WO2016034259A2

WO2016034259A2 - Drive train for a vehicle, particularly a hybrid vehicle

Info

Publication number: WO2016034259A2
Application number: PCT/EP2015/001460
Authority: WO
Inventors: Randy Gene Doolittle; Johannes Schweers
Original assignee: Daimler Ag
Priority date: 2014-09-06
Filing date: 2015-07-16
Publication date: 2016-03-10
Also published as: DE102014013195A1; WO2016034259A3

Abstract

The invention relates to a drive train (10) for a vehicle, in particular a hybrid vehicle, comprising a double clutch transmission (12) having two sub-transmissions (14, 16), and at least one electrical machine (46) which is arranged laterally and axially parallel in relation to the sub-transmissions (14, 16) and which can be operated in an engine mode and a generator mode. According to the invention, the electrical machine (46) is coupled to one of the sub-transmissions (14, 16) and has at least a first connection (72), by which the electrical machine (46) can be electrically connected to a first power network (68) of the vehicle, which can be operated with a first electrical voltage, and at least a second connection (74), by which the electrical machine (46) can be electrically connected to a second power network (70) of the vehicle, which can be operated with a second electrical voltage that is higher than the first electrical voltage.

Description

Daimler AG

Drive train for a vehicle, in particular a hybrid vehicle

The invention relates to a drive train for a vehicle, in particular a

Hybrid vehicle, according to the preamble of claim 1.

Such a drive train for a vehicle, in particular a hybrid vehicle, is known from DE102004050757A1. The powertrain includes a dual-clutch transmission with two partial transmissions. In addition, the powertrain has an electrical

An engine operable in an engine operation and a generator operation and coupled to one of the sub-transmissions. This means that the electric machine in its generator mode via the one partial transmission and thus over the

Dual clutch transmission is driven, so that for example from the

Double clutch transmission via which a partial transmission provided mechanical energy by means of the electric machine is converted into electrical energy.

In the engine operation of the electric machine, however, a partial transmission of the electric machine is driven, so that for example one with the

Dual-clutch transmission coupled internal combustion engine over the one

Partial gear can be driven by the electric machine in the engine operation.

To keep the space requirement of the powertrain low, is the electric

Machine laterally of the partial transmission and arranged axially parallel to these. This means that an axis of rotation about which a rotor of the electric machine is rotatable extends at least substantially parallel to respective axes of rotation about which respective shafts of the partial transmissions are rotatable. On these shafts of the partial transmission, for example, idler gears are arranged, the respective, switchable gears of

Dual clutch transmission are assigned.

Object of the present invention is to provide a drive train of the type mentioned, by means of which a particularly efficient and thus Low-energy operation of the powertrain and thus the vehicle can be realized.

This object is achieved by a drive train having the features of patent claim 1. Advantageous embodiments with expedient developments of the invention are specified in the remaining claims.

To provide a drive train specified in the preamble of claim 1 species, by means of which a particularly efficient and thus

low-energy operation can be realized, it is provided according to the invention that the electric machine has at least one first connection, via which the electric machine with a first electrical network operable first power network of the vehicle is electrically connected, and at least one second terminal, via which the electric machine with an operable with a relation to the first electrical voltage higher second electrical voltage operable second power network of the vehicle is electrically connected. In other words, the electric machine is designed as a multi-phase electric machine which, for example, at least one associated with the first terminal and thus the first power grid first winding for operation with the first electrical voltage and at least one second terminal and thus the second power network associated second Winding for operation with the second electrical voltage.

In this case, the first winding can be connected via the first connection to the first electrical power network, wherein the second winding can be connected via the second connection to the second electrical power system. Thus, for example, in its generator mode, the electrical machine can provide the first electrical voltage via its first connection or its first winding, and thus feed electrical current with the first electrical voltage into the first power network. Furthermore, the electric machine can, for example, in its generator mode via its second terminal or its second winding provide the second electrical voltage greater than the first electrical voltage and thus feed electrical current with the second electrical voltage in the second power grid. In addition, it is possible to supply the electrical machine, for example, in its engine operation via the first power grid and thus via the first terminal with electrical current to the first voltage. Furthermore, it is possible to use the electric machine in its engine operation via the second power grid supply electrical current with the second electrical voltage. The power grids can thus be connected via the terminals of the electric machine parallel to each other to the electric machine.

The invention is based on the idea that in conventional powertrains for hybrid vehicles two operable with different electrical voltages power networks are provided, which are connected to each other or arranged in series and electrically coupled to each other via a converter such as a DC-DC converter (DC-DC converter). One of these power grids is connected to the electric machine, so that the other of the power grids is coupled via the Gieichsiromwandier and a power grid with the electric machine, so that the other power grid is not directly connected to the electric machine. This is conventionally provided since the electrical machine is usually designed only for operation with the electrical voltage of a power grid.

