect the ring gear HR3 of the planetary gear PG3 to a housing-fixed component or a housing part or to another rotationally fixed component of the transmission 1 when the shift element L is closed. This creates a low-speed range. When the shift element S of the fifth double shift element S5 is closed, the ring gear HR3 of the planetary gear PG3 can be connected to the output shaft 3 and thus also to the carrier ST3 of the planetary gear PG3. The carrier ST3 is rotationally fixedly connected to the output shaft 3. The components carrier ST3 and ring gear HR3 are thus locked together when the shift element S is closed and create a high-speed range.The double switching element S5 can also be switched to neutral.

[0063] The second planetary gear PG2 of the drive assembly 1 is arranged as a planetary stage between the electric machine 2 and the transmission input shaft 4. The electric machine 6 has the stator 9, which is non-rotatably connected to a component fixed to the housing, so that the stator 9 cannot assume any rotational speed. The rotatably mounted rotor 8 of the electric machine 6 is permanently non-rotatably connected to the planetary gear set shaft of the planetary stage PG2, which is designed as the sun gear SR2 of the second planetary gear PG2.

[0064] The web ST2 of the second planetary gear PG2 is permanently connected in a rotationally fixed manner to the first transmission input shaft 4. The ring gear HR2 of the second planetary gear PG2 can, as described above in the detail, be connected to the transmission input shaft 5 via the triple shift element S6 when the shift element I is closed, can be locked to the housing when the shift element J is closed, and can be coupled to the ring gear HR1 of the first planetary gear PG1 when the shift element K is closed.

[0065] Due to the arrangement of the electric machine 2 with the planetary stage PG2 on the transmission input shaft 4, the electric machine 6 is assigned to the first partial transmission.

[0066] The transmission input shaft 5 is driven by the combustion engine 7. The combustion engine 7 is permanently connected or connectable to the second transmission input shaft 5.

[0067] Each sub-transmission is assigned shiftable gears via the assigned gear levels R1 to R5. The first gear level R1 and the second gear level R2 of the main transmission HG are assigned to the first transmission input shaft 4 and thus to the first sub-transmission of the main transmission HG. This enables purely electric driving via the two gears formed by the two gear levels R1 and R2. The range group PG3 creates four shiftable purely electric gears. The third gear level R3 and the fourth gear level R4 of the main transmission HG are assigned to the second transmission input shaft 5 and thus to the second sub-transmission of the main transmission HG. The fifth gear level R5 serves as the output constant for both sub-transmissions of the main transmission HG. Due to the sub-transmission coupling via the double shift element S2 when the shift element C is closed, the combustion engine 7 and the electric machine 6 can still use the gears of the other sub-transmission.However, the electric machine 6 cannot use the third gear plane R3 of the main gearbox HG.

[0068] The two sub-transmissions allow the combustion engine 7 and the electric motor 6 to operate with different gear ratios. This allows suitable operating points to be selected for the combustion engine 7 and the electric motor 6 depending on the driving situation. The electric motor 6 can also be partially decoupled and remain stationary, thus avoiding no-load losses. The electric motor 6 can be decoupled using the double switching elements S1 and S2, which must not connect the first transmission input shaft 4 to any other component.

[0069] By coupling the partial transmission via the double switching element S2 with the switching element C closed, the combustion engine 7 can be connected to the electric machine 6 without any torque being transmitted to the output shaft 3. At least the double switching element S1 and double switching element S3 of the main transmission HG are not actuated, but in a neutral position. This allows the combustion engine 7 to be started with the electric machine 6, or electricity can be generated in neutral, i.e., independent of the driving speed, even when stationary. The combustion engine 7 drives the electric machine 6. The electric machine 6 operates as a generator.

[0070] The Fig. Figure 1 shows only the upper half of the gear set of transmission 1, which is symmetrical to the axis of the transmission input shafts 4, 5, the main shaft 11, and the output shaft 3. The mirroring on this axis results in a variant with two countershafts VW, which serve to split the power. However, the gear set is functionally identical in the version with only one countershaft VW. This means that the countershaft VW, including the associated fixed gears, are not mirrored.

