DE102019131580A1 - Gear unit with two axially overlapping planetary gear sets and a motor vehicle with such a gear unit - Google Patents

Abstract

The invention relates to a transmission unit (1) for a hybrid motor vehicle (2) in order to transfer torque between an internal combustion engine (3) and / or an electric machine (4) on the one hand and a transmission output (5) on the other hand, or between the internal combustion engine (3) and the electric machine (4), comprising a planetary gear (6) present in the torque flow with at least a first planetary gear set (7) and a second planetary gear set (8), each of the planetary gear sets (7, 8) having a sun gear (9, 10 ), which meshes with at least one planet gear of the corresponding planetary gear set (7, 8), which in turn meshes with a ring gear (11, 12) of the respective planetary gear set (7, 8) Planetary gear carrier (13, 14) one of the two planetary gear sets (7, 8) is passed on to the transmission output (5), the sun gear (10) of one planetary gear set (8) being the ring gear (11) s represents another planetary gear set (7). The invention also relates to a motor vehicle (2) with an internal combustion engine (3) and a transmission unit (1) connected or connectable with its transmission input (33) to a crankshaft (30) of the internal combustion engine (3).

Description

The invention relates to a transmission unit with the features according to the preamble of claim 1. The invention also relates to a motor vehicle with the features according to claim 12.

In particular, the invention relates to a transmission unit for a hybrid motor vehicle to spend torque between on the one hand an internal combustion engine and / or an electrical machine and on the other hand a transmission output or between the internal combustion engine and the electrical machine, comprising a planetary gear present in the torque flow with at least one first Planetary gear set and a second planetary gear set, each of the planetary gear sets comprising a sun gear that meshes with at least one planet gear of the corresponding planetary gear set, which in turn meshes with a ring gear of the respective planetary gear set, an embodiment being such that the torque from a planetary gear carrier of one of the two Planetary gear sets is passed on to the transmission output, the sun gear of one planetary gear set representing the ring gear of the other planetary gear set. The invention also relates to a motor vehicle with an internal combustion engine and a transmission unit connected or connectable with its transmission input to a crankshaft of the internal combustion engine.

In principle, there are already transmission units that couple electrical operating modes at low vehicle speeds (EV modes) and types of combustion (ICE modes) at high vehicle speeds. Dedicated hybrid transmissions (DHT) are also enjoying increasing popularity.

In principle, two different transmission architectures are known from the prior art: For example, P2 parallel hybrids are known that work with an electrical machine located between the internal combustion engine and the transmission, with a separating clutch used to separate the internal combustion engine from the drive train . In this case, operation can take place in pure electric mode, with the electric machine delivering the torque to the transmission and not to the internal combustion engine. The advantage of this hybrid variant is that it is possible to use an existing transmission with an electric motor and a separating clutch to separate the internal combustion engine from the drive train.

On the other hand, serial, serial-parallel or power-split hybrids are known from the prior art, in which a generator driven by the internal combustion engine generates electricity that is used to drive an electric motor that drives the vehicle (series operation). These transmissions are also called power split transmissions. In most arrangements, however, part of the power of the internal combustion engine is transferred mechanically to the wheels (series parallel operation).

From the prior art is that DE 10 2016 221 045 A1 known, which relates to a transmission arrangement for a hybrid vehicle, in which a connection for an internal combustion engine, a connection for an electrical machine and a transmission part of the transmission arrangement are arranged such that they can be coupled to one another. The gear part comprises a simple Ravigneaux planetary gear set with two planetary gears and a single ring gear. The transmission part also has two brakes and two clutches as frictional shifting elements. The publication also discloses a drive arrangement with such a transmission arrangement as well as an internal combustion engine connected to it and a connected electrical machine. Also part of the DE 10 2016 221 045 A1 is a method for operating such a drive arrangement and a hybrid vehicle equipped with such a drive arrangement.

In summary, that seems DE 10 2016 221 045 A1 to disclose a concept with two planetary gear sets and four clutch devices in order to map up to four forward gears for the combustion engine, two gears for the electric motor, one gear of the electrically continuously variable transmission (EVT, Electrically Variable Transmission) and a mode for stationary charging.

Furthermore, from the prior art, the EP 2 146 855 B1 known that a hybrid drive system for a vehicle, comprising a torsional vibration damper arrangement with a primary side to be coupled to a drive shaft of a drive unit for common rotation about an axis of rotation and with a secondary side supported by a damper element arrangement with respect to the primary side for torque transmission and rotatable with respect to the primary side about the axis of rotation, a clutch arrangement with an input area, which is coupled or to be coupled to the secondary side for common rotation about the axis of rotation (A), and with an output area that can be coupled by frictional engagement with the input area for rotation, an electric machine, with a stator arrangement of the electric machine on a stationary assembly is carried or to be carried and a rotor assembly of the electric machine is coupled to the output region of the clutch assembly for common rotation about the axis of rotation, the input region of the clutch assembly with the secondary side of the Torsional vibration damper arrangement is connected or connectable via a Hirth serration and / or a plug connection with relative axial displacement, wherein the coupling arrangement comprises a housing and that a coupling-side part of the Hirth serration or the plug connection is formed on a housing hub area.

