DE102020004928A1 - Method for operating a turbocharger of a motor vehicle, in particular a motor vehicle - Google Patents

Abstract

The invention relates to a method for operating a turbocharger (10) of a motor vehicle, in which the turbocharger (10) has a compressor wheel (38) for compressing air to be supplied to an energy converter (12) of the motor vehicle and a turbine wheel that can be driven by exhaust gas from the energy converter (12). (42), wherein in at least one operating state of the turbocharger (10) a first speed of the compressor wheel (38) is set by means of a first electric machine (68) of the turbocharger (10) and by means of a second speed provided in addition to the first electric machine (68). electrical machine (70) of the turbocharger (10), a second speed, different from the first speed, of the turbine wheel (42), which can be rotated in at least one direction of rotation relative to the compressor wheel (38), is set, whereby the compressor wheel (38) rotates at the first speed and at the same time the turbine wheel (42) is operated at the second speed, which is different from the first speed.

Description

The invention relates to a method for operating a turbocharger of a motor vehicle, in particular a motor vehicle, according to the preamble of patent claim 1.

the DE 103 06 234 B4 discloses a method for supplying air to a fuel cell with an expander and a compressor driven at least partially by it, with hot exhaust gases from combustion in a burner flowing through the expander at least at times.

The object of the present invention is to create a method for operating a turbocharger of a motor vehicle, so that particularly advantageous operation can be implemented.

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

The invention relates to a method for operating a turbocharger of a motor vehicle, in particular a motor vehicle. The motor vehicle is preferably designed as a commercial vehicle, but the motor vehicle could alternatively be designed as a passenger car. In the method, the turbocharger has a compressor wheel, by means of which air is compressed or is to be compressed, which air is to be supplied or is being supplied to an energy converter of the motor vehicle. This means that the motor vehicle has the turbocharger and the energy converter in its fully manufactured state. The energy converter is, for example, an internal combustion engine, which can be designed in particular as a reciprocating piston engine. In particular, the internal combustion engine can be an Otto engine or else a diesel engine. In this case, the internal combustion engine has at least one combustion chamber, to which the air compressed by means of the compressor is or is to be supplied. In this case, the motor vehicle can be or is driven by means of the internal combustion engine. It is also conceivable that the energy converter is a fuel cell or comprises at least one or more fuel cells, with chemical reaction energy of a fuel fed, in particular continuously, to the fuel cell and an oxidizing agent being convertible or being converted into electrical energy by means of the fuel cell. The fuel is preferably hydrogen (H ₂ ). Oxygen from the air that is to be or is being supplied to the fuel cell is preferably used as the oxidizing agent. Thus, the motor vehicle can include the fuel cell in its fully manufactured state. In addition, the motor vehicle can have at least one electric traction machine, for example, which can be supplied with the electrical energy provided by the fuel cell. As a result, the traction machine can be operated as an electric drive motor, by means of which the motor vehicle, in particular purely electrically, can be driven or is driven. The motor vehicle can thus be designed as a motor vehicle that can be driven purely by an internal combustion engine, as a hybrid vehicle or as an electric vehicle, in particular as a hydrogen-electric vehicle. The internal combustion engine, also referred to as an internal combustion engine, can also be a hydrogen engine, ie a hydrogen internal combustion engine, in which hydrogen as the fuel is combusted with the air during fired operation of the internal combustion engine.

The turbocharger also has a turbine wheel that can be driven by exhaust gas from the energy converter. The exhaust gas can be air provided by the energy converter and also referred to as exhaust air, in particular when the energy converter is or includes the aforementioned fuel cell. Furthermore, the exhaust gas can be, for example, an exhaust gas that results from combustion processes that take place in the energy converter, in particular in the internal combustion engine and very particularly in the aforementioned combustion chamber. As part of the respective combustion process, a fuel-air mixture is burned, for example, from which the exhaust gas results or is formed.

The fuel-air mixture includes, for example, the air supplied to the energy converter, in particular the internal combustion engine and in particular the combustion chamber, and an in particular liquid or gaseous fuel which is supplied to the energy converter, in particular the internal combustion engine and in particular the combustion chamber. The fuel can be an Otto fuel or a diesel fuel or else hydrogen. The combustion processes drive, for example, a piston that partially delimits the combustion chamber and uses it to drive an output shaft of the energy converter, in particular the internal combustion engine, embodied as a crankshaft, whereby the energy converter can or does drive the motor vehicle via the output shaft.

To now a particularly advantageous operation of the turbocharger and thus the energy To be able to realize the converter as a whole, it is provided according to the invention that in at least one operating state of the turbocharger a first speed of the compressor wheel is set and thus effected by means of a first electric machine of the turbocharger. In the at least one operating state of the turbocharger, a second electric machine of the turbocharger, which is provided in addition to the first electric machine, sets a second speed, which differs from the first speed, of the turbine wheel, which can be rotated in at least one direction of rotation relative to the compressor wheel, and thus causes the compressor wheel to rotate is operated at the first speed and at the same time the turbine wheel is operated at the second speed, which is different from the first speed. This means that at least in the at least one operating state, the compressor wheel and the turbine wheel, which are also referred to collectively as impellers, are mechanically decoupled or separated from one another at least in such a way that the turbine wheel can be rotated at least in at least one direction of rotation relative to the compressor wheel, in particular is rotated. Thus, at least in the at least one operating state, the impellers rotate simultaneously at speeds that differ from one another. As a result, the speeds of the running wheels can advantageously be adapted to the respective operating points of the energy converter, in particular in such a way that the speeds differ from one another. This means in particular that the second speed is greater or less than the first speed, so that during the at least one operating state the impellers rotate simultaneously at different speeds and thus in particular relative to one another. As a result, a particularly high degree of efficiency of the turbocharger and thus of the energy converter can be created.

The turbine wheel is, for example, part of a turbine of the turbocharger, through which the exhaust gas can flow. The turbine can include a turbine housing through which the exhaust gas can flow and in which the turbine wheel is rotatably arranged. Thus, for example, the turbine wheel can rotate about a turbine wheel axis of rotation relative to the turbine housing. It is also conceivable for the turbocharger to have a compressor through which the air to be compressed can flow. The compressor can have a compressor housing in which the compressor wheel is rotatably arranged. Thus, the compressor wheel can rotate about a compressor wheel axis of rotation relative to the compressor housing. The turbine wheel axis of rotation and the compressor wheel axis of rotation preferably run parallel to one another. The impellers are preferably arranged coaxially with one another, so that the axis of rotation of the turbine wheel coincides with the axis of rotation of the compressor wheel, or vice versa. It is also conceivable for the compressor housing and the turbine housing to be components of a turbocharger housing, with the turbine housing and the compressor housing being able to be designed separately from one another and connected to one another. The impellers are thus arranged, for example, in the common turbocharger housing. It is preferably provided that the electrical machines are also arranged in the turbocharger housing. Since, at least in the at least one operating state, the impellers rotate simultaneously at different speeds, in particular around the turbine wheel axis of rotation or around the compressor wheel axis of rotation and relative to the turbocharger housing, the compressor and the turbine are speed-independent at least in the at least one operating state, i.e. in With regard to the speeds of the impellers operated independently.