According to the invention, the electrical machine is designed both for operation with the first electrical voltage and for operation with the second electrical voltage, so that both power grids can be arranged parallel to one another and in each case can be connected directly to the electric machine. Thus, it is not necessary to arrange the power grids in series with each other and to couple with each other via a converter such as a DC-DC converter so that, for example, a DC-DC converter can be omitted compared to conventional drive trains. Alternatively, it is possible to electrically connect the electric power grids to each other via a converter such as a DC-DC converter, which DC-DC converter may have a much lower power than that provided by conventional powertrains

DC converter. As a result, the drive train according to the invention, and thus the vehicle designed, for example, as a hybrid vehicle, can be operated particularly efficiently and thus with low energy consumption, since, in comparison to

conventional powertrains improve functionality such as

For example, can represent an improved recuperation of energy and improved boost functionality.

Under the recuperation of energy is to be understood that by means of the electric machine in its generator mode mechanical energy, which is provided by the one partial transmission, is converted into electrical energy. The Mechanical energy is by the one partial transmission, for example by

provided that the one partial transmission is driven by wheels of the moving and thus rolling on a road vehicle, so that so kinetic energy of the vehicle via the one partial transmission and the electric machine in the

Generator operation can be converted into electrical energy.

If the vehicle is embodied, for example, as a hybrid vehicle, then the vehicle, in particular the drive train, has an internal combustion engine, for example designed as a reciprocating internal combustion engine, for driving the vehicle. The internal combustion engine is thereby, for example via a starting element such as a Dcppelkupplung the Doppeikuppiungsgetriebes coupled with this, so that the wheels of the vehicle on the dual clutch transmission of the internal combustion engine in a traction operation are driven by this.

Conversely, the internal combustion engine, for example, in a pushing operation of this over the dual-clutch transmission of the wheels of the moving

Drivable vehicle. In the aforementioned boost function, which is also referred to as boost operation or boost, the drive of the wheels caused by the internal combustion engine, that is to say the traction operation of the internal combustion engine, is assisted by the electric machine in its engine operation. In other words, the internal combustion engine is supported in its train operation in boost mode, so that, for example, the vehicle by the internal combustion engine and

supportive can be accelerated particularly strong by the electric machine. By the above-described embodiment of the electric machine as a multi-phase electric machine, such functionalities can be particularly advantageous, so that a particularly fuel-efficient operation of the

Internal combustion engine with only low C0 ₂ emissions can be realized.

The designed for the operation with different levels of electrical voltage electrical machine is also referred to as two-voltage electric motor (E machine - electric machine), since the two different levels of electrical

Voltages can also be referred to as voltage levels. Compared to

conventional powertrains can be realized by using the two-voltage electric motor, a higher power of the first power grid, so that over the first power network corresponding consumers of the vehicle can be very well supplied with electric power. This makes it especially

implement advantageous functionalities. Furthermore, it is possible by the elimination of the DC-DC converter or by the use of a DC-DC converter with only a small amount Performance to keep the complexity and the cost of the powertrain particularly low. In addition, an emergency operation of the drive train can be displayed in a simple manner. If, for example, one of the power grids fails, operation via the other of the power grids can be readily ensured.

Since the electric machine in the drive train according to the invention not on the internal combustion engine, but at a different location in the

Drive train, namely the dual-clutch transmission, is connected, compared to the connection of the electric machine to the internal combustion engine, a larger space can be realized. This space can be used particularly advantageously for electrical components such as a Leisiungseiektronik and / or electrical lines, so that, for example, corresponding target values for each power of the power grids can be achieved safely. The lateral arrangement of the electric machine is also referred to as a side-by-side arrangement (sbs arrangement) and allows the representation of a particularly large

Installation space.

Preferably, the first electrical voltage is 12 volts. The first power grid is thus designed as a conventional 12-volt electrical system, via which can be supplied with electrical current conventional electrical consumers. Accordingly, the second electrical voltage is greater than 12 volts, wherein the second electrical

Voltage is preferably 48 volts. The second power grid is thus preferably designed as a 48-volt electrical system, via which powerful electrical components such as the electric machine can be operated particularly advantageous.

It has proven to be particularly advantageous if a power electronics unit that is electrically connected to the electrical machine is provided, which is fastened directly to the electrical machine. The dual-clutch transmission, the electric

Machine and the power electronics thus make a composite or a component

Aggregate, the space requirement can be kept very low.

In particular, the connection of the power electronics can be realized in a particularly simple, space-and weight-favorable manner. Due to the direct connection of the power electronics to the electric machine direct contacts between the electric machine and the power electronics can be realized, so that

Usually prescribed for a high-voltage range of a hybrid vehicle

Safety precautions can be avoided because on the AC side (AC Page) is the threshold voltage of low voltage to high voltage at 30 volts and not - as on the DC side (DC side) - at 60 volts.

