WO2013167267A2

WO2013167267A2 - Range extender system having an improved cooling circuit

Info

Publication number: WO2013167267A2
Application number: PCT/EP2013/001358
Authority: WO
Inventors: Vincent Benda; Peter Ebner; Richard Schneider; Bernhard Sifferlinger
Original assignee: Avl List Gmbh
Priority date: 2012-05-10
Filing date: 2013-05-07
Publication date: 2013-11-14
Also published as: WO2013167267A3; AT512850B1; DE112013002393A5; AT512850A1

Abstract

The invention relates to a range-extender system (1), in particular for a motor vehicle (8), preferably an electric motor vehicle, comprising a first electromechanical energy converter (2) and an internal combustion machine (3) which can be coupled to the first electromechanical energy converter (2). Said first electromechanical energy converter (2) and the internal combustion engine (3) have a common cooling circuit (5) containing a cooling medium.

Description

Range extender system with an improved cooling circuit

The present invention relates to a range extender system, in particular for a motor vehicle, preferably an electric motor vehicle, which has a first electromechanical energy converter and an internal combustion engine, which can be coupled to the electromechanical energy converter.

Range extender refers to additional units in an electric motor vehicle, which usually consist of an internal combustion engine, which drives a generator to supply an energy storage device or an electric motor with electrical energy. However, range extenders can also be used in houses as combined heat and power plants or as generator units in mobile applications.

Electric motor vehicles are electric motor driven vehicles. For their energy supply batteries or batteries are usually used as energy storage device, which can be charged locally via the power grid or mobile range extender, or solar modules.

In the case of an electric motor vehicle with range extender, therefore, the motor vehicle usually comprises a first electromechanical energy converter, which is part of the edge extender and predominantly serves as a generator and a second electromechanical energy converter, which is part of the drive train and predominantly as Motor is used.

In general, the power consumers (electric motors, air conditioning, etc.), the electricity suppliers (generators, solar modules, etc.) and the energy storage device of the electric motor vehicle via a power electronics, in particular a converter to a DC link connected, which decouples the different power systems of the supplier side of the consumer side.

In the case of electric motor vehicles with a range extender, the internal combustion engine of the range extender is generally started and stopped while driving without the driver's direct influence, in particular as a function of the state of charge of the energy storage device. The electromechanical energy converter, which is usually a permanently excited synchronous machine, usually has at least two operating modes, which are controlled by a corresponding control electronics: The generator mode is the normal operation of the range extender. Conversely, this can also be operated in the motor mode. This engine mode is commonly used to start the internal combustion engine.

The drive of an electric motor vehicle with a range extender via at least one additional second electromechanical energy converter, usually a permanently excited synchronous machine, which is also connected via a power electronics, in particular a converter to the DC intermediate circuit for supply. In operation, this drives in the engine mode, the electric motor vehicle or recuperates energy through the generator mode, eg. B. during deceleration or when driving downhill. Both in generating the electrical energy, the conversion of electrical energy, the storage of electrical energy as well as converting the electrical energy into mechanical energy while waste heat is generated. This waste heat is a loss of energy and enters as efficiency-reducing in the efficiency of the drive of the electric motor vehicle.

In order to avoid heat damage and to maintain the performance of the individual components of the drive, this energy must also be dissipated as efficiently as possible. In the internal combustion engine, peak temperatures of more than 2000 ° C. occur locally in the combustion chamber. To prevent thermal overload of the materials used for, depending on the type of engine, for. B. cylinder head, valves, spark plugs, injector, prechamber, seal, piston, piston rings, cylinder tube and engine block must be Cooling of the individual components done. In this case, about one third of the fuel energy used is dissipated by heat to the cooling.

This is usually done by means of direct cooling (air) or media cooling (cooling liquid), which is designed as evaporative cooling, thermosiphon cooling or forced circulation cooling with a cooling circuit.

As a coolant usually serves water with a cooling medium additive. The volume in the entire cooling circuit is approximately four to six times the stroke volume and is circulated approximately ten times per minute by a cooling circuit pump. To limit the cooling volume when starting the engine in the warm-up phase, the temperature is controlled by a thermostat. In the cold state, the cooling circuit is initially limited to the engine-internal circuit for faster heating of the engine. Only when the opening temperature of the thermostat is reached, the way to the cooling circuit is released, so that the critical temperature of the internal combustion engine, under which more wear and bad combustion values occur, are quickly exceeded.