The invention is based in particular on the following findings: In conventional drive devices that have at least one energy converter such as an internal combustion engine, also referred to as an internal combustion engine, and/or a fuel cell and, if appropriate, at least one or more other units, an air supply device is used to convert the energy converter to be supplied with air, in particular with compressed air. In such a conventional air supply device, the compressor and the turbine or its impellers are mechanically connected to one another in such a way that the impellers are mechanically and permanently non-rotatably connected to one another, so that the impellers always rotate at the same speed and thus together relative to the turbocharger housing.

This can bring disadvantages, since the design of the turbine and the design of the compressor are mutually dependent and are therefore carried out with compromises. This can now be avoided since the compressor wheel and the turbine wheel are mechanically separated from one another at least in the at least one operating state such that the turbine wheel can rotate at least in the at least one direction of rotation relative to the compressor wheel. For example, an electrical coupling of the running wheels is provided, which means in particular that the electrical machines are electrically coupled to one another. This electrical coupling of the electrical machines and thus the wheels is to be understood in particular that the electrical machines, in particular by means of an electronic computing device, are operated in dependence on each other, so it is conceivable that the speeds of the wheels in dependence be set by each other. Due to the mechanical separation or decoupling of the impellers, the compressor and the turbine can be particularly advantageously adapted to respective, different operating points of the energy converter with regard to the speeds of the impellers. This means that the respective speeds and thus the respective high-speed ratios of the compressor and the turbine can deviate from one another, so that a particularly high degree of efficiency of the turbocharger and thus of the energy converter can be achieved.

The electrical coupling takes place, for example, via an electrical interface, via which the electrical machines are actuated, for example, by the electronic computing device common to the electrical machines, and are thus operated, in particular regulated or controlled. The electronic computing device is preferably part of the motor vehicle. Since the speeds are different from one another, the compressor or the compressor wheel can run or rotate slower or faster than the turbine or the turbine wheel. The speeds are set, for example, solely by or as a function of key figures.

It has proven to be advantageous if the respective electrical machine has an electrical voltage, in particular an electrical operating or nominal voltage, which is greater than 12 volts, in particular greater than 30 volts. The electrical voltage, in particular the electrical operating or nominal voltage, of the respective electrical machine is preferably at least 48 volts. It has proven to be particularly advantageous if the electrical voltage, in particular the electrical operating or nominal voltage, of the respective electrical machine is greater than 50 volts, in particular greater than 60 volts, and preferably amounts to several hundred volts. In other words, it has proven to be particularly advantageous if the electrical machines are operated at least in the at least one operating state simultaneously with respective electrical voltages, in particular electrical operating or nominal voltages, with the electrical voltage, in particular the electrical operating or nominal voltage, of the first electrical machine and at the same time the electrical voltage, in particular the electrical operating or nominal voltage, of the second electrical machine is greater than 12 volts, in particular greater than 30 volts, and is preferably at least or exactly 48 volts, or is greater than 48 volts, preferably greater than 50 volts, more preferably greater than 60 volts, and most preferably several hundred volts. In particular, the electrical voltage, in particular the electrical operating or nominal voltage, can be 12 volts, 24 volts, 48 volts, 400 volts or 800 volts. It is also conceivable that the electrical voltage is at least or exactly 12 volts, in particular at least or exactly 24 volts. The electrical machine can thus draw electrical energy from and/or feed it into the vehicle electrical system, the electrical voltage of which, in particular electrical operating or nominal voltage, is preferably greater than 12 volts, in particular greater than 30 volts, and is very preferably 48 volts or is greater than 48 volts, in particular greater than 50 volts and most particularly greater than 60 volts, or is preferably several hundred volts. It is therefore preferably provided that the respective electrical machine is a high-voltage component, which is also referred to as a high-voltage component. It is therefore preferably provided that the respective electric machine can be operated or is operated by means of high voltage of, for example, 800 volts. As a result, the space requirement, the costs and the weight of the electrical machine can be kept particularly low, and electrical losses can be kept particularly low, in particular in comparison with low-voltage systems. Due to the mechanical decoupling or separation of the impellers at least in the at least one operating state and at least in the at least one direction of rotation, respective characteristic diagrams of the turbine and the compressor can be used particularly advantageously, as a result of which the turbocharger and thus the energy converter can be operated particularly effectively and efficiently. As a result, the energy consumption, in particular the fuel consumption, of the energy converter, in particular of the internal combustion engine, can be kept particularly low.

The turbocharger, in particular at least one of the electrical machines, can be operated, for example, as a generator whose electrical voltage, in particular electrical operating or nominal voltage, can be, for example, at least 12 volts or at least 24 volts or at least 48 volts or more, with the generator being electrical Can provide energy with which at least one or more ancillaries such as an electric water pump and / or an electric oil pump can be supplied in particular bypassing the vehicle electrical system. Thus, the ancillary unit, which can be supplied, for example, with a first electrical voltage, i.e. can be operated using the first electrical voltage, can be supplied with electrical energy by means of the generator, with the vehicle electrical system simultaneously having a voltage that is significantly greater than the first electrical voltage and, for example, at least ten times higher , second may have electrical voltage. In particular, the one electrical machine that can be operated as a generator can be the second electrical machine that can be driven, for example, by the turbine wheel, which in turn can be driven by the exhaust gas. As a result, energy contained in the exhaust gas can be converted into electrical energy, which is provided by the generator, by means of the generator.

The turbocharger is preferably designed as a single-stage turbocharger, by means of which the air can be compressed exactly once, ie on a single stage. It has proven to be advantageous if the motor vehicle as a whole has a single-stage compression implemented by means of the turbocharger, so that the entire motor vehicle can compress the air to be supplied to the energy converter only exactly once, i.e. at exactly one stage, by means of the compressor.

The motor vehicle can have at least one energy store designed to store electrical energy, which is also referred to as an electrical energy store. The electrical energy store can be a battery, in particular a high-voltage battery, so that the previous and following statements on the electrical voltage, in particular on the electrical operating or nominal voltage, of the respective electrical machine can also be easily applied to the energy store and vice versa. It is therefore conceivable that the electrical energy that is provided by the turbocharger, in particular by one electric machine and is fed into the vehicle electrical system, for example, can be supplied to the energy storage device in particular via the vehicle electrical system and stored in the energy storage device. It is thus conceivable, for example, that one of the electrical machines or both electrical machines, in particular the vehicle electrical system, can be supplied with the electrical energy stored in the energy store in order to operate the respective electrical machine as an electric motor.

Overall, it can be seen that the compressor and the turbine can be or are being operated mechanically independently of one another with regard to the speeds of the rotors, so that particularly advantageous thermal-dynamic conditions can be set. As a result, its energy or fuel consumption can be kept particularly low in the entire characteristic map of the energy converter and/or in special operationally relevant areas. In addition, the respective electric machine can provide electrical support and thereby drive the respective impeller, so that a particularly fast response or starting behavior of the turbocharger can be implemented. In addition, an advantageous heat or thermal management of the energy converter can be presented. In comparison to conventional exhaust gas turbochargers, there is also no need to use a bypass device, also known as a waste gate or waste gate valve, via which at least part of the exhaust gas can bypass the turbine wheel, for example, so that the costs, the installation space requirement and the weight can be kept to a particularly low level

In order to be able to implement particularly advantageous operation, one embodiment of the invention provides that, in the at least one operating state, the first electric machine is operated in motor mode and thereby as an electric motor. For this purpose, for example, the first electrical machine is supplied with electrical energy stored in the energy store. The compressor wheel is driven by the electric motor, as a result of which the first rotational speed of the compressor wheel is set and the air is compressed by means of the compressor wheel. As a result, the air can also be compressed in a particularly advantageous manner and, as a result, the energy converter can also be supplied with air compressed by means of the compressor in a particularly advantageous manner when the energy converter provides no or only a small amount of exhaust gas, i.e. when the compressor wheel does not or only with a low power can be driven by the turbine wheel.

