DE102020214519A1 - Hybrid transmission for an automotive powertrain - Google Patents

Abstract

Hybrid transmission (14) for a motor vehicle drive train (10), with a first shaft (20) for connection to an internal combustion engine (12); with a second shaft (22) which can be connected to the first shaft (20) via at least one gear wheel set (24; 30) which can be shifted by means of a shifting element (C;A), the second shaft (22) having an output (17) connected is; with a third shaft (40) which can be connected to a first electric machine (EM1) by means of at least one switching element (E;F), the first electric machine (EM1) being arranged coaxially with the third shaft (40) and the third shaft (40) is connected to the second shaft (22) via a coupling gear set (42); wherein the third shaft (40) is arranged offset parallel to the first shaft (20), so that the first electric machine (EM1) is arranged off-axis relative to the first shaft (20).

Description

The present invention relates to a hybrid transmission for a motor vehicle drive train, with a first shaft for connection to an internal combustion engine, with a second shaft which can be connected to the first shaft via at least one gear wheel set that can be shifted by means of a shifting element, the second shaft having an output is connected, and with a third shaft which can be connected to a first electric machine by means of at least one switching element.

Hybrid drive trains for motor vehicles generally have an internal combustion engine that can provide drive power for driving the motor vehicle, and an electric machine that can provide drive power for the motor vehicle as an alternative or in addition to the internal combustion engine, depending on the operating mode.

In the case of hybrid drive trains, a distinction is made between a large number of different concepts, each of which provides for a different connection of the electric machine to a transmission arrangement of the hybrid drive train. In the case of double clutch transmissions, a typical variant is to arrange an electric machine concentrically to an input element of the double clutch arrangement. It is also known to assign an electric machine to one of the two sub-transmissions in dual-clutch transmissions.

It is also known to arrange an electrical machine concentrically to a first input shaft, with a rotor of the electrical machine being connected to a hollow shaft which is arranged around the input shaft.

From the document DE 10 2013 215 114 A1 a hybrid drive of a motor vehicle is known, in which an electric machine can be connected to an output shaft of a hybrid transmission via a spur gear set. It is also known from this document to arrange an electric machine coaxially to a transmission output shaft, namely axially offset to a planetary gear set, which is designed as a superimposed transmission for electric motor drive power and for internal combustion engine drive power.

Hybrid transmissions are preferably designed as power shift transmissions. The axial overall length of the hybrid transmission is of great importance, particularly when installed in a motor vehicle transversely to the drive direction (front-transverse or rear-transverse). Furthermore, when installing transversely to the direction of travel, the installation environment must often be taken into account. Bottlenecks may be a side shaft joint, a transmission mount and/or a lower longitudinal member of the vehicle.

It is generally preferred if an electric machine that provides drive power for a hybrid drive train has a large outer diameter. Such electric machines often have an axially short design, but often do not fit well into an installation space due to the large outside diameter. This applies in particular when the electric machine is arranged on a side facing away from the internal combustion engine in the direction of a wheel of the motor vehicle.

Against this background, it is an object of the present invention to specify an improved hybrid transmission for a motor vehicle drive train.

The above object is achieved by a hybrid transmission for a motor vehicle drive train, with a first shaft for connection to an internal combustion engine with a second shaft, which can be connected to the first shaft via at least one gear wheel set that can be shifted by means of a shifting element, the second shaft being connected to a is connected to the output, with a third shaft, which can be connected to a first electric machine by means of at least one shifting element, the first electric machine being arranged coaxially to the third shaft and the third shaft being connected to the second shaft via a coupling gear set, the third Shaft is arranged offset parallel to the first shaft, so that the first electric machine is arranged off-axis relative to the first shaft.

The hybrid transmission includes a first electric machine for providing drive power. The hybrid transmission also includes a first shaft for connection to an internal combustion engine. The first shaft is preferably a transmission input shaft and is preferably to be connected coaxially to the internal combustion engine. The hybrid transmission is designed to carry out a purely internal combustion engine driving operation, with internal combustion engine drive power being able to be routed to the output via the first shaft, the at least one switchable gear wheel set and the second shaft.

The output can include a power distribution device such as a differential.

Furthermore, electromotive drive power of the first electric machine can be routed via the at least one switching element to the third shaft, and from there via the coupling gear set to the second shaft, which is connected to the output.

The coupling gear set is preferably a spur gear set, by means of which a gear ratio can be set up between the first electric machine and the second shaft. Combustion engine power and electromotive power can be summed up in the second wave. The hybrid transmission may include a planetary gear set for establishing a further pre-ratio between the first electric machine and the second shaft, the planetary gear set preferably being arranged coaxially with the third shaft.

The third shaft is offset parallel to the first shaft in such a way that the first electric machine is offset from the axis of the first shaft.

This measure allows an axial offset to be set up essentially between the first shaft, which is preferably arranged coaxially to an internal combustion engine drive shaft, and the first electric machine, which is arranged coaxially to the third shaft.