In addition, from the publication WO 2016/075336 a torque transmission device known, comprising: an input shaft, a first planetary gear set, which has as first gear elements at least one first planetary gear for meshing with a first sun gear and with a first ring gear of the first planetary gear set and a planet carrier for rotatably supporting at least one of the first planetary gears, a second Planetary gear set, which has as second gear elements at least one second planetary gear for meshing with a second sun gear and with a second ring gear of the second planetary gear set and for meshing with one of the first planetary gears, at least one of the second planetary gears being rotatably supported by the planet carrier, a first braking device, designed for releasably securing the second sun gear, and a second braking device designed for releasably securing at least one of the first transmission elements, a first separating clutch, designed ltet for rotary connection of the input shaft with at least one of the first transmission elements, and a second separating clutch, configured for rotary connection of the input shaft with another of the first transmission elements or with one of the second transmission elements, an output shaft which is rotationally connected with another of the second transmission elements, an electric machine , which is rotatably connected to one of the gear elements.

In addition, the DE 10 2018 130 498 A1 referenced, which discloses a gear unit for a hybrid motor vehicle, with a planetary gear, wherein the planetary gear is equipped with a first planetary gear set and a second planetary gear set, an electrical machine coupled to a component of the planetary gear and several, each forming a brake or a clutch and Shifting devices adjustable between an activated position and a deactivated position, the shifting devices being used to shift different gear ratios between an input that can be coupled to an internal combustion engine and an output and / or between the electrical machine and the output, with no more than four switching devices for conversion at least two different gear ratios in a drive state of the internal combustion engine, at least one gear ratio in a drive state of the electrical machine and at least one Gear ratio in a recuperation state of the electrical machine are available through their activated and deactivated positions.

The disadvantage of the known prior art is that when changing to high electrical machine outputs it is very difficult to integrate the respective machine into the transmission, since the overall size of the drive train increases disproportionately. The space restrictions when arranging the machine between the motor and the gearbox require a switch to permanent magnet machines, which are very complex to manufacture. On the other hand, simulations show that as the performance of the electrical system increases compared to the combustion engine, fewer gear ratios are required to achieve the same vehicle performance. In other words, the prior art discloses gear units which are very cumbersome and complex in terms of performance.

The disadvantages are, among other things, the additional weight and the costs that arise from the use of two electric machines, while only one is actually used to drive the vehicle. If, for example, a 60 kW electric motor is required to drive the vehicle in series operation, a 60 kW generator is also required. So twice the drive power has to be taken on board. The known concepts are also disadvantageous because the electric motor each requires an additional gear ratio so that the two electric gears can be adapted to the high speeds. This additional gear ratio leads to a loss of efficiency when driving purely on electric power.

It is the object of the present invention to provide a gear unit that is more compact, more efficient, easier to manufacture and, particularly in the axial direction, that optimizes installation space. The disadvantages known from the prior art should also be eliminated or at least reduced.

In the case of a generic transmission unit comprising a first planet carrier, this object is achieved according to the invention in that the sun gear of one planetary gear set represents the ring gear of the other planetary gear set.

In such an embodiment according to the invention, the number of switching devices present is advantageously reduced, although different gear ratios in a drive state of the internal combustion engine and of the electrical machine are sufficient Enable power conversion. In a particularly advantageous manner, no separating clutch is required for the internal combustion engine (ICE separating clutch), since the first and second clutches, i.e. the clutch of the first planetary gear set and the clutch of the second planetary gear set, already fulfill this function. Overall, a gear unit is thus provided which is overall more efficient, more compact and easier to manufacture than the gear units known from the prior art.

The newly created transmission has the characteristics that it has 2 to 4 gears, which can be used for driving the vehicle forward by the internal combustion engine. Furthermore, it has 1 to 2 gears for driving the vehicle in forward travel by the electric motor and at least one reverse gear in electric mode. This is in line with the trend to set 3 to 6 gears for driving the vehicle forward by the internal combustion engine and 1 to 3 gears for driving the vehicle in forward driving by the electric motor.

The number of gears connected to the electric motor is tailored to the needs of a hybrid vehicle, which means that no unnecessary equipment is required to achieve 6 or 8 gears. The 2 electrical gears make it possible to adapt the operation of the electrical machine in its speed and torque ranges where it is most efficient. As a result, a high wheel torque is also achieved for vehicle start-up, while the engine speeds are reduced for higher vehicle speeds.

• - nicht mehr als vier Kupplungen umfasst,
• - mindestens zwei elektrische Gänge umfasst, die es ermöglichen, den Elektromotor ohne zusätzliche Übersetzung für einen optimalen Wirkungsgrad zu verwenden,
• - einen Electrically-Variable-Transmission-Modus (EVT-Modus) aufweist, der es ermöglicht, den Verbrennungsmotor für den Fahrzeugstart ohne Startkupplung zu verwenden, und feste Übersetzungen bereitstellt, die zusammen mindestens vier gleichbleibende Übersetzungen für den Verbrennungsmotor darstellen.
• - kohärente Möglichkeiten vereinfachter Versionen durch Entfernen einer oder mehrerer Kupplungen, um Varianten mit weniger Funktionen, aber auch kostengünstiger zu erhalten.