This causes the cooling to begin only when needed, i. not during the warm-up phase. This warms the engine faster, reducing fuel consumption and HC and CO emissions.

The AT 505 950 discloses a power generator, in which an internal combustion engine and a generator for cooling and to reduce the sound radiation in a cool air flowed through housing are arranged.

Also, the power electronics unit, the so-called power inverter module which removes energy in the DC voltage intermediate circuit or feeds into it and thereby generates considerable waste heat is usually cooled either by air cooling or a cooling circuit. The same applies to the energy storage device, z. B. in a lithium-ion battery. Electric vehicles of the latest generation therefore generally have three cooling circuits: On the one hand those for the power electronics, those for the energy storage device and those for the internal combustion engine of the range extender. This causes significant costs, which contribute to the high purchase prices of electric vehicles with range extender over conventional vehicles with internal combustion engine.

DE 10 2009020421 A1 discloses a drive system which has a Stirling engine and a thermoelectric generator which process the heat energy which is emitted in the exhaust gases emerging from the internal combustion engine of a motor vehicle and generate mechanical power or electric power. Furthermore, the overall system has a cooling circuit with a coolant pump, which is in operative contact with the Stirling engine and / or the thermoelectric generator in order to increase at least the thermoelectric generator in its efficiency again.

In addition, the internal combustion engine usually has an oil circuit. This is formed in modern internal combustion engines of a range extender usually as pressure circulation lubrication in a closed system. In this case, all relatively moving engine components are lubricated to reduce friction and filled the hydraulic actuators. In addition to lubrication and friction reduction, the heat dissipation and distribution is another essential task for the oil cycle. This also includes fine sealing on the piston rings, release of combustion residues and the removal of wear particles.

If the oil circuit requires extensive cooling tasks, an oil cooler is installed in the circuit, which is designed either as a water / oil or as an air / oil heat exchanger. This separate oil circuit also has its own pumps, pressure relief valves, oil filters, etc.

An electric motor vehicle with range extender combines the technology of a pure electric vehicle with that of an internal combustion engine. This leads to a multiplication of the systems, since such a motor vehicle usually all elements of a pure Electric motor vehicle and a motor vehicle having an internal combustion engine.

The number of potential sources of error is multiplied, which on the one hand causes more defects and on the other hand defects are more difficult to find.

Another disadvantage of a motor vehicle with range extender may be that the electromechanical energy converter causes disturbing noises during the starting process of the internal combustion engine, as usually high power has to be applied in a short time to start the internal combustion engine.

The present invention has for its object to provide an improved range extender system, which reduces the above-mentioned problems in a motor vehicle with range extender.

This object is achieved by the teaching of the independent claims. Advantageous embodiments are claimed in the dependent claims.

In the range extender system according to the invention, the first electromechanical energy converter and the internal combustion engine have a common cooling circuit with a cooling medium.

An electromechanical energy converter in the context of the invention is used for the conversion of electrical energy into mechanical energy and vice versa. These include, in particular, electric motors and electric generators. Depending on the direction of the transmitted power is in the electromechanical energy converters between engine operation, this power is transmitted from the electrical side to the mechanical side, and the generator operation with opposite power flow distinguished. Under an internal combustion engine in the context of the invention heat engines are to be understood, which convert chemical energy of a fuel into mechanical energy via a combustion process. In the operation of an internal combustion engine, the expansion of an air-fuel mixture during combustion in a working chamber usually results in a drive commonly referred to as a piston. selement displaced from the combustion chamber area, causing it a drive shaft in motion, preferably in rotation, offset.

A motor vehicle in the sense of the invention is a mobile means of transport, which serves the transport of goods, tools or persons and is driven by a machine.

An electric motor vehicle in the sense of the invention is preferably understood to mean a motor vehicle which is operated with electrical energy from an energy storage device, preferably an electrochemical energy store, an accumulator or a battery. If the accumulator or the battery is emptied, it must be recharged, either via the mains or a mobile supply device, preferably a range extender or solar cells.

Under cooling circuit according to the invention is a forced circulation cooling to understand. In this case, in a closed cooling circuit by means of a pump, a cooling medium from a hot area, in particular the combustion chamber region of the internal combustion engine or the induction region of the electromechanical energy converter to a heat exchanger, preferably a radiator conveyed and there via the airstream, in particular with the support of a mechanical or electrically driven fan, recooled.