A further embodiment is characterized in that in the at least one operating state the second electrical machine is operated in generator mode and thereby as a generator, which is driven by means of the turbine wheel, setting the second speed of the turbine wheel, which is driven by the exhaust gas of the energy converter . As a result, energy contained in the exhaust gas of the energy converter can be used to drive the turbine wheel and, via this, the second electrical machine. Thus, by means of the turbine wheel and by means of the generator, energy contained in the exhaust gas of the energy converter is converted into electrical energy, which is provided by the generator and stored, for example, in the energy store and/or can be used directly to generate at least one or more electrically operable components, such as to operate the first electrical machine and/or a pump electrically. As a result, particularly energy-efficient operation can be implemented.

It has also been shown to be particularly advantageous if, in the at least one operating state, the compressor wheel and the turbo rotate the wheel in the same direction of rotation. In this way, a particularly efficient and effective operation can be achieved. This same direction of rotation, in which the running wheels rotate simultaneously, in particular at different speeds, is in particular a second direction of rotation opposite to the at least one direction of rotation.

In order to be able to implement a particularly efficient operation of the turbocharger and thus of the energy converter in a particularly cost-effective manner, it is provided in a further embodiment of the invention that the compressor wheel and the turbine wheel are completely mechanically decoupled from one another, in particular permanently, so that the turbine wheel can be at least one direction of rotation and in the at least one direction of rotation opposite, second direction of rotation, in particular freely, that is unlimited, limitless or infinitely often, is rotatable relative to the compressor wheel. This is to be understood in particular as meaning that the turbocharger and in particular the motor vehicle as a whole is free of a coupling device, by means of which the running wheels are or can be coupled to one another in a torque-transmitting, in particular non-rotatable manner. As a result, the speeds of the impellers can be set as required, so that the turbocharger can be adapted to the respective operating points of the energy converter as required.

In order to be able to implement a particularly energy-efficient operation of the turbocharger and thus of the energy converter, it is provided in a further embodiment of the invention that the turbine wheel can be rotated in the at least one direction of rotation, in particular freely and therefore unlimitedly, limitlessly or infinitely often, relative to the compressor wheel , wherein the turbine wheel is coupled to the compressor wheel in a torque-transmitting manner, in particular in a rotationally fixed manner, in the second direction of rotation, which is opposite to the at least one direction of rotation. In other words, the turbine wheel is rotated, for example, in the at least one direction of rotation, which is also referred to as the first direction of rotation, for example in such a way that the compressor wheel does not rotate in the first direction of rotation or that the compressor wheel rotates at a lower speed than the turbine wheel in the first direction first direction of rotation is rotated, the turbine wheel is rotated in the first direction of rotation relative to the compressor wheel or the turbine wheel rotates in the first direction of rotation at a higher speed and thus faster than the compressor wheel. However, if the turbine wheel is rotated in the second direction of rotation, in which the turbine wheel is coupled to the compressor wheel in a torque-transmitting manner, in particular in a torque-proof manner, the turbine wheel takes the compressor wheel with it, and the turbine wheel therefore drives the compressor wheel, so that the compressor wheel with the turbine wheel rotates in the second direction of rotation is also rotated. This also means that the compressor wheel can rotate in the second direction of rotation relative to the turbine wheel, so that, for example, the impellers can rotate simultaneously in the second direction of rotation, such that the compressor wheel rotates in the second direction of rotation at a greater speed than the turbine wheel , and the compressor wheel may rotate in the second direction of rotation relative to the turbine wheel while rotating the turbine wheel in the second direction of rotation. If the compressor wheel is rotated in the second direction of rotation, the compressor wheel does not take the turbine wheel with it in the second direction of rotation, and the turbine wheel is therefore not driven or rotated in the second direction of rotation by the compressor wheel.

In other words, the compressor wheel can overtake the turbine wheel in the second direction of rotation, in particular in the manner of a freewheel arranged between the running wheels, so that the turbine wheel is not driven by the compressor wheel. The compressor wheel does not take the turbine wheel with it when the compressor wheel is rotated in the second direction of rotation. However, if the turbine wheel is rotated in the second direction of rotation, which is opposite to the first direction of rotation, the turbine wheel drives the compressor or the turbine wheel takes the compressor wheel with it. Conversely, this means that when the turbine wheel is rotated in the first direction of rotation, the turbine wheel does not take the compressor wheel with it, so that the turbine wheel does not drive the compressor wheel in the first direction of rotation. The turbine wheel can thus drive the compressor wheel in the second direction of rotation, so that, for example, the compressor wheel can be driven via the turbine wheel by means of the exhaust gas of the energy converter and can be rotated in the second direction of rotation. However, for example, the first electrical machine can drive the compressor wheel and thereby rotate in the second direction of rotation relative to the turbine wheel, without the turbine wheel being driven by the compressor wheel or by the first electrical machine. The compressor wheel can rotate faster in the second direction of rotation than the turbine wheel, so that when the energy converter provides the exhaust gas, the turbine wheel can be driven by the exhaust gas and rotated in the second direction of rotation, but for example at a lower speed than the compressor wheel . Thus, the impellers can rotate simultaneously in the second direction of rotation, but at different speeds or rotational speeds that are greater than zero.

This torque-transmitting or non-rotatable coupling of the wheels can be realized, for example, via the aforementioned freewheel. Thus, for example, the freewheel releases the turbine wheel for rotation relative to the compressor wheel in the first direction of rotation, with the freewheel locking the turbine wheel against rotation in the second direction of rotation relative to the compressor wheel. This makes it possible to realize in a particularly cost-effective manner that, on the one hand, the compressor wheel can be driven by the turbine wheel using the exhaust gas from the energy converter and, on the other hand, the first electric machine can drive the compressor wheel without driving the turbine wheel, while the turbine wheel can be driven by exhaust gas from the energy converter or is driven. A particularly advantageous operation can be ensured in this way.

In order to be able to implement a particularly needs-based and thus advantageous operation, it is provided in a further embodiment of the invention that a coupling device of the turbocharger is switched over from a first state to a second state. In one of the states, the coupling device releases the turbine wheel at least for one, preferably free, rotation in the at least one direction of rotation relative to the compressor wheel, so that in one state the turbine wheel rotates at least in the first direction of rotation, and preferably also in the second direction of rotation. can be rotated freely and thus indefinitely relative to the compressor wheel. In the other state, however, the turbine wheel is coupled to the compressor wheel by means of the coupling device in such a way that the turbine wheel transmits torque to the compressor wheel by means of the coupling device at least in the at least one direction of rotation and preferably also in the second direction of rotation opposite to the at least one direction of rotation, in particular non-rotatably. is coupled. In one state, the coupling device preferably also releases the compressor wheel and the turbine wheel for rotation, in particular free rotation, relative to one another in the second direction of rotation. The coupling device can, for example, provide a magnetic field and thus magnetic forces in the other state, so that in the other state the running wheels are coupled to one another as described by means of the magnetic field or by means of the magnetic forces. In one state, the magnetic field is not provided by the coupling device, so that in one state the running wheels can be rotated relative to one another at least in the at least one direction of rotation and preferably also in the second direction of rotation. As a result, the impellers can be mechanically coupled to one another and decoupled from one another in a particularly need-based manner, so that operation that is particularly needs-based and therefore more effective and efficient can be represented.