In other words, a solution of the transmission according to the invention is thus presented, which

• - includes no more than four couplings,
• - includes at least two electrical gears that allow the electric motor to be used without additional transmission for optimum efficiency,
• - Has an Electrically Variable Transmission Mode (EVT mode), which makes it possible to use the internal combustion engine for starting the vehicle without a starter clutch, and provides fixed ratios that together represent at least four constant ratios for the internal combustion engine.
• - coherent possibilities of simplified versions by removing one or more couplings in order to obtain variants with fewer functions but also more cost-effectively.

• - zwei Planetenradsätze,
• - vier Schaltelemente (zwei Bremsen und zwei Kupplungen) und
• - eine Elektromaschine.

The idea according to the invention is therefore to propose a dedicated hybrid transmission (DHT concept) which comprises at least the following elements:

• - two planetary gear sets,
• - four switching elements (two brakes and two clutches) and
• - an electric machine.

• - Ein Electrical-Vehicle-Transmission-Modus (EVT-Modus)
• - vier Vorwärtsgänge im Verbrennerbetrieb (ICE-Vorwärts-Gänge)
• - zwei elektrische Gänge, die vorwärts und rückwärts verwendet werden können.
• - Laden im Stillstand und die
• - Möglichkeit des Boostens und der Rekuperation in den ICE-Gängen.

With the presented elements of the dedicated hybrid transmission, the following functions are fulfilled:

• - An electrical vehicle transmission mode (EVT mode)
• - four forward gears in combustion mode (ICE forward gears)
• - two electric gears that can be used forwards and backwards.
• - Loading at a standstill and the
• - Possibility of boosting and recuperation in the ICE aisles.

The electric machine can be arranged coaxially or axially parallel to the internal combustion engine, for example with a chain or spur gear. It should also be pointed out that consistent options for simplified designs can be made available by removing one or more couplings.

A planetary gear set is also referred to as a partial planetary gear, each partial planetary gear comprising a sun gear, a planetary gear carrier with rotating planetary gears and a ring gear. The planetary gear carriers of the first and second planetary gear sets are, for example, rigid, one-piece or one-material connected to one another in order to ensure a non-positive connection.

Advantageous embodiments are claimed in the subclaims and are explained in more detail below.

In a further embodiment, it is advantageous that the two planetary gear sets each have a planetary gear carrier that are connected to one another. As a result, the transmission output can advantageously be controlled skilfully by the first and / or the second planetary gear set. By activating or deactivating the first, second or third switching device (i.e. the first brake, the second brake, the first clutch and the second clutch), the individual planetary gear sets can be controlled directly, whereby the torque flow from the electrical machine and / or the Combustion engine can be variably activated on the transmission output.

Furthermore, it is advantageous if the first planetary gear set is arranged radially on the inside of the second planetary gear set and / or both planetary gear sets are arranged so that they overlap at least partially axially. By arranging the two planetary gear sets in one plane, the axial design can be saved in an advantageous manner, as a result of which the gear unit is designed to be more compact and space-saving overall.

It has proven itself when the sun gear of the second planetary gear set is permanently connected to the electrical machine in a rotationally fixed manner.

Another embodiment is characterized in that a second switching device is arranged between the internal combustion engine and the ring gear of the first planetary gear set.

If a third switching device is arranged between the internal combustion engine and one of the ring gears of the second planetary gear set, this results in a particularly robust embodiment.

It is particularly preferred if the second switching device is designed as an overrunning clutch.

If the transmission unit is further developed in that a first switching device is present for fixing the sun gear of the first planetary gear set, additional advantages arise.

It is preferred if the sun gear of the first planetary gear set is fixed in a rotationally fixed manner to an area fixed to the vehicle frame and / or a further switching device is available for fixing the ring gear of the second planetary gear set and / or the electrical machine is arranged axially parallel or coaxially to a crankshaft of the internal combustion engine.

It has proven useful if a first switching device is arranged at least between a housing of the transmission unit and the first sun gear of the first planetary gear set, so that the sun gear of the first planetary gear set can be locked. As a result, the housing can advantageously be decoupled or coupled to the sun gear of the first planetary gear set in an advantageous manner. In the activated position of the first switching device, i.e. the brake B1 , the housing is rotationally connected to the sun gear of the first planetary gear set and in the deactivated position of the brake B1 the housing is decoupled from the sun gear of the first planetary gear set.

In a further preferred embodiment, a second switching device is provided between the internal combustion engine and the electrical machine, which transmits the torque in the switched state to a torque transmission component which is designed to transmit the torque to the ring gear of the second planetary gear set. In the activated position of the first switchable clutch K1 the rotation of the torque transmission component is permanently connected to the electrical machine and in the deactivated position of the first switchable brake the rotation of the torque transmission component is thus decoupled from the electrical machine. However, the torque transmission component is always connected to the internal combustion engine in a rotationally fixed manner. In an embodiment not shown, however, a switchable rotary decoupling can also be provided between the torque transmission component and the internal combustion engine, which enables an additional degree of freedom.