Furthermore, the first electric machine is preferably arranged in the area of an axial end of the hybrid transmission. The first electric machine preferably has a relatively large outer diameter. Due to the axial offset between the first shaft and the third shaft, it is still possible to accommodate such a large electric machine in a front transverse installation space in a motor vehicle, with bottlenecks such as a joint of a side shaft of the vehicle, a transmission suspension and/or a lower vehicle longitudinal member can be "avoided" or do not prevent installation. In other words, despite these bottlenecks, a comparatively large first electric machine with a large diameter can be used in the hybrid transmission.

The hybrid transmission preferably contains at least two and preferably a maximum of six forward gears for driving with the internal combustion engine. It is particularly preferred if the number of forward gears for purely internal combustion engine driving is four. As a result, internal combustion engine driving can be implemented over a large speed range.

For driving with an electric motor, the hybrid transmission is designed in such a way that it can either be implemented in a single gear, but preferably in two different gears. Consequently, electric motor driving can also be implemented over a relatively large speed range.

Electromotive drive power and internal combustion engine drive power can preferably be summed up in the second shaft in order to then be guided together to the output.

The hybrid transmission preferably has no mechanical reverse gear stage. Reversing operation is preferably carried out exclusively by means of the first electric machine (and/or by means of an optionally provided second electric machine).

The first electric machine can also be used to support the traction when changing gears in purely combustion engine driving mode.

Because the third shaft can be connected to the first electric machine by means of at least one switching element, the first electric machine can be decoupled in purely internal combustion engine driving mode, so that drag losses are avoided.

• Eine Radpaarung beinhaltet genau zwei Zahnräder, die miteinander in Eingriff stehen. Zwei miteinander in Eingriff stehende Zahnräder sind insbesondere als zwei Zahnräder zu verstehen, deren Verzahnungen kämmen. Die Zahnräder weisen vorzugsweise jeweils eine Stirnverzahnung auf, sind vorzugsweise in einer radialen Ebene angeordnet und sind vorzugsweise jeweils einer anderen Welle zugeordnet. Die Zahnräder der Radpaarung können zwei Festräder sein (sog. Konstanten-Radsatz). Bei einer schaltbaren Radpaarung können die zwei Zahnräder ein Festrad und ein Losrad (s.u.) sein, die vorzugsweise gemeinsam eine Gangstufe (s.u.) definieren.

In the context of the present disclosure, the following terms can be understood in particular as follows:

• A pair of wheels contains exactly two gears that mesh with each other. Two meshing gears are to be understood in particular as two gears whose teeth mesh. The gear wheels preferably each have face teeth, are preferably arranged in a radial plane and are preferably each associated with a different shaft. The gears of the gear pair can be two fixed gears (so-called constant gear set). In a switchable pair of wheels, the two gears can be a fixed wheel and a loose wheel (see below), which preferably together define a gear (see below).

A wheel set contains at least two mutually meshing (in particular meshing) gears, and can contain one or more wheel pairs, which preferably lie in a common radial wheel set plane. If a wheelset has a fixed wheel that meshes with two different loose wheels, the wheelset can define two gears; in this case one also speaks of a dual use of the fixed wheel. In general, a gear set can also be a planetary gear set.

A loose wheel is a gear wheel which is rotatably mounted on a shaft and which can be connected to or decoupled from the shaft by means of a switching element. A fixed wheel is a gear wheel fixed to a shaft in a rotationally fixed manner.

A shifting element is used to connect or release links, such as a loose wheel and a shaft, and is formed here in particular by a shifting clutch, in particular a positive shifting clutch, such as a claw clutch. However, the clutch can also be a synchronous clutch.

A double switching element contains two switching elements, which are preferably assigned to different idler wheels on a shaft and which can be switched alternatively by means of a single actuating device in order to connect one of the idler wheels to the shaft. Furthermore, the double switching element includes a neutral position in which neither of the two loose wheels is connected to the shaft.

Two relatively rotatable members are connected when they are positively rotating at a proportional speed. The term connected is to be equated with "effectively connected". A "rotational connection" means that the two links rotate at the same speed. Two members are connectable if they can either be connected or disconnected from each other. The links can preferably be connected to one another by means of a switching element such as a clutch or a brake.

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

The task is completely solved.

According to a preferred embodiment of the hybrid transmission, the coupling gear set has a fixed wheel fixed to the third shaft and a fixed wheel fixed to the second shaft, which are either directly engaged with one another or are connected via an intermediate wheel.

The coupling gear set is preferably located axially in an area between the at least one shiftable gear set and the first electric machine.

If the fixed wheels are connected via an intermediate wheel, it is preferred if the intermediate wheel is rotatably mounted on the first shaft. In this way, a defined and relatively large axial offset can be set up between the third shaft and the first shaft. In addition, a separate shaft for the intermediate wheel can be saved.

It is advantageous here if the fixed wheel fixed to the third shaft and the fixed wheel fixed to the second shaft are arranged in a common wheelset plane.

In this case, the coupling wheel set lies in this common wheel set plane, in which the intermediate wheel is also arranged. As a result, an axially compact structure can be achieved.

According to a further preferred embodiment, the intermediate wheel is a double gear wheel which meshes with the fixed wheel fixed to the third shaft in a first wheel set plane and which meshes with the fixed wheel fixed to the second shaft in an axially offset second wheel set plane.

