Gear for setting up an axle offset, wheelset arrangement and hybrid transmission for a motor vehicle powertrain

Abstract

Hybrid transmission (14) for a motor vehicle powertrain (10), with - a transmission input shaft (19) for connection to an internal combustion engine (12); - a first shaft (20) which is connected or connectable to the transmission input shaft (19); - a second shaft (22) which can be connected to the first shaft (20) via at least one gear set (24;30) which can be switched by means of a switching element (B;D) and which is connected to an output (17); - a first electric machine (EM1) which is connected or connectable to the first shaft (20); and - a wheelset arrangement (60) to establish an axle offset (V) between - the first electric motor (EM1) and the transmission input shaft (19) and / or - the first electric machine (EM1) and the first shaft (20) and / or - the first electric machine (EM1) and the second shaft (22), wherein the wheelset arrangement (60) has: - a first gear (38) having the first axis of rotation (A1), wherein the first gear (38) has a rim section (64) with an internal toothing (40) and an external toothing (44); and - a second gear (42) having the second axis of rotation (A2), wherein the second gear (42) has an external toothing (42a) which engages with the internal toothing (40) of the first gear (38), wherein the gear set arrangement (60) further comprises: - a third gear (48) having a third axis of rotation (A4), wherein the third gear (48) has an external toothing (48a) which engages with the external toothing (44) of the first gear (38), wherein the first gear (38), the second gear (42) and also the third gear (48) are arranged in a common radial plane (R).

Description

[0001] The present invention relates to a hybrid transmission for a motor vehicle drivetrain, comprising a transmission input shaft for connection to an internal combustion engine, a first shaft which is connected or connectable to the transmission input shaft; a second shaft which is connectable to the first shaft via at least one gear set switchable by means of a switching element and which is connected to an output; and a first electric machine which is connected or connectable to the first shaft.

[0002] Hybrid powertrains for motor vehicles generally feature an internal combustion engine that can provide drive power to propel the vehicle, as well as an electric machine that can provide drive power for the vehicle alternatively or additionally, depending on the operating mode.

[0003] Hybrid powertrains utilize a variety of different concepts, each employing a different approach to connecting the electric motor to the hybrid transmission's gearbox. In dual-clutch transmissions, a typical variant involves arranging the electric motor concentrically to one of the input components of the dual-clutch system. It is also known to assign an electric motor to one of the two sub-transmissions in dual-clutch transmissions.

[0004] Furthermore, it is known to arrange an electric machine concentrically to a first input shaft, wherein a rotor of the electric machine is connected to a hollow shaft that is arranged around the first input shaft.

[0005] Document DE 10 2013 215 114 A1 discloses a hybrid drive for a motor vehicle in which an electric motor can be connected to an output shaft of a hybrid transmission via a spur gear set. Furthermore, this document discloses arranging an electric motor coaxially to a transmission output shaft, axially offset from a planetary gear set, which serves as a superimposed transmission for electric motors.

[0006] Drive power and is designed for internal combustion engine drive power.

[0007] Hybrid transmissions are preferably designed as powershift transmissions. The axial length of the hybrid transmission is particularly important when installed transversely to the direction of travel in a vehicle (front-transverse or rear-transverse). Furthermore, when installed transversely to the direction of travel, the surrounding installation environment often needs to be considered. Potential bottlenecks include a joint between side shafts, a transmission mount, and / or a lower longitudinal member of the vehicle.

[0008] Furthermore, it is generally preferred for an electric motor that provides drive power for a hybrid powertrain to have a large outer diameter. Such electric motors often have a short axial design, but due to their large outer diameter, they frequently fit poorly into installation space. This is particularly true when the electric motor is essentially coaxial with an internal combustion engine shaft and, axially speaking, is arranged on a side facing away from the internal combustion engine, towards a wheel of the vehicle.

[0009] Planetary gear sets are known from documents DE 10 2020 204 973 A1, DE 10 2017 206 510 A1, DE 22 24 771 A, DE 10 2017 222 710 A1, EP 3 530 983 A1, DE 41 10 733 A1, DE 10 2017 221 885 A1 and DE 10 2004 018 947 A1, in which a ring gear has external teeth.

[0010] Against this background, it is an object of the present invention to provide an improved hybrid transmission for a motor vehicle powertrain.

[0011] The above problem is solved by a hybrid transmission for a motor vehicle powertrain according to claim 1. Preferred embodiments are specified in the dependent claims.

[0012] The hybrid transmission preferably includes a gear for establishing an axial offset in a spur gear transmission, with a base body having a radially inner section and a radially outer section, wherein an axis of rotation of the gear passes through the radially inner section, and with a rim section projecting axially from the radially outer section of the base body and being rigidly connected to the base body, wherein the rim section has an internal toothing into which an external toothing of a first axially offset gear can engage, which is to be arranged radially inside the rim section, and wherein the rim section has an external toothing into which an external toothing of a second axially offset gear, which is to be arranged radially outside the rim section, or on which external toothing a traction element can engage.

