DE102015200602A1 - Internal combustion engine with mechanical supercharger and electric machine and method for operating such an internal combustion engine - Google Patents

Abstract

The invention relates to a supercharged internal combustion engine (1) having - a crankshaft, - an intake system (2) for supplying charge air, - an exhaust gas removal system (4) for discharging the exhaust gas, - a mechanical supercharger (8) operating in the intake system (2) is arranged and which has at least one arranged on a drive shaft (8a) impeller and a bypass line (8b) downstream of the loader (8) in the intake system (2) opens, - an electric machine (7) via a shaft ( 7a) and as a drive motor by means of a first clutch (11) with the drive shaft (8a) of the supercharger (6) is drive-connected, and - a battery (9), wherein - the electric machine (7) is operable as a generator that receives power - A traction mechanism drive (10) is provided, which in addition to the traction means on the crankshaft of the internal combustion engine (1) arranged first wheel (10a) and on the shaft (7a) of the electric machine (7) arranged second wheel (10b) surrounded sst, wherein the second wheel (10b) is a freely rotating wheel (10b) which freewheels when the rotational speed nshaft of the shaft (7a) of the electric machine (7) is greater than the rotational speed nwheel of the second wheel (10b); and the shaft (7a) of the electric machine (7) can be drive-connected to the second wheel (10b) by means of a second clutch (12).

Description

• – einer Kurbelwelle,
• – einem Ansaugsystem zum Zuführen von Ladeluft,
• – einem Abgasabführsystem zum Abführen des Abgases,
• – einem mechanischen Lader, der im Ansaugsystem angeordnet ist und der über mindestens ein auf einer Antriebswelle angeordnetes Laufrad und eine Bypassleitung verfügt, die stromabwärts des Laders in das Ansaugsystem mündet,
• – einer Elektromaschine, die über eine Welle verfügt und als Antriebsmotor mittels einer ersten Kupplung mit der Antriebswelle des Laders antriebsverbindbar ist, und
• – einer Batterie.

The invention relates to a supercharged internal combustion engine with

• - a crankshaft,
• An intake system for supplying charge air,
• An exhaust gas discharge system for discharging the exhaust gas,
• A mechanical supercharger disposed in the intake system and having at least one impeller arranged on a drive shaft and a bypass line which opens into the intake system downstream of the supercharger,
• - An electric machine which has a shaft and is drive-connected as a drive motor by means of a first clutch to the drive shaft of the supercharger, and
• - a battery.

Furthermore, the invention relates to a method for operating such an internal combustion engine.

An internal combustion engine of the type mentioned with a mechanical charger and an electric machine describes the US 2008/0173017 A1 wherein the electric machine can drive the charger as an electric auxiliary drive or is used as a generator for energy recovery, which is driven by means of the crankshaft of the internal combustion engine and via a traction drive. Several clutches are provided to connect the electric machine to the loader and the crankshaft to the loader.

That in the US 2008/0173017 A1 described concept has two switchable drive trains, wherein a first switchable drive train between the electric machine and the supercharger runs and a second switchable drive train is provided, which connects the traction drive with the first drive train or can connect. This makes the combination of loader and drive very complex and bulky. A costly gear transmission is required to connect the two drive trains together.

An internal combustion engine of the type mentioned is used as a motor vehicle drive. In the context of the present invention, the term internal combustion engine includes diesel engines and gasoline engines, but also hybrid internal combustion engines, which use a hybrid combustion process, and hybrid drives, which in addition to the internal combustion engine comprise an electric motor which can be electrically connected to the internal combustion engine, which receives power from the internal combustion engine or as switchable auxiliary drive additionally delivers power.

In recent years, there has been a trend toward small, supercharged engines, the supercharging being primarily a performance enhancement method that compresses the air needed for the engine combustion process, thereby providing each cylinder with greater air mass per cycle can. As a result, the fuel mass and thus the medium pressure can be increased.