[0071] With the design of the Fig. 4, a starting function known as EDA, electrodynamic starting, can be implemented. The electric motor 6 can be used purely or only to support the combustion engine 7 for starting and acceleration.

[0072] During purely electric start-up, an increased start-up torque can be provided via the second planetary gear PG2, which acts as a constant gear ratio. In order to start off electrodynamically, the switching element I on the triple switching element S6 must be closed for a forward start-up direction and the switching element K for a reverse start-up direction. The transmission 2 is then in EDA mode. Furthermore, a gear of the first sub-transmission, which is assigned to the transmission input shaft 4, must be engaged and the second sub-transmission must be shifted to neutral, without transmitting torque. The first gear of the transmission 1 is preferably assigned to the first gear plane R1. The first gear plane R1 is assigned to the first sub-transmission.

[0073] This means that the first double shift element S1 can be used for electrodynamic starting with the shift element A closed, and in the further power flow for first gear the fourth double shift element S4 can be used with the shift element G closed and the fifth double shift element S5 with the shift element L closed. This prepares a power flow in first gear from the transmission input shaft 4 via the first gear plane R1, the countershaft VW, the output constant R5, the main shaft 11 and the range group PG3 in the low range. When the vehicle is stationary the combustion engine 7 rotates at idling speed, for example. When the shift element I is closed the electric machine 6 rotates in reverse for forward starting, the web ST2 of the plate gear PG2 is stationary.When shift element K is closed for reversing, the speed is reversed and slowed down via the plate gear PG1, the electric motor 6 rotates forward and the web ST2 of the plate gear PG2 is stationary. The torque ratios at the plate gear PG2 are constant. The torque of the combustion engine 7 and the torque of the electric motor 6 add up at the web ST2 of the plate gear PG2. During electrodynamic forward starting with shift element I closed, the speed of the electric motor 6 changes up to the block revolution on the planetary stage PG2, whereupon starting can be ended by closing shift element C on the second double shift element S2 and thus blocking the planetary stage PG2.Electrodynamic starting in the forward and reverse directions can also be performed in a higher gear of transmission 2, namely when higher starting speeds are desired. These gears are assigned to the first sub-gearbox of the main transmission HG.

[0074] If transmission 1 is operated in EDA mode, electrodynamic shifting (EDS) is possible as a powershift function. In this case, shift element I on the triple shift element S6 is preferably closed. A gear assigned to the first sub-transmission and thus to transmission input shaft 4 must be engaged. This serves as a backup gear through which the power flow is directed during powershifting. The backup gear can be identical to the actual gear or a target gear. However, another gear of the first sub-transmission can also be used.

[0075] The shifting process begins with a load transfer phase. During this phase, the torques on the combustion engine 7 and the electric motor 6 are adjusted to correspond to the stationary gear ratio of the planetary gear stage PG2. This means that there is only a power flow via the carrier ST2 of the planetary gear stage PG2 and the support gear. All other shifting elements of transmission 2 are de-loaded. The shifting elements of the actual gear that are now de-loaded are disengaged. The speed of the combustion engine 7 and the electric motor 6 are regulated so that the shifting element of the target gear to be engaged becomes synchronous. Once synchronization is established, the shifting element of the target gear is engaged. This completes the shifting process and the load on the electric motor 6 can be reduced if necessary.The EDL shifting process has the advantage that the engaging shift element of the target gear is synchronized through the interaction of the electric motor 6 and the combustion engine 7, with the electric motor 6 being very easily controllable. A further advantage of the EDL shifting process is that high tractive force can be achieved, since the torques of the combustion engine 6 and the electric motor 7 are summed at the second planetary gear PG2.

[0076] With the gearbox of the Fig. 1, a function known as ISG (Integrated Starter Generator) can also be implemented, in which the combustion engine 7 can be started and accelerated via the electric motor 6, and the electric motor 6 can also be used as a generator. In ISG mode, the switching element J on the triple switching element S6 is closed and connects the ring gear HR2 to a component fixed to the housing.

[0077] The gear set of gearbox 2 of the Fig. 4 serves, in particular, to provide 10 gears from the perspective of the internal combustion engine 7. When the internal combustion engine 7 transmits a power flow through the second sub-transmission, via the solid shaft 5, a gear can be preselected in the first sub-transmission, which is free of power flow, via the hollow shaft 4, or the sub-transmissions can be coupled. The preselected gear is preselected for the internal combustion engine 7 and, at the same time, is already active for the electric motor 6.