Cooling media in the context of the invention are gaseous or liquid substances or mixtures of substances which are used for the removal of heat. A cooling medium according to the invention is both heat transfer medium and refrigerant. As a rule, the cooling medium used is water, air or oil, preferably thermal oil.

By integrating a cooling circuit for the first electromechanical energy converter in the cooling circuit of the internal combustion engine additional components for a second cooling circuit can be saved. Thus, preferably a pump for the cooling medium and a collecting container for the cooling medium, it is preferably sufficient a heat exchanger for cooling the cooling medium and the regulation of the pressure in the cooling circuit must preferably be carried out only once. Such a system is also of particular advantage because the range extender can be implemented as a self-contained system. This is particularly important if the range extender is to be integrated as a removable module in an electric motor vehicle. Furthermore, by including the first electromechanical energy converter in the cooling circuit of the internal combustion engine, the cooling medium is heated more quickly when the range extender is started by the two existing heat sources and the operating temperature of the internal combustion engine is reached much faster. This can greatly reduce fuel consumption and HC and CO emissions. Furthermore, the noise development is reduced by the electromechanical energy converter at the start of the internal combustion engine by the sound and vibration damping property of the coolant.

The invention is applicable to all types of range extenders which include an internal combustion engine in which a piston moves in a working space and an electromechanical energy converter which is usable as both an electric motor and an electric generator.

In an advantageous embodiment of the invention, the internal combustion engine is a rotary piston machine.

Under a rotary piston machine according to the invention is preferably to understand a device in which a preferably substantially triangular piston or rotor during operation of the internal combustion engine in the housing performs a rotation about a major axis, wherein the piston rotates about its own axis, which also moves in addition to a preferred own circular path. In other words, the piston performs a planetary motion about the major axis. In a preferred embodiment, such a rotary piston engine is a Wankel engine. The invention can also be used in rotary piston machines with two, three or more juxtaposed pistons. Furthermore, the invention can also be used with any other type of internal combustion engines, such as preferably a reciprocating piston engine.

The rotary piston machine has in a particularly advantageous manner in operation on a high smoothness, so that the occupants of a motor vehicle not by vibrations ge be disturbed. Furthermore, the rotary piston machine compared to a conventional gasoline or diesel engine to a significantly lower noise. Finally, much higher speeds can be achieved than with a reciprocating engine.

In a further advantageous embodiment, oil can be used as the cooling medium.

For the purposes of the invention, oil means liquids which can not be mixed with water. These are especially lubricating oils and thermal oils. Lubricating oils prevent the development of noise and especially the wear of materials, as they are technical lubricants. In addition, the use of lubricating oil also allows the heat dissipation. Lubricating oil forms a conductive film between moving surfaces. Preferably mineral, synthetic and / or biogenic oils come into question. In particular, multigrade oils are also to be considered which only change their viscosity to a small extent at different temperatures.

The use of oil as a cooling medium has the particular advantage that oils have excellent insulating properties and a higher boiling point than water. This is particularly important in the flow of the cooling medium through the first electromechanical see energy converter, since the oil is usually in some places in contact with components with different potential, which could be shorted to a conductive cooling medium. Furthermore, the cooling circuit can be driven by the higher boiling point at a higher temperature. In a further advantageous embodiment of the invention, the lubrication system of the internal combustion engine is integrated into the cooling circuit.

A lubrication system according to the invention is used for lubricating the moving parts of the engine. This is preferably an oil circuit.

By integrating the oil circuit in the cooling circuit can be dispensed with a separate circuit for lubrication. Furthermore, in this way, the oil circuit of the internal combustion engine can be used more efficiently for cooling the same become. It also ensures that the lubrication oil is sufficiently cooled.

By incorporating the oil circuit of the internal combustion engine, a continuous lubrication of the machine, even at a standstill is also achieved. As a result, the engine is already lubricated when starting and friction losses are thus avoided.

In a further advantageous embodiment of the invention, an energy storage device of the motor vehicle via the cooling circuit is additionally cooled.