In a particularly advantageous embodiment of the invention, it is provided that in at least one further operating state of the turbocharger, a third speed of the compressor wheel is set by means of the first electric machine and a fourth speed of the turbine wheel, which corresponds to the third speed, is set by means of the second electric machine, whereby the Compressor wheel with the third speed and at the same time the turbine wheel is operated with the fourth speed. The third and fourth speeds may correspond to the first or the second speed, with the third speed and the fourth speed being the same. Thus, the turbocharger is preferably also designed to operate the turbine and the compressor in terms of their speeds at the same speed and thus at the same speed, so that the impellers, at least in the at least one other operating state, rotate at the same time or at the same speed, in particular relative to the Turbocharger housing, rotate. This can be the case in particular when the turbine wheel drives the compressor wheel and thereby rotates, for example, in the at least one direction of rotation.

It has thus proven to be advantageous if, in the at least one further operating state, the compressor wheel and the turbine wheel rotate in the same direction of rotation, in particular in the second direction of rotation.

In a further advantageous embodiment of the invention, the aforementioned electronic computing device is provided, by means of which the electrical machines are controlled, as a result of which the speeds are set. Controlling is to be understood in particular as meaning that the electronic computing device provides signals, in particular electrical signals, which are received by the electrical machines. As a result, the electrical machines are controlled and thereby operated, in particular controlled or regulated.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without going beyond the scope of the leave invention.

• 1 eine schematische Schnittansicht eines Turboladers für einen Energiewandler eines Kraftfahrzeugs;
• 2 eine schematische Darstellung einer Antriebseinrichtung des Kraftfahrzeugs, dessen Antriebseinrichtung den Energiewandler und den Turbolader gemäß einer ersten Ausführungsform umfasst;
• 3 eine schematische Darstellung des Turboladers gemäß der ersten Ausführungsform;
• 4 eine schematische Darstellung des Turboladers gemäß einer zweiten Ausführungsform;
• 5 eine schematische Darstellung des Turboladers gemäß einer dritten Ausführungsform; und
• 6 eine schematische Darstellung des Turboladers gemäß einer vierten Ausführungsform.

The drawing shows in:

• 1 a schematic sectional view of a turbocharger for an energy converter of a motor vehicle;
• 2 a schematic representation of a drive device of the motor vehicle, the drive device of which comprises the energy converter and the turbocharger according to a first embodiment;
• 3 a schematic representation of the turbocharger according to the first embodiment;
• 4 a schematic representation of the turbocharger according to a second embodiment;
• 5 a schematic representation of the turbocharger according to a third embodiment; and
• 6 a schematic representation of the turbocharger according to a fourth embodiment.

Elements that are the same or have the same function are provided with the same reference symbols in the figures.

1 shows a schematic sectional view of a turbocharger 10 for a 2 particularly schematically illustrated energy converter 12 of a preferably designed as a motor vehicle motor vehicle. This means that the motor vehicle in its fully manufactured condition has an in 2 includes a particularly schematic illustrated drive device 14, by means of which the motor vehicle can be driven. The drive device 14 includes the energy converter 12 and the turbocharger 10, which is explained in more detail below. At the in 1 and 2 In the exemplary embodiment shown, energy converter 12 is embodied as an internal combustion engine, also referred to as an internal combustion engine and designed as a reciprocating piston machine, which has a housing element 16 embodied, for example, as a cylinder housing, in particular as a cylinder crankcase, which has, delimits or forms a plurality of cylinders 18, in this case exactly six. In the present example, the cylinders 18 are arranged in a row, so that the internal combustion engine is designed as an in-line engine, in particular as a six-cylinder in-line engine. The energy converter 12 also has an output shaft 20, via which the energy converter 12 can provide torque for driving the motor vehicle. In the respective cylinder 18, a respective piston is accommodated in a translationally movable manner, which is connected in an articulated manner to the output shaft 20, which is preferably designed as a crankshaft. As a result, the translatory movements of the piston can be converted into a rotary movement of the output shaft 20 . The respective cylinder 18 and the respective piston arranged therein delimit a respective combustion chamber 22 of the energy converter 12. During fired operation of the energy converter 12, combustion processes take place in the respective combustion chamber 22, during which a respective fuel-air mixture is burned. This results in exhaust gas from the energy converter 12. The fuel-air mixture comprises at least one fuel and air. The fuel can be a liquid fuel such as diesel fuel or gasoline. Furthermore, the fuel can be a gaseous fuel such as, in particular, hydrogen (H ₂ ). The internal combustion engine can thus be designed as an Otto engine or as a diesel engine or as a gas engine, in particular as a hydrogen internal combustion engine.

The energy converter 12 has an exhaust gas tract 24 through which the exhaust gas from the combustion chamber 22 can flow, which can have two flows 26a, b. The flows 26a, b are at least partially fluidically separated from one another, with the exhaust gas from exactly three first combustion chambers 22 being combined to form the flow 26a and the exhaust gas from exactly three second combustion chambers 22 to be combined to form the flow 26b.
The turbocharger 10, which is presently designed as an exhaust gas turbocharger, has a compressor 28 and a turbine 30. In addition, the turbocharger 10 includes a turbocharger housing 32, which is preferably designed in several parts and thus has at least one first housing part and at least one second housing part. The housing parts can be formed separately from one another and connected to one another. The first housing part is, for example, a compressor housing 34 of the compressor 28 , the second housing part being a turbine housing 36 of the turbine 30 , for example. In this case, the compressor 28 comprises a compressor wheel 38 which is arranged rotatably in the compressor housing 34 and which can be rotated about a compressor wheel axis of rotation 40 relative to the turbocharger housing 32 . The turbine 30 includes a turbine wheel 42 which is rotatably arranged in the turbine housing 36 and which can be rotated about a turbine wheel axis of rotation 44 relative to the turbocharger housing 32, which is also simply referred to as the housing. the end 1 it can be seen that the compressor wheel 38 and the turbine wheel 42, which are also referred to collectively as impellers, are arranged coaxially with one another, so that the compressor wheel axis of rotation 40 coincides with the turbine wheel axis of rotation 44 or vice versa. This means that the compressor wheel axis of rotation 40 and the turbine wheel axis of rotation 44 lie on a common axis of rotation about which the impellers can be rotated relative to the turbocharger housing 32 .

The compressor wheel 38 is, for example, a component of a first rotor 46 of the compressor 28 . The rotor 46 is mounted on the turbocharger housing 32 such that it can rotate about the axis of rotation relative to the turbocharger housing 32 . For this purpose, for example, bearings 48 are provided, which can be designed as roller bearings. The rotor 46 is rotatably mounted on the turbocharger housing 32 via the bearings 48 . The bearings 48 are spaced apart from one another in the axial direction of the rotor 46, the axial direction of the rotor 46 coinciding with the axis of rotation. The rotor 46 can have a first shaft 50, the compressor wheel 38 being connected to the shaft 50 in a rotationally fixed manner. In particular, the compressor wheel 38 can be formed in one piece with the shaft 50 . It can be seen that the rotor 46 is rotatably mounted on the turbocharger housing 32 via the shaft 50 .