It has also proven useful that a third switching device is provided between the torque transmission component, the housing of the transmission unit and the ring gear of the second planetary gear set. The third switching device advantageously enables the internal combustion engine, the electrical machine or the housing to be coupled or decoupled from the ring gear of the second planetary gear set. Overall, the torque can thereby be variably transmitted from the two drive machines to the ring gear of the second planetary gear set.

A further preferred embodiment consists in that the third switching device comprises at least one braking device which is provided for controlling the ring gear of the second planetary gear set. The braking device B1 is intended to fix the ring gear of the second planetary gear set on the housing. In a deactivated position of the braking device B2 the ring gear of the second planetary gear set can thus be freely rotated relative to the housing, whereas in an activated position of the braking device B2 the ring gear of the second planetary gear set is fixed to the housing.

In a further preferred embodiment, the third switching device additionally comprises at least one clutch device that is used to transmit torque between the torque transmission component and the ring gear of the first planetary gear set is provided. This switchable clutch device is provided for fixing the ring gear on the torque transmission component, the clutch in its activated position coupling the torque transmission component to the ring gear of the second planetary gear set and in its deactivated position allowing a relative rotational movement between the torque transmission component and the ring gear of the second planetary gear set.

In a further embodiment, a torque output component permanently coupled to the two planetary gear carriers is rotatably mounted on the housing. The torque output component is preferably supported on the housing in order to be able to transmit a sufficiently high torque with a space-saving structural design. The rotary bearing between the component and the housing can be brought about, for example, by a roller bearing or a sliding bearing, the component being in particular an output shaft which derives the converted torque from the gear unit. The component is preferably supported on the housing in order to be able to transmit a sufficiently high torque with a space-saving structural design. The rotary bearing between the component and the housing can be brought about, for example, by a roller bearing or a sliding bearing.

The torque output component can preferably be designed as a spur gear, which is preferably helical or straight-toothed, as a result of which sufficient torque can be transmitted to the transmission output with correspondingly smooth running. With the helical gearing, smoother running or less noise is achieved, since each gear pair runs with a continuous transition into and out of mesh and thus the transmission of the torque proceeds more evenly. In the case of the helical toothing, the tooth root and the dimple load-bearing capacity are advantageously greater with the same number of teeth. In the case of straight-toothed spur gears, the manufacturing costs are advantageously lower.

The torque output component is preferably supported on the housing of the gear unit via a support bearing. The torque output component is thus advantageously both radially supported and axially supported, it being possible to use plain bearings or roller bearings to support the torque output component. As a result, a compact or space-saving design of the gear unit can be represented in a particularly advantageous manner.

The invention also relates to a motor vehicle with an internal combustion engine, such as an Otto or diesel engine, and a transmission unit connected or connectable with its input to an output shaft of the internal combustion engine according to at least one of the embodiments described above.

• 1 eine schematische Ansicht einer Getriebeeinheit nach einem ersten Ausführungsbeispiel;
• 2 eine tabellarische Übersicht der mit der Getriebeeinheit nach dem ersten Ausführungsbeispiel umsetzbaren Betriebsmodi;
• 3 eine schematische Ansicht einer Getriebeeinheit nach einem zweiten Ausführungsbeispiel;
• 4 eine tabellarische Übersicht der mit der Getriebeeinheit nach dem zweiten Ausführungsbeispiel umsetzbaren Betriebsmodi;
• 5 eine schematische Ansicht einer Getriebeeinheit nach einem dritten Ausführungsbeispiel;
• 6 eine tabellarische Übersicht der mit der Getriebeeinheit nach dem dritten Ausführungsbeispiel umsetzbaren Betriebsmodi;
• 7 eine schematische Ansicht einer Getriebeeinheit nach einem vierten Ausführungsbeispiel;
• 8 eine tabellarische Übersicht der mit der Getriebeeinheit nach dem vierten Ausführungsbeispiel umsetzbaren Betriebsmodi;
• 9 eine schematische Ansicht einer Getriebeeinheit nach einer Modifikation des vierten Ausführungsbeispiels,
• 10 eine tabellarische Übersicht der mit der Getriebeeinheit nach der Modifikation des vierten Ausführungsbeispiels umsetzbaren Betriebsmodi und
• 11 eine schematische Darstellung eines Kraftfahrzeuges samt der erfindungsgemäßen Getriebeeinheit, wobei die Getriebeeinheit an der Vorderachse des Kraftfahrzeuges sowie in einer Queranordnung mit dem Verbrennungsmotor eingesetzt ist.