An energy storage device in the sense of the invention is to be understood as meaning a device for storing energy, in particular electrical energy, in particular an electromechanical energy store or an accumulator. Due to the internal resistance of the energy storage device and the high currents during charging and removal of energy, the energy storage device develops waste heat. By incorporating the cooling of the energy storage device in the cooling circuit a very efficient cooling of the battery is achieved. In particular, the large amount of cooling liquid in the common cooling circuit allows efficient cooling of the energy storage device. Furthermore, the internal combustion engine, which is connected to the same cooling circuit, heated to a certain temperature by the transported away from the cooling medium waste heat. Thus, it achieves its operating temperature much faster at the start, whereby the fuel consumption and the HC and CO emissions can be significantly reduced.

In a further advantageous embodiment of the invention, a second electromechanical energy converter for driving a motor vehicle via the common cooling circuit is additionally cooled. This integration of the second electromechanical energy converter also avoids an increase in the number of cooling systems due to a further cooling circuit in the motor vehicle. Furthermore, the second electromechanical energy converter is kept at operating temperature during its standstill via the waste heat of the energy storage. This is z. For example, the case during a charging process on the mains at very low outside temperatures. Finally, the waste heat of the second electromechanical energy converter also serves to maintain the operating temperature of the internal combustion engine at its stoppage. In order to limit the heating of the electromechanical energy converter, preferably the starter and the rotor are cooled.

In a further advantageous embodiment of the invention, the power electronics of the first electromechanical energy converter, the power electronics of the second electromechanical energy converter and / or the power electronics of the energy storage device via the cooling circuit can be cooled.

An effective cooling of the power electronics is indispensable for their function. Particularly advantageous in the case of cooling via the common cooling circuit is also the large amount of cooling medium which is located in the cooling circuit and therefore can be cooled back efficiently.

In a further advantageous embodiment of the invention, a heat exchanger is arranged in the cooling circuit in such a way that the air for the interior of a motor vehicle can be heated.

This has the advantage that the air for the interior of the motor vehicle can be heated without the need for an additional electrical heater to be switched on. This represents an energy saving and has the effect that the range of an electric motor vehicle is increased many times over in cold weather. An increase in range is an essential precondition for the implementation of electromobility over other forms of propulsion. A connection of the internal combustion engine is not absolutely necessary for the heating of the air, since the waste heat of the other components of the cooling circuit is sufficient. It is a kind of cogeneration or waste heat recovery.

In a further advantageous embodiment of the invention, a power heating machine is further arranged in the cooling circuit in such a way that waste heat into mechanical energy and / or electrical energy is convertible. This can increase the efficiency of the range extender system or electric motor vehicle. Energy lost due to waste heat is captured by the power heat engine and either used to drive the motor vehicle, to drive ancillary units or to generate electrical energy, which in turn is fed into the DC intermediate circuit.

In a further preferred embodiment of the invention, the control of the first electromechanical energy converter and / or the second electromechanical energy converter and the control of the internal combustion engine is integrated in a common control device. Also by this measure, a reduction of the components of an electric motor vehicle is achieved. In particular, a safety-critical communication between the two control units is eliminated. Thus, the susceptibility to interference is reduced. Furthermore, signals representing control electronic parameters only need to be evaluated once more. Examples are speed, speed, etc.

The above and other advantages, features and applications of the present invention will become apparent from the following description of a preferred embodiment with reference to the drawings. Show:

Figure 1 is a schematic representation of a range extender system of a first embodiment of the invention; Figure 2 is a schematic representation of a range extender system according to a second embodiment of the invention;

Figure 3 is a schematic representation of a range extender system according to a third and fourth embodiment of the invention;

Figure 4 is a schematic representation of a cooling circuit of a range extender system according to the invention according to a fifth, sixth and seventh embodiment; Figure 5 is a schematic representation of a range extender according to an eighth embodiment of the range extender system according to the invention.

Referring to Figure 1, a first embodiment of the invention is explained in more detail. The invention is described using the example of a range extender system 1 with a rotary piston machine with a substantially triangular rotary piston or rotor 10 as an internal combustion engine 3. The rotary piston machine 3 is shown in such a way that its disc is rotated in the image plane, whereby both the triangular shape of the rotors 6, 7, as well as the trochoidal shape of the disc is visible.

The range extender system 1 has a rotary piston machine 3 and an electromechanical energy converter 2, which can be coupled to the shaft 14 of the rotary piston machine 3. The coupling is made in any suitable manner to transmit a torque of the shaft 14 of the rotary piston machine 3 to the rotor 15 of the first electromechanical energy converter 2. Preferably, a mechanical connection is used, in particular a rigid extension of the shaft 14, in which case the rotor 15 of the first electromechanical energy converter 2 and the eccentric of the rotary piston machine 3 lie on the same shaft 14.