[0078] The power flow in a first gear from the perspective of the combustion engine 7 is preferably directed to the output shaft 3 via the transmission input shaft 5, the second double shifting element S2 with the shift element C closed, the first double shifting element S1 with the shift element A closed, the first gear plane R1, the countershaft VW, the output constant R5, the fourth double shifting element S4 with the shift element G closed, and the range group PG3 shifted in the slow range. The power flow in a second gear from the perspective of the combustion engine 7 is directed to the output shaft 3 via the transmission input shaft 5, the second double shifting element S2 with the shift element D closed, the third gear plane R3, the countershaft VW, the output constant R5, the fourth double shifting element S4 with the shift element G closed, and the range group PG3 shifted in the slow range.In this case, first gear and thus the first gear plane R1 can be preselected via the first double shift element S1 when shift element A is closed, and fourth gear and thus the second gear plane R2 can be preselected via the first double shift element S1 when shift element B is closed. The preselected gears are assigned to the first sub-transmission. The power flow in what is considered to be the third gear from the perspective of the combustion engine 7 is transmitted to the output shaft 3 via the transmission input shaft 5, the third double shift element S3 when shift element E is closed, the fourth gear plane R4, the countershaft VW, the output constant R5, the fourth double shift element S4 when shift element G is closed, and the range group PG3 shifted in the low range. In this case, fourth gear and thus the second gear plane R2 can be preselected via the first double shift element S1 when shift element B is closed.The power flow in a fourth gear from the perspective of the combustion engine 7 is directed to the output shaft 3 via the transmission input shaft 5, the second double shift element S2 with the shift element C closed, the transmission input shaft 4, the first double shift element S1 with the shift element B closed, the second gear plane R2, the countershaft VW, the output constant R5, the fourth double shift element S4 with the shift element G closed, the range group PG3 switched in the slow range.

[0079] The power flow in a fifth gear from the perspective of the combustion engine 7 is directed to the output shaft 3 via the transmission input shaft 5, the third double shift element S3 with the shift element F closed, and the range group PG3 shifted in the low range. Fourth gear can be preselected via the first double shift element S1 with the shift element B closed and via the fourth double shift element S4 with the shift element G closed. Alternatively, a ninth gear can be preselected via the first double shift element S1 with the shift element B closed and via the fourth double shift element S4 with the shift element H closed. Likewise, a sixth gear can be preselected via the first double shift element S1 with the shift element A closed and via the fourth double shift element S4 with the shift element H closed.The power flow in a sixth gear from the perspective of the combustion engine 7 is directed via the transmission input shaft 5, the second double shifting element S2 with the shift element C closed, the transmission input shaft 4, the first double shifting element with the shift element A closed, the first gear plane R1, the countershaft VW, the output constant R5, the fourth double shifting element S4 with the shift element H closed and via the range group PG3 switched into the fast range to the output shaft 3. The power flow in a seventh gear from the perspective of the combustion engine 7 is directed via the transmission input shaft 5, the second double shifting element S2 with the shift element D closed, the third gear plane R3, the countershaft VW, the output constant R5, the fourth double shifting element S4 with the shift element H closed and via the range group PG3 switched into the fast range to the output shaft 3.In this case, sixth gear can be engaged via the first double shift element S1 when shift element A is closed, or ninth gear can be engaged via the first double shift element S1 when shift element B is closed. The power flow in an eighth gear from the perspective of the combustion engine 7 is directed to the output shaft 3 via the transmission input shaft 5, the third double shift element S3 with shift element E closed, the fourth gear plane R4, the countershaft VW, the output constant R5, the fourth double shift element S4 with shift element H closed, and via the range group PG3 switched to the fast range. In this case, ninth gear can be engaged via the first double shift element S1 when shift element B is closed.