The charge is a suitable means to increase the capacity of an internal combustion engine with unchanged displacement or to reduce the displacement at the same power. In any case, the charging leads to an increase in space performance and a lower power mass. If the displacement is reduced, then the load spectrum can be shifted to higher loads, where the specific fuel consumption is lower. By charging in combination with a suitable transmission design and a so-called downspeeding can be realized, in which also a lower specific fuel consumption can be achieved.

Charging thus supports the constant effort in the development of internal combustion engines to minimize fuel consumption, d. H. to improve the efficiency of the internal combustion engine.

Frequently, an exhaust gas turbocharger is used for charging, in which a compressor and a turbine are arranged on the same shaft. The hot exhaust stream is supplied to the turbine and relaxes with energy release in the turbine, causing the shaft to rotate. The energy emitted by the exhaust gas flow to the turbine and finally to the shaft is used to drive the compressor, which is also arranged on the shaft. The compressor conveys and compresses the charge air supplied to it, whereby a charging of the cylinder is achieved. Advantageously, a charge air cooler is provided downstream of the compressor in the intake system, with which the compressed charge air is cooled before entering the at least one cylinder. The radiator lowers the temperature and thus increases the density of the charge air, so that the cooler to a better filling of the cylinder, d. H. contributes to a larger air mass. There is a compaction by cooling.

The advantage of an exhaust gas turbocharger in comparison to a mechanical supercharger is that an exhaust gas turbocharger uses the exhaust gas energy of the hot exhaust gases, while a mechanical supercharger obtains the energy required for its drive directly or indirectly from the internal combustion engine. As a rule, a mechanical connection for power transmission between the charger and the internal combustion engine required.

The advantage of a mechanical supercharger over an exhaust-gas turbocharger is that the mechanical supercharger always generates and makes available the required boost pressure, regardless of the operating state of the internal combustion engine, in particular independently of the currently present rotational speed of the crankshaft. This applies in particular to a mechanical loader which can be driven by means of an electric machine.

In fact, according to the state of the art, it is difficult to increase the power by means of turbocharging in all engine speed ranges. It is observed a greater torque drop when falling below a certain speed. This torque drop becomes understandable if it is taken into account that the boost pressure ratio depends on the turbine pressure ratio. If the engine speed is reduced, this leads to a smaller exhaust gas mass flow and thus to a smaller turbine pressure ratio. Consequently, the boost pressure ratio also decreases toward lower speeds. This is synonymous with a torque drop.

The torque characteristic of a charged by turbocharging internal combustion engine is trying to improve the prior art by various measures.

For example, by a small design of the turbine cross-section and simultaneous Abgasabblasung. For this purpose, the turbine is equipped with a blow-off line which branches off from the exhaust-gas removal system upstream of the turbine and in which a shut-off element is arranged. Such a turbine is also referred to as a waste gate turbine. If the exhaust gas mass flow exceeds a critical size, part of the exhaust gas flow is guided past the turbine via the blow-off line as part of the so-called exhaust gas blow-off, d. H. blown off. This approach has the disadvantage that the high-energy blown exhaust gas remains unused and the charging behavior is regularly insufficient at higher speeds.

A turbine with variable turbine geometry allows a further adaptation to the respective operating point of the internal combustion engine by adjusting the turbine geometry or the effective turbine cross-section, to some extent a speed-dependent or load-dependent control of the turbine geometry can be done.

The torque characteristic of a supercharged internal combustion engine may also be represented by a plurality of turbochargers arranged in parallel, i. H. be improved by a plurality of parallel turbines of smaller turbine cross-section, with turbines are switched successively with increasing exhaust gas quantity; similar to a register charge.

The torque characteristic can also be advantageously influenced by means of a plurality of exhaust-gas turbochargers connected in series. By switching in series of two exhaust gas turbochargers, one of which is an exhaust gas turbocharger as a high pressure stage and an exhaust gas turbocharger as a low pressure stage, the compressor map can be widened in an advantageous manner, both towards smaller compressor streams as well as towards larger compressor streams.