The electromechanical energy converter 2 can be designed as a pure generator and / or as a generator / motor. In the generator mode, this generates electrical energy by means of a torque which is provided to it via the shaft 14 of the rotary piston machine 3. The electrical energy is generated by electromagnetic induction generated by the rotor 15 in the stator 16a, 16b of the first electromechanical energy converter 2. This energy is fed via a power electronics 18a in a power grid. This is preferably a DC intermediate circuit of an electric motor vehicle. 3 mass balances 12, 13 are preferably mounted on the shaft 14 of the rotary piston machine to compensate for the imbalance of the rotary piston machine 3 by the movement of the eccentric and the rotor 10 of the rotary piston machine 3. The rotary piston machine 3 and the first electromechanical energy converter 2 are cooled by a common cooling circuit 5. In the cooling circuit 5, a cooling medium is used, preferably cooling water, which may preferably be mixed with an antifreeze, more preferably alcohol and particularly preferably oil. The cooling medium in the cooling circuit 5 first flows through the rotary piston machine 3 and then the electromechanical energy converter 2. In this case, the medium flows through cooling channels 9a, 9b, which are introduced in the engine block of the rotary piston machine 3 and / or in the stator 16a, 16b. Preferably, it is also provided that the cooling medium flows through moving parts such as the rotor 10 of the rotary piston machine and / or the rotor 15 of the electromechanical energy converter 3 and / or the shaft 14.

The cooling circuit 5 preferably forms a closed system. However, this can also be divided into subcircuits, which flow out of the cooling circuit 5 only individual components, and then open again in the cooling circuit 5. Furthermore, the line of the coolant circuit shown in FIG. 1, which conveys the cooling medium, can be embodied both as single-core and as multi-core, for example, for discharging the cooling medium back and forth to a component. When flowing through the respective components, a heat exchange between the components and the cooling medium takes place. The components release heat energy to the coolant. Here it is important that the cooling channels are arranged in such a way that the heat energy is optimally exchangeable between the individual components and the cooling medium. In order to ensure improved heat exchange, the individual components of the rotary piston machine 3 and / or the electromechanical energy converter 2 may have heat exchange elements, which preferably consist of a highly thermally conductive material such as copper or tin, to make the heat exchange even more effective. Of course, the cooling circuit 5 can flow through the range extender system 1 in the opposite direction, ie first, the electromechanical energy converter 2 and then the rotary piston machine 3 flows through. The cooling medium is transported by a pump 22 which is arranged in the cooling circuit 5. The pump 22 may be an electrically operated pump or a mechanically operated pump. In the case of a mechanically operated pump 22, this is preferably coupled to the shaft 14 in order to be operated by the latter.

The cooling of the coolant in the cooling circuit 5 via a cooler 21. In this, the cooling medium is cooled by a heat exchanger, preferably with an air flow, more preferably with water.

Preferably, such a described range extender system 1 can be used in a motor vehicle 8, particularly preferably in an electric motor vehicle. An energy storage device of the motor vehicle can be charged with the range extender system 1 when no mains power is available. The motor vehicle 8 in this case preferably has a tank for fossil fuel to supply the rotary piston engine 3 of the range extender system 1 with fuel.

With reference to FIG. 2, a second embodiment of a range extender system 1 according to the invention will now be described.

This second embodiment can advantageously be combined with the previously explained first embodiment of FIG. The second embodiment differs from the first embodiment in that the lubrication system 6 of the rotary piston machine 3 is also integrated in the cooling circuit 5. That is, the cooling medium not only flows through parts of the first electromechanical energy converter 2 and the rotary piston machine 3 in cooling channels or heat exchange elements, but is also used for lubrication of the moving parts of the rotary piston machine 3.

Lubrication has the task of reducing friction between two surfaces. Friction is the resistance of one surface to move against another; the direction of the force that must be expended to move a body is that thereby opposing friction. Friction always leads to a loss of energy.

The separation of mutually moving metal surfaces is the main task of a lubricant, in this case in particular the lubrication of the rotor 10 of the internal combustion engine 3 and the shaft 14. At the same time cools the coolant or rotary piston engine 3 from the inside. The lubrication system is preferably designed as an oil circuit. Preferably, in this embodiment, oil is suitable as a coolant and thus also as a lubricant, since it has particularly advantageous lubricating properties.