[0080] The power flow in the ninth gear from the perspective of the combustion engine 7 is directed via the transmission input shaft 5, the second double shift element with the shift element C closed, the transmission input shaft 4, the first double shift element S1 with the shift element B closed, the second gear plane R2, the countershaft VW, the output constant R5, the fourth double shift element S4 with the shift element H closed and via the range group switched to the fast range, which is provided by the first planetary gear PG3, to the output shaft 3. The power flow in a tenth gear from the perspective of the combustion engine is directed via the transmission input shaft 5, the third double shift element S3 with the shift element F closed, the main shaft 11 and via the range group PG3 switched to the fast range to the output shaft 3.It is advantageous if the second double shift element S2 is also engaged when the shift element C is closed, as this means that the first transmission input shaft 4 is driven at a defined speed, in this case the speed of the transmission input shaft 5. The ninth gear can be preselected via the first double shift element S1 when the shift element B is closed and the fourth double shift element S4 when the shift element H is closed. However, the sixth gear can also be preselected via the first double shift element S1 with the shift element A closed and the second double shift element S2 with the shift element C closed. This makes it possible to reduce the countershaft speed. By preselecting the first double shift element S1 with the shift element A closed, the electric motor 2 and the countershaft VW can also be brought to a standstill in tenth gear.In the sixth, seventh, eighth, and ninth gears of transmission 2, the fifth double shift element S5 could also remain closed in the first shift position L or with the shift element L closed, instead of in the second shift position S or instead of with the shift element S closed, since the fifth double shift element S5 is load-free in both shift positions L and S when the power flow is directed directly to the web ST3 of the first planetary gear PG3 via the fourth double shift element S4 with the shift element H closed. However, due to the speed ratios in the range group PG3, it is advantageous to make the change from the first shift position L of the fifth double shift element S5 to the second shift position S as early as possible.

[0081] The PG3 range group shift without interruption in traction usually occurs when changing from fifth to sixth gear. In fifth gear when driving with an internal combustion engine or hybrid in ISG mode, this is shifted via a direct gear in the slow PG3 range group. The third double shift element S3 is in its shift position F and the fifth double shift element is in its first shift position L. Due to its previous history, the electric machine 6 is still operating in fourth gear, with the first double shift element S1 in its shift position B and the fourth double shift element S4 in its shift position G. In order to shift into sixth gear without interruption in traction, the following process steps are carried out: If there is a load on the electric machine 6, a load reduction takes place here. The combustion engine 7 takes over the load.The fourth double shift element S4 can then be opened from shift position G. The shift position H of the fourth double shift element S4 is actively synchronized via the speed control of the electric machine 6. For this to happen, the speed of the electric machine 6 must be reduced. The speed is reduced by the factor of the gear ratio of the range group PG3. The fourth double shift element S4 can then be shifted into shift position H without load. In this state, the ninth gear is temporarily engaged, as the first double shift element S1 is still in its shift position B. This can now be opened without load. The shift position A of the first double shift element S1 is now actively synchronized via the speed control of the electric machine 6. For this to happen, the speed of the electric machine 6 must be increased to the target speed level of the sixth gear.The engine speed is increased by the ratio of the gear ratio of the two gears assigned to the first transmission input shaft. This allows the first double shift element S1 to be moved to shift position A without load, while simultaneously preselecting the subsequent gear, sixth gear. Subsequently, a load transfer takes place from the combustion engine 7 to the electric motor 6. This means that only the electric motor 6 supports the tractive force in the target gear, sixth gear. Once the combustion engine 7 is free of load, shift position F of the third double shift element S3 is opened.

[0082] Optionally, the fifth double shift element S5 can now change from the shift position L to its shift position S while the shift position F of the third double shift element S3 is open. This offers the advantage that only the main shaft 11 and thus a low inertial mass acts on the sun gear SR3 of the first planetary gear PG3. Synchronization takes place via the double shift element S5 itself, which is designed to be synchronized. The shift position S of the fifth double shift element S5 can then be closed. The shift position S cannot be actively synchronized with the combustion engine 7 because the combustion engine 7 cannot reduce the speed far enough, since the speed level of the tenth gear (the third double shift element S3 and the fifth double shift element S5 each in the shift positions F and S) would be required here, even though the sixth gear is the target gear.As already mentioned, switching from the L position of the fifth double shift element S5 to the S position of the fifth double shift element S5 at this point is advantageous but not absolutely necessary. The change could also occur outside of the shift from fifth gear to sixth gear at a later time. The fifth double shift element S5 would then remain in the L position for the time being.