[0013] The hybrid transmission includes a gear set arrangement comprising: a first gear having a first axis of rotation, in particular a gear of the type mentioned above, wherein the first gear has a rim section with internal teeth and external teeth; a second gear having a second axis of rotation, wherein the second gear has external teeth that mesh with the internal teeth of the first gear; and preferably a third gear having a third axis of rotation, wherein the third gear has external teeth that mesh with the external teeth of the first gear.

[0014] The hybrid transmission is designed with a transmission input shaft for connection to an internal combustion engine; with a first shaft that is connected or connectable to the transmission input shaft; with a second shaft that is connectable to the first shaft via at least one gear set switchable by means of a switching element and that is connected to an output shaft; with a first electric machine that is connected or connectable to the first shaft; and with a gear set arrangement of the type according to the invention to establish an axis offset between the first electric machine and the transmission input shaft and / or between the first electric machine and the first shaft and / or between the first electric machine and the second shaft.

[0015] The disclosed gear has a rim section with internal teeth on its radial inner side and external teeth on its radial outer side. Therefore, the gear can establish an axial offset to a shaft via the internal teeth, which is offset parallel to the element's axis of rotation. Since both the external and internal teeth are arranged on the rim section, it is not necessary to provide the internal and external teeth axially offset on the gear. Consequently, the gear can be axially compact. Therefore, the gear is particularly suitable for use in a hybrid transmission where an axial offset of an electric motor to a shaft of the hybrid transmission is required (for space reasons). The external teeth of the first gear can be designed such that another spur gear with external teeth can mesh with it.Alternatively, the external teeth of the ring section of the first gear can be designed in such a way that a traction element can be attached to it, for example a chain or a toothed belt.

[0016] The axis of rotation of the gear does not need to pass through material of the radially inner section of the base body, since the base body can be designed with a bore for receiving a shaft.

[0017] The internal and external gearing are preferably not axial splined gears, but rather gears for meshing or meshing with other gears. Preferably, the internal and external gearing are helical gears.

[0018] The gear set assembly comprises a first gear having a rim section with internal and external teeth, in particular a gear of the type according to the invention. Furthermore, the gear set assembly comprises a second gear and preferably a third gear, wherein the second gear engages with the internal teeth of the first gear, and wherein the third gear preferably engages with the external teeth of the first gear.

[0019] A compact axial offset can therefore be established between the first and second gears. The third gear can be used, without requiring additional axial space, to connect another element of the hybrid transmission, for example, a second electric motor or a loose gear of a gear set. In this case, the first gear preferably forms a fixed gear of such a gear set. The gear set arrangement thus allows for a parallel axial offset, in particular a double parallel axial offset.

[0020] It is particularly advantageous if the first gear, the second gear and preferably also the third gear are arranged in a common radial or gear set plane.

[0021] Consequently, the wheelset arrangement can be axially compact.

[0022] The hybrid transmission according to the invention includes a first electric motor for providing drive power. Furthermore, the hybrid transmission includes a transmission input shaft for connection to an internal combustion engine. The hybrid transmission is designed to perform either purely combustion engine-based driving operation, in which combustion engine drive power can be transmitted via the transmission input shaft, the first shaft, and at least one gear set to the second shaft, from where the combustion engine drive power can be directed to the output shaft. The output shaft can include a power distribution device such as a differential. The transmission input shaft is preferably arranged coaxially with a drive shaft of the internal combustion engine.

[0023] Furthermore, the combustion engine drive power of the first electric motor can be transmitted to the first shaft, and from there, via a switchable gear set, to the second shaft. Alternatively, it is possible to direct the electric motor drive power of the first electric motor directly to the second shaft, bypassing the first shaft, and from there to the output shaft.

[0024] In many cases, the combustion engine's drive power and the electric motor's drive power of the first electric motor can be superimposed via the first shaft. In some cases, a hybrid transmission can also include a planetary gear set for power superposition. In other cases, a hybrid transmission can also include a planetary gear set for establishing a pre-reduction between the electric motor and the transmission assembly.

[0025] If an axial offset is established between the first electric motor and the transmission input shaft, this axial offset is essentially established between a drive shaft or crankshaft of the internal combustion engine and a rotational axis of the first electric motor. The gear set arrangement according to the invention allows for a relatively small axial offset compared to a spur gear pair in which the electric motor is connected to a first spur gear with external teeth and in which the transmission input shaft or the first shaft is connected to a further spur gear with external teeth that meshes with the other spur gear.

[0026] Furthermore, in some embodiments, the gear set arrangement allows for a pre-reduction between the transmission input shaft, and consequently the internal combustion engine, and the first shaft. This pre-reduction can be a speed reduction. In this case, the first gear is typically connected to the transmission input shaft. Additionally, in this case, the second gear is typically connected to the first shaft. For a speed reduction, the first gear of the gear set arrangement according to the invention can also be connected to the first shaft, and the transmission input shaft can be connected to the second gear of the gear set arrangement according to the invention.