With reference to FIG. 3, a third and a fourth embodiment of the range extender system 1 according to the invention will be described.

The third and the fourth embodiment can be advantageously combined with the preceding first and second embodiment of Figures 1 and 2.

In addition to the first electromechanical energy converter 2 and the rotary piston machine 3, the cooling medium in the third embodiment also flows through the energy storage device 7. This energy storage device 7 is preferably an electrochemical energy store or an accumulator. The energy storage device 7 provides the electrical energy for the supply of a DC intermediate circuit 23, to which all consumers, such as electric motors, air conditioning, etc. and utilities such as range extenders, solar cells, mains, etc. are connected via respective power electronics 18a, 18b. The energy storage device 7 advantageously has cooling channels 9c.

The fourth embodiment differs from the preceding embodiments in that the second electromechanical energy converter 4 can also be cooled via the common cooling circuit 5.

The second electromechanical energy converter 4 serves a motor vehicle 8, preferably an electric motor vehicle, for driving. The torque of the second electric mechanical energy converter 4 is transmitted via a differential 26 and an axis 25 to the wheels 11a and 11b. The second electromechanical energy converter 4 draws its energy from the DC intermediate circuit 23, which is fed by the energy storage device 7. The second electromechanical energy converter 4 also has a stator 17a, 17b and a rotor 19. The cooling of the individual components of the second electromechanical energy converter 4 takes place in the same way as in the first electromechanical energy converter 2.

Both in the first and / or second electromechanical energy converter 2, 4, the cooling medium according to this embodiment or one of the preceding embodiments can also be used for lubricating movable components.

In a preferred manner, all four wheels, 11 a, 11 b, 11 c, 11 d are operated. The second electromechanical energy converter 4 for driving the motor vehicle can also be designed as a decentralized electromechanical energy converter on each individual wheel 11 a, 11 b, 11 c, 11 d of a motor vehicle, preferably as a motor or curved electric linear machine, or directly on or in the wheel is arranged.

Referring to Figures 4 and 5 further embodiments of the range extender system 1 according to the invention will be described.

These embodiments can be combined in an advantageous manner with one of the preceding embodiments.

A fifth embodiment differs from the preceding embodiments in that the power electronics 18a of the first electromechanical energy converter 2, the power electronics 18b of the second electromechanical energy converter 4 and / or the power electronics of the energy storage device 7 can be cooled via the common cooling circuit 5. For this purpose, the power electronics 18a, 18b cooling channels 9d on. With respect to the first electromechanical energy converter this is shown in FIG. A sixth embodiment differs from the preceding embodiments in that it additionally has a heat exchanger 27, which is arranged in the common cooling circuit 5 in such a way that the air for the interior of a motor vehicle 8 can be heated.

The heat exchanger 27 is therefore on the one hand flows through the cooling medium, on the other hand, air which is provided for the interior, flows through it. The heat exchanger 27 can be arranged at any point of the cooling circuit 5. In a preferred manner, the cooling circuit 5 can pass through the heat exchanger 27 several times in order to optimally warm the interior air, depending on the heat development of the individual components 2, 18a, 3, 4, 18b, 7, which are preferably connected to the cooling circuit 5 ,

As shown in FIG. 4, the cooling circuit 5 preferably flows through all the components. However, the order is purely exemplary and could be changed in any way. The direction of flow could also be clockwise as well as counterclockwise. Finally, as described in the preceding embodiments, only individual components are preferably flowed through. Other components are not flowed through or are traversed by a subcooling circuit, which flows out of the cooling circuit 5 only individual components, and then re-enter the cooling circuit 5.

In a seventh embodiment, the cooling circuit 5 further comprises a power heating machine 20. Waste heat from the individual components, which are connected to the cooling circuit 5, can thus be converted into mechanical energy and / or electrical energy. Preferably, this is a Stirling machine or a thermoelectric generator.

As shown in FIG. 5, in an eighth embodiment, the control of the first electromechanical power converter 2 and the controller 31 of the internal combustion engine 3 are integrated in a common control device. The controls in each case include the control electronics and the power electronics 18a. The control of the rotary piston machine 3 preferably controls the exhaust valve, the Dros- be 30, fuel injection 29 and / or spark plug 28 and other elements to be controlled of the rotary piston machine. 3

In all embodiments of the invention, the cooling medium of the cooling circuit 5 can also be used for lubricating other moving parts of a motor vehicle 8.