A double gear is understood here to mean that it contains two axially offset gears on a base body, which in particular have different diameters and/or different numbers of teeth. In this way, the double gear wheel can be used to be able to adjust the size of the translation between the speed of the fixed wheel fixed to the third shaft and the speed of the fixed wheel fixed to the second shaft in an even larger range.

This measure also makes it possible to be able to vary the relative position of the first electric machine in relation to the first shaft to an even greater extent, i.e. the possibility of accommodating a radially large first electric machine in a narrow front, transverse or rear To realize transverse installation space. These advantages can compensate for a disadvantage of a somewhat greater axial length that may be associated with this.

In a further alternative embodiment, the intermediate wheel is rotatably mounted on a fifth shaft, which is arranged offset in parallel both with respect to the first shaft and with respect to the third shaft.

In this case, the intermediate wheel is preferably rotatably mounted on its own shaft, so that there is also a high degree of variability with regard to the transmission ratio between the third shaft and the second shaft.

The fifth wave is also preferably offset parallel to the second wave.

Overall, it is also advantageous if the hybrid transmission has a fourth shaft, which can be connected to the first shaft via at least one gear wheel set that can be shifted by means of a shifting element, the fourth shaft being connected to the output.

In this embodiment, the second shaft and the fourth shaft form an output shaft assembly. A driven wheel is preferably fixed on both shafts, with the two driven wheels of the second shaft and the fourth shaft being in engagement with an input element of a power distribution device such as a differential. The driven wheels are preferably arranged between the gear wheel sets and an input of the hybrid transmission, ie in particular between the gear wheel sets and an internal combustion engine.

It is preferred if the second shaft can be connected to the first shaft via two switchable gear wheel sets and/or if the fourth shaft can be connected to the first shaft via two switchable gear wheel sets.

It is particularly preferred if there are exactly two switchable gear wheel sets in each case. As a result of the four shiftable gear sets in total, four different forward gears can be set up for driving with an internal combustion engine.

According to a further preferred embodiment, at least one switchable gear set for connecting the first shaft to the second shaft and at least one switchable gear set for connecting the first shaft to the fourth shaft share a fixed wheel fixed to the first shaft.

It is particularly preferable if the second shaft and the fourth shaft can each be connected to the first shaft via two switchable gear sets and if both switchable gear sets are used to connect the first shaft to the second shaft and both switchable gear sets are used to connect the first shaft to the fourth shaft each share a fixed gear fixed to the first shaft.

In this case, therefore, exactly two fixed gears are preferably fixed on the first shaft, each of which meshes with two loose gears that are rotatably mounted on the second shaft or on the fourth shaft.

Overall, this results in an axially particularly compact structure. This further contributes to the fact that the hybrid transmission according to the invention can be easily installed in a front-transverse or rear-transverse installation space.

According to an overall preferred embodiment, the first electric machine can be connected to the third shaft via at least one planetary gear set.

The planetary gear set is preferably a switchable planetary gear set. It is particularly advantageous if two of the three members of the planetary gear set can be connected to one another and/or if one member of the planetary gear set can be connected to a housing. Furthermore, it is preferred here if at least one member of the planetary gear set is connected to a rotor of the first electric machine.

It is also advantageous here if a first member of the planetary gear set is connected to the third shaft and/or if a second member of the planetary gear set can be connected to a housing and/or if a third member of the planetary gear set is connected to a rotor of the first electric machine.

The first member of the planetary gear set is preferably a sun gear of the planetary gear set. The second member of the planetary gear set is preferably a ring gear of the planetary gear set. The third member of the planetary gear set is preferably a planet carrier (carrier) of the planetary gear set.

It is also advantageous if the second member of the planetary gear set can be connected to the housing by means of a shifting element. Furthermore, it is preferred if the second link can be connected to the first link by means of a further switching element. It is also advantageous here if the two switching elements are integrated into a double switching element, by means of which a neutral position can also be set up so that neither one nor the other switching element is switched and consequently the first electric machine is decoupled from the third shaft. As a result, drag losses in pure combustion engine driving can be reduced. According to a further preferred embodiment, the planetary gear set is arranged at least partially radially inside a rotor of the first electric machine and/or is arranged at least partially overlapping axially with the rotor of the first electric machine.

As a result, when using a first electric machine with a relatively large diameter, axial installation space can be saved. The hybrid transmission can therefore be axially compact. Overall, it is also advantageous if a second electric machine is connected to the first shaft via a further set of coupling gears.

The second electric machine is preferably arranged in such a way that it is connected to the first shaft via a spur gear connection. Preferably is the second electric machine is consequently arranged offset in parallel with the first shaft. The second electric machine is preferably arranged to axially overlap with at least one gear set of the hybrid transmission, and is preferably radially and/or axially spaced from the first electric machine.

The additional coupling wheel set preferably contains a pinion which is connected in a rotationally fixed manner to the drive shaft of the second electric machine, and also contains a fixed wheel which is fixedly connected to the first shaft. The fixed wheel can be a fixed wheel of a gear wheel set. Alternatively, the pinion can also be connected to a loose wheel of one of the gear wheel sets or be in engagement with it.