[0027] In cases where an axis offset is arranged between the first electric machine and the transmission input shaft or the first shaft, the electric motor drive power of the first electric machine is preferably directed to the first shaft.

[0028] Provided that the axis offset is set up between the first electric machine and the second shaft, the electric motor drive power of the first electric machine can also be directed to the second shaft.

[0029] The axis offset in the hybrid transmission is generally established between the axis of rotation of the first gear and the axis of rotation of the second gear. This also generally creates a reduction ratio between the links connected to the first and second gear sets.

[0030] In general, the hybrid transmission is implemented as a spur gear design. Preferably, all gear sets of the hybrid transmission are arranged between the first and second shafts. If the hybrid transmission includes a planetary gear set, the planetary gear set can generally serve for power superposition. Preferably, however, the planetary gear set is used to establish a pre-reduction between the first electric motor and a shaft that is arranged coaxially with the first electric motor. This pre-reduction is preferably switchable, so that the first electric motor can also be decoupled from this shaft by releasing a locking mechanism between two elements of the planetary gear set or by disconnecting an element of the planetary gear set from a housing.

[0031] The hybrid transmission preferably has exactly two sets of gears.

[0032] If the gear set arrangement according to the invention in the hybrid transmission is designed such that the first gear is used as a fixed gear of a gear set of the hybrid transmission, such that its external teeth mesh with a loose gear of the gear set, a second electric motor may optionally be present. In this case, this second electric motor may also be connected to the first shaft via a separate gear. However, the second electric motor is optional in this case.

[0033] The following terms can be understood in the context of this disclosure in particular as follows: A gear pair comprises exactly two gears that mesh with each other. Two meshing gears are to be understood in particular as two gears whose teeth mesh. The gears preferably each have spur teeth, are preferably arranged in a radial plane, and are preferably each assigned to a different shaft. The gears of the gear pair can be two fixed gears (so-called constant gear set). In a switchable gear pair, the two gears can be a fixed gear and a floating gear (su), which preferably together define a gear stage.

[0034] A gear set comprises at least two meshing (especially mating) gears and can include one or more gear pairs, preferably located in a common radial gear set plane. If a gear set has a fixed gear meshing with two different loose gears, the gear set can define two gear ratios; this is also referred to as dual use of the fixed gear. Generally, a gear set can also be a planetary gear set.

[0035] A loose gear is a gear mounted on a shaft so that it can rotate freely and can be connected to or disconnected from the shaft by means of a switching element. A fixed gear is a gear that is fixed to a shaft and cannot rotate.

[0036] A switching element serves to connect or disconnect links, such as a gear and a shaft, and is in this case formed in particular by a switching clutch, especially a positive-locking switching clutch, such as a jaw clutch. However, the switching clutch can also be a synchronous switching clutch.

[0037] A double switching element comprises two switching elements, preferably assigned to different loose gears on a shaft, which can be switched alternatively by means of a single actuating device to connect one of the loose gears to the shaft at a time. Furthermore, the double switching element includes a neutral position in which neither of the loose gears is connected to the shaft.

[0038] Two elements that can rotate relative to each other are connected if they necessarily rotate at a proportional speed. The term "connected" is synonymous with "functionally connected." A "rotationally fixed connection" means that the two elements rotate at the same speed. Two elements can be connected if they can either be engaged or disengaged from each other. Preferably, the elements can be connected by means of a switching element such as a clutch or a brake.

[0039] Two elements are axially aligned if they overlap at least partially in the axial direction and / or if they lie in a common radial plane.

[0040] The task is completely solved.

[0041] According to a preferred embodiment of the hybrid transmission, the external teeth of the first gear mesh with a gear that is connected to a second electric machine.

[0042] In this way, the hybrid transmission can connect a second electric motor in a structurally and axially compact manner. The second electric motor is preferably arranged such that it is connected to the external teeth of the first gear via a spur gear connection. The second electric motor is therefore preferably arranged parallel to and offset from the first shaft. The second electric motor is preferably arranged such that it is axially overlapping with at least one gear set of the hybrid transmission, and preferably radially and axially spaced from the first electric motor.

[0043] According to a further preferred embodiment, the first gear, whose rim section has internal and external teeth, is connected to the transmission input shaft in a rotationally fixed manner, wherein the second gear, whose external teeth engage with the internal teeth of the rim section of the first gear, is connected to the first shaft.

[0044] Preferably, all gear sets of the hybrid transmission are arranged between the first and second shafts. Consequently, this design results in the entire transmission of the hybrid gearbox being offset on its axis relative to the combustion engine. This axis offset acts as a pre-reduction gear for the combustion engine, specifically a higher gear ratio.

[0045] Consequently, the axis offset can be implemented without impacting installation space, preferably by nesting it with the connection of the second electric motor. The remaining gearbox, including the first electric motor, is offset and can be optimally arranged within the installation space.

[0046] According to a further preferred embodiment, the first gear, whose rim section has internal and external teeth, is connected to the transmission input shaft in a rotationally fixed manner, wherein the second gear, whose external teeth engage with the internal teeth of the rim section of the first gear, is connected to a shaft that is concentric to the first electric machine.