Another embodiment is characterized in that the power electronics are arranged coaxially with the electrical machine. This makes it possible to realize a particularly advantageous and in particular space-saving and simple connection and electrical contacting of the power electronics with the electric machine.

In a further embodiment of the invention, it is provided that the electrical machine in the axial direction, in particular in the coaxial direction, with the

Power electronics is contacted electrically. This means that the electric

Contacting runs parallel to a rotational axis of a rotor of the electric machine, wherein the rotor is rotatable about the axis of rotation, for example relative to a housing of the electric machine. As a result, the power electronics can be electrically connected to the electric machine, for example, if the power electronics are attached to the electric machine. In other words, it can be realized that the electrical connection simultaneously with the attachment of the

Power electronics associated with the electric machine.

In a further advantageous embodiment of the invention, the electric machine is screwed in the axial direction, in particular in the coaxial direction, with the power electronics. In other words, at least one screw is provided for fastening the power electronics to the electric machine, which extends parallel to the axis of rotation of the rotor. This is a particularly space-saving and easy to manufacture structure can be displayed, in which preferably the electrical contacting of the power electronics with the electric machine, the screwing of the power electronics with the electric machine and the axis of rotation of the rotor are rectified, that is, at least substantially parallel to each other.

To realize a particularly small space requirement, it is provided in a further embodiment of the invention that in the axial direction between the electric machine and the power electronics at least one gear is arranged, via which the electric machine is coupled to the one partial transmission. As a result, in particular the space requirement in the radial direction of the electric machine and a partial transmission can be kept low.

The gear does not completely fill the cylindrical space between

Power electronics and electrical machine, making the above

described direct contacts between the electric machine and the Power electronics can also be accommodated in this cylindrical space. Next, this space for a position sensor of the electrical

Machine can be used, so that advantageously no additional space required for the position encoder.

Finally, it has proven to be particularly advantageous if the electric machine is designed as a preassemblable module part, which is connected to the dual-clutch transmission. In other words, the electric machine as a sub-assembly, that is, as a so-called sub-assembly, formed, this module part considered in itself is already fully functional. This means that the electric machine is already functional and operable independent of the dual-clutch transmission and thus a separate, that is independent of

Dual-clutch transmission testable unit represents. This makes it possible, for example, to test the electric machine not yet connected to the dual-clutch transmission by means of a test stand, in particular test bench power electronics or a test unit comprising an electric machine and power electronics. If the test has shown that the electrical machine to be connected to the dual-clutch transmission is functional or has desired functionality, then the electric machine can be disconnected from the test bench and connected as a power package, ie as a so-called power pack, to the dual-clutch transmission.

The electrical machine has, for example, as a housing on a metal pot, which serves both as a housing for pre-assembly and housing in the finished drive train. The sheet metal pot is preferably formed thin-walled and has a wall thickness in a range of from 3 millimeters to 4 millimeters inclusive, since the sheet metal cup is attached to the dual-clutch transmission, in particular to a housing of the dual-clutch transmission. Here, the tin pot does not have to meet IP protection requirements.

The electric machine is designed for example as an asynchronous machine and is operable with an electrical voltage, in particular DC voltage, of 48 volts. For example, the electric machine has a power of 15 kilowatts over a period of at least about 10 seconds, with time periods of up to about 20 seconds being possible, and 48 volts. Further, it is possible for the electric machine to have a continuous power at 48 volts in a range of 6 kilowatts to 8 kilowatts inclusive. The electric machine can be powered at 48 volts Time span of about 2 seconds, with time periods up to 20 seconds are possible to provide a torque of more than 45 Newton meters.

The electric machine has, for example, a stator with an outer diameter of approximately 160 millimeters and an active length of approximately 70 millimeters. The stator has, for example, cooling in the form of oil cooling. In other words, the electric machine, in particular the stator, for example, oil-cooled. As a result, a particularly high performance can be realized even over a long time span. Preferably, the rotor of the electric machine has a cooling in the form of oil cooling. Alternatively, it is possible that the electric machine is preferably designed as a synchronous machine with inexpensive ferrite magnets. To realize a particularly small space requirement, however, the stator cooling can be omitted.