In particular, in the case of the exhaust-gas turbocharger serving as a high-pressure stage, the pumping limit can be shifted toward smaller compressor flows, which means that high boost pressure ratios can be achieved even with small compressor flows and the torque characteristic in the lower rpm range is markedly improved. This is achieved by designing the high-pressure turbine for small exhaust gas mass flows and providing a blow-off line with which exhaust gas is increasingly conducted past the high-pressure turbine as the exhaust gas mass flow increases. For this purpose, the blow-off line branches off the exhaust-gas removal system upstream of the high-pressure turbine and returns into the exhaust-gas removal system upstream of the low-pressure turbine. In the blow-off line, a shut-off element is arranged in order to control the exhaust gas flow conducted past the high-pressure turbine.

In addition to an exhaust gas turbocharger, a mechanical supercharger can in principle also be provided. Since an exhaust gas turbocharging is expensive, in particular when using a plurality of exhaust gas turbochargers, instead of an exhaust gas turbocharging, charging by means of a mechanical supercharger can also be carried out. The advantages are those already mentioned above.

The internal combustion engine object of the present invention has a mechanical supercharger for charging.

In light of the above, it is an object of the present invention to provide a supercharged internal combustion engine according to the preamble of claim 1, which overcomes the disadvantages known from the prior art and which has improved charging.

A further sub-task of the present invention is to show a method for operating such an internal combustion engine.

The first subtask is solved by a supercharged internal combustion engine

• - a crankshaft,
• An intake system for supplying charge air,
• An exhaust gas discharge system for discharging the exhaust gas,
• A mechanical supercharger disposed in the intake system and having at least one impeller arranged on a drive shaft and a bypass line which opens into the intake system downstream of the supercharger,
• - An electric machine which has a shaft and is drive-connected as a drive motor by means of a first clutch to the drive shaft of the supercharger, and
• - a battery, which is characterized in that
• The electric machine is operable as a generator receiving power,
• A traction mechanism drive is provided which comprises, in addition to the traction means, a first wheel arranged on the crankshaft of the internal combustion engine and a second wheel arranged on the shaft of the electric motor, wherein the second wheel is a wheel free-wheeling in a rotational direction, which freewheels when the rotational speed n _{shaft of} the shaft of the electric machine is greater than the rotational speed n _{wheel of} the second wheel, and the shaft of the electric machine is drive-connected by means of a second clutch with the second wheel.

In contrast to the prior art, only a switchable drive train is provided in the internal combustion engine according to the invention, namely the strand between the electric machine and the loader. The shaft of the electric machine and the drive shaft of the supercharger can be connected or disconnected by operating a first clutch.

This also takes into account the fact that the loader is basically driven by the electric machine or should be driven as long as the battery that powers the electric machine provides sufficient electrical energy.

The via the first wheel to the crankshaft drive-connected traction drive is directly connected to this drive train or connectable. For this purpose, a second wheel of the traction drive is arranged on the shaft of the electric machine, which runs free when the rotational speed n _{shaft of} the shaft of the electric machine is greater than the rotational speed n _{wheel of} the second wheel. This second wheel can be frictionally connected to the shaft of the electric machine by operating a second clutch.

A second switchable powertrain, as in the US 2008/0173017 A1 described, which connects the traction mechanism drive with the first drive train and can be interrupted by means of coupling, if necessary, is eliminated or reduced to the second clutch. This makes the combination of loader and drive less expensive and less bulky. A costly gear transmission is eliminated.

A direct drive of the mechanical supercharger by the internal combustion engine, bypassing the electric machine, as in the US 2008/0173017 A1 is described, is not provided according to the invention. Either the loader is driven by the electric machine as a drive motor or the electric machine is connected via traction drive with the crankshaft of the internal combustion engine and is operated as a generator, wherein the charger is indirectly driven by the internal combustion engine with closed first clutch via electric machine.

In contrast to the prior art, the electric machine of the internal combustion engine according to the invention can also be used as a starting device for the internal combustion engine, with which the crankshaft is forcibly set in rotation when starting. When the first clutch is open and the second clutch is closed, the electric machine powered by the battery then drives the crankshaft of the internal combustion engine via the traction mechanism drive. The second clutch must be closed in the present case only for starting.

The usually provided starting device can be dispensed with, so that the inventive concept concerning a mechanical loader together with the drive contributes to a tight packaging of a less voluminous drive unit.

