Driving device for mobile crane

Abstract

The present invention relates to a drive device for a mobile crane, comprising an internal combustion engine for delivering power, an electric machine for delivering power in its motor mode and / or for generating power in its generator mode, a distribution gearbox for selectively distributing power delivered to the distribution gearbox to a drive mechanism for moving the mobile crane, and a pump arrangement for performing crane operation, wherein the internal combustion engine interacts with an input shaft of the distribution gearbox, the input shaft interacts with the drive mechanism, the electric machine interacts with an intermediate shaft of the distribution gearbox, and the pump arrangement interacts with an output shaft of the distribution gearbox.The drive device is characterized by a first coupling arranged between the input shaft and the intermediate shaft to couple or disconnect the input shaft and the intermediate shaft as required, and a second coupling arranged between the intermediate shaft and the output shaft to couple or disconnect the intermediate shaft and the output shaft as required.

Description

[0001] The present invention relates to a drive device for a mobile crane.

[0002] A mobile crane differs from other crane types in that it has its own drive system for moving the crane, making it particularly flexible in terms of its deployment location. A typical mobile crane consists of a carrier vehicle and a crane mounted on it. The carrier vehicle is usually either a type of truck chassis or a specially designed vehicle chassis connected to the rotating crane via a slewing ring.

[0003] With the increasing electrification of drives, it is now also possible to operate mobile cranes, particularly their crane operation, using an electric motor. For example, the hydraulic pumps required for crane operation are driven by an electric motor, although, according to current technology, the actual movement of the mobile crane still relies on an internal combustion engine.

[0004] The aim of the present invention is to provide an improved hybrid drive device for a mobile crane which requires as few components as possible while simultaneously having a large number of desirable functions.

[0005] This is achieved with the drive device for a mobile crane, which is defined in independent claim 1. Advantageous embodiments of the drive device are found in the dependent claims. Furthermore, the invention also includes an advantageous method for operating such a drive device, which offers particular advantages with regard to the travel drive of the mobile crane and / or with regard to the reduction of emissions.

[0006] According to the invention, a drive device for a mobile crane is provided, comprising an internal combustion engine, in particular a diesel engine, for delivering power, an electric machine for delivering power in its motor mode and / or for generating power in its generator mode, and a distribution gearbox for selectively distributing power delivered to the distribution gearbox to a drive mechanism for moving the mobile crane and to a pump arrangement for performing crane operation, wherein the internal combustion engine interacts with an input shaft of the distribution gearbox, the input shaft interacts with the drive mechanism, the electric machine interacts with an intermediate shaft of the distribution gearbox, and the pump arrangement interacts with an output shaft of the distribution gearbox.The drive device is characterized by a first coupling arranged between the input shaft and the intermediate shaft to couple or disconnect the input shaft and the intermediate shaft as required, and a second coupling arranged between the intermediate shaft and the output shaft to couple or disconnect the intermediate shaft and the output shaft as required.

[0007] An advantage of the drive device according to the invention is that the transfer case has an output shaft which, depending on the positions of the first and second clutches, can be driven by both the internal combustion engine and the electric motor. For example, if it is desired to operate the crane purely electrically, the first clutch can be opened and the second clutch closed, so that the electric motor drives the intermediate shaft and, via the closed second clutch, also actuates the output shaft of the transfer case, thus enabling crane operation (by actuating the pumps).

[0008] The transfer case is designed so that both the internal combustion engine and the electric motor can supply power to it. This power can then be transmitted by the transfer case to the drive mechanism and the pump assembly. When the first clutch (K1) is open, the electric motor can simultaneously power the pump assembly via the transfer case, and the internal combustion engine can simultaneously power the drive mechanism for moving the mobile crane via the transfer case.

[0009] The design of the drive device according to the invention for the mobile crane is redundant with respect to the drive of the output shaft, since in the event of a failure of the electric motor that drives the output shaft (which operates the crane using the hydraulic pumps), the internal combustion engine is also available as an alternative. By engaging the first clutch and then the second clutch, a positive connection is created between the input shaft and the output shaft of the transfer case, so that the output shaft can also be driven by the internal combustion engine. Therefore, crane operation is still possible even if the electric motor is defective, so that the crane does not come to a standstill, but can continue operating.