• - ein Verbrennungsmotorstart aus einem rein elektrischen Fahrbetrieb mittels der ersten Elektromaschine;
• - eine Bordnetzversorgung;
• - ein serielles Kriechen, bei dem die zweite Elektromaschine von dem Verbrennungsmotor angetrieben wird, um eine Batterie zu laden, ohne dass verbrennungsmotorische Antriebsleistung auf den Abtrieb gelangt, und wobei ein Fahrbetrieb im Kriechen mittels der ersten Elektromaschine eingerichtet wird, und zwar mittels Energie aus der Fahrzeugbatterie, die durch generatorischen Betrieb der zweiten Elektromaschine gespeist wird;
• - ein Fahren vorwärts und rückwärts, wobei hierbei sämtliche Gangstufen der Gangradsätze genutzt werden können, die auch für den verbrennungsmotorischen Fahrbetrieb genutzt werden können;
• - eine Unterstützung einer Drehzahlregelung des Verbrennungsmotors beim Ankoppeln und bei Schaltungen; dabei kann aus einem rein elektromotorischen Fahrbetrieb mittels der ersten Elektromaschine heraus der Verbrennungsmotor vorzugsweise in sämtlichen Vorwärtsgangstufen angekoppelt werden;
• - es können Lastschaltungen im verbrennungsmotorischen Fahrbetrieb durchgeführt werden, und zwar auch dann, wenn die Schaltelemente, die den schaltbaren Gangradsätzen zugeordnet sind, als Klauenkupplungen ausgeführt sind; hierbei kann an einem Quell-Schaltelement ein Lastabbau erfolgen und ein gleichzeitiger Lastaufbau an der ersten Elektromaschine erfolgen (wozu die erste Elektromaschine mit der dritten Welle verbunden sein muss); der Lastabbau kann dann erfolgen, indem der Verbrennungsmotor und/oder die zweite Elektromaschine das Moment abbauen; anschließend kann das Quell-Schaltelement für eine niedrige Ausgangsgangstufe geöffnet werden; dann werden die Drehzahlen des Verbrennungsmotors bzw. der zweiten Elektromaschine abgesenkt, so dass ein Ziel-Schaltelement synchron wird; dazu kann beispielsweise die zweite Elektromaschine generatorisch arbeiten (bevorzugt), oder der Verbrennungsmotor kann in den Schubbetrieb gehen; schließlich kann das Ziel-Schaltelement für eine höhere Anschlussgangstufe eingelegt werden;
• - ein Absenken der Drehzahl der ersten Elektromaschine im Hybridbetrieb kann erfolgen, wobei lastfrei im Hintergrund zwischen Gangstufen der ersten Elektromaschine gewechselt werden kann, wodurch deren Drehzahl beispielsweise verringert wird; diese Umschaltung kann erfolgen, während der Verbrennungsmotor (und/oder die zweite Elektromaschine) in einer der verbrennungsmotorischen Vorwärtsgangstufen die Zugkraft aufrechterhält;
• - im Hybridbetrieb kann die erste Elektromaschine abgekoppelt werden, so dass ein effizienter verbrennungsmotorischer Fahrbetrieb möglich ist.

For example, the following functions can be covered with the second electric machine:

• - An internal combustion engine start from a purely electric driving mode by means of the first electric machine;
• - an on-board power supply;
• - a serial creep, in which the second electric machine is driven by the internal combustion engine in order to charge a battery without combustion engine drive power being applied to the output, and wherein a driving operation in creep is set up by means of the first electric machine, namely by means of energy from the Vehicle battery, which is fed by generator operation of the second electric machine;
• - Driving forwards and backwards, in which case all gear stages of the gear wheel sets can be used, which can also be used for internal combustion engine driving;
• - A support for a speed control of the internal combustion engine when coupling and circuits; In this case, the internal combustion engine can preferably be coupled in all forward gears from a purely electric driving operation by means of the first electric machine;
• - It can be carried out power shifts in internal combustion engine driving, even if the switching elements that are assigned to the switchable gear wheel sets are designed as dog clutches; in this case, a load reduction can take place on a source switching element and a simultaneous load build-up on the first electric machine (for which the first electric machine must be connected to the third shaft); the load reduction can then take place in that the internal combustion engine and/or the second electric machine reduce the torque; then the source switching element can be opened for a low output ratio; then the speeds of the internal combustion engine or the second electric machine are lowered, so that a target switching element becomes synchronous; for this purpose, for example, the second electric machine can work as a generator (preferred), or the internal combustion engine can go into overrun mode; finally, the target switching element can be inserted for a higher connection gear;
• - A lowering of the speed of the first electric machine in hybrid operation can take place, with load-free in the background can be changed between gears of the first electric machine, whereby its speed is reduced, for example; this switching may occur while the engine (and/or the second electric machine) is maintaining traction in one of the engine forward gears;
• - In hybrid operation, the first electric machine can be decoupled so that efficient combustion engine driving is possible.

It is also advantageous overall if the hybrid transmission has a separating clutch for connecting the first shaft to an internal combustion engine. The separating clutch can be a form-fit shifting element, but it can also be a friction clutch.