The invention is explained in more detail below with the aid of a drawing. Show it:

• 1 a schematic view of a transmission unit according to a first embodiment;
• 2 a tabular overview of the operating modes that can be implemented with the transmission unit according to the first exemplary embodiment;
• 3rd a schematic view of a transmission unit according to a second embodiment;
• 4th a tabular overview of the operating modes that can be implemented with the transmission unit according to the second exemplary embodiment;
• 5 a schematic view of a transmission unit according to a third embodiment;
• 6th a tabular overview of the operating modes that can be implemented with the transmission unit according to the third exemplary embodiment;
• 7th a schematic view of a transmission unit according to a fourth embodiment;
• 8th a tabular overview of the operating modes that can be implemented with the transmission unit according to the fourth exemplary embodiment;
• 9 a schematic view of a transmission unit according to a modification of the fourth embodiment,
• 10 a tabular overview of the operating modes that can be implemented with the transmission unit according to the modification of the fourth exemplary embodiment and
• 11 a schematic representation of a motor vehicle including the transmission unit according to the invention, the transmission unit being used on the front axle of the motor vehicle and in a transverse arrangement with the internal combustion engine.

The figures are only of a schematic nature and are only used for understanding the invention. The same elements are provided with the same reference symbols. In principle, the features of the various exemplary embodiments can be freely combined with one another.

1 shows schematically a gear unit 1 for a hybrid motor vehicle 2 , hereinafter also simply as a hybrid transmission 1 referred to, according to a first embodiment. In order to achieve torque between on the one hand an internal combustion engine 3rd and / or an electrical machine 4th and on the other hand a transmission output designed as an output shaft 5 to spend or between the internal combustion engine 3rd and the electric machine 4th to spend is in the hybrid transmission 1 a Planetary gear 6th with two actively connected planetary gear sets 7th , 8th arranged.

According to the design as a hybrid transmission, the transmission unit 1 a two-stage planetary gear 6th as well as an electrical machine that is operatively connected to this planetary gear 4th on. The basic structure of the gear unit 1 is particularly good at 1 to recognize. Accordingly, the planetary gear 6th a first planetary gear set 7th on, which is the first gear stage of the planetary gear 7th forms, and a second planetary gear set 8th on, which is the second stage of the planetary gear 6th forms, on.

The first planetary gear set 7th forms the first gear stage of the planetary gear 6th and the second planetary gear set 8th forms the second stage of the planetary gear 6th . The first planetary gear set 7th has a first sun gear 9 and a first ring gear 11 on, the second planetary gear set 8th a second sun gear 10 , and a second ring gear 12th having, with all said wheels being operatively connected to one another. The first planetary gear set 7th additionally comprises a first planet carrier 13th and the second planetary gear set 8th comprises a second planetary carrier 14th , wherein the respective planet carrier each have rotatably mounted planet gears. Both planetary gear carriers 13, 14 are each directly non-rotatable with the torque output component 36 and thus with the transmission output 5 the gear unit 1 connected. The planet carriers 13, 14 are thus also coupled to one another.

The torque output component 36 is on the housing 34 pivoted. The torque output component 36 can be designed as a spur gear. The spur gear can be helical or straight.

The first ring gear 11 of the first planetary gear set 7th sets the sun gear at the same time 10 of the second planetary gear set 8th consequently are the first planetary gear set 7th and the second planetary gear set 8th non-rotatably with each other via the ring gear 11 coupled, which is the sun gear 10 corresponds to.

The electric machine 4th typically has a stator and a rotor mounted rotatably relative to the stator, the rotor being rotatably received within the stator. The rotor is typically rotationally fixed on a drive shaft of the electrical machine 4th attached, the drive shaft with its axis of rotation via a torque transmission component 37 to the first switching device 20th , K1 and to the second sun gear 10 , which is also the first ring gear 11 represents, is connected. Hence the electric machine 4th with the first planetary gear set 7th and the second planetary gear set 8th effectively connected. The electrical machine is in further versions 4th with their stator / rotor unit also not necessarily coaxial with the central axis of rotation 38 arranged, but for example with their torque transmission component 37 coaxial to the central axis of rotation 38 arranged. The drive shaft of the electrical machine 4th is also via a first switching device 20th , K1 with the internal combustion engine 3rd rotationally coupled.

A torque transmission component can be used on the input side 32 a transmission input 33 of the hybrid transmission 1 with an output shaft / crankshaft 30th of the internal combustion engine 3rd coupled or connected to this, so that in operation of the internal combustion engine 3rd generated torque via the crankshaft 30th in the hybrid transmission 1 is initiated. Between the crankshaft 30th and the torque transfer component 32 can also, as in 1 shown, a torsional vibration damper 31 to get integrated. The torsional vibration damper 31 can, for example, be designed as a dual-mass flywheel or a hydrodynamic damper.

As in 1 shown are in the hybrid transmission 1 according to the first embodiment, four switching devices 20th , 21 , 22nd , 23 integrated to the individual operating modes / gear ratios / gears as they are from their deactivated (open) and activated (closed) positions 2 emerge, implement. The second switching device 21 , K2 and the fourth switching device 23 , B2 to a combined switching device 25th be combined. With this configuration there would then be the three switching devices 20th , 22nd and 25th .