[0010] A further advantage of the inventive system of the drive device is that when the output shaft of the distribution gearbox is driven by the internal combustion engine, the electric machine can also be operated in generator mode, so that auxiliary consumers can be supplied with electricity.

[0011] A separate alternator, as is otherwise common in implementations based on the state of the art, can therefore be omitted.

[0012] According to the present invention, the internal combustion engine can thus be used to drive the input shaft of the transfer case. The internal combustion engine can be coupled to the input shaft in such a way that it drives the input shaft of the transfer case.

[0013] Furthermore, according to the invention, the electric machine can serve to drive the intermediate shaft of the transfer case or to be driven by it. The electric machine can be coupled to the intermediate shaft in such a way that it drives the intermediate shaft of the transfer case.

[0014] After a further advantageous modification, the output shaft of the distribution gearbox serves to drive crane pumps, in particular hydraulic pumps, to pump a hydraulic fluid which is used to perform a crane function.

[0015] According to an advantageous modification of the present invention, the drive device can further include an energy storage device connected to the electric machine in order to store energy from the electric machine in generator mode or to supply energy to the electric machine in motor mode. The energy storage device thus serves to absorb power generated by the electric machine or to power the electric machine if it is operated in motor mode.

[0016] Furthermore, the power stored in the energy storage system can also be used to supply energy to auxiliary consumers.

[0017] In an optional further development of the present invention, it can also be provided that the energy storage device can be charged by an external energy source via a charging port. When the electric machine is operating in motor mode, the energy supplied via the charging port can also be used to operate the electric machine in motor mode, so that in such a state the energy storage device is no longer charged or only charged at a slower rate.

[0018] According to an optional further development of the present invention, it can further be provided that the drive device also comprises at least one auxiliary consumer, in particular a heating element for temperature control of a cabin and / or driver's cab of the mobile crane and / or a compressor of an air conditioning system for temperature control of a cabin of the mobile crane, and / or a heat pump for temperature control of an energy storage device and / or a heating element for temperature control of an energy storage device, wherein preferably the at least one auxiliary consumer is connected to the electric machine in an intermediate circuit for energy supply.

[0019] It can be provided that the at least one auxiliary load is connected to the electric machine in such a way that the machine supplies the at least one auxiliary load with energy in generator mode. The at least one auxiliary load, preferably together with the energy storage device, can thus be arranged in an intermediate circuit, in particular a DC intermediate circuit, into which the energy generated by the electric machine is fed. An energy supply using energy from the energy storage device is also possible.

[0020] The advantage of the implementation according to the invention is that, in electric crane operation, the electric machine is used to drive the hydraulic pumps, while in operation using the internal combustion engine, it can be used both during crane operation and during mobile crane travel to supply energy to at least one auxiliary consumer. Thus, only one electric machine is required, eliminating the need for the 24V alternator typically coupled to the internal combustion engine. In electric crane operation, the electric machine acts as a motor to drive the crane components, whereas in drive operation using the internal combustion engine for travel and / or crane operation, the electric machine is used as a generator.

[0021] Conventional heating systems utilize the waste heat from the internal combustion engine or rely on a fuel-powered auxiliary heater. According to the invention, however, a heating unit or a compressor of a cooling circuit can be operated with energy from the intermediate circuit, the electric machine, or the energy storage device, so that air conditioning is also possible independently of the operation of the internal combustion engine or the consumption of fuel.

[0022] In a further optional embodiment of the present invention, the intermediate circuit can be provided with a connection to an external power supply. This connection not only allows the energy storage device to be charged, but also enables the continuous operation of the electric motor in a motor mode for crane operation. For example, when using a mobile crane, it may be desirable to operate it without using the internal combustion engine after it has been moved to its work site, thus preventing exhaust and noise emissions. For this purpose, an external power supply can be connected, providing the energy required for crane operation.

[0023] According to a further advantageous embodiment of the present invention, the intermediate circuit can be connected to the electric machine via at least one contactor and / or an inverter. This allows the electric machine to be isolated from the inverter and the intermediate circuit, which is advantageous, for example, in the event of an inverter failure during operation.

[0024] Furthermore, according to the invention, it can be provided that an on-board power supply, in particular a 12 V or 24 V on-board power supply, is connected to the intermediate circuit via a DC-DC converter.

[0025] According to the invention, it can further be provided that the intermediate circuit has a voltage level which is more than 48 V, preferably at least 200 V, preferably at least 500 V and most preferably at least 700 V.