If the separating clutch is open, electric motor driving can take place by means of the first electric machine and by means of the second electric machine.

In internal combustion engine or hybrid operation, the separating clutch always remains closed. In this way, the internal combustion engine is always connected to the second electric machine.

It goes without saying that the features mentioned above and those still to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

• 1 eine schematische Darstellung einer Ausführungsform eines Kraftfahrzeugantriebsstranges mit einem Hybrid-Getriebe;
• 2 eine Schalttabelle für das Hybrid-Getriebe der 1;
• 3 eine schematische Darstellung einer weiteren Ausführungsform eines Hybrid-Getriebes;
• 4 eine schematische Darstellung einer weiteren Ausführungsform eines Hybrid-Getriebes;
• 5 eine schematische Darstellung einer weiteren Ausführungsform eines Hybrid-Getriebes;
• 6 eine schematische Darstellung einer weiteren Ausführungsform eines Hybrid-Getriebes.

An embodiment of the invention is shown in the drawings and is explained in more detail in the following description. Show it:

• 1 a schematic representation of an embodiment of a motor vehicle drive train with a hybrid transmission;
• 2 a shift table for the hybrid transmission 1 ;
• 3 a schematic representation of a further embodiment of a hybrid transmission;
• 4 a schematic representation of a further embodiment of a hybrid transmission;
• 5 a schematic representation of a further embodiment of a hybrid transmission;
• 6 a schematic representation of a further embodiment of a hybrid transmission.

In 1 1 is a motor vehicle powertrain shown in schematic form and generally designated 10 . The motor vehicle drive train 10 includes an internal combustion engine 12 and a hybrid transmission 14. The hybrid transmission 14 includes an output 17 with a power distribution device 16. The power distribution device 16 is designed to distribute drive power to driven wheels 18L, 18R. The motor vehicle drive train 10 is designed in particular for installation transversely in a motor vehicle, ie either front-transverse or rear-transverse.

The hybrid transmission 14 includes a first shaft 20 and a second shaft 22. The second shaft 22 can be connected to the first shaft 20 via a first gear wheel set 24. The first gear wheel set 24 includes a fixed wheel 26 which is fixed in a rotationally fixed manner on the first shaft and a loose wheel 28 which is rotatably mounted on the second shaft 22 . The loose wheel 28 can be connected to the second shaft 22 by means of a switching element C in order to engage a gear.

The second shaft 22 can also be connected to the first shaft 20 via a second gear wheel set 30 . The second gear set 30 includes a fixed gear 32 fixed to the first shaft 20 and an idler gear 34 rotatably supported on the second shaft 22 . The loose wheel 34 can be connected to the second shaft 22 by means of a shifting element A in order to set up a further gear stage.

The second shaft 22 is firmly connected to a driven wheel 36 which is in engagement with an input member of the power distribution device 16 .

The first shaft 20 is preferably arranged coaxially to a drive shaft of the internal combustion engine 12 . The first shaft is preferably connected to the output member of a separating clutch K0, the input member of which can be connected to the internal combustion engine 12. As shown, the separating clutch K0 can be a positive clutch, such as a claw clutch, but it can also be a friction clutch. Alternatively, the first shaft 20 can also be connected in a torque-proof manner to a drive shaft of the internal combustion engine 12 .

When the separating clutch K0 is closed, drive power from the internal combustion engine can be routed via the first gear wheel set 24 or the second gear wheel set 30 to the second shaft 22 and from there via the output 17 (including the output wheel 36) to the power distribution device 16 in order to enable internal combustion engine driving in two different gears set up.

The hybrid transmission 14 also includes a third shaft 40 . The third shaft 40 is connected to the second shaft 22 via a coupling gear set 42 . The coupling gear set 42 is preferably a spur gear set. As an alternative or in addition to this, it is preferred if the coupling gear set is a constant gear set.

The Koppelradsatz 42 includes a fixed wheel 44, which is fixed to the third shaft 40, and a fixed wheel 46, which is fixed to the second shaft 22. In one possible embodiment, the fixed gears 44, 46 mesh directly with one another.

In the present case, however, the coupling wheel set 42 also includes an intermediate wheel 48 , with both the fixed wheel 44 and the fixed wheel 46 being in mesh with the intermediate wheel 48 .

The intermediate wheel 48 can be rotatably mounted on a separate shaft. In the present case, however, the intermediate wheel 48 is rotatably mounted on the first shaft 20 .

The coupling gear set 42 is arranged on a side of the gear wheel sets 24, 30 facing away from the separating clutch K0, as seen in the axial direction.

The hybrid transmission includes a first electric machine EM1, which has a relatively large diameter. The first electric machine EM1 is arranged on a side of the gear wheel sets 24, 30 facing away from the separating clutch K0 and is preferably arranged on an axial end of the hybrid transmission 14 facing away from the separating clutch K0. The first electric motor EM1 is arranged coaxially to the third shaft 40 and can be connected to the third shaft by means of at least one switching element E, F.