The turbine wheel 42 can be part of a second rotor 52 of the turbine 30 . The rotor 52 includes a second shaft 54, with the turbine wheel 42 being connected to the shaft 54 in a rotationally fixed manner. In particular, the turbine wheel 42 can be formed in one piece with the shaft 54 . The rotor 52 is mounted on the turbocharger housing 32 via its shaft 54 so as to be rotatable about the axis of rotation relative to the turbocharger housing 32 . The shaft 54 is rotatably mounted on the turbocharger housing 32 via further bearings 56, the bearings 56 being able to be in the form of roller bearings. The bearings 56 are also spaced apart from one another in the axial direction of the rotor 52 , the axial direction of the rotor 52 coinciding with the axis of rotation and thus with the axial direction of the rotor 46 .

At the in 1 shown embodiment, the compressor 28 is designed as a radial compressor, so that the compressor wheel 38 is designed as a radial compressor wheel. The aforementioned air, which is to be supplied or is being supplied to the energy converter 12 , can be compressed by means of the compressor wheel 38 . For this purpose, the compressor wheel 38 is rotated about the axis of rotation relative to the turbocharger housing 32 . the end 2 it can be seen that the drive device 14 has an intake tract 58 through which the air can flow, by means of which the air flowing through the intake tract 58 is guided to and into the combustion chambers 22 and thus to and into the energy converter 12 . The air flowing through the intake tract 58 is compressed by means of the compressor wheel 38 .

In this case, an air filter 60 is arranged in the intake tract 58 upstream of the compressor wheel 38, by means of which the air flowing through the intake tract 58 is filtered. The air has a first pressure p1 upstream of the compressor wheel 38 and downstream of the air filter 60 . The air flowing through the intake tract 58 is compressed and thereby heated by means of the compressor wheel 38 . In order nevertheless to achieve particularly high degrees of supercharging, an intercooler 62 is arranged in the intake tract 58 upstream of the combustion chambers 22 and downstream of the compressor wheel 38 . The air flowing through the charge air cooler 62 is cooled by means of the charge air cooler 62 after it has been compressed. Compressor wheel 38 is used to compress the air from pressure p1 to a second pressure p2, which prevails in relation to pressure p1 and which prevails in intake tract 58 downstream of compressor wheel 38 and upstream of charge air cooler 62 .

the end 2 It can be seen that the compressor 28 and thus the compressor wheel 38 are arranged in the intake tract 58, namely downstream of the air filter 60 and upstream of the charge air cooler 62.

As in 1 is illustrated by an arrow 64, the air to be compressed by means of the compressor wheel 38 flows in the axial direction of the compressor wheel 38 onto the compressor wheel 38. The air compressed by means of the compressor wheel 38 flows off the compressor wheel 38 in the radial direction of the compressor wheel 38 . The air flows through the compressor housing 34. Furthermore, is off 1 and 2 recognizable that the turbine 30 and thus the turbine wheel 42 are arranged in the exhaust tract 24, namely downstream of the combustion chambers 22. The turbine 30, in particular the turbine housing 36, can be flowed through by the exhaust gas from the combustion chambers 22, with the turbine wheel 42 being Exhaust gas from the combustion chambers 22 can be driven and thereby rotated about the axis of rotation relative to the turbocharger housing 32 . The turbine 30 is designed as a radial turbine, so that the turbine wheel 42 is also designed as a radial turbine wheel. This means that the exhaust gas from the combustion chambers 22 flows against the turbine wheel 42 in the radial direction of the turbine wheel 42 and thereby drives it, after which the exhaust gas flows out of the turbine wheel 42 in the axial direction of the turbine wheel 42 . this is in 1 illustrated by arrow 66 . It can be seen that the fact that the respective impeller rotates about the axis of rotation relative to the turbocharger housing 32 means in particular that the respective rotor 46 or 52 rotates about the axis of rotation relative to the turbocharger housing 32 .

In order to now be able to implement a particularly advantageous and particularly efficient operation of the turbocharger 10 , the turbocharger 10 has a first electrical machine 68 and a second electrical machine 70 provided in addition to the first electrical machine 68 . The electric machines 68 and 70 are housed in the turbocharger housing 32 . The respective electrical machine 68 or 70 has a respective stator 72 or 74, wel cher is arranged in turbocharger housing 32 and is at least indirectly, in particular directly, fixed to turbocharger housing 32, in particular in such a way that relative rotations about the axis of rotation between respective stator 72 or 74 and turbocharger housing 32 are suppressed. In addition, the respective electric machine 68 or 70 has a respective machine rotor, which can be rotated about the axis of rotation relative to the respective stator 72 or 74 and thus relative to the turbocharger housing 32 . The machine rotor of the electric machine 68 can include at least part of the rotor 46 or the entire rotor 46 . For example, the machine rotor of the electric machine 68 includes at least the shaft 50. Accordingly, the machine rotor of the electric machine 70 can include at least part of the rotor 52 or the entire rotor 52. In particular, the machine rotor of the electrical machine 70 can include at least the shaft 54 . The machine rotors or the rotors 46 and 52 are accommodated at least partially, in particular at least predominantly or completely, in the turbocharger housing 32 .

In addition, an electronic computing device 76 is provided, which is, for example, an electronic computing device common to the electrical machines 68 and 70 . It can be seen that the electronic computing device 76 is accommodated in the turbocharger housing 32 . The electronic arithmetic unit 76 is coupled to the electrical machines 68 and 70 at least in terms of signal transmission technology, so that the electronic arithmetic unit 76 can actuate the electrical machines 68 and 70 and thus operate them, in particular regulate or control them. The electronic computing device 76 is therefore also referred to as a closed-loop or open-loop control, for example. The feature that the regulation or control is coupled to the electrical machines 68 and 70 at least in terms of signals or signal transmission technology can be understood in particular to mean that the regulation or control can provide electrical signals for actuating the electrical machines 68 and 70 . The electric machines 68 and 70, also simply referred to as electric machines, can receive the signals provided by the regulation or control, as a result of which the electric machines are controlled and thus operated, in particular controlled or regulated. For example, the electric machines are coupled to the regulation or control system via at least one respective, physical or physically existing line and/or wirelessly and thus, for example, by radio, so that the respective signal can be provided and received via the line or wirelessly.