[0047] The shaft concentric with the first electric motor can be the first shaft. However, the shaft concentric with the first electric motor can also be a separate shaft from the first and second shafts, offset from the transmission input shaft. In the latter case, the first shaft is preferably arranged coaxially with the transmission input shaft and non-rotatably connected to it. In this case, the gear sets are preferably arranged between the first and second shafts, so that no further gears are connected to the shaft coaxial with the first electric motor. Consequently, in this variant, only the first electric motor and, if applicable, a directly associated planetary gear set are offset from the axis.

[0048] In this embodiment, the axis offset can be achieved in a way that is essentially space-neutral. The first electric motor is offset along its axis and can be optimally positioned within the installation space.

[0049] It is particularly advantageous if the external teeth of the rim section of the first gear mesh with a loose gear rotatably mounted on the second shaft. In this case, the first gear of the gear set can form a fixed gear of a gear set, which is preferably fixed to the first shaft in a rotationally fixed manner.

[0050] According to an alternative embodiment, the first gear, whose rim section has internal and external teeth, is non-rotatably connected to the second shaft, wherein the second gear, whose external teeth engage with the internal teeth of the rim section of the first gear, is connected to a shaft that is concentric to the first electric machine, wherein the external teeth of the rim section of the first gear engage with a loose gear rotatably mounted on the first shaft.

[0051] Preferably, no further gears are connected to the shaft coaxial with the first electric motor. Consequently, essentially only the first electric motor is offset along its axis. The remaining transmission system with gear ratios between the first and second shafts is essentially unaffected by this.

[0052] The first gear of the gear set can be used, on the one hand, to establish the axle offset to the first electric motor and, on the other hand, as a fixed gear for a gear set. In this case, the loose gear is rotatably mounted on the first shaft and can preferably be switched by means of a switching element located there, in order to establish a gear ratio between the first shaft and the second shaft and consequently engage a gear.

[0053] According to another alternative embodiment, the first gear, whose rim section has internal and external teeth, is connected to the first shaft in a rotationally fixed manner, and the second gear, whose external teeth engage with the internal teeth of the rim section of the first gear, is connected to the transmission input shaft.

[0054] In this embodiment, a pre-reduction to slower speeds can be implemented between the transmission input shaft and the first shaft.

[0055] The first electric motor is preferably arranged coaxially with the first shaft and is preferably connected to it in a rotationally fixed manner or connectable to it via a planetary gear set. In other words, in this embodiment, the entire transmission is offset on its axis relative to the internal combustion engine. This axial offset can be accommodated in a largely space-saving manner. The remaining transmission, including the first electric motor, is offset on its axis and can be optimally arranged within the installation space. The first gear is also preferably used to connect a second electric motor via its external teeth.

[0056] Overall, in the hybrid transmission according to the invention, it is advantageous if the first electric machine can be connected via at least one planetary gear set to a shaft coaxial to the first electric machine, which is connected to the transmission input shaft via the gear set arrangement according to the invention, or which is connected to the first shaft via the gear set arrangement according to the invention, or which is connected to the second shaft via the gear set arrangement according to the invention.

[0057] The planetary gear set can establish a fixed reduction ratio between the first electric motor and the coaxial shaft. However, the planetary gear set is preferably a switchable gear set in which either two elements of the planetary gear set can be locked together or one element of the planetary gear set can be connected to a housing. In this case, internal combustion engine operation can be established without having to tow the first electric motor.

[0058] It is further advantageous if a first member of the planetary gear set is connected to the shaft coaxial with the first electric machine and / or a second member of the planetary gear set can be connected to a housing and / or a third member of the planetary gear set is connected to a rotor of the first electric machine.

[0059] The third member is preferably a planet carrier of the planetary gear set. The second member is preferably a ring gear of the planetary gear set. The first member is preferably a sun gear of the planetary gear set.

[0060] Furthermore, it is advantageous if the planetary gear set is arranged at least partially radially within a rotor of the first electric machine and / or at least partially axially overlapping with the rotor of the first electric machine.

[0061] This allows for a saving of axial installation space when using an electric motor with a relatively large diameter. Consequently, the hybrid gearbox can be built with a compact axial design.

[0062] The transmission input shaft can be directly and rotationally fixed to an input shaft of the internal combustion engine (crankshaft), particularly when a second electric motor is connected to it. Preferably, however, a disconnect clutch is provided to connect the transmission input shaft to the internal combustion engine, with the disconnect clutch being arranged coaxially to the transmission input shaft.

[0063] In this case, the wheelset arrangement according to the invention is preferably arranged behind the disconnect clutch in the direction of the power flow of combustion engine power.

[0064] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0065] Exemplary embodiments of the invention are shown in the drawing and are explained in more detail in the following description. They show: Fig. 1 a schematic representation of a hybrid powertrain for a motor vehicle with a hybrid transmission; Fig. 2 a schematic axial view of a wheelset arrangement; Fig. 3 a sectional view along line III-III in Fig. 2; Fig. 4 a schematic representation of another embodiment of a hybrid transmission; Fig. 5 a schematic representation of another embodiment of a hybrid transmission; and Fig. 6 a schematic representation of another embodiment of a hybrid transmission.