[0083] Immediately after the switch position F of the third double switching element S3 has been opened, which may mean simultaneously with the step just mentioned, the combustion engine 7 synchronizes to the target speed of the sixth gear. This synchronizes the switch position C of the second double switching element S2 and can then be closed without load. This engages the sixth gear and completes the shifting process. The load transfer from the electric machine 6 to the combustion engine 7 can then take place depending on the operating strategy. To move from fifth gear to sixth gear, both the fourth double switching element S4 and the first double switching element S1 must be switched. In this case, the fourth double switching element S4 is switched first and only then the first double switching element S1. This means that the electric machine 6 is reduced in speed first and can synchronize with high torque.

[0084] In gearbox 2 of the Fig. 4, shift elements A, B, C, D, E, F, G, and H are unsynchronized, positive-locking shift elements. Shift elements I, J, and K of drive assembly 1 are also unsynchronized, positive-locking shift elements. Shift elements L and S of transmission 2, however, are synchronized, positive-locking shift elements. Shift elements A, B, G, H, I, J, and K can be actively synchronized via a speed-controlled electric machine 6. Shift elements C, D, E, and F can be actively synchronized via a speed-controlled combustion engine 7, or via the electrodynamic shifting (EDS) described above. Reference symbol 1 Drive arrangement 2 gearboxes 3 Output shaft 4 Gearbox input shaft 5 Gearbox input shaft 6 electric machine 7 Internal combustion engine 8 Rotor 9 Stator 10 Actuator 11 Main shaft A switching element B switching element C switching element D switching element E switching element F switching element G switching element H switching element I Switching element J Switching element K Switching element HG main gearbox PG1 planetary gear SR1 sun gear ST1 Bridge HR1 ring gear PG2 planetary gear SR2 sun gear ST2 Bridge HR2 ring gear PG3 planetary gear SR3 sun gear ST3 Bridge HR3 ring gear R1 wheel plane R2 wheel plane R3 wheel plane R4 wheel plane R5 wheel plane S1 double switching element S2 double switching element S3 double switching element S4 double switching element S5 double switching element S6 triple switching element