Furthermore, a voltage converter 78 can be provided, which is designed, for example, to convert an electrical DC voltage into an electrical AC voltage. As an alternative or in addition, the voltage converter 78 can be designed to convert an alternating electrical voltage into a direct electrical voltage. It is conceivable that at least one of the electrical machines 68 and 70, in particular the electrical machine 68 and/or the electrical machine 70, can be supplied with electrical energy, i.e. with electrical current, via the voltage converter 78 Voltage source such as an electrical energy store of the motor vehicle is provided. The voltage source can provide the electrical energy with the aforementioned DC voltage, which is converted by voltage converter 78 into an AC voltage, with which electrical machine 68 and/or 70 can be or is supplied, in order to thereby, for example, switch on the respective electrical machine 68 and / or 70 to operate in a motor mode and thus as an electric motor. Alternatively or additionally, it is conceivable that at least one of the electrical machines 68 and 70, in particular the electrical machine 70 and/or the electrical machine 70 and/or the electrical machine 68, is or is operated in a generator mode and thus can be operated as a generator, which provides electrical energy. For example, the electrical energy provided by the generator can be supplied to the energy store via voltage converter 78 and thereby stored in the energy store and/or the electrical energy provided by the generator can be supplied, in particular via voltage converter 78, to at least one further electrically operable component of the motor vehicle be, in order thereby to operate the at least one additional electrical component electrically. For example, the generator can provide the electrical energy as AC voltage, which can be converted or is converted into DC voltage by means of the voltage converter 78 . This supply of electrical energy to electrical machine 68 and/or 70 via voltage converter 78 and the respective provision of electrical energy by means of electrical machine 70 and/or 68 via voltage converter 78 is in 1 illustrated by double arrows 80 . In other words, the double arrows 80 illustrate a bidirectional flow of electrical energy from the voltage or energy source via the voltage converter 78 to at least one of the elec ric machines 68 and 70 flows and/or is provided by at least one of the electrical machines 70 and 68 and flows via the voltage converter 78 to the energy store and/or to the component. it's over 1 recognizable that the electrical energy from the voltage converter 78 can be supplied or is supplied to the electrical machine 68 and/or 70 via the computing device 76 and/or the electrical energy provided by the electrical machine 70 and/or 68 can be supplied to the voltage converter 78 via the computing device 76 are supplied. In particular, the electrical energy that is supplied to the electrical machine and/or 70 and/or the electrical energy that is provided by the electrical machine 70 and/or 68 can be adjusted by means of the computing device 76 .

Arrows 82 illustrate that a cooling device for cooling turbocharger 10 can be provided. The cooling device comprises, for example, a cooling circuit through which a coolant can flow, in which the turbocharger 10 can be arranged. The turbocharger 10 can be cooled by means of the coolant via the cooling circuit. The coolant is preferably a liquid which can at least partially, in particular at least predominantly or completely, comprise water. The coolant can be supplied to the turbocharger 10 via the cooling circuit. The turbocharger 10 can give off heat to the coolant, whereupon the coolant can be removed from the turbocharger 10 again via the cooling circuit.

In addition, 1 A lubricant supply, in particular an oil supply, of the turbocharger 10 is illustrated by arrows 84 . The lubricant supply is also referred to as a lubricant supply device and includes, for example, a lubricant circuit through which a lubricant such as oil can flow. In this case, the turbocharger 10 is arranged in the lubricant circuit. The lubricant can be supplied to turbocharger 10 by means of the lubricant circuit, so that at least two components of turbocharger 10 can be lubricated and/or cooled by means of the lubricant. The lubricant can then be discharged from the turbocharger 10 via the lubricant circuit. The lubricant is preferably a liquid, in particular oil. Preferably the lubricant is electrically non-conductive.

In order to be able to implement a particularly advantageous and particularly energy-efficient operation of turbocharger 10 and thus of energy converter 12, a method for operating turbocharger 10 provides that, in at least one operating state of turbocharger 10, a first speed is set by means of first electric machine 68 of compressor wheel 38 and, by means of electric machine 70, a second speed, different from the first speed, of turbine wheel 42, which is rotatable in at least one direction of rotation about the axis of rotation relative to compressor wheel 38, is set, causing compressor wheel 38 to rotate at the first speed and turbine wheel 42 at the same time operated at the second speed, which differs from the first speed, that is to say is rotated about the axis of rotation relative to the turbocharger housing 32 .

For example, in the at least one operating state, electric machine 68 is operated in motor mode and thus as an electric motor, by means of which compressor wheel 38 is driven, whereby the first rotational speed of compressor wheel 38 is set and the air is compressed by means of compressor wheel 38 and, for example, compressor wheel 38 is rotated about the axis of rotation in a second direction of rotation opposite to the first direction of rotation relative to the turbocharger housing 32 and relative to the turbine wheel 42 . Thus, for example, in the at least one operating state, electrical machine 68 is supplied with electrical energy stored in the energy store via voltage converter 78 and is thereby operated in motor mode. Furthermore, it is preferably provided that in the at least one operating state, electric machine 70 is operated in generator mode and thereby as a generator, which is driven by setting the second speed of turbine wheel 42 by means of turbine wheel 42, which is driven by the exhaust gas of energy converter 12 will. Setting the respective speed is to be understood in particular as meaning that the respective speed results from a respective operation of the respective electrical machine. For example, setting the respective speed can be understood in particular as meaning that the respective electric machine 68 or 70 is operated in such a way, that is, for example, activated and thereby regulated or controlled, that from the operation of the electric machine 68 or 70, i.e. in particular from the activation, the respective speed results. This can apply in particular to electric machine 68, which is operated in motor mode, in particular by activating electric machine 68, so that compressor wheel 38 is actively driven, for example, by means of electric machine 68. With regard to the electric machine 70, setting the respective speed can be understood in particular as meaning that the electric machine 70 is operated in generator mode, in particular by driving the electric machine 70, from which the rotary Number of the turbine wheel 42 results. Here, for example, the turbine wheel 42 is rotated in the second direction of rotation relative to the turbocharger housing 32 about the axis of rotation, but for example the compressor wheel 38 by means of the electric machine 68 compared to the turbine wheel 42 at a higher speed in the second direction of rotation about the axis of rotation relative to the turbocharger housing 32 is rotated. Since turbine wheel 42 can be rotated about the axis of rotation in at least one direction of rotation, which is also referred to as the first direction of rotation, relative to compressor wheel 38, when compressor wheel 38 rotates at a higher speed than turbine wheel 42 in the second direction of rotation, relative is rotated to the turbocharger housing 32, the compressor wheel 38 does not drive the turbine wheel 42, so that the electric machine 68 drives the compressor wheel 38 but not the turbine wheel 42. It is conceivable that the turbine wheel 42 can be rotated, in particular freely, in both the first direction of rotation and in the second direction of rotation relative to the compressor wheel 38, so that the impellers can be rotated in both directions of rotation relative to one another, in particular freely and thus indefinitely. It is thus conceivable that the compressor wheel 38 and the turbine wheel 42 are permanently completely mechanically decoupled from one another, so that the compressor wheel 38 and the turbine wheel 42 can be rotated relative to one another around the axis of rotation indefinitely both in the first direction of rotation and in the second direction of rotation.