The hybrid transmission 14 also includes a planetary gear set 50. The planetary gear set is preferably at least partially arranged radially inside a rotor 52 of the first electric machine EM1 and/or at least partially axially over it lapped with the rotor 52. The first electric machine EM1 also includes a stator 54 which is connected to a housing 56 .

The planetary gear set 50 includes a first member 58, a second member 60 and a third member 62. The first member 58 is preferably a sun gear and is preferably connected to the third shaft 40 for rotation therewith. The second member 60 is preferably a ring gear. The third member 62 is preferably a planet carrier. The third member 62 is preferably non-rotatably connected to the rotor 52 .

The second member 60 can be connected to the third shaft 40 or the first member 58 by means of a switching element E. Furthermore, the second link 60 can be connected to the housing 56 by means of a further switching element F.

The shifting elements E and F form a double shifting element that can also establish a neutral position in which the second member 60 of the planetary gear set 50 is connected neither to the housing 56 nor to the first member 58 . In this case, the first electric machine EM1 is decoupled from the output. This neutral position can be set up when driving purely with the internal combustion engine in order to reduce drag losses.

1 FIG. 12 further shows that a parking lock wheel P can be arranged on the third shaft 40 . However, the parking lock gear P, which is part of a parking lock assembly, may alternatively be disposed on the second shaft 22 (or the fourth shaft, described below).

The shifting elements E and F are preferably arranged between the planetary gear set 50 and the coupling gear set 44 in the axial direction. The coupling gear set 44 is preferably axially adjacent to one of the gear wheel sets, in this case axially adjacent to the second shiftable gear wheel set 30.

like it in 4 is shown, an axial offset V is set up between the first shaft 20 and the third shaft 40 via the coupling wheel set 42, more precisely via the pair of wheels between the fixed wheel 44 and the intermediate wheel 48. This allows the use of a first electric machine with a relatively large axial diameter even in difficult installation situations in a front transverse installation space of a motor vehicle.

The hybrid transmission 14 further includes a fourth shaft 64 . The fourth shaft 64 is non-rotatably connected to an output gear 66 which lies in the same radial plane as the output gear 36 and which is connected to an input member of the power distribution device 16 .

The fourth shaft 64 can be connected to the first shaft 20 via a third gear wheel set 68 . The third gear set 68 includes the fixed wheel 26 and a loose wheel 70 which is rotatably mounted on the fourth shaft 64. The loose wheel 70 can be connected to the fourth shaft 64 by means of a shifting element D.

The fourth shaft 64 can also be connected to the first shaft 20 by means of a fourth gear wheel set 72 . The fourth gear set 72 includes a fixed gear fixed to the first shaft 20, in this case the fixed gear 32 of the second gear set. Furthermore, the fourth gear wheel set 72 has an idler wheel 74 which is rotatably supported on the fourth shaft 64 . The loose wheel 74 can be connected to the fourth shaft 64 by means of a shifting element B.

The shifting elements A and C of the first and the second gear wheel set form a double shifting element, by means of which either the shifting element C or the shifting element A is shifted. However, the double switching element can also set up a neutral position in which neither of the two switching elements C and A is switched.

Furthermore, the switching element D and the switching element B form a double switching element, so that either the switching element D is switched or the switching element B is switched or a neutral position is set up.

The dual shifting elements C, A and D, B are arranged in the axial direction between the first and second gear sets 24, 30 and the third and fourth gear sets 68, 72, respectively.

Optionally, the hybrid transmission 14 also includes a second electric machine EM2. The second electric machine EM2 has a motor shaft 76 on which a fixed wheel (pinion) 78 is fixed. The fixed gear 78 meshes with one of the gear sets, in this case with the fixed gear 26 of the first gear set 24. Consequently, the second electric machine EM2 is connected to the first shaft 20.

The first shaft 20 and the optionally provided separating clutch K0 are preferably arranged on a first axis A1, on which a drive shaft or crankshaft 80 of the internal combustion engine 12 is also arranged if it is connected to the hybrid transmission. The second shaft 22 lies on an axis A2, together with the loose wheels 24, 30 and the double shifting element C, A. The fourth shaft 64 lies on a fourth axis A4, together with the loose wheels 70, 74 and the double switching element D, B.

The third shaft 40 lies on a third axis A3. The power divider 16 lies on an axis A5 and the motor shaft 76 lies on an axis A6. The axes A1 to A6 are preferably offset differently from one another or parallel to one another.

The hybrid transmission 14 has a plurality of radial planes. The output with the output gears 36, 66 is located in a first radial plane, seen from an input of the hybrid transmission 14. The first gear wheel set 24 and the third gear wheel set 68 are located in an axially adjoining plane. The double shifting elements are located in an adjoining radial plane C, A or D, B. The second gear wheel set 30 and the fourth gear wheel set 72 lie in an adjoining radial plane. The coupling gear set 42 lies in an adjoining radial plane.

The double shifting element E, F is located in an adjoining radial plane, and the first electrical machine EM1 and the planetary gear set 50 are located in a radial plane located at the outermost axial end.

The second electric machine EM2 is designed to overlap axially with the radial plane in which the second and fourth gear sets 30, 72 are arranged, and/or preferably overlap axially with the radial plane in which the coupling gear set 42 is arranged.