A further embodiment is characterized in that the electric machine can be operated in a first operating mode, in which the electric machine can be operated in a generator mode with regard to its first voltage position and the first power network and with regard to its second voltage position and the second power network. Alternatively or additionally, the electric machine can be operated in a second operating mode, in which the electric machine can be operated in a motor operation with regard to its first voltage position and the first power network and with regard to its second voltage position and the second power network. Alternatively or additionally, the electric machine can be operated in a third operating mode, in which the electric machine with respect to its first voltage position and the first power network in

Motor operation and in terms of their second voltage level and the second power system in the generator mode is operable. Alternatively or additionally, the electric machine can be operated in a fourth operating mode in which the electric machine can be operated in generator mode with regard to its first voltage position and the first power network and with respect to its second voltage position and the second power network during engine operation. As a result, a particularly efficient operation of the drive train can be realized. In particular, a mechanical reloading can be realized, in the context of which the electric machine can be supplied with respect to a voltage level, for example, with electric current from a first battery and operated in motor operation and in terms of their second voltage position in the generator mode, so that electric power can be used from the first battery to charge a second battery with electric current. in a further embodiment of the invention. Are the power grids electrically connected to each other via a DC-DC converter. Alternatively or additionally, in each case at least one battery for storing electrical current is arranged in the power supply networks, a fifth operating mode being provided, in which electric power can be transmitted from the battery arranged in one of the power networks to the battery arranged in the other power network and / or wherein a sixth mode is provided, in which electric current from that in the other

Power network arranged battery is transferable to the disposed in the one power grid battery. As a result, an electrical transfer can be realized, in the context of which electrical power is transferred from one of the batteries to the other.

The invention also includes a vehicle, in particular a hybrid vehicle, with a drive train according to the invention. Advantageous embodiments of the

Drive train according to the invention are as advantageous embodiments of

View the vehicle according to the invention and vice versa. The vehicle thus has the first power grid with the first electrical voltage and the second power grid with the second electric power higher than the first electrical voltage

Voltage, wherein the first power grid is electrically connected via the at least one first terminal and the second power grid via the at least one second terminal to the electric machine.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features mentioned above in the description and

Feature combinations as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures are not only in the respectively indicated combination but also in others

Combinations or alone, without departing from the scope of the invention.

The drawing shows in:

Fig. 1 is a schematic representation of a drive train for a vehicle in

Form of a hybrid vehicle, with a two-part transmission having dual-clutch transmission and with a side of the partial transmission and axially parallel to these arranged and operable in a motor operation and a generator operation electric machine, which with a the partial transmission is coupled, wherein the electric machine is designed as a two-voltage electric motor;

Fig. 2 is a circuit diagram of the drive train according to a first

embodiment;

Fig. 3 is a circuit diagram of the drive train according to a second

embodiment; and

4a-f are each a schematic representation of the two-voltage position E machine in different modes.

In the figures, the same or functionally identical elements are provided with the same reference numerals.

1 shows, in a schematic and perspective side view, a drive train as a whole designated 10 for a vehicle designed as a hybrid vehicle. The powertrain 10 is shown in FIG. 1 with reference to a dashed line and includes a generally designated 12 dual-clutch transmission with a first partial transmission 14 and a second partial transmission 16. From Fig. 1 is particularly well seen that the dual-clutch transmission 12, a first input shaft 18 of the the first sub-transmission 14 and a hollow shaft designed as a second input shaft 20 of the second sub-transmission 16, wherein the first input shaft 18 at least partially in the second

Input shaft 20 is received. The dual-clutch transmission 12 has a first output shaft 22, with which a gear 23 is rotatably connected. Furthermore, the dual-clutch transmission 12 has a second output shaft 32, with which a gear 33 is rotatably connected.

The powertrain 10 further includes an internal combustion engine 13, which is designed as a reciprocating internal combustion engine. The internal combustion engine 13 is for example part of the drive train 10 and serves to drive the vehicle. The internal combustion engine 13 is coupled via a torsion damper 15 to an input element 17 of a starting element in the form of a double clutch 19 of the dual-clutch transmission 12. The dual clutch 19 comprises a first clutch K1 assigned to the first partial transmission 14 and a second partial transmission 16 associated, second clutch K2, which are formed for example as disconnect couplings.

The clutches K1 and K2 are optionally apparent and closable, so that in a traction mode of the internal combustion engine 13, the first input shaft 18 is driven via the first clutch K1 of the internal combustion engine 13, when the first clutch K1 is closed and the second clutch K2 is opened, wherein the second input shaft 20 is not driven by the internal combustion engine 13 via the second clutch K2. However, if the first clutch K1 is open to traction operation of the internal combustion engine 13 and the second clutch K2 is closed, the second input shaft 20 is driven by the internal combustion engine via the second clutch K2 while the first input shaft 18 is not driven by the internal combustion engine 13 via the clutch K1 becomes.

This will be in Zugbetrieb - depending on the gear of the

Dual clutch transmission 12 - wheels of the vehicle via the dual clutch transmission 12 driven by the internal combustion engine 13. Conversely, it is possible in a coasting operation of the internal combustion engine 13 that the

Internal combustion engine 13 is driven by the wheels of the moving and therefore along a roadway rolling vehicle via the dual-clutch transmission 12.