[0066] In Fig. Figure 1 is a schematic representation of a motor vehicle powertrain and is generally designated by 10.

[0067] The powertrain 10 includes an internal combustion engine 12 and a hybrid transmission 14. An input of the hybrid transmission 14 is connected to the internal combustion engine 12. An output 17 of the hybrid transmission 14 is connected to a power distribution device 16, such as a differential, for distributing drive power to the driven wheels 18L and 18R of the powertrain 10.

[0068] The hybrid transmission 14 includes a transmission input shaft 19. The transmission input shaft 19 is preferably arranged concentrically to a drive shaft (crankshaft) of the internal combustion engine 12. The transmission input shaft 19 is preferably connected to the drive shaft of the internal combustion engine 12 via a disconnect clutch K0.

[0069] Furthermore, the hybrid transmission 14 has a first shaft 20 and a second shaft 22.

[0070] The first shaft 20 can be connected to the second shaft by means of a first switchable gear set 24. The first gear set 24 has a fixed gear 26 connected to the first shaft 20 and a loose gear 28 rotatably mounted on the second shaft 22. The loose gear 28 can be connected to the second shaft 22 by means of a first switching element B. Furthermore, the first shaft 20 can be connected to the second shaft 22 by means of a second gear set 30. The second gear set 30 has a fixed gear 32 connected to the first shaft 20 and a loose gear 34 rotatably mounted on the second shaft 22. The loose gear 34 can be connected to the second shaft by means of a second switching element D. The first switching element B and the second switching element D form a double switching element, which is arranged in an axial direction on the second shaft 22 between the first gear set 24 and the second gear set 30.

[0071] A driven gear 36 of an unspecified driven gear set is fixed to the second shaft 22. The driven gear 36 engages with an input element of the power distribution device 16. Furthermore, a parking lock gear P can be fixed to the second shaft 22, as shown in Fig. 1 is shown schematically.

[0072] The output gear 36 and preferably also the parking lock gear P are preferably arranged in an axial direction between the first gear set 24 and the internal combustion engine 12.

[0073] The first shaft 20 is offset parallel to the transmission input shaft 19 by an axis offset V.

[0074] To set the axial offset V, the transmission input shaft 19 is non-rotatably connected to an axial offset gear 38. The axial offset gear 38, which could also be described as a ring gear, includes an internal toothing 40. The internal toothing 40 engages with a fixed gear 42, which is arranged radially inside the internal toothing 40 and non-rotatably connected to the first shaft 20.

[0075] More precisely, the fixed wheel has 42 (see Fig. 2 and Fig. 3) an external toothing 42a which engages with the internal toothing 40 of the offset gear 38. A diameter of the fixed gear 42 is smaller than an inner diameter of the offset gear 38, preferably smaller than half the inner diameter of the offset gear 38 in the area of ​​the internal toothing 40.

[0076] The offset gear 38 further comprises an external toothing 44 on its outer circumference. The external toothing 44 and the internal toothing 40 lie in a common radial plane or are axially aligned with each other. The external toothing 44 engages with a fixed gear 48 (directly or via an intermediate gear), which is fixed to a third shaft 46. The third shaft 46 is a motor shaft of a second electric machine EM2. The second electric machine EM2 is arranged parallel to and offset from the first shaft 20 and preferably overlaps axially with at least one of the gear sets 24, 30.

[0077] By having the offset gear 38 have both internal teeth 40 and external teeth 44 in a single radial plane, two functions can be achieved using the offset gear 38. These are, firstly, the offset to the first shaft 20 and, secondly, the connection of the second electric machine EM2. All of this can be realized within a small axial installation space.

[0078] As it is in Fig. 2 and Fig. As shown in Figure 3, the fixed gear 48 has an external toothing 48a which engages with the external toothing 44.

[0079] The axle offset gear 38 is arranged in the axial direction between the first gear set 24 and the internal combustion engine 12 or the disconnecting clutch K0.

[0080] On an axially opposite side of the gear sets 24, 30, i.e., facing away from the internal combustion engine 12, a first electric machine EM1 is connected to the first shaft 42. The first electric machine EM1 has a rotor 52 which is rotationally fixed to the first shaft 20. Furthermore, the first electric machine EM1 includes a stator 54 which is fixed to a housing 50.

[0081] The first electric motor EM1 has a comparatively large diameter, allowing for a short axial design. Due to the axial offset V established by the offset gear 38, the first electric motor EM1 is offset relative to the transmission input shaft 19 and thus relative to a drive or crankshaft 58 of the internal combustion engine 12. This allows the hybrid transmission 14, with its radially large first electric motor EM1, to be easily installed in a space transverse to a longitudinal axis of the vehicle. In particular, this allows the joint of a side shaft (as indicated in 18L, 18R), a transmission mount (if applicable), and a lower longitudinal member of the vehicle to be bypassed. In other words, despite these constraints, a comparatively large first electric motor EM1 can be used.