When the second clutch is open, the first clutch is closed to connect the shaft of the electric machine to the drive shaft of the mechanical supercharger and to drive the mechanical supercharger. In this case, the shaft of the electric machine is rotated with a rotational speed n _shaft , which is greater than the rotational speed n _{wheel of} the second wheel, so that the shaft rotates freely under the second wheel.

The electric machine can also be operated as a generator, for example, in overrun operation of the internal combustion engine or if the battery falls below a predetermined minimum state of charge. Then the traction drive is operated in such a way that the speed n _{wheel of} the second wheel is not smaller than the speed n _{shaft of} the shaft of the electric machine. The electric machine is then used for energy recovery. When the first clutch is closed, the mechanical supercharger is also driven.

With the internal combustion engine according to the invention, the first object of the invention is achieved, namely provided a supercharged internal combustion engine according to the preamble of claim 1, with which the known from the prior art disadvantages are overcome and which has an improved charge.

Further advantageous embodiments of the internal combustion engine according to the invention are discussed in connection with the subclaims.

Embodiments of the supercharged internal combustion engine in which the shaft of the electric machine is drive-connected to the drive shaft of the mechanical supercharger by means of the first clutch are advantageous. Then, when the second clutch is open, the speed n _{shaft of} the shaft of the electric machine is greater than the speed n _{wheel of} the second wheel, the second wheel runs free on the shaft of the electric machine and the electric machine drives the loader.

Namely, the supercharger is preferably driven by the electric machine, so that the energy required for driving the supercharger at least does not originate directly from the internal combustion engine and the power provided or can be provided by the internal combustion engine is not reduced. In this respect, when operating the internal combustion engine, no consideration must be given to the requirements of the supercharger, as long as the battery which powers the electric machine supplies sufficient electrical energy. Ie. the operation of the internal combustion engine is independent of the loader operation and vice versa, which increases the flexibility of the charge.

In this context, embodiments of the supercharged internal combustion engine in which the bypass line of the mechanical supercharger is closed are advantageous, so that the charge air can not bypass the supercharger, but must flow through it.

Also advantageous are embodiments of the supercharged internal combustion engine, in which the electric machine is used for energy recovery as a generator and the battery stores the power absorbed by the generator as electrical energy. If, with the second clutch open, the speed n _{wheel of} the second wheel is not smaller than the speed n _{shaft of} the shaft of the electric machine, the second wheel drives the shaft of the electric machine and the electric machine acts as a generator.

If the battery falls below a predefinable minimum state of charge and can no longer provide the electrical energy for driving the electric machine, but acts as a generator, the internal combustion engine must drive the mechanical supercharger. When the first clutch is closed then the supercharger is driven by the internal combustion engine and indirectly via electric machine.

For the energy recovery, in particular the overrun operation of the internal combustion engine is suitable. In this case, the generator acts like an engine brake, wherein the degraded according to the prior art of the engine brake and thus unused energy according to the invention can be recovered by means of generator and, if necessary, also recovered. This effect can be reinforced and supported by switching off the valves on the intake side and / or exhaust side during energy recovery in overrun mode. The first clutch remains preferably open in the context of energy recovery, if the loader does not need to be driven by internal combustion engine.

Embodiments of the supercharged internal combustion engine in which the shaft of the electric machine is drive-connected to the second wheel of the traction mechanism drive by means of the second clutch can also be advantageous. The closing of the second clutch ensures a frictional connection in both directions of rotation of the second wheel and thus creates the possibility of transmitting a torque from the electric machine to the crankshaft for starting the internal combustion engine.

Also advantageous are embodiments of the supercharged internal combustion engine, in which the electric machine serves as a starting device for starting the internal combustion engine and the battery provides the required electrical energy. In this case, the first clutch is preferably open, unless the loader is accelerated before starting or simultaneously with the starting of the internal combustion engine, d. H. be brought to speed. The fact that the electric machine according to the embodiment in question can be used as a starting device, can be dispensed with a further additional starting device, so that the equipment of the supercharger with a - serving primarily as an auxiliary drive - electric machine is cost-neutral compared to an internal combustion engine, not has such an electric machine and requires a different starting device.