The first partial transmission 14 has a plurality of gear wheels in the form of loose wheels 1,

3, 5 and 7, wherein the idler gears 3 and 7 are rotatably mounted on the output shaft 22 and the idler gears 1 and 5 rotatably mounted on the output shaft 32. With the

Output shaft 22 is a gear 24 rotatably connected, which is coupled via a shift sleeve 28 optionally with the idler gear 3 or 7. With the output shaft 32, a gear 26 is rotatably connected, which is coupled via a shift sleeve 30 optionally with the idler gear 1 or 5.

The second partial transmission 16 has a plurality of gear wheels in the form of loose wheels 2,

4, 6 and R, wherein the idler gears 6 and R are rotatably mounted on the output shaft 22 and the idler gears 2 and 4 are rotatably mounted on the output shaft 32. With the

Output shaft 22 is a gear 34 rotatably connected, which is coupled via a shift sleeve 38 with the idler gear 6. With the output shaft 32, a gear 36 is rotatably connected, which via a shift sleeve 40 optionally with the idler gear 2 or 4th can be coupled. In addition, a shift sleeve 41 is provided by means of which the idler gear R is rotatably coupled to the idler gear 3. Further, the output shaft 32 is rotatably connected to a parking lock gear P.

The output shafts 22 and 32 are via the gears 23 and 33 with a

Output element coupled in the form of a gear 42, via which, for example, via the respective output shafts 22 and 32 provided torques can be introduced into a not shown in Fig. 1 differential gear, so that the wheels of the vehicle via the differential gear and - depending on the gear of the

Doppelkupplungsgetriebes 12 - are driven via the output shaft 22 or the output shaft 32.

Overall, it can be seen from FIG. 1 that the dual-clutch transmission 12 has seven shiftable forward gears and one reverse gear. To insert the first gear, the idler gear 1 is rotatably coupled via the shift sleeve 30 with the output shaft 32. To engage the second gear, the idler gear 2 is coupled via the shift sleeve 40 with the output shaft 32. If the third gear is engaged, the idler gear 3 is coupled via the shift sleeve 28 with the output shaft 22. When pickled fourth gear, the idler gear 4 is coupled via the shift sleeve 40 with the output shaft 32. To insert the fifth gear, the idler gear 5 via the shift sleeve 30 with the

Output shaft 32 coupled. When engaged sixth gear, the idler gear 6 is coupled via the shift sleeve 38 to the output shaft 22. When seventh gear is engaged, the idler gear 7 is coupled via the shift sleeve 28 with the output shaft 22. To engage the reverse gear R, the idler gear R is coupled via the shift sleeve 41 with the idler gear 3 and the idler gear 3 via the shift sleeve 28 with the output shaft 22, wherein the idler gear R is driven via the idler gear 2, which in turn from the second input shaft 20th is driven.

About the parking lock gear P is a parking brake of the dual clutch transmission 12 can be realized, so that the vehicle can be secured against unwanted Wegroilen for example on a slope.

It can also be seen from FIG. 1 that the drive train 10 furthermore has an electric machine 46, which-as will be explained below-is embodied as a two-voltage electric motor. The electric machine 46 is in the radial direction of the partial transmission 14, 16, that is in the radial direction of

Output shafts 22, 32, the side of the partial transmission 14, 16 and axially parallel to the Part-driven 14 and 16 formed. The electric machine 46 has a rotor 48, which can be partially seen in FIG. 1, which is mounted about an axis of rotation relative to a rotor 48

Housing 50 of the electric machine 46 is rotatable. The rotor 48 is at least partially disposed in the housing 50 and has a shaft 52 which is led out of the housing 50. The shaft 52 is rotatably connected to a gear 54. The gear 54 meshes with the idler gear 3 in the present case.

It may alternatively be provided that the gear 54 meshes with one with a simple gear, which in turn having a two teeth

Double gear meshes. The simple gear meshes with a first of the

Gears of the double gear, which then meshes with its idler gear 3 via its second toothing, for example.

In the present case, the electric machine 46 that can be operated in an engine mode and a generator mode is coupled to the first partial transmission 14. This means that, for example, the first partial transmission 14 can be driven by the latter during engine operation of the electric machine 46. In its generator mode, the electric machine 46 can be driven via the first partial transmission 14.

By arranged with respect to a force or torque flow between the electric machine 46 and the first partial transmission 14 gear 54 and the idler gear 3 or by the optionally arranged between the electric machine 46 and the first partial transmission 14 simple gear and the double gear is for example at least one Translation stage, preferably with one of 1 different translation, created. In other words, based on the torque flow between the electric machine 46 and the first partial transmission 14 is a transmission, preferably with one of 1 different

Translation, created so that the first partial transmission 14 can be driven particularly advantageous by the electric machine 46 and vice versa.