Claims

[1] Drive arrangement (1) for a hybrid vehicle, wherein the hybrid vehicle has a hybrid drive with an internal combustion engine (7) and an electric machine (6) and a transmission (2) with two transmission input shafts (4, 5) and one output shaft (3), wherein the drive arrangement comprises at least the following, a first planetary gear (PG1) with the elements web (ST1), sun gear (SR1) and ring gear (HR1), wherein a first element of the first planetary gear can be connected to one of the transmission input shafts (5) in a rotationally fixed manner, and wherein a second element of the first planetary gear (PG1) can be connected to the housing; a second planetary gear (PG2) with the elements web (ST2), sun gear (SR2) and ring gear (HR2), wherein a first element of the second planetary gear (PG2) can be fixedly connected to the electric machine (6) in a rotationally fixed manner, and wherein a second element of the second planetary gear (PG2) can be connected to another of the transmission input shafts (4) in a rotationally fixed manner; at least three switching elements (I, J, K), where when a first switching element (J) is closed, a third element of the second planetary gear (PG2) is fixed to the housing; when a second switching element (I) is closed, the third element of the second planetary gear (PG2) is connected in a rotationally fixed manner to the transmission input shaft (5), to which the first element of the first planetary gear (PG1) is also connected in a rotationally fixed manner; when a third switching element (K) is closed, the third element of the second planetary gear (PG2) is connected in a rotationally fixed manner to a third element of the first planetary gear (PG1). [2] Drive arrangement according to claim 1, characterized by that the first element of the first planetary gear (PG1) is designed as a sun gear (SR1), the second element of the first planetary gear (PG1) as a web (ST1) and the third element of the first planetary gear (PG1) as a ring gear (HR1). [3] Drive arrangement according to claim 1, characterized by that the first element of the second planetary gear (PG2) is designed as a sun gear (SR2), the second element of the second planetary gear (PG2) is designed as a web (ST2) and the third element of the second planetary gear (PG2) is designed as a ring gear (HR2). [4] Drive arrangement according to one of claims 1 to 3, characterized by that the first switching element (J) and the second switching element (I) and the third switching element (K) can be actuated via a common actuator (10) in such a way that only one of these switching elements is closed at any one time. [5] Drive arrangement according to one of claims 1 to 4, characterized by that the first switching element (J) and the second switching element (I) and the third switching element (K) are arranged such that the second switching element (I) is arranged between the first switching element (J) and the third switching element (K). [6] Drive arrangement according to claim 5, characterized bythat starting from a closed switching element position of the first switching element (J), a closed switching element position of the second switching element (I) must first be passed through before a closed switching element position of the third switching element (K) can be assumed. [7] Drive arrangement according to one of claims 1 to 4, characterized by that the first switching element (J) and the second switching element (I) and the third switching element (K) are arranged such that the first switching element (J) is arranged between the second switching element (I) and the third switching element (K). [8] Drive arrangement according to claim 7, characterized by that starting from a closed switching element position of the second switching element (I), a closed switching element position of the first switching element (J) must first be passed through before a closed switching element position of the third switching element (K) can be assumed. [9] Drive arrangement according to one of claims 1 to 8, characterized by that the first switching element (J) and the second switching element (I) and the third switching element (J) have five switching element positions, namely three closed switching element positions and two neutral switching element positions. [10] Drive arrangement according to one of claims 1 to 9, characterized by a fourth switching element (C), wherein when the fourth switching element (C) is closed, the two transmission input shafts (4, 5) are coupled to one another in a rotationally fixed manner. [11] Drive train for a hybrid vehicle, with a hybrid drive having an internal combustion engine (7) and an electric machine (6), with a transmission (2) having two transmission input shafts (4, 5) and one output shaft (3), and with a drive arrangement (2) according to one of claims 1 to 10. [12] Drive train according to claim 11, characterized bythat the internal combustion engine (7) is permanently or alternatively with the interposition of a separating coupling coupled to the transmission input shaft (5), to which the first element of the first planetary gear (PG1) is rotationally fixedly coupled, and that the electric machine (6) is permanently coupled to the first element of the second planetary gear (PG2). [13] Drive train according to claim 11 or 12, characterized by that the transmission (2) comprises a main transmission (HG) comprising two partial transmissions connected in parallel with the two transmission input shafts (4, 5) and the output shaft (3), wherein the main transmission (HG) comprises a first gear plane (R1), a second gear plane (R2), a third gear plane (R3), a fourth gear plane (R4) and a fifth gear plane (R5), the transmission comprises a first double shifting element (S1), a second double shifting element (S2), a third double shifting element (S3), a fourth double shifting element (S4) and a fifth double shifting element (S5), the transmission comprises a further planetary gear train (PG3) which is connected to the main transmission (HG) as a range group in such a way that the fourth double shifting element (S4) connects the fifth gear plane (R5) and a first element (ST3) of the further planetary gear train (PG3) in a rotationally fixed manner when the shifting element (H) of the fourth double shifting element (S4) is closed, and that the fifth double shifting element (S5) couples a second element (HR3) of the further planetary gear train (PG3) to the output shaft (3) when the shifting element (S) of the fifth double shifting element (S5) is closed and locks it fixed to the housing when the shifting element (L) of the fifth double shifting element (S5) is closed. [14] Drive train according to claim 13, characterized bythat the fourth double switching element (S4) connects the fifth gear plane (R5) of the main transmission (HG) to a main shaft (11) of the transmission (2) when another switching element (G) of the fourth double switching element (S4) is closed, and is rotationally fixedly coupled to a third element (SR3) of the further planetary transmission (PG3). [15] Drive train according to claim 13 or 14, characterized by , that the main gearbox (HG) comprises at least one countershaft (VW), whereby all gears on the countershaft (VW) are designed as fixed gears, all gear planes (R1, R2, R3, R4, R5) are designed as forward gear planes and a reverse gear is generated by reversing the direction of rotation of the electric machine (6), and all shift elements in the main gearbox (S1, S2, S3, S4) are designed as unsynchronized claw shift elements.

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