[0082] In the hybrid transmission 14, the entire transmission unit with gear sets 25, 30 and the second shaft 22 is also offset axially relative to the transmission input shaft 19, so that an optimal arrangement within the installation space can be achieved. In the Fig. 2 and Fig. Figure 3 shows a wheelset arrangement 60 which can be used for the hybrid transmission 14 described above, but also for other transmissions.

[0083] The gear set 60 includes a gear 38. The gear 38 can be implemented as an offset gear and comprises a base body 62, which is rotationally symmetrical about an axis A1. The base body 62 has a radially inner section 62i. In the region of the radially inner section 62i, the base body 62 is typically connected to a shaft, such as the transmission input shaft 19.

[0084] Furthermore, the base body 62 has a radially outer section 62a. In the region of the radially outer section 62a, the gear 38 includes a rim section 64, which projects axially relative to the radially outer section 62a of the base body 62.

[0085] The ring section 64 includes an internal toothing 40 on its inner circumference and an external toothing 44 on its outer circumference. Consequently, the gear 38 of the Fig. 2 and Fig. 3, for example, as gear 38 of the hybrid transmission of the Fig. 1 can be used.

[0086] In the Fig. 2 and Fig. Figure 3 further shows the gear set arrangement 60, which, in addition to the first gear 38, includes a second gear 42 arranged coaxially to a second axle A2, for example, coaxially to the first shaft 20, to which it is preferably rigidly connected. The second gear 42 has external teeth 42a, which mesh with the internal teeth 40 of the rim section 64. Consequently, an axle offset V is established between axles A1 and A2.

[0087] Furthermore, the wheelset arrangement 60 includes a third gear 48, which is, for example, gear 48 of the hybrid transmission 14 of the Fig. 1 can act. The third gear 48 includes an external toothing 48a which engages with the external toothing 44 of the ring section 64.

[0088] Alternatively, the wheelset arrangement 60 can also include only the first gear 38 and the second gear 42. In some embodiments, the external teeth 44 can also be designed as traction teeth or omitted entirely.

[0089] The internal teeth 40 of the ring section 64 are spur gear teeth, in particular helical gear teeth. The external teeth 44 can also have spur gear teeth, for example helical gear teeth. Alternatively, the external teeth 44 can also be designed to interact with a traction element 65, for example a toothed belt or a chain. The traction element 65 is in Fig. 2 only indicated schematically.

[0090] In the Fig. 4, Fig. 5 to Fig. Figure 6 shows further embodiments of hybrid transmissions which, in terms of structure and function, are generally similar to the hybrid transmission 14 of the Fig. 1. Identical elements are therefore identified by the same reference symbols. The differences are explained below.

[0091] The in Fig. The hybrid transmission 14' shown includes a first shaft 20, which is arranged coaxially to the transmission input shaft 19. The second electric machine EM2 is connected via its fixed gear 48 to an unspecified fixed gear on the first shaft 20, thus independently of an offset gear.

[0092] An offset gear 38', on the other hand, is rotationally fixed to the first shaft 20. In this case, the offset gear 38' forms the fixed gear 32' of the second gear set 30'. In other words, the external teeth 44 of the offset gear 38' mesh with an external tooth of the loose gear 34 of the second gear set 30.

[0093] The internal toothing 40 of the axle offset gear 38' engages with a fixed gear 42 (pinion) which is rotationally fixed to a fourth shaft 74.

[0094] The fourth shaft 74 is arranged coaxially with the first electric machine EM1. The first electric machine EM1 can be connected to the fourth shaft 74 via a planetary gear set 66.

[0095] The planetary gear set 66 includes a first element 68, which is rotationally fixed to the fourth shaft 74. The first element 68 is preferably a sun gear of the planetary gear set 66.

[0096] Furthermore, the planetary gear set 66 includes a second element 70, which can be connected to the housing 50 by means of a third switching element E. The second element 70 is preferably a ring gear of the planetary gear set 66. The planetary gear set 66 also includes a third element 72, which is rotationally fixed to the rotor 52 of the first electric machine EM1. The third element 72 is preferably a planet carrier of the planetary gear set 66.

[0097] In a purely combustion engine operation, the third switching element E can be opened to decouple the first electric machine EM1 from the power flow via the first gear set 24 or the second gear set 30'.

[0098] The first electric machine EM1 is also connected to the fourth shaft 74 via the transmission (especially stationary transmission) of the planetary gear set 66 when the third switching element E is closed.

[0099] In the hybrid transmission 14', essentially only the first electric motor EM1 with the planetary gear set 66 is offset axially from the transmission input shaft 19. The first shaft 20, on the other hand, is arranged coaxially to the transmission input shaft 19.

[0100] The planetary gear set 66 is preferably arranged at least partially radially within the rotor 52 of the first electric machine EM1 and at least partially axially overlapping with the rotor 52. This allows the planetary gear set 66 to be implemented in a space-saving manner.