The electric machine 46 is, for example, a starter generator (SGR), by means of which the internal combustion engine 13 in the engine operation of the electric machine 46 via the first partial transmission 14 and thus via the dual-clutch transmission 12 started, that is, can be started. Furthermore, the representation of a boost function is possible, in which the wheels are driven by the internal combustion engine 13 and in addition by the electric machine 46 in its engine operation. In Fig. 1, a power flow is illustrated by directional arrows when the third gear is engaged and the electric machine 46 is operated in its engine operation. Here, a provided by the electric machine 46 power via the gear 54 to the idler gear 3 of the third gear and from there via the shift sleeve 28 and the gear 24 to the output shaft 22, so that thereby the

Internal combustion engine 13 is supported in their operation and the wheels are driven by both the internal combustion engine 13 and supportive means of the electric machine 46. In other words, a power provided in boost mode by the internal combustion engine 3 and a power provided by the electric machine 46 in the boost mode are transmitted to the wheels via the gear 23, so that, for example, the vehicle can be accelerated particularly strongly.

The lateral arrangement of the electric machine 46, the space requirement of the drive train 10 can be kept low, so that the electric machine 46 can be formed in a particularly simple and advantageous manner as a two-voltage electric motor. The dual-clutch transmission 12 and the electric machine 46 are accommodated, for example, in a common housing, so that the drive train 10 has a particularly compact construction. In addition, for example, a power electronics is provided, which is electrically connected to the electric machine 46 and attached directly to the electric machine 46.

In order to keep the space requirement of the drive train 10 is particularly low, preferably at least the aforementioned simple gear in the axial direction of the electric machine 46 and thus of the rotor 48 between the power electronics and the electric machine 46, in particular its housing 50, respectively. Furthermore, the gear 54 is arranged in the axial direction between the electric machine 46 and the power electronics.

The power electronics are preferably coaxial with the electric machine 46

arranged and electrically contacted in coaxial with the electric machine 46. Preferably, it is provided that the power electronics is so directly attached to the electric machine 46, that the power electronics is bolted to the electric machine 46. In this case, a coaxial with the electric machine 46 extending screw is preferably provided. Overall, it is preferably provided that the electrical contact between the electric machine 46 and the power electronics, the screw and the shaft 52 and the axis of rotation about which the rotor 48 is rotatable, at least in Are substantially parallel and preferably coaxial with each other or rectified.

The description of the configuration of the electric machine 46 as a two-voltage electric motor is described below with reference to FIGS. 2 and 3, FIG. 2 a circuit diagram of the drive train 10 according to a first embodiment and FIG. 3 a circuit diagram of the powertrain 10 according to FIG a second embodiment shows. From FIGS. 2 and 3 it can be seen that the vehicle has a first electrical circuit or a first power grid 68 which is operated with a first electrical voltage of, for example, at least substantially 12 V (12 V). Further, the vehicle has a second electrical circuit or a second power grid 70, which is operated with a second voltage of for example 48 volts. This means that the second electrical voltage is greater than the first electrical voltage. The electrical machine 46 now has at least one first connection 72, via which the electrical machine 46 is electrically connected to the first power supply 68.

Furthermore, the electric machine 46 has at least one second connection 74, via which the electrical machine 46 is electrically connected to the second power network 70. This means that the electric machine 46 is designed both for operation at 12 volts and for operation at 48 volts. The electric machine 46 is via a rectifier device 76 (AC-DC converter), which

is preferably part of the power electronics, electrically connected to the power grid 68 and the power grid 70. The electric machine 46 is thus, for example, in its generator mode with electric power with 12 volts from the power grid 68 and alternatively or additionally supplied with electrical power at 48 volts from the power grid 70. Further, for example, in its engine operation, the electric machine 46 may provide a voltage of 12 volts across its first terminal 72 and, thus, feed electrical power into the grid 68. Accordingly, the electric machine 46 may provide 48 volts of electrical power via its second terminal 74 and, accordingly, inject electrical power into the power grid 70. For this purpose, the electric machine 46 is designed, for example, as a multi-phase electric machine which has at least one first connection 72 associated with the first winding 78 for operation with 12 volts and at least one winding 74 associated with the second connection 74 for operation with 48 volts. In the power grid 68, a first battery 82 is arranged with an electrical voltage of 12 volts, wherein the first battery 82 is formed for example as a lead battery (Pb battery). Furthermore, at least one electrical load 84 is arranged in the power grid 68, which can be supplied via the first power grid 68 with electric current with a voltage of 12 volts. In the second power grid 70, a second battery 86 is arranged with a voltage of 48 volts, wherein the second battery 86 may be formed, for example, as a lithium-ion battery. Further, in the second power grid 70 at least one consumer 88 is arranged, which can be supplied via the power grid 70 with electric power at 48 volts.