With the hybrid transmission 14, the following gears can be set up, as in the shift table 2 is shown.

The gears that can be set include four forward gears V1 to V4 based on the internal combustion engine. In all of these gears V1 to V4, the separating clutch K0 is closed, if one is present. In the first internal combustion engine gear V1 (start gear), the switching element A is closed. In the second internal combustion engine gear V2, the switching element B is closed. In the third internal combustion engine gear V3, the switching element C is closed. In the fourth internal combustion engine gear V4, the switching element D is closed.

The same switching elements are to be closed when hybrid operation is set up using internal combustion engine 12 and second electrical machine EM2. Furthermore, by means of the same switching elements A to D, a purely electromotive driving operation can be set up by means of the second electric machine EM2, with the separating clutch K0 being opened in this case.

The separating clutch K0 is also opened in order to set up a purely electric driving mode by means of the first electric machine EM1. Two grades E1 and E2 are then possible. In the first electromotive gear E1, the switching element E is closed. In the second electromotive gear E2, the switching element F is closed.

In the case of the electromotive gear stages E1 and E2, both forward and reverse driving can be set up. Furthermore, electromotive power from the first electric machine EM1 can be summed with electromotive power from the second electric machine EM2 if, for example, one of the switching elements A to D is closed.

Serial operation is possible in two gears, as shown in 2 is shown at Ser1 and Ser2. In both cases the clutch K0 is closed and none of the elements A to D are closed. Consequently, the internal combustion engine can be driven to drive the second electric machine EM2, which as a generator generates electric power for charging a battery (not shown). During this operation, the first electric machine EM1 can provide electromotive drive power, with either the switching element E or the switching element F being closed. Electromotive drive power consequently flows from the third shaft 40 via the coupling gear set 42 to the second shaft 22, and from there to the output 17.

The electrical power drawn from the vehicle battery for this driving operation is compensated or “recharged” by the generator operation of the second electric machine EM2. Consequently, purely electromotive driving, especially in a creep mode (i.e. at a particularly slow speed (below a purely combustion engine minimum speed), can be maintained for a relatively long period of time, even if the vehicle battery is relatively small.

In the 3 until 6 further embodiments of hybrid transmissions are shown, which generally correspond to the hybrid transmission 14 in terms of structure and function 1 correspond. Furthermore, in all of the hybrid transmissions 3 until 6 the switching table of 2 applicable. The main differences are explained below.

In 3 a hybrid transmission 14' is shown in which the separating clutch K0 is not present. In this case, the crankshaft 80 and the first shaft 20 are connected to one another in a torque-proof manner. In this variant, which is comparatively inexpensive, purely electric driving operation using the second electric machine EM2 cannot generally be implemented since the internal combustion engine 12 would have to be dragged along.

In 4 A hybrid transmission 14" is shown using an alternative planetary gear set 50". The alternative planetary gear set 50" includes a first member 58" in the form of a ring gear fixedly connected to the third shaft 40 for rotation therewith. The alternative planetary gear set 50" further includes a second member 60" formed by the sun gear of the planetary gear set. The second member 60'' can be connected to the housing 56 by means of the switching element F or to the third member 62'' by means of the switching element E. The third link 62" (planetary carrier) of the alternative planetary gear set 50" is connected in a rotationally fixed manner to the rotor 52 of the first electric machine EM1.

The alternative planetary gear set 50'' can be used in place of the planetary gear set 50 in all embodiments. Likewise, in all embodiments of the planetary gear 50 of 1 be used.

5 shows a hybrid transmission 14''' with an alternative implementation of a coupling wheel set 42'''.

The coupling gear set 42''' includes the fixed gears 44, 46 which are connected to the third shaft 40 and the second shaft 22, respectively, and an intermediate gear 48'''. The intermediate wheel 48''' is not rotatably mounted on the first shaft 20 as in the previous embodiments. Rather, the idler gear 48''' is non-rotatably connected to a fifth shaft 84 which is rotatably mounted on a housing on an axis A7 which differs from the axis A1 of the first shaft 20 and which preferably also does not correspond to any of the others Axes A2 to A6 coincide.

The measure of arranging the intermediate wheel 48''' on a separate fifth shaft 84 achieves greater freedom in arranging the first electric machine EM1 in the installation space.

In 6 Another hybrid transmission 14 ^IV is shown, which also includes an alternative embodiment of a coupling gear set 42 ^IV . The coupling wheel set 42 ^IV contains the fixed wheel 44 in a first radial plane R1, which is fixed to the third shaft 40. Furthermore, the coupling wheel set 40 ^IV includes the fixed wheel 46 which is fixed to the second shaft 22 . The fixed wheel 46 lies in a second axially adjacent radial plane R2.

An intermediate gear 48 ^IV is designed as a double gear, with two gears connected to one another in a torque-proof manner, one of which lies in the first radial plane R1 and the other of which lies in the second radial plane R2. One gear of the double gear meshes with the fixed gear 44. The other gear of the double gear meshes with the fixed gear 46. The intermediate gear 48 ^IV , designed as a double gear, is rotatably mounted on the first shaft 20 in the present case, but can also be mounted on a fifth shaft 84 be stored, similar to the embodiment of 5 .