In principle, embodiments of the supercharged internal combustion engine in which the bypass line of the mechanical supercharger is open are advantageous.

Both in the context of energy recovery and when starting the internal combustion engine, it makes sense to open the bypass line, so that not sucked by the cylinders charge air must flow through the loader, which in both cases only represents a flow resistance. Unless the first clutch is closed to drive the charger. Then, the bypass line of the mechanical supercharger is preferably closed, so that the charge air can not bypass the loader, but must flow through the loader.

Embodiments of the supercharged internal combustion engine in which the first clutch and / or the second clutch is an electromagnetic clutch are advantageous. An electromagnetic clutch is characterized by the fast switching times. This allows a quick closing and opening, d. H. a quick activation and deactivation of the clutch.

Embodiments of the supercharged internal combustion engine in which at least one exhaust-gas turbocharger is provided, which comprises a turbine arranged in the exhaust-gas removal system and a compressor arranged in the intake system, are advantageous, wherein the turbine and the compressor are arranged on the same rotatable shaft.

If the compressor of the at least one exhaust gas turbocharger and the supercharger are arranged in series, the compressor can be arranged downstream or upstream of the mechanical supercharger in the intake system.

Among other things, embodiments of the supercharged internal combustion engine in which the compressor of the at least one exhaust-gas turbocharger is arranged downstream of the mechanical supercharger in the intake system are advantageous. In the present case, the compressor of the exhaust gas turbocharger serves as a high-pressure stage, in which a shift of the surge line to smaller compressor streams is possible, so that even at low compressor flows high boost pressure ratios can be achieved and the torque characteristics in the lower speed range is significantly improved.

But can also be advantageous embodiments of the supercharged internal combustion engine, in which the compressor of the at least one exhaust gas turbocharger is arranged upstream of the mechanical supercharger in the intake system. Here, the mechanical supercharger is used as a high-pressure stage and the compressor of the at least one exhaust gas turbocharger as a low-pressure stage, which is interpreted to large compressor flows, d. H. is to be dimensioned accordingly.

Embodiments of the supercharged internal combustion engine in which a charge air cooler is arranged in the intake system downstream of the mechanical supercharger are advantageous. The intercooler lowers the air temperature and thus increases the density of the air, whereby the radiator to a better filling of the combustion chamber with air, d. H. contributes to a larger air mass.

Embodiments of the supercharged internal combustion engine in which exhaust gas recirculation is provided are advantageous.

In this context, embodiments of the supercharged internal combustion engine in which exhaust gas recirculation is provided, which includes a line which opens into the intake system downstream of the supercharger, are advantageous.

To comply with future limits for nitrogen oxide emissions, an exhaust gas recirculation is increasingly used, ie the return of exhaust gases from the exhaust side to the inlet side, in which the nitrogen oxide emissions can be significantly reduced with increasing exhaust gas recirculation rate. In this case, the exhaust gas recirculation rate x _{AGR is} determined by x _AGR = m _AGR / (m _AGR + m _{fresh air} ), where m _{AGR designates} the mass of recirculated exhaust gas and m _{fresh air} the charge air guided through the compressor and compressed.

Exhaust gas recirculation is also suitable for reducing emissions of unburned hydrocarbons in the partial load range. In order to achieve a significant reduction in nitrogen oxide emissions, high exhaust gas recirculation rates may be required, which may be on the order of x _AGR ≈ 60% to 70%.

Embodiments in which the line for exhaust gas recirculation leads downstream of a charge air cooler into the intake system are advantageous. In this way, the exhaust gas flow is not passed through the intercooler and consequently can not pollute this radiator by deposits of pollutants contained in the exhaust stream, in particular soot particles and oil.

Embodiments in which an additional cooler is provided in the exhaust gas recirculation line are advantageous. This additional cooler lowers the temperature in the hot exhaust gas flow and thus increases the density of the exhaust gases. The temperature of the cylinder fresh charge, which occurs in the mixture of fresh air with the recirculated exhaust gases, is consequently further reduced, whereby the additional radiator contributes to a better filling of the combustion chamber with charge air.