Furthermore, the electromechanical energy converters 2, 4 may preferably be pole machines, more preferably external pole machines, more preferably asynchronous machines, more preferably self-excited asynchronous machines, or most preferably reluctance machines.

LIST OF REFERENCE NUMBERS

Range extender system 1

First electromechanical energy converter 2

Internal combustion engine 3

Second electromechanical energy converter 4

Cooling circuit 5

Lubrication system of the rotary piston machine 6

Energy storage device 7

Motor vehicle 8

Cooling channels 9a, 9b, 9c, 9d

Rotor of the rotary piston machine 10

Wheels 11a, 11b, 11c, 11d

Mass balance 12

Mass balance 13

Wave 14

Rotor of the first electromechanical energy converter 15

Stator of the first electromechanical energy converter 16a, 16b

Stator of the second electromechanical energy converter 17a, 17b

Power electronics 18a, 18b

Rotor of the second electromechanical energy converter 19

Power heating machine 20

Cooler 21

Pump 22

DC intermediate circuit 23

Drive train 4, 24, 25, 26

Drive shaft 24

Axis 25

Differential 26

Heat exchanger 27

Spark plug 28

Kraftstroffeinspritzung 29

Throttle 30

Control of the internal combustion engine 31

Claims

Patent claims

Range extender system (1), in particular for a motor vehicle (8), preferably an electric vehicle, comprising:

a first electromechanical energy converter (2); and

an internal combustion engine (3) which can be coupled to the first electromechanical energy converter (2),

wherein the first electromechanical energy converter (2) and the internal combustion engine (3) share a common cooling circuit

(5) have a cooling medium.

Range extender system (1) according to claim 1, wherein the internal combustion engine (3) is a rotary piston engine.

Range extender system (1) according to claim 1 or 2, wherein oil can be used as a cooling medium.

Range extender system (1) according to one of the preceding claims, wherein the lubrication system

(6) of the internal combustion engine (3) is at least partially integrated into the cooling circuit (5).

Range extender system (1) according to one of the preceding claims, wherein an energy storage device (7) of the motor vehicle can also be cooled via the common cooling circuit (5).

Range extender system (1) according to one of the preceding claims, wherein in addition a second electromechanical energy converter (4) for driving a motor vehicle can be cooled via the common cooling circuit (5).

7. Range extender system (1) according to one of the preceding claims, wherein additionally the power electronics (18a) of the first electromechanical energy converter (2), the power electronics (18b) of the second electromechanical energy converter (4) and / or the power electronics of the energy storage device (7) can be cooled via the common cooling circuit (5).

8. Range extender system (1) according to one of the preceding claims, wherein the components through which the cooling circuit (5) flows have cooling channels (9a, 9b) and / or heat exchange elements.

9. Range extender system (1) according to claim 8, wherein the cooling channels (9a, 9b, 9c) are arranged in such a way that thermal energy between the stator (16a, 16b; 17a, 17b) of the respective electromechanical energy converter (2 , 4), the engine block of the internal combustion engine (3) and / or the storage elements of the energy storage device (7) and the cooling channels (9a, 9b, 9c) and / or the heat exchange elements is interchangeable.

10. Range extender system (1) according to one of the preceding claims, wherein the cooling medium of the cooling circuit can be used to lubricate the movable elements of the first electromechanical energy converter (2) and / or the second electromechanical energy converter (4).

1 1. Range extender system (1) according to one of the preceding claims, wherein the cooling medium of the cooling circuit (5) can be used to lubricate moving parts of a motor vehicle (8).

12. Range extender system (1) according to one of the preceding claims, wherein a heat exchanger (27) is arranged in the cooling circuit in such a way that the air for the interior of a motor vehicle can be heated.

13. Range extender system (1) according to one of the preceding claims, wherein a combined heat and power machine (13) is arranged in the cooling circuit (5) in such a way that that waste heat can be converted into mechanical energy and/or electrical energy.

14. Range extender system (1) according to one of the preceding claims, wherein the control (18a) of the first electromechanical energy converter (2) and / or the control (18b) of the second electromechanical energy converter (4) and the control (31) the internal combustion engine (3) are integrated in a common control device.

15. Motor vehicle (8), in particular an electric motor vehicle, with a range extender system (1) according to one of claims 1 to 14.