The first switching device 20th , K1 is implemented as a coupling. The first switching device 20th , K1 is between the gearbox input 33 and the second sun gear 10 , which is also the first ring gear 11 represents, acting used. By forming the first switching device 20th , K1 as a clutch, is the transmission input 33 , and thus in the operation of the motor vehicle 2 the crankshaft 30th of the internal combustion engine 3rd , in an activated position of the switching device 20th , K1 rotatably with the second sun gear 10 and the first ring gear 11 coupled and in a deactivated position of the switching device 20th , K1 from the second sun gear 10 and the first ring gear 11 rotationally decoupled, ie freely rotatable relative to this. The activated position of the first switching device 20th , K1 is thus a closed clutch position, whereas the deactivated position is an open clutch position. In addition, the electrical machine is according to the invention 4th between the first switching device 20th , K1 and the second sun gear 10 via a torque transmission component 37 effectively involved, that is, among other things, that when the first switching device is activated 20th , K1 a direct connection between the internal combustion engine 3rd and the electric machine 4th is present. The first switching device 20th , K1 also conducts torque with a torque transmission component 32 connected to the second switching device 21 , K2 or to the combined switching device 25th is coupled.

A second switching device 21 , K2 is also implemented as a coupling. The second switching device 21 , K2 is between the gearbox input 33 and the second ring gear 12th of the second planetary gear set 8th used effectively. Accordingly, the transmission input is 33 , and thus in the operation of the motor vehicle 2 the crankshaft 30th of the internal combustion engine 3rd , in the activated position of the second switching device 21 , K2 non-rotatably with the second ring gear 12th connected and in a deactivated position of the second switching device 21 , K2 from the second ring gear 12th rotationally decoupled, ie arranged freely rotatable relative to this. This is the activated position of the second switching device 21 , K2 a closed clutch position and the deactivated position of the second switching device 21 , K2 an open clutch position.

A third switching device 22nd , B1 is implemented as a brake and with a housing 34 the gear unit 1 coupled. The case 34 provides an area fixed to the vehicle frame 35 The third switching device 22nd , B1 is the brake that works with the first sun gear 9 cooperates. The third switching device 22nd , B1 is thus capable of the first sun gear 9 compared to an area fixed to the vehicle frame 35 of the motor vehicle 2 to slow down / to hold. In an activated position of the third switching device 22nd , B1 the third switching device acts 22nd , B1 so on the first sun gear 9 that this is in its rotation relative to the area fixed to the vehicle frame 35 of the motor vehicle 2 are blocked. In a deactivated position of the third switching device 22nd , B1 however, is the third switching device 22nd , B1 arranged to allow free rotation of the first sun gear 9 relative to the area 35 enables / allows.

A fourth switching device 23 , B2 is implemented as a brake and together with the second switching device 21 , K2 as a combined switching device 25th realized. The fourth switching device 23 , B2 is with the case 34 the gear unit 1 coupled. The case 34 provides an area fixed to the vehicle frame 35 The fourth switching device 23 , B2 acts essentially in a similar way to the third switching device 22nd , B1 . In particular, is the fourth switching device 23 , B2 but with the second ring gear 12th of the second planetary gear set 8th connected so that this is in an activated position of the fourth switching device 23 , B2 on the area fixed to the vehicle frame 35 is held and in a deactivated position of the fourth switching device 23 , B2 can move relative to this. The fourth switching device 23 , B2 acts indirectly on the second planet carrier 14th .

The first planetary gear set 7th comprises a first planet carrier 13th the non-rotatably with the second ring gear 12th of the second planetary gear set 8th is coupled.

In the following description of each in 2 operating modes shown, it is clear that the second and fourth switching device 21 , K2 or. 23 , B2 not both are activated at the same time, since this is the drive torque of the internal combustion engine 3rd directly via the second switching device 21 , K2 and the fourth switching device 23 , B2 in the area fixed to the vehicle frame 35 would be directed. How out 2 can be seen with the hybrid transmission 1 according to the first embodiment by switching the four switching devices 20th , 21 , 22nd , 23 ten operating modes can be implemented. In 2 in the first column the different operating modes stationary charging, EM1, EM2, ICE1, ICE2, ICE3, ICE4, EVT, EM-R1 and EM-R2 are listed. In the stationary charging operating mode, the electric machine can 4th when the vehicle is stationary 2 directly with the combustion engine 3rd coupled and driven by this to generate electrical power. EM1 and EM2 describe two operating modes in which the vehicle 2 only by the electric machine 4th is driven, and ICE1, ICE2, ICE3 and ICE4 four operating modes with different gear ratios i in which the vehicle 2 only by the internal combustion engine 3rd is driven. The two operating modes EM-R1 and EM-R2 represent two purely electric reverse gears and the operating mode EVT allows recuperation when the vehicle is moving 2 . In the second column are those in the different operating modes through the hybrid transmission 1 converted gear ratios i, whereas the third column lists whether the internal combustion engine ICE 3rd is connected or disconnected or operated or not operated. The fourth column shows the operating modes of the electrical machine 4th . It is between a generator mode Gen, in which the electric machine 4th is driven and thus generates electrical power, and a motor mode Mot, in which the electrical machine 4th is operated as a motor and generates torque. The remaining columns each show the positions of the individual switching devices 20th , 21 , 22nd , 23 , where an empty field represents the deactivated position and an x stands for the activated position.