Embodiments in which a shut-off element is provided in the line for exhaust gas recirculation are advantageous. This shut-off element is used to control the exhaust gas recirculation rate.

The second sub-task underlying the invention, namely to show a method for operating a supercharged internal combustion engine of the type described above, is achieved by a method which is characterized in that when the second clutch is open, the first clutch is closed to the shaft of the electric machine connect the drive shaft of the mechanical supercharger and drive the mechanical supercharger, wherein the shaft of the electric machine is rotated at a speed n _shaft , which is greater than the speed n _{wheel of} the second wheel.

What has already been said for the internal combustion engine according to the invention also applies to the method according to the invention, which is why at this point in general reference is made to the statements made above with regard to the internal combustion engine according to the invention. The different internal combustion engines sometimes require different process variants.

• – bei geschlossener erster Kupplung den mechanischen Lader anzutreiben, und
• – die Elektromaschine zur Energierückgewinnung als Generator zu betreiben.

Advantageous embodiments of the method in which the traction mechanism, if the battery falls below a predetermined minimum state of charge, is operated in such a way that the rotational speed n _{wheel of} the second wheel is not smaller than the rotational speed n _{shaft of} the shaft of the electric machine

• - To drive the mechanical supercharger with the first clutch closed, and
• - To operate the electric machine for energy recovery as a generator.

In this case, embodiments of the method in which the bypass line of the mechanical supercharger is closed are advantageous.

If the speed n _{wheel of} the second wheel is not smaller than the speed n _{shaft of} the shaft of the electric machine, process variants are advantageous in which the first clutch is opened to operate the electric machine exclusively for energy recovery as a generator and to charge the battery by means of a generator.

• – das zweite Rad des Zugmitteltriebs kraftschlüssig mit der Welle der Elektromaschine zu verbinden, und
• – die Elektromaschine als Startvorrichtung zum Starten der Brennkraftmaschine zu betreiben, wobei die Batterie die erforderliche elektrische Energie liefert.

Embodiments of the method in which the first clutch is opened and the second clutch is closed are also advantageous

• - To connect the second wheel of the traction drive frictionally with the shaft of the electric machine, and
• - To operate the electric machine as a starting device for starting the internal combustion engine, the battery provides the required electrical energy.

With regard to the latter two variants of the method, embodiments are advantageous in which the bypass line of the mechanical supercharger is opened.

In the following the invention is based on an embodiment according to 1 described in more detail. Hereby shows:

1 schematically a first embodiment of the internal combustion engine.

1 shows a first embodiment of the supercharged internal combustion engine 1 the example of a four-cylinder in-line engine 1 ,

For discharging the hot exhaust gases have the four cylinders arranged in series 3 via an exhaust gas removal system 4 , Furthermore, the cylinders have 3 via an intake system 2 and a plenum 13 for supplying charge air.

The internal combustion engine 1 is with an exhaust gas turbocharger 6 equipped, the one in the exhaust system 4 arranged turbine 6a and one in the intake system 2 arranged compressor 6b includes, the turbine 6a and the compressor 6b are arranged on the same rotatable shaft and the turbine 6a has a variable turbine geometry.

Downstream of the compressor 6b is a charge air cooler 5 in the intake system 2 arranged. The intercooler 5 lowers the charge air temperature and thus increases the density of the air, which is why the radiator 5 to a better filling of the cylinder 3 contributes with charge air.

The internal combustion engine 1 is furthermore with a mechanical loader 8th equipped, the upstream of the compressor 6b in the intake system 2 is arranged and at least one on a drive shaft 8a arranged impeller has. A bypass line 8b is provided upstream of the charger 8th from the intake system 2 branches off and downstream of the loader 8th back into the intake system 2 opens and in the a shut-off 8c is arranged.

In addition, an electric machine 7 and a battery 9 intended. The wave 7a the electric machine 7 is by means of a first clutch 11 with the drive shaft 8a the loader 8th drivingly. The electric machine acts here 7 as a drive and the bypass line 8b is preferably closed.