[0101] Because the first electric machine EM1 is offset axially relative to the transmission input shaft 19 and consequently relative to the combustion engine 12, it can be optimally arranged in the installation space.

[0102] In Fig. Figure 5 shows another embodiment of a hybrid transmission 14''.

[0103] In the hybrid transmission 14'', the second gear set 30'' includes a loose gear 34'' rotatably mounted on the first shaft 20, which can be switched by means of the second switching element D, which is also arranged on the first shaft 20.

[0104] The second gear set 30'' further includes a fixed gear 32'', which is rotationally fixed to the second shaft 22. The fixed gear 32'' is formed by an offset gear 38''. It features an external toothing (not shown in detail below). Fig. 5 shown) of the axle offset gear 38'' in engagement with an external toothing of the loose gear 34''.

[0105] As with the hybrid transmission 14' of the Fig. 4 is also the 14'' hybrid transmission Fig. 5 the first shaft 20 is arranged coaxially to the gearbox input shaft 19 and connected to it in a rotationally fixed manner.

[0106] The first electric machine EM1 is, as in the embodiment of the Fig. 4 can be connected via a planetary gear set 66 to a fourth shaft 74, on which a fixed gear 42'' is fixed, the external teeth of which engage with the internal teeth of the axle offset gear 38''.

[0107] In other words, the fourth shaft 74 is offset from the second shaft 22 by means of the offset gear 38''.

[0108] In this embodiment as well, the first electric motor can be optimally arranged within the installation space. However, the gear sets 24, 30'' are not offset from the internal combustion engine 12, as in the Fig. 1.

[0109] The 14'' hybrid transmission of the Fig. 5 is advantageous with regard to the transmission efficiency in electric driving mode. This is because the first electric motor EM1 is connected to the power distribution device 16 with only two transmission stages. In other words, the electric motor drive power from the first electric motor EM1 can be essentially transmitted directly to the second shaft 22, bypassing the first shaft 20.

[0110] As with the embodiment of the Fig. 4 The second electric machine EM2 is optionally connected to the first shaft 20 via an unspecified fixed gear. In the embodiments of the Fig. 4 and Fig. The second electric motor EM2 is optional. The hybrid transmissions 14' and 14'' can therefore also be implemented without the second electric motor EM2. This is shown in Fig. 4 indicated by the fact that the second electric machine EM2 is shown with a dashed line.

[0111] In Fig. Figure 6 shows a further embodiment of a hybrid transmission 14''' which, in terms of structure and function, is generally similar to the hybrid transmission 14 of the Fig. 1 corresponds to.

[0112] While in the hybrid transmission 14 of the Fig. 1 where the transmission input shaft 19 is connected to an offset gear 38, in the hybrid transmission 14''' the first shaft 20 is connected to an offset gear 38'''.

[0113] While in the hybrid transmission 14 of the Fig. 1 the first shaft is connected to a gear 42 which engages with an internal toothing of the axle offset gear 38, is in the hybrid transmission 14''' the Fig. 6 The transmission input shaft 19 is non-rotatably connected to a fixed gear 43''' which engages with an internal toothing of the offset gear 38'''. An external toothing of the offset gear 38''' engages with a fixed gear 48, which is assigned to the second electric machine EM2.

[0114] In the hybrid transmission 14''', not only the first electric motor EM1, but also the transmission gearbox with gear sets 24, 30 is offset axially from the crankshaft or drive shaft 58 of the internal combustion engine 12.

[0115] While the axle offset gear 38 of the Fig. The axle offset gear 38''' serves to implement a speed reduction between the transmission input shaft 19 and the first shaft 20. Fig. 6 to implement a reduction in speed from the transmission input shaft 19 to the first shaft 20. Reference sign 10 Automotive powertrain 12 Internal combustion engine 14 hybrid transmissions 17 Drive 16. Service distribution system 18L / R driven wheels 19 Gearbox input shaft 20 first wave 22 second wave 24 first gear set 26" fixed wheel 28 Loose wheel 30 second gear set 32 Fixed wheel 34 Loose wheel 36 Output gear 38 Axle offset gear 40 internal teeth 42 Fixed gear (sprocket) 42a External toothing 42 44 External teeth 46 third wave 48 Fixed wheel (EM2) 48a External toothing 48 50 cases 52 Rotor EM1 54 Stator EM1 56 cases 58 Crankshaft 60 Wheelset arrangement 62 Basic body 38 62i radial inner section 62a radial outer section 64 wreath section 65 traction elements 66 Planetary gear set 68 first item 70 second item 72 third item 74 fourth wave K0 disconnect coupling EM1 first electric machine V-axis offset EM2 second electric machine P Parking lock wheel A1-A5 axes B first switching element The second switching element The third switching element R radial plane