The turbocharger 10 can optionally be designed in such a way that the impellers are partially mechanically coupled to one another. This means in particular the following: The turbocharger 10 can optionally have an in 1 have a particularly diagrammatically illustrated coupling device 86, which is designed, for example, as a freewheel, in particular between the running wheels. Turbine wheel 42 is rotatable in the first direction of rotation, in particular freely, relative to compressor wheel 38, turbine wheel 42 being coupled to compressor wheel 38 in the second direction of rotation, opposite the first direction of rotation, in a torque-transmitting manner, in particular in a rotationally fixed manner, by means of coupling device 86. This means that the coupling device 86 embodied as a freewheel, for example, releases the turbine wheel 42 for rotation in the first direction of rotation about the axis of rotation relative to the compressor wheel 38 . However, the coupling device 86 connects the turbine wheel 42 in a torque-transmitting manner, in particular in a rotationally fixed manner, to the compressor wheel 38 for a rotation taking place in the second direction of rotation about the axis of rotation. Expressed again in other words, the turbine wheel 42 is coupled to the compressor wheel 38 in the second direction of rotation about the axis of rotation by means of the coupling device 86 in a torque-transmitting manner, in particular in a torque-proof manner. If, for example, the turbine wheel 42 is driven by the exhaust gas of the energy converter 12 and is thus rotated in the second direction of rotation about the axis of rotation relative to the turbocharger housing 32, while the compressor wheel 38 is not rotated faster than the turbine wheel 42 in the second direction of rotation, this is the case the turbine wheel 42 takes the compressor wheel 38 with it, and consequently the turbine wheel 42 drives the compressor wheel 38 . As a result, energy contained in the exhaust gas of the energy converter 12 can be used to compress the air to be supplied to the combustion chambers 22 via the compressor wheel 38 . In addition, the turbine wheel 42 can drive the generator, so that energy contained in the exhaust gas can be converted at least in part into electrical energy by means of the generator. However, if energy converter 12 does not provide any exhaust gas or only a small amount of exhaust gas, compressor wheel 38 can be driven by electric machine 68 and thus rotated faster in the second direction of rotation than would be possible solely by means of exhaust gas via turbine wheel 42. At the same time, the turbine wheel 42 can be driven by the exhaust gas, so that the energy contained in the exhaust gas can be converted into electrical energy by means of the generator.

Furthermore, it is conceivable that the coupling device 86 can be switched between a first state and a second state. In one of the states, coupling device 86 releases turbine wheel 42 for at least one free rotation in the at least one first direction of rotation and preferably also for one in the second direction of rotation relative to compressor wheel 38, so that it is preferably provided that the impellers are completely mechanically decoupled from each other in one state. Thus, in one state, the turbine wheel 42 can be rotated about the axis of rotation relative to the turbocharger housing 32 and relative to the compressor wheel 38 both in the first direction of rotation and in the second direction of rotation. In the other state, however, turbine wheel 42 is coupled to compressor wheel 38 by means of coupling device 86 in such a way that turbine wheel 42 is coupled to compressor wheel 38 by means of coupling device 86 in a torque-transmitting manner, in particular in a rotationally fixed manner, at least in the first direction of rotation and preferably also in the second direction of rotation is. As a result, for example, the compressor wheel 38 can be driven and thus rotated by the turbine wheel 42 at least in the second direction of rotation and preferably also in the first direction of rotation.

For example, if the turbine wheel 42 drives the compressor wheel 38 in the second direction of rotation, the impellers rotate at the same speed about the axis of rotation relative to the turbocharger housing 32, in particular in the second direction of rotation. For example, in at least one additional operating state of turbocharger 10, a third speed of compressor wheel 38 can be set using first electric machine 68, and a fourth speed of turbine wheel 42, corresponding to the third speed, can be set using second electric machine 70, whereby the compressor wheel 38 is operated at the third speed and at the same time the turbine wheel 42 at the fourth speed. It is conceivable that in the at least one further operating state the impellers rotate in the same direction of rotation and, for example, in the second direction of rotation at the same speed and thus at the same speed.

3 shows a first embodiment of the turbocharger 10, the first embodiment for example in the drive device 14 according to FIG 2 is used. In the first embodiment, it is provided that the running wheels are permanently and completely mechanically decoupled from one another. This means that the motor vehicle as a whole is free of the coupling device 86, i.e. completely free of a coupling device, by means of which the running wheels could be coupled to one another in a torque-transmitting manner in the first direction of rotation or in the second direction of rotation, in particular non-rotatably. In 3 An electrical coupling of the electrical machines 68 and 70 is illustrated by a block 88, the electrical machines being coupled to one another by the electrical coupling, for example with regard to their performance. In particular, electrical coupling can be understood to mean that the electric machines are operated by means of the regulation or control as a function of one another and/or the electric machines are operated by means of the electronic computing device 76 common to the electric machines, in particular simultaneously. In addition, 3 a motor and/or another unit and/or an on-board power supply of the motor vehicle is illustrated by a block 90, via the on-board power supply of which, for example, the electrical energy stored in the energy store can be supplied to the respective electric machines and/or via the on-board power supply that can be supplied by the respective electric machine Provided electrical energy is supplied to the energy store and stored in the energy store. A control of the turbocharger 10 is illustrated by a block 92 and a control of the assembly is illustrated by a block 94 . As an alternative to control, regulation can be used. At the in 3 First embodiment shown, block 88 and thus the electrical coupling illustrated by block 88 are part of turbocharger 10 and are arranged in turbocharger housing 32, for example, while block 92 and block 94 and block 90, for example, are not part of the turbocharger 10 are or can be arranged outside of the turbocharger housing 32. Alternatively, it is conceivable that the block 92 is also a component of the turbocharger 10 or is arranged in the turbocharger housing 32 .

In 2 a block 96 illustrates power electronics and/or the energy store, embodied, for example, as a battery. In particular from 2 it can be seen that, for example, the electrical energy provided by the electrical machine 70 in its generator mode can be stored in the energy store. In addition, the electrical energy stored in the energy store can be supplied to the electrical machine 68 in order to operate the electrical machine 68 in motor mode.

An exhaust gas aftertreatment device 98 is arranged in the exhaust tract 24 downstream of the turbine wheel 42, by means of which the exhaust gas of the energy converter 12, in particular of the internal combustion engine, is aftertreated. There is a pressure p4 of the exhaust gas downstream of the turbine wheel 42 and, for example, upstream of the exhaust gas aftertreatment device 98 . Upstream of the turbine wheel 42 and downstream of the combustion chambers 22 there is a pressure p3 or p31 and p32 of the exhaust gas in the exhaust tract 24, the pressure p4 being lower than the pressure p3 or p31 and p32. The exhaust gas is thus expanded by means of the turbine wheel 42 . The pressure p31 prevails, for example, in the flood 26a, and the pressure p32 prevails, for example, in the flood 26b.

4 12 shows a second embodiment, in which a block 101 illustrates the voltage converter. It is conceivable that block 88 and block 101 (voltage converter 78) and preferably block 92 (control or regulation of turbocharger 10) are part of turbocharger 10 and are arranged in particular in turbocharger housing 32, in particular while block 90 and the block 94 is not part of the turbocharger 10 or is arranged outside of the turbocharger housing 32 . Otherwise, the second embodiment corresponds to the first embodiment, so that in the first embodiment and in the second embodiment the impellers are permanently completely mechanically decoupled from one another. Thus, no coupling device such as the coupling device 86 is provided.

5 shows a third embodiment, which basically according to the first embodiment 3 corresponds, with the difference that at the third embodiment, the coupling device 86 is provided.