A traction drive 10 is provided, in addition to the traction means on the crankshaft of the internal combustion engine 1 arranged first wheel 10a and one on the wave 7a the electric machine 7 arranged second wheel 10b includes. The second wheel 10b is a free wheel in one direction of rotation 10b which freewheels when the speed n _{shaft of} the shaft 7a the electric machine 7 is greater than the speed n _{wheel of} the second wheel 10b , The second wheel 10b can by means of a second clutch 12 with the wave 7a the electric machine 7 be positively connected.

When the second clutch is open 12 becomes the first clutch 11 closed to the shaft 7a the electric machine 7 with the drive shaft 8a of the mechanical loader 8th to connect and the mechanical loader 8th drive. At the same time the wave becomes 7a the electric machine 7 set in rotation with a speed n _shaft , which is greater than the speed n _{wheel of} the second wheel 10b so that the shaft 7a under the second wheel 10b through freely.

The electric machine 7 but can also be operated as a generator that receives power.

If the battery 9 falls below a predetermined minimum state of charge, the traction mechanism 10 operated in the way that the speed n _{wheel of} the second wheel 10b not less than the speed n _{shaft of} the shaft 7a the electric machine 7 , The electric machine 7 then serves as a generator for energy recovery. With the first clutch closed 11 In addition, the mechanical loader 8th are driven.

In overrun mode of the internal combustion engine 1 can the electric machine 7 basically be used as a generator for energy recovery, the battery 9 stores the power consumed by the generator as electrical energy.

When the first clutch is open 11 can the second clutch 12 be closed to the second wheel 10b of the traction mechanism drive 10 non-positive with the shaft 7a the electric machine 7 to connect and the electric machine 7 as starting device for starting the internal combustion engine 1 to operate, with the battery 9 provides the required electrical energy. The bypass line 8b of the mechanical loader 8th is preferably opened.

The second clutch 12 only needs to be closed when the electric machine acts as a starting device. For energy recovery, it is not necessary, the second clutch 12 close. This offers advantages in particular if the second clutch 12 An electromagnetic clutch is because the battery 9 in the context of energy recovery absorbs power and can not give or give off electrical energy.

LIST OF REFERENCE NUMBERS

1

 supercharged internal combustion engine, four-cylinder in-line engine

2

 intake system

3

 cylinder

4

 Abgasabführsystem

5

 Intercooler

6

 turbocharger

6a

 turbine

6b

 compressor

7

 electric machine

7a

 Wave of the electric machine

8th

 mechanical loader

8a

 Drive shaft of the loader

8b

 bypass line

8c

 shut-off

9

 battery

10

 traction drive

10a

 first bike

10b

 second wheel, in a direction of rotation freewheeling wheel

11

 first clutch

12

 second clutch

13

 plenum

n _shaft

 Speed of the shaft of the electric machine

n _wheel

 Speed of the second wheel

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• US 2008/0173017 A1 [0003, 0004, 0027, 0028]

Claims (16)