Claims

[1] Hybrid transmission (14) for a motor vehicle powertrain (10), with - a transmission input shaft (19) for connection to an internal combustion engine (12); - a first shaft (20) which is connected or connectable to the transmission input shaft (19); - a second shaft (22) which can be connected to the first shaft (20) via at least one gear set (24;30) which can be switched by means of a switching element (B;D) and which is connected to an output (17); - a first electric machine (EM1) which is connected or connectable to the first shaft (20); and - a wheelset arrangement (60) to establish an axle offset (V) between - the first electric motor (EM1) and the transmission input shaft (19) and / or - the first electric machine (EM1) and the first shaft (20) and / or - the first electric machine (EM1) and the second shaft (22), wherein the wheelset arrangement (60) has: - a first gear (38) having the first axis of rotation (A1), wherein the first gear (38) has a rim section (64) with an internal toothing (40) and an external toothing (44); and - a second gear (42) having the second axis of rotation (A2), wherein the second gear (42) has an external toothing (42a) which engages with the internal toothing (40) of the first gear (38), wherein the gear set arrangement (60) further comprises: - a third gear (48) having a third axis of rotation (A4), wherein the third gear (48) has an external toothing (48a) which engages with the external toothing (44) of the first gear (38), wherein the first gear (38), the second gear (42) and also the third gear (48) are arranged in a common radial plane (R). [2] Hybrid transmission according to claim 1, wherein the first gear (38) is formed with a base body (62) having a radially inner section (62i) and a radially outer section (62a), wherein the first axis of rotation (A1) of the gear (38) passes through the radially inner section (62i), and with a rim section (64) projecting axially from the radially outer section (62a) of the base body (62) and being rigidly connected to the base body (62), wherein the rim section (64) has an internal toothing (40) into which an external toothing (42a) of the second gear (42), which is arranged radially inside the rim section (64), engages, and wherein the rim section (64) has an external toothing (44) into which an external toothing (48a) of a third gear (48), which is arranged radially outside the rim section (64), engages. where a traction element (65) can engage. [3] Hybrid transmission according to one of claims 1-2, wherein the external toothing (44) of the first gear (38) engages with a third gear (48) which is connected to a second electric machine (EM2). [4] Hybrid transmission according to one of claims 1-3, wherein the first gear (38), whose rim section (64) has the internal teeth (40) and the external teeth (44), is connected to the transmission input shaft (19) in a rotationally fixed manner, and wherein the second gear (42), whose external teeth (42a) engage with the internal teeth (40) of the rim section (64) of the first gear (38), is connected to the first shaft (20). [5] Hybrid transmission according to claim 1 or 3, wherein the first gear (38), whose rim section (64) has the internal teeth (40) and the external teeth (44), is connected to the transmission input shaft (19) in a rotationally fixed manner, and wherein the second gear (42), whose external teeth (42a) engage with the internal teeth (40) of the rim section (64) of the first gear (38), is connected to a shaft (20;74) which is concentric to the first electric machine (EM1). [6] Hybrid transmission according to claim 5, wherein the external toothing (44) of the rim section (64) of the first gear (38) engages with a loose gear (34) rotatably mounted on the second shaft (22). [7] Hybrid transmission according to claim 1 or 3, wherein the first gear (38), whose rim section (64) has the internal teeth (40) and the external teeth (44), is non-rotatably connected to the second shaft (22) and wherein the second gear (42), whose external teeth (42a) engage with the internal teeth (40) of the rim section (64) of the first gear (38), is connected to a shaft (74) which is concentric to the first electric machine (EM1), wherein the external teeth (44) of the rim section (64) of the first gear (38) engage with a loose gear (34'') rotatably mounted on the first shaft (20). [8] Hybrid transmission according to claim 1 or 3, wherein the first gear (38), whose rim section (64) has the internal teeth (40) and the external teeth (44), is connected to the first shaft (20) in a rotationally fixed manner and wherein the second gear (42), whose external teeth (42a) engage with the internal teeth (40) of the rim section (64) of the first gear (38), is connected to the transmission input shaft (19). [9] Hybrid transmission according to one of claims 1 or 3-8, wherein the first electric machine (EM1) can be connected via at least one switchable planetary gear set (66) to a shaft (74) coaxial to the first electric machine (EM1), which - is connected to the transmission input shaft (19) via the wheelset arrangement (60) or - is connected to the first shaft (20) via the wheelset arrangement (60) or - is connected to the second shaft (22) via the wheelset arrangement (60). [10] Hybrid transmission according to claim 9, wherein a - a first member (68) of the planetary gear set (66) is connected to the shaft (74) coaxial with the first electric machine (EM1) and / or - a second member (70) of the planetary gear set (66) can be connected to a housing (50) and / or - a third link (72) of the planetary gear set (66) is connected to a rotor (52) of the first electric machine (EM1). [11] Hybrid transmission according to claim 9 or 10, wherein the planetary gear set (66) is arranged at least partially radially within a rotor (52) of the first electric machine (EM1) and / or at least partially axially overlapping with the rotor (52) of the first electric machine (EM1). [12] Hybrid transmission according to one of claims 1-11, with a disconnecting clutch (K0) for connecting the transmission input shaft (19) to an internal combustion engine (12), wherein the disconnecting clutch (K0) is arranged coaxially to the transmission input shaft (19).

Images