Finally shows 6 a fourth embodiment, which basically according to the second embodiment 4 corresponds, with the difference that the coupling device 86 is provided in the fourth embodiment. Since turbine wheel 42, at least in the at least one operating state and at least in the first direction of rotation, can be rotated or is rotated relative to compressor wheel 38, which can be implemented in particular by rotating compressor wheel 38 at a higher speed than turbine wheel 42 in the second direction of rotation the axis of rotation is rotated relative to the turbocharger housing 32, a limitation of the operation of the turbocharger 10 caused by a permanently non-rotatable coupling of the impellers can be avoided. In conventional systems, the compressor and turbine run at the same speed, with the turbine enabling a desired operating point of the compressor or the operating point of the compressor being determined by the output of the turbine. Depending on the respective operating point of the energy converter 12, this results in constraints both for the turbine and for the compressor, with these constraints excluding optimal designs and thus optimal operation.

the end 2 it can be seen that the drive device 14 also includes an exhaust gas recirculation device 100 which has at least one exhaust gas recirculation line 102 . The exhaust gas recirculation line 102 is fluidly connected to the exhaust tract 24 at a branching point, in particular to the flow 26a, and at an introduction point to the intake tract 58. As a result, at least part of the exhaust gas flowing through the exhaust gas duct 24, in particular the flow 26a, can be branched off at the branching point from the exhaust gas duct 24, in particular from the flow 26a, and introduced into the exhaust gas recirculation line 102. The exhaust gas that is branched off and introduced into the exhaust gas recirculation line 102 can flow through the exhaust gas recirculation line 102 and is routed from the branch point to the introduction point by means of the exhaust gas recirculation line 102 . The exhaust gas flowing through the exhaust gas recirculation line 102 can flow or be introduced into the intake tract 58 at the point of introduction and can be entrained into the combustion chambers 22 by the air flowing through the intake tract 58 . The branching point is arranged downstream of the combustion chambers 22 and upstream of the turbine wheel 42 . The point of introduction is arranged downstream of the intercooler 62 and upstream of the combustion chambers 22 . The exhaust gas recirculation device 100 includes an exhaust gas recirculation valve 104, by means of which a quantity of the exhaust gas flowing through the exhaust gas recirculation line 102 can be adjusted. Furthermore, the exhaust gas recirculation device 100 comprises an exhaust gas recirculation cooler 106 arranged in the exhaust gas recirculation line 102, by means of which the exhaust gas flowing through the exhaust gas recirculation line 102 and to be recirculated or recirculated is to be cooled.

For a radial turbine, an advantageous degree of efficiency is achieved with a speed ratio that is greater than or equal to 0.6 and less than or equal to 0.8. However, such a high-speed number is usually undercut during operation at relevant operating points due to the speed limitation. An increase in an entry radius is often not possible due to mechanical limitations.

The mechanical separation of the compressor wheel 38 and the turbine wheel 42 and intelligent control or regulation of the compressor 28 and the turbine 30 or the electric machines make it possible to achieve particularly high efficiencies of the compressor 28 and the turbine 30 at relevant operating points, since one or the specific speed of the compressor 28 or of the compressor wheel 38 and at the same time the or a speed ratio of the turbine 30 or of the turbine wheel 42 that differs from the specific speed can be set, specifically for a respective load or operating point. The specific speed of the compressor 28 is, for example, greater than or equal to 0.5 and less than or equal to 0.7, the speed ratio preferably being greater than or equal to 0.6 and less than or equal to 0.8. The specific speed of the compressor 28 is also referred to as Ns, the high-speed number being referred to as u/c0, for example. Thus, the compressor 28 and the turbine 30 are operated independently of each other's speed, i.e. the compressor wheel 38 can run slower, faster or at the same speed as the turbine wheel 42, the respective speed of the impeller is determined solely by the above-mentioned key figures in the form of the specific speeds of the high-speed number set.

Reference List

10

turbocharger

12

energy converter

14

drive device

16

housing element

18

cylinder

20

output shaft

22

combustion chamber

24

exhaust tract

26a, b

flood

28

compressor

30

turbine

32

turbocharger housing

34

compressor housing

36

turbine housing

38

compressor wheel

40

compressor wheel axis of rotation

42

turbine wheel

44

turbine wheel axis of rotation

46

rotor

48

warehouse

50

wave

52

rotor

54

wave

56

warehouse

58

intake tract

60

air filter

62

intercooler

64

arrow

66

arrow

68

electric machine

70

electric machine

72

stator

74

stator

76

electronic computing device

78

voltage converter

80

double arrow

82

arrows

84

arrows

86

coupling device

88

block

90

block

92

block

94

block

96

block

98

exhaust aftertreatment device

100

exhaust gas recirculation device

101

block

102

exhaust gas recirculation line

104

exhaust gas recirculation valve

106

exhaust gas recirculation cooler

p1

print

p2

print

p3

print

p4

print

QUOTES INCLUDED IN DESCRIPTION

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

Patent Literature Cited

• DE 10306234 B4 [0002]

Claims (9)

Method for operating a turbocharger (10) of a motor vehicle, in which the turbocharger (10) has a compressor wheel (38) for compressing air to be supplied to an energy converter (12) of the motor vehicle and a turbine wheel (42) that can be driven by exhaust gas from the energy converter (12). , characterized in that in at least one operating state of the turbocharger (10) by means of a first electric machine (68) of the turbocharger (10) a first speed of the compressor wheel (38) and by means of a second electric machine provided in addition to the first electric machine (68). Machine (70) of the turbocharger (10), a second speed, different from the first speed, of the turbine wheel (42), which can be rotated in at least one direction of rotation relative to the compressor wheel (38), is set, whereby the compressor wheel (38) rotates at the first speed and simultaneously the turbine wheel (42) is operated at the second speed, which is different from the first speed. procedure after claim 1 , characterized in that in the at least one operating state the first electrical machine (68) is operated in a motor mode and thereby as an electric motor, by means of which the compressor wheel (38) is driven, whereby the first speed of the compressor wheel (38) is set and the air is compressed by means of the compressor wheel (38). procedure after claim 1 or 2 , characterized in that in the at least one operating state the second electric machine (70) is operated in generator mode and thereby as a generator, which is driven by means of the turbine wheel (42) while setting the second speed of the turbine wheel (42), which is driven by the Exhaust gas of the energy converter (12) is driven. Method according to one of the preceding claims, characterized in that in the at least one operating state the compressor wheel (38) and the turbine wheel (42) rotate in the same direction of rotation. Method according to one of the preceding claims, characterized in that the compressor wheel (38) and the turbine wheel (38) are completely mechanically decoupled from one another, so that the turbine wheel (42) rotates both in the at least one direction of rotation and in one of the at least one direction of rotation opposite, second direction of rotation, in particular freely, relative to the compressor wheel (38) is rotatable. Procedure according to one of Claims 1 until 4 , characterized in that the turbine wheel (42) is rotatable in at least one direction of rotation, in particular freely, relative to the compressor wheel (38), wherein the turbine wheel (42) in a second direction of rotation opposite to the at least one direction of rotation transmits torque with the compressor wheel ( 38) is coupled. Procedure according to one of Claims 1 until 4 , characterized in that a coupling device (86) of the turbocharger (10) is switched from a first state to a second state, wherein: - in one of the states the coupling device (68) switches the turbine wheel (42) at least for one into the at least one direction of rotation relative to the compressor wheel (38) releases rotation; and - in the other state, the turbine wheel (42) is coupled to the compressor wheel (38) by means of the coupling device (86) in such a way that the turbine wheel (42) is coupled to the compressor wheel (38) by means of the coupling device (86) at least in the at least one Direction of rotation is coupled to transmit torque. Method according to one of the preceding claims, characterized in that in at least one further operating state of the turbocharger (10) by means of the first electric machine (68) a third speed of the compressor wheel (38) and by means of the second electric machine (70) one of the third speed corresponding, fourth speed of the turbine wheel (42) is set, whereby the compressor wheel (38) is operated at the third speed and at the same time the turbine wheel (42) at the fourth speed. procedure after claim 8 , characterized in that rotate in the at least one other operating state, the compressor wheel (38) and the turbine wheel (42) in the same direction of rotation.

Images