Charged internal combustion engine ( 1 ) with - a crankshaft, - an intake system ( 2 ) for supplying charge air, - an exhaust gas removal system ( 4 ) for discharging the exhaust gas, - a mechanical loader ( 8th ) in the intake system ( 2 ) is arranged and the at least one on a drive shaft ( 8a ) arranged impeller and a bypass line ( 8b ) located downstream of the charger ( 8th ) into the intake system ( 2 ), - an electric machine ( 7 ), which have a wave ( 7a ) and as a drive motor by means of a first clutch ( 11 ) with the drive shaft ( 8a ) of the loader ( 8th ) is driveabverbindverbindbar, and - a battery ( 9 ), characterized in that - the electric machine ( 7 ) is operable as a generator that absorbs power, - a traction drive ( 10 ) is provided, which in addition to the traction means on the crankshaft of the internal combustion engine ( 1 ) arranged first wheel ( 10a ) and one on the shaft ( 7a ) of the electric machine ( 7 ) arranged second wheel ( 10b ), wherein the second wheel ( 10b ) a wheel running freely in one direction of rotation ( 10b ) which freewheels when the rotational speed n _{shaft of} the shaft ( 7a ) of the electric machine ( 7 ) is greater than the speed n _{wheel of} the second wheel ( 10b ), and the wave ( 7a ) of the electric machine ( 7 ) by means of a second clutch ( 12 ) with the second wheel ( 10b ) is drive-connected. Charged internal combustion engine ( 1 ) according to claim 1, characterized in that the shaft ( 7a ) of the electric machine ( 7 ) by means of the first clutch ( 11 ) with the drive shaft ( 8a ) of the mechanical loader ( 8th ) is drive-connected. Charged internal combustion engine ( 1 ) according to claim 2, characterized in that the bypass line ( 8b ) of the mechanical loader ( 8th ) closed is. Charged internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that the electric machine ( 7 ) serves as a generator for energy recovery and the battery ( 9 ) stores the power consumed by the generator as electrical energy. Charged internal combustion engine ( 1 ) according to claim 1, characterized in that the shaft ( 7a ) of the electric machine ( 7 ) by means of the second clutch ( 12 ) with the second wheel ( 10b ) of the traction mechanism drive ( 10 ) is drive-connected. Charged internal combustion engine ( 1 ) according to claim 5, characterized in that the electric machine ( 7 ) as starting device for starting the internal combustion engine ( 1 ) and the battery ( 9 ) supplies the required electrical energy. Charged internal combustion engine ( 1 ) according to one of claims 4 to 6, characterized in that the bypass line ( 8b ) of the mechanical loader ( 8th ) is open. Charged internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that at least one exhaust gas turbocharger ( 6 ) is provided, the one in Abgasabführsystem ( 4 ) arranged turbine ( 6a ) and one in the intake system ( 2 ) arranged compressors ( 6b ), wherein the turbine ( 6a ) and the compressor ( 6b ) are arranged on the same rotatable shaft. Charged internal combustion engine ( 1 ) according to claim 8, characterized in that the compressor ( 6b ) of the at least one exhaust gas turbocharger ( 6 ) downstream of the mechanical loader ( 8th ) in the intake system ( 2 ) is arranged. Charged internal combustion engine ( 1 ) according to claim 8, characterized in that the compressor ( 6b ) of the at least one exhaust gas turbocharger ( 6 ) upstream of the mechanical supercharger ( 8th ) in the intake system ( 2 ) is arranged. Method for operating a supercharged internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that when the second clutch is open ( 12 ) the first clutch ( 11 ) is closed to the shaft ( 7a ) of the electric machine ( 7 ) with the drive shaft ( 8a ) of the mechanical loader ( 8th ) and the mechanical loader ( 8th ), whereby the wave ( 7a ) of the electric machine ( 7 ) is rotated at a speed n _shaft , which is greater than the speed n _{wheel of} the second wheel ( 10b ). A method according to claim 11, characterized in that the traction mechanism drive ( 10 ), if the battery ( 9 ) is below a predetermined minimum state of charge, is operated in such a way that the speed n _{wheel of} the second wheel ( 10b ) is not smaller than the rotational speed n _{shaft of} the shaft ( 7a ) of the electric machine ( 7 ), to - when the first clutch is closed ( 11 ) the mechanical loader ( 8th ), and - the electric machine ( 7 ) to operate as a generator for energy recovery. A method according to claim 11 or 12, characterized in that the bypass line ( 8b ) of the mechanical loader ( 8th ) is closed. Method according to claim 12, characterized in that the first clutch ( 11 ) is opened to the electric machine ( 7 ) to operate as a generator for energy recovery and the battery ( 9 ) by means of a generator. Method according to claim 11, characterized in that the first clutch ( 11 ) and the second clutch ( 12 ) is closed to - the second wheel ( 10b ) of the traction mechanism drive ( 10 ) frictionally with the shaft ( 7a ) of the electric machine ( 7 ), and - the electric machine ( 7 ) as starting device for starting the internal combustion engine ( 1 ), whereby the battery ( 9 ) supplies the required electrical energy. A method according to claim 14 or 15, characterized in that the bypass line ( 8b ) of the mechanical loader ( 8th ) is opened.

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