An additional translation for the first electric machine EM1 can be realized by the double gear 48 ^IV and the additional pair of spur gears realized with it.

Reference List

10

automotive powertrain

12

combustion engine

14

hybrid transmission

17

downforce

16

power distribution device

18L/R

driven wheels

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

40

third wave

42

coupling wheel set

44

fixed wheel

46

fixed wheel

48

intermediate wheel

50

planetary gear set

52

Rotor EM1

54

Stator EM1

56

Housing

58

first link

60

second limb

62

third link

64

fourth wave

66

output gear

68

third gear set

70

loose wheel

72

fourth gear set

74

loose wheel

76

Motor shaft EM2

78

fixed wheel

80

crankshaft

84

fifth wave

K0

disconnect clutch

EM1

first electric machine

V

offset

EM2

second electric machine

P

parking lock wheel

A1-A7

Axles

C

first switching element

A

second switching element

D

third switching element

B

fourth shell element

E

fifth switching element

f

sixth switching element

R1

first radial plane

R2

second radial plane

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102013215114 A1 [0005]

Claims (15)

Hybrid transmission (14) for a motor vehicle drive train (10), with - A first shaft (20) for connection to an internal combustion engine (12); - a second shaft (22) which can be connected to the first shaft (20) via at least one gear wheel set (24; 30) which can be shifted by means of a shifting element (C;A), the second shaft (22) having an output (17) connected is; - a third shaft (40) which can be connected to a first electric machine (EM1) by means of at least one switching element (E;F), the first electric machine (EM1) being arranged coaxially with the third shaft (40) and the third shaft (40) is connected to the second shaft (22) via a coupling gear set (42); wherein the third shaft (40) is arranged offset parallel to the first shaft (20), so that the first electric machine (EM1) is arranged off-axis relative to the first shaft (20). hybrid transmission claim 1 , wherein the coupling wheel set (42) has a fixed wheel (44) fixed to the third shaft (40) and a fixed wheel (46) fixed to the second shaft (22), which mesh directly with one another or are connected via an intermediate wheel (48). are. hybrid transmission claim 2 , wherein the intermediate wheel (48) is rotatably mounted on the first shaft (20). hybrid transmission claim 2 or 3 , wherein the fixed wheel (44) fixed to the third shaft (40) and the fixed wheel (46) fixed to the second shaft (22) are arranged in a common wheel set plane (R1). hybrid transmission claim 3 , wherein the intermediate wheel (48 ^IV ) is a double toothed wheel which meshes with the fixed wheel (44) fixed to the third shaft (40) in a first wheel set plane (R1) and which in an axially offset second wheel set plane (R2) with the fixed gear fixed to the second shaft (46). hybrid transmission claim 2 , wherein the intermediate wheel (48 ^III ) is rotatably mounted on a fifth shaft (84) which is arranged offset in parallel both with respect to the first shaft (20) and with respect to the third shaft (40). Hybrid transmission after one of Claims 1 - 6 , having a fourth shaft (64) which can be connected to the first shaft (20) via at least one gear wheel set (68; 72) which can be shifted by means of a shifting element (D; B), the fourth shaft (64) being connected to the output (17th ) connected is. hybrid transmission claim 7 , wherein the second shaft (22) can be connected to the first shaft (20) via two switchable gear wheel sets (24, 30) and/or wherein the fourth shaft (64) can be connected to the first shaft ( 20) is connectable. hybrid transmission claim 7 or 8th , wherein at least one shiftable gear wheel set (24, 30) for connecting the first shaft (20) to the second shaft (22) and at least one shiftable gear wheel set (68, 72) for connecting the first shaft (20) to the fourth shaft (64 ) share a fixed wheel (26, 30) fixed to the first shaft (20). Hybrid transmission after one of Claims 1 - 9 , The first electric machine (EM1) being connectable to the third shaft (40) via at least one planetary gear set (50). hybrid transmission claim 10 , wherein two (58, 60; 60 ^II , 62 ^II ) of three members of the planetary gear set (50) can be connected to one another and/or one member (60, 60 ^II ) of the planetary gear set (50) can be connected to a housing (56). hybrid transmission claim 10 or 11 , wherein - a first member (58) of the planetary gear set (50) is connected to the third shaft (40), and/or - a second member (60) of the planetary gear set (50) can be connected to a housing (56), and/ or - a third member (62) of the planetary gear set (50) is connected to a rotor (52) of the first electric machine (EM1). Hybrid transmission after one of Claims 10 until 12 , wherein the planetary gear set (50) is arranged at least partially radially within a rotor (52) of the first electric machine (EM1) and/or at least partially overlapping axially with the rotor (52) of the first electric machine (EM1). Hybrid transmission after one of Claims 1 - 13 , A second electric machine (EM2) being connected to the first shaft (20) via a further set of coupling gears (78, 26). Hybrid transmission after one of Claims 1 - 14 , With a separating clutch (K0) for connecting the first shaft (20) to an internal combustion engine (12).

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