In the illustrated in Fig. 2 the first embodiment is a

DC converter 90 (DC-DC converter) is provided, via which the

Power grids 68 and 70 are electrically connected together. By way of example, the DC-DC converter 90 has an electrical power of 3 kilowatts. However, since the electric machine 46 is formed as a two-time three-phase voltage-E machine and thus directly connected via the terminals 72, 74 with two power grids 68, 70, the electrical power of the DC-DC converter 90 can be kept particularly low. In other words, it is provided in the drive train 10, that the power grids 68 and 70 are not arranged or connected in series with each other, but the power grids 68 and 70 are arranged parallel to each other or designed and each directly via the terminals 72 and 74 to the electrical Machine 46 connected. As a result, both a generator operation with 12 volts and 48 volts and a motor operation with 12 volts and 48 volts of the electric machine 46 can be displayed.

In the illustrated with reference to FIG. 3 second embodiment of the

DC-DC converter 90 is not provided. That is, in the second embodiment, the power grids 68 and 70 are not electrically connected to each other via a DC-DC converter. Also in the second embodiment, the electric machine 46 is configured as a two-phase, three-phase, two-voltage electric machine and is operable in both 2 volt and 48 volt generator mode and 12 volt and 48 volt motor mode ,

Different operating modes of the electric machine 46 or of the drive train 10 are illustrated on the basis of FIGS. 4a-f, respective main operating modes being shown with reference to FIGS. 4a and 4b. The different levels of electrical voltages of the power grids 68, 70 are also referred to as voltage levels. 4a shows a first main operating mode in which the dual-clutch transmission 12 provides a torque M via the first partial transmission 14, so that a power flow illustrated by a directional arrow 92 from the dual-clutch transmission 12 is present in the direction of the electric machine 46. In the first main mode, the electric machine 46 is in the first voltage, that is with respect to the first electric voltage of 12 volts and / or with respect to the second

Voltage, that is operated in generator mode with respect to the second electrical voltage of 48 volts, with a respective output power for both

Voltage levels is adjustable. In this case, the battery 82 and / or the battery 86 is supplied with electrical power and thereby charged, the electric current being provided by the electric machine 46 via the first voltage position or the first connection 72 and / or via the second voltage position or the second connection 74 becomes.

The electric machine 46 is designed, for example, as a starter generator with a total of six phases and is used in particular for realizing an automatic start-stop function in order to automatically reactivate the internal combustion engine 13 after automatic deactivation. In this case, three of the six phases of the first voltage level or the first terminal 72 and the other three of the six phases of the second voltage level or the second terminal 74 are assigned.

FIG. 4 b shows a second main operating mode, in which the electric machine 46 with respect to its first voltage position and / or with respect to its second

Voltage is operated in engine operation. In this case, the boost function described above is provided, for example, via the first voltage position and / or the second voltage position, wherein a torque control for both

Voltage is feasible. Overall, it can be seen that at the second

Main mode, a power flow from the electric machine 46 to the

Double clutch transmission 12 is present, so that now the electric machine 46 provides a torque which receives the dual-clutch transmission 12. In the respective engine operation, the electric machine 46 is via its first voltage position or its first terminal 72 or via its second

Voltage or the second terminal 74 supplied with power from the respective battery 82 and / or 86. Because the different voltage levels

For example, be realized by the different windings 78 and 80, the voltage levels are also used as machine parts of the electric machine 46th EP2015 / 001460

18 denotes. Because of this subdivision or distinction of

Tension layers or machine parts are provided in FIG. 4a-f for the electrical machine 46 two reference numerals 46, wherein the respective, left

Reference numeral 46 denotes the first voltage position (12 volts) and the right-hand reference numeral 46 denotes the second voltage position (48 volts). In the main modes, the dual-clutch transmission 2, in particular the idler gear 3, a speed which is greater than 0.

FIG. 4 c shows an operating mode in which a so-called mechanical transfer takes place from the battery 82 to the battery 86. This reloading is referred to as mechanical reloading, since the dual-clutch transmission 12 or the idler gear 3 rotates. In this mechanical reload, the electric machine 46 is operated at its first voltage level (12 volts) in motor mode while the electric machine 46 is operated in generator mode with respect to its second voltage level (48 volts). Thus, electric current is drawn from the battery 82, by means of which the electric machine 46 is operated via its first voltage position during engine operation. Motor operation of the first voltage level is used to operate the electric machine 46 via its second voltage position in generator mode, so that the electric machine 46 can provide electrical current via its second terminal 74, which is fed into the battery 86.