By activating the first switching device 20th , K1 as well as by deactivating the second switching device 21 , K2 as well as by deactivation the third and fourth switching devices 22nd , 23 , B1 , B2 the electric machine is operated in generator mode and the internal combustion engine 3rd charges the battery. In the activated state of the fourth switching device 23 , B2 and in the deactivated state of the first and second switching device 20th , 21 , K1 , K2 and the third switching device 22nd , B1 becomes the electric machine 4th operated in motor mode, the internal combustion engine 3rd is deactivated. By activating the third switching device 22nd , B1 and deactivation of the first and second switching devices 20th , 21 , K1 , K2 and deactivation of the fourth switching device 23 , B2 the electric machine is operated in a smaller gear ratio of 1.46, with the internal combustion engine 3rd is deactivated. in the 1 . up to 4th gear of the internal combustion engine 3rd transmission ratios of 2.65, 1.46, 1.00 and 0.73 are controlled or can be controlled, whereby in the table the 2 it is listed which clutches or brakes must be activated in each case in order to effect the respective gear ratios. In the electric variable transmission gear (EVT gear), a gear ratio of 1.61 is achieved, with only the second shifting device 21 , K2 is in the activated state. Furthermore, reverse gears are provided by the electric machine 4th can be brought about when the internal combustion engine 3rd is deactivated and the third switching device 22nd , B1 or the fourth switching device 23 , B2 is activated.

The hybrid transmission was mentioned above 1 according to the first embodiment with exactly four switching devices 20th , 21 , 22nd , 23 explained. Further exemplary embodiments of the hybrid transmission are now intended below 1 to get presented. Only the differences to the hybrid transmission are mentioned here 1 in accordance with the first embodiment, and a complete description of the structure will be omitted.

In 3rd is the hybrid transmission 1 executed according to a second embodiment. This is the fourth switching device 23 , B2 omitted, with a direct connection between the housing 34 and the ring gear 12th is therefore not controllable. The further structure of the 3rd shown gear unit 1 is identical to that in the 1 shown gear unit 1 .

4th shows the operating modes that can be used with the hybrid transmission 1 can be implemented according to the second embodiment. The number of operating modes is reduced from ten to seven in comparison with the first exemplary embodiment. In particular, the second electric forward and the second electric reverse gear EM2, EM-R2 and the fourth operating mode for exclusive drive by the internal combustion engine are omitted 3rd ICE4. By activating the first switching device 20th , K1 the stationary charging mode can be brought about and in the drive state of the electric machine 4th a gear ratio of 1.46 or, in the three different internal combustion engine drive states, gear ratios of 1.46, 1.00 and 0.73 can be achieved, the EVT gear causing a gear ratio of 1.61 and the reverse gear of the electric machine being able to produce a gear ratio of 1.46.

5 shows a third embodiment, which is a further simplification of the hybrid transmission 1 according to the second embodiment. In addition to the removal of the fourth switching device 23 , B2 becomes the third switching device 22nd , B1 removed, the third switching direction 22nd , B1 by means of a non-rotatable connection with the housing 34 is replaced. So is the first sun gear 9 permanently on the area fixed to the vehicle frame 35 tied up. That is, a rotation of the first sun gear 9 is permanently prevented.

As in 6th the number of operational modes that can be implemented is further reduced to four. In comparison with the second exemplary embodiment, the stationary charging, ICE3 and EVT operating modes, ie the one with the hybrid transmission, are also omitted 1 vehicle equipped according to the third exemplary embodiment 2 can drive purely electrically forwards (EM1) or backwards (EM-R1) with only one gear ratio and has only two gears for the drive by the combustion engine 3rd .

A hybrid transmission 1 according to a fourth embodiment is in 7th pictured. Compared to the in 1 hybrid transmission shown 1 according to the first embodiment, the first switching device is here 20th , K1 omitted. The second sun gear 10 is thus permanently non-rotatable via the torque transmission component 37 with the electric machine 4th coupled and is no longer with the internal combustion engine 3rd connectable.

With this configuration, the in 8th implement the operating modes shown. In comparison with the first exemplary embodiment, three gears ICE2, ICE3 and ICE4 are omitted for the exclusive drive by the internal combustion engine 3rd .

In 9 and 10 is a modification of the hybrid transmission 1 mapped according to the fourth exemplary embodiment and the operating modes that can be implemented with it. The second switching device, designed as a switchable clutch, is used 21 , K2 as a one-way clutch 24 , FW2 executed. In comparison with the fourth exemplary embodiment, this eliminates the possibility of using the vehicle 2 to reverse drive purely electrically with two different gear ratios.

In the fifth column of 10 are the switching positions of the overrunning clutch 24 , FW2 listed for the operational modes that can be implemented. L corresponds to a closed switch position locked and UL corresponds to an open switch position unlocked.

The 11 shows a schematic representation of a motor vehicle 2 , comprising first and second drive wheels 40 and a gear unit 1 attached to the internal combustion engine 3rd is flanged. It can be seen here that the gear unit 1 with the drive train on a front axle of the motor vehicle 2 is used effectively.