[0026] According to the invention, it can further be provided that the drive device also includes a transmission for switching different gears, which is arranged between the input shaft of the transfer case and an engine output shaft of the internal combustion engine, wherein the output of the transmission interacts with or is the input shaft of the transfer case.

[0027] To move the mobile crane, it is advantageous if the internal combustion engine can deliver different gear ratios to the input shaft of the transfer case via a transmission. The drive device according to the invention enables the interruption of traction during gear changes to be reduced by engaging the first clutch. This allows the electric motor connected to the intermediate shaft to operate temporarily in motor mode, preventing a complete loss of traction during gear changes. Driving with no or less of an interruption in traction is more comfortable for the operator of the mobile crane and results in an improved driving experience.

[0028] According to an optional embodiment of the present invention, the electric machine can be a high-voltage electric motor. Preferably, a high-voltage electric motor has an output voltage of at least 400 V.

[0029] According to an optional modification of the present invention, the transfer case can be configured to deliver power from the internal combustion engine to the drive mechanism (e.g., wheel axle) when the first clutch is engaged and the second clutch is disengaged, enabling the mobile crane to move. To transmit the power input by the internal combustion engine to the input shaft and then to the drive mechanism, for example, a drive axle connected to wheels or the like, a third clutch can also be provided. This third clutch selectively engages or disengages a force transmission between the input shaft and the drive mechanism, particularly a drive axle. This third clutch can also be located within the transfer case.

[0030] Furthermore, according to an advantageous modification, the transfer case can be designed to establish a positive connection with the electric machine when the first clutch is closed and the second clutch is open, so that the electric machine can generate energy in generator mode or support the power of the internal combustion engine in motor mode. It can also be provided that the electric machine, in its motor mode, is solely responsible for the operation of the mobile crane, i.e., it provides for the movement of the mobile crane without the support of the internal combustion engine.

[0031] According to a further development of the present invention, it can be provided that, when the second clutch is closed, the distribution gearbox is designed to decouple the drive mechanism from the input shaft by means of a third clutch, in order to make it possible to operate the crane only when the mobile crane is stationary.

[0032] The invention further relates to a mobile crane with a drive device according to one of the preceding aspects, preferably wherein the mobile crane is a large mobile crane with a load moment of at least 400kNm.

[0033] The invention also relates to a method for operating a drive device according to one of the aspects discussed or a mobile crane according to the preceding aspect.

[0034] It may also be provided that during a shifting operation in the gearbox, the electric machine is operated by motor in order to reduce any interruption of traction caused by the shifting operation.

[0035] Therefore, during a gear change of the manual transmission, to change the gear ratio of the internal combustion engine with which the internal combustion engine drives the input shaft of the transfer case, a force to drive the drive system is supplied by the electric machine so that the interruption of traction force occurring during a gear change is mitigated or even completely eliminated.

[0036] Furthermore, according to the inventive method, it can be provided that during an idle phase of crane operation, the internal combustion engine is nevertheless loaded by a generator mode of the electric machine in order to maintain the exhaust gas temperature at a predetermined level, preferably to carry out exhaust gas aftertreatment with high efficiency, and / or after a complete charge or upon reaching a desired state of charge of the energy storage device, the internal combustion engine is switched off and the crane operation is continued via the energy storage device in order to cease the noise or exhaust emissions generated during the operation of the internal combustion engine. The internal combustion engine only restarts after the energy storage device's charge level falls below a predetermined level.

[0037] Further features, details, and advantages of the invention will become apparent from the following description of the figures. These show: Fig. 1: a side view of a mobile crane, Fig. 2: a schematic representation of a drive device for a mobile crane according to the prior art, Fig. 3: a drive device for a crane according to the present invention, and Fig. 4: a schematic representation of the connection of the electric machine 22 in the drive device according to the invention.

[0038] Fig. 1 shows a side view of a mobile crane.

[0039] The mobile crane 1 has an undercarriage 2 and a superstructure 3. The undercarriage 2 has a driver's cab 4 and the superstructure 3 has a cabin 5. The undercarriage 2 has axles 6 with wheels 7. The crane 1 has a boom (also called a crane arm) that is extendable and pivotally connected to the undercarriage.

[0040] Fig. 2 Figure 1 shows a schematic representation of a drive device for a mobile crane 1, as is known from the prior art.

[0041] An internal combustion engine 8, in particular a diesel engine, located in the undercarriage 2, drives the axles 6 and thus the wheels 7 via the powershift transmission 9. The internal combustion engine 8 is started by the starter 10. The starter 10 receives its energy from the vehicle battery 11, typically with a voltage of 12 V or 24 V (connection not shown), via the vehicle electrical system 12. The alternator 13 is driven by the internal combustion engine 8, supplies power to the vehicle electrical system 12, and charges the vehicle battery 11. This configuration is a known system in a vehicle.

[0042] The vehicle electrical system 12 supplies all crane components with power for their control systems. This means that the power required by most components does not need to be supplied by the vehicle battery 11, but rather by the combustion engine 8. The vehicle battery only provides the energy required for the electronic control of the components.

[0043] A clutch (not shown) is provided between the powershift transmission 9 and the transfer case 14, which ensures that energy transfer to the transfer case 14 is excluded during driving operation, so that the crane boom cannot move while the mobile crane is driving.

[0044] In crane operation, the combustion engine 8 drives the components for crane operation (and consequently also the at least one hydraulic pump 15). According to the diagram shown, the power flow is via the powershift transmission 9 and the transfer case 14 to the at least one hydraulic pump 15 via a mechanical connection. The hydraulic lines to the crane actuators are not shown. The at least one hydraulic pump 15 receives the electrical energy required for its control from the vehicle's electrical system 12 and can be implemented by different pump types, e.g., a slewing pump.

[0045] If emission-free operation is desired, the mobile crane 1 can also use an external power supply 16 as its primary energy source. This external power supply 16 is typically connected to the mobile crane 1 via a plug connection. The rectifier 18 then provides a DC intermediate circuit 19 via contactors 17. All crane components with high energy demands are connected to this DC intermediate circuit 19. The DC intermediate circuit 19 is present, for example, in the undercarriage 2 and the superstructure 3. It is routed through the slewing ring between the undercarriage 2 and the superstructure 3.

[0046] Cabin 5 is heated by a high-voltage heater 20 and a high-voltage air conditioning compressor 21. The electrical control of these components is achieved via the vehicle electrical system 12. The high-voltage electric motor 22 is connected to and powered by the DC intermediate circuit 19 via an inverter 23. Since the powershift transmission 9 is disconnected from the transfer case 14 during emission-free crane operation, no energy flows into the powershift transmission via an unwanted path. Therefore, all energy from the high-voltage electric motor 22 passes through mechanical connections and the transfer case 14 to the hydraulic pumps 15. The combustion engine 8 is inactive in this operating state (emission-free operation) and therefore cannot drive the alternator 13, which in turn cannot supply the vehicle electrical system 12.This task is performed by the DC / DC converter 24, which converts the energy supplied by the external power supply accordingly, so that the vehicle electrical system is supplied with the appropriate voltage.

[0047] Without such a supply of the vehicle electrical system via the external energy source, the relatively small vehicle battery 11 would be quickly discharged, as the power requirement of the vehicle electrical system is quite high and is approximately 1 kW.

[0048] A disadvantage of this configuration is that, with such a setup, a DC intermediate circuit 19 is not possible when operating the crane using the internal combustion engine 8. This circuit would supply energy to, for example, a high-voltage heater or a high-voltage air conditioning compressor. A generator 25 is explicitly required for this purpose, which, unlike the existing alternator, must generate a voltage in the high-voltage range. Therefore, if it is desired that the cabin 5 is also heated via the high-voltage heater 20 and the high-voltage air conditioning compressor 21 when operating the crane with the internal combustion engine 8, an additional high-voltage generator 25 must be provided on the internal combustion engine 8 (as shown in...). Fig. 1(shown) to supply these auxiliary consumers with energy. This also goes via the contactors 17 to the rectifier 18 and is powerful enough to cover the (relatively low) energy demand in the DC intermediate circuit 19. The high-voltage electric motor 22 is decoupled and out of operation when the crane is powered by the combustion engine.

[0049] Fig. 3 shows a drive device for a crane according to the present invention.

[0050] In contrast to the prior art, the electric machine 22 is integrated into the transfer case 14 of the drive unit of the mobile crane 1 in a very specific manner. The internal combustion engine 8, which is a diesel engine, and the attached gearbox 9 are visible. The output shaft of the gearbox 9 drives the input shaft of the transfer case 14, which in turn drives the wheel drive 7 of the mobile crane. The input shaft can be coupled to an intermediate shaft, to which the electric machine 22 is connected, via a first coupling K1. The intermediate shaft, in turn, can be coupled to the output shaft of the transfer case 14 via a second coupling K2. The output shaft drives at least one pump necessary for crane operation.

[0051] Fig. 4 This shows which components are connected to the electric machine 22 according to the invention.

[0052] The electric machine 22 is connected via a contactor 28 and an inverter 23 to a DC intermediate circuit 19, to which several auxiliary consumers are connected and draw their energy.

[0053] An energy storage device 26 is identified, which, when the electric machine 22 is operating in generator mode, is designed to store the energy generated by the electric machine 22. Alternatively, the energy stored in the energy storage device 26 can be used to drive the electric machine 22 in motor mode.

[0054] In addition, it can be seen that a high-voltage heater 20 and an air conditioning compressor 21 are provided for temperature control of a cabin of the mobile crane and also draw their energy from the intermediate circuit 19.

[0055] The vehicle electrical system 12, which typically operates at 12 V or 24 V, is also connected to the intermediate circuit 19 via a DC-DC converter 24. A heat pump 101 and an additional heating element 102 can also be provided and serve to regulate the temperature of the energy storage device 26. It is known to those skilled in the art that large-volume energy storage devices are sensitive to temperature, so maintaining them within a favorable temperature range is advantageous for improved performance and the longest possible service life. This is particularly true during charging of the energy storage device, as energy storage can only occur quickly and gently on the battery 26 within a suitable temperature range.

[0056] In addition, an external power supply 16 is visible, which can charge the energy storage device 26 via at least one battery charger. Alternatively, the energy from the external power supply 16 can also be used directly to drive the electric machine 22. Optionally, a distribution box 29 containing fuses and corresponding connections can be provided to control the energy flows in the DC link 19. Such an optional distribution box 29 can also contain at least one contactor to establish a connection to the battery chargers. Each device can connect to the DC link 19 and draw power from it. The optional distribution box 29 does not interfere with this.

[0057] As can be seen from the overall picture of the Fig. 3 and Fig. 4As can be seen, by closing the coupling K1, the electric machine 22 can be connected to the drive train of the internal combustion engine 8. In a movement of the mobile crane 1, the electric machine 22 can assist the internal combustion engine 8 during travel or even provide the entire propulsion for the mobile crane.

[0058] Furthermore, during driving operation, the electric machine 22 can be engaged via the first clutch K 1 by means of the internal combustion engine and act as a generator. This allows auxiliary consumers (for example, for battery-powered air conditioning 101, 102, a high-voltage heater 20, a high-voltage air conditioning compressor 21) to be supplied and / or the energy storage device in the form of a high-voltage battery 26 to be charged. This is done via the DC intermediate circuit 19, whereby clutch K 2 is naturally open in such a state.

[0059] In driving mode using an internal combustion engine, recuperation by the electric machine 22 is also possible, so that the energy storage device 26 is charged by the generator mode of the electric machine 22.

[0060] In crane operation, clutch K 2 is always closed, as this is the only way to supply sufficient energy to the at least one crane pump 15. By actuating the first clutch K 1, the crane can be operated either by the internal combustion engine 8 (clutch K 1 closed) or electrically (clutch K 1 open).

[0061] When the first clutch K1 is closed, the crane is operated using the internal combustion engine 8, and the electric machine 22 acts as a generator. The energy generated by the electric machine 22 is used to power auxiliary consumers or to charge the energy storage device 26. The advantage of this is that no additional heating or mechanical air conditioning compressor is required, as the operation of these components is possible using the DC link 19 and the generator mode of the electric machine 22.

[0062] Thus, in crane operation, regardless of whether the crane is powered by the internal combustion engine or the electric motor 22, the cabin 5 is always air-conditioned (by means of high-voltage heater 20 and high-voltage air conditioning compressor 21) using high-voltage components. This has the advantage that air conditioning is possible even when the output shaft 27 is stationary and fuel combustion is not desired.

[0063] In an electric crane operation, where the internal combustion engine 8 is inactive, the energy for the auxiliary consumers comes either from the energy storage 26 or from the external power supply 16.

[0064