FIG. 4 d shows an operating mode in which mechanical reloading, but now from the battery 86 to the battery 82 takes place. This means that the electric machine 46 is operated in its second voltage position (48 volts) in motor operation, while the electric machine 46 is operated in generator operation with respect to its first voltage position (12 volts). Thus, electric current stored therein is dissipated from the battery 86 and used for motor operation of the second voltage level. The motor operation of the second voltage layer is used for the generator operation of the first voltage layer in order to provide, by means of the first voltage line or via the first terminal 74, electrical current which is fed into the battery 82. Even in the case of the mechanical reloading illustrated with reference to FIG. 4d, the dual-clutch transmission 12, in particular the idler gear 3, has a speed of greater than zero.

4e shows an electrical transfer from the battery 82 to the battery 86, wherein the dual-clutch transmission 12 may have a speed of 0 or greater than 0. In other words, in the mode of operation illustrated in FIG. 4e, for example, electric power is transferred from the battery 82 to the battery 86 transhipped, but without driving the idler gear 3, as it is intended in the mechanical reload to drive or have to drive. In Fig. 4f, the electrical transfer takes place, but now from the battery 86 to the battery 82, wherein the idler gear 3 has a speed of 0 or may have. The described mechanical reloading can be realized, for example, in the first embodiment and in the second embodiment. Said electrical reloading is preferably realizable in the second embodiment shown in FIG.

Claims

Daimler AG claims

A drive train (10) for a vehicle, in particular a hybrid vehicle, with a two-part transmission (14, 16) having dual-clutch transmission (12), and arranged with at least one side of the partial transmission (14, 16) and axially parallel to these and in a motor operation and a generator mode operable electric machine (46) coupled to one of the partial transmissions (14, 16),

characterized in that

the electric machine (46) has at least one first connection (72) via which the electric machine (46) can be electrically connected to a first power network (68) of the vehicle which can be operated with a first electrical voltage, and has at least one second connection (74) , via which the electrical machine (46) can be electrically connected to a second power network (70) of the vehicle which can be operated with a second electrical voltage higher than the first electrical voltage.

2. Drive train (10) according to claim 1,

characterized in that

a power electronics (66) electrically connected to the electric machine (46) is provided, which is directly attached to the electrical machine (46).

3. Drive train (10) according to claim 2,

characterized in that

the power electronics (66) is arranged coaxially with the electrical machine (46).

4. Drive train (10) according to one of claims 2 or 3,

characterized in that

the electric machine (46) in the axial direction, in particular in coaxial

Direction with the power electronics (66) is electrically contacted.

5. Drive train (10) according to one of claims 2 to 4,

characterized in that

the electric machine (46) is screwed to the power electronics (66) in the axial direction, in particular in the coaxial direction.

6. driveline (10) according to any one of claims 2 to 5,

characterized in that

in the axial direction between the electric machine (46) and the

Power electronics (66) at least one gear (58) is arranged, via which the electric machine (46) is coupled to the one partial transmission (16).

7. Drive train (10) according to one of the preceding claims,

characterized in that

the electric machine (46) is designed as a preassemblable module part, which is connected to the dual-clutch transmission (12).

8. Drive train (10) according to one of the preceding claims,

characterized in that

the electric machine (46)

- Is operable in a first mode in which the electrical machine (46) in terms of their first voltage and the first power grid (68) and in terms of their second voltage and the second power system (70) is operable in a generator mode, and / or

- Is operable in a second operating mode, in which the electrical machine (46) in terms of their first voltage and the first power grid (68) and in terms of their second voltage and the second power grid (70) is operable in a motor operation, and / or

- Is operable in a third operating mode, in which the electrical machine (46) in terms of their first voltage and the first power system (68) in the engine operation and in terms of their second voltage and the second power system (70) is operable in the generator mode, and / or - Is operable in a fourth operating mode, in which the electrical machine (46) in terms of their first voltage and the first power grid (68) in the generator mode and in terms of their second voltage and the second power system (70) is operable during engine operation.

9. Drive train (10) according to one of the preceding claims,

characterized in that

- The power grids (68, 70) via a DC-DC converter (90) electrically

are connected to each other and / or that

- In the power networks (68, 70) each have at least one battery (82, 86) for

Saving electric current is arranged, wherein

o a fifth mode is provided in which electrical power from the in one of the power grids (68, 70) arranged battery (82) to the other power grid (68, 70) arranged battery (86) is transferable and / or o a sixth Operating mode is provided, in which electrical power from the in the other power grid (68, 70) arranged battery (82) to the one in the power grid (68, 70) arranged battery (86) is transferable.

10. vehicle, in particular hybrid vehicle, with a drive train (10) according to one of the preceding claims.