In other words, according to the invention, a DHT concept (dedicated hybrid transmission (gear unit 1 )) proposed with the following elements: two planetary gear sets 7th , 8th ; four switching elements 20th , 21 , 22nd , 23 (two brakes and two clutches); and an electric machine 4th . The following functions are fulfilled with the elements of the proposed DHT concept: four ICE gears (forward gears / gears for combustion engine 3rd ); two EM gears (gears for electrical machine 4th ); two EM reverse gears; Charging at a standstill; Boost and recuperation possible in all gears; serial operation with an additional drive axle: first drive axle with combustion engine 3rd , the electric machine 4th drives, the electric machine 4th a battery charges and / or sends power to the e-axle, and the second drive axle, which is the vehicle 2 drives. No ICE disconnect clutch is required because K1 and K2 fulfill this function. The electric machine 4th can be arranged coaxially or axially parallel (with a chain or spur gear).

Furthermore, the DHT concept (Dedicated Hybrid Transmission) includes two planetary gear sets, which can advantageously be staggered. This means that the sun gear of the second set forms a single part with the ring gear of the first set and that both planetary gear sets are in a plan d. H. located in one plane, which reduces the axial installation space in an advantageous manner. In addition, four switching elements, i.e. two brakes and two clutches, are provided, and an electric machine is also provided.

List of reference symbols

1

Gear unit

2

Motor vehicle

3

Internal combustion engine

4th

electric machine

5

Transmission output

6th

Planetary gear

7th

first planetary gear set

8th

second planetary gear set

9

first sun gear

10

second sun gear

11

first ring gear

12th

second ring gear

13th

first planet carrier

14th

second planet carrier

20, K1

first switching device

21, K2

second switching device

22, B1

third switching device

23, B2

fourth switching device

24, FW2

One-way clutch

25th

combined switching device

30th

crankshaft

31

Torsional vibration damper

32

Torque transmission component

33

Transmission input

34

casing

35

area fixed to the vehicle frame

36

Torque output component

37

Torque transmission component

38

central axis of rotation

40

drive wheel

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed 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 102016221045 A1 [0006, 0007]
• EP 2146855 B1 [0008]
• WO 2016/075336 [0009]
• DE 102018130498 A1 [0010]

Claims (12)

Gear unit (1) for a hybrid motor vehicle (2) to pass torque between an internal combustion engine (3) and / or an electrical machine (4) on the one hand and a gear output (5) on the other hand, or between the internal combustion engine (3) and the electrical machine (4), comprising a planetary gear (6) present in the torque flow with at least a first planetary gear set (7) and a second planetary gear set (8), each of the planetary gear sets (7, 8) comprising a sun gear (9, 10) which meshes with at least one planetary gear of the corresponding planetary gear set (7, 8), which in turn meshes with a ring gear (11, 12) of the respective planetary gear set (7, 8), the configuration being such that the torque from a planetary gear carrier (13, 14) one of the two planetary gear sets (7, 8) is passed on to the transmission output (5), characterized in that the sun gear (10) of one planetary gear set (8) is the ring gear (11) of the represents the planetary gear set (7). Gear unit (1) Claim 1 , characterized in that the two planetary gear sets (7, 8) each have a planetary gear carrier (13, 14) which are connected to one another. Gear unit (1) Claim 1 or 2 , characterized in that the first planetary gear set (7) is arranged radially on the inside of the second planetary gear set (8) and / or that both planetary gear sets (7, 8) are arranged at least partially axially overlapping. Gear unit (1) according to one of the Claims 1 to 3rd , characterized in that the sun gear (10) of the second planetary gear set (8) is permanently non-rotatably connected to the electrical machine (4). Gear unit (1) according to one of the Claims 1 to 4th , characterized in that a first switching device (20; K1) is arranged between the internal combustion engine (3) and the ring gear (11) of the first planetary gear set (7). Gear unit (1) according to one of the Claims 1 to 5 , characterized in that a second switching device (21; K2) is arranged between the internal combustion engine (3) and the ring gear (12) of the second planetary gear set (8). Gear unit (1) Claim 6 , characterized in that the second switching device (21; K2) is designed as an overrunning clutch (FW2). Gear unit (1) according to one of the Claims 1 to 7th , characterized in that a third switching device (22; B1) for fixing the sun gear (9) of the first planetary gear set (7) is present. Gear unit (1) according to one of the Claims 1 to 7th , characterized in that the sun gear (9) of the first planetary gear set (7) is fixed in a rotationally fixed manner on an area (35) fixed to the vehicle frame. Gear unit (1) according to one of the Claims 1 to 8th , characterized in that a fourth switching device (23, B2) for fixing the ring gear (12) of the second planetary gear set (8) is present. Gear unit (1) Claim 1 , characterized in that the electrical machine (4) is arranged axially parallel or coaxially to a crankshaft (30) of the internal combustion engine (3). Motor vehicle (2) with an internal combustion engine (3) and a transmission unit (1) connected or connectable to a crankshaft (30) of the internal combustion engine (3) with its transmission input (33), which according to one of the Claims 1 to 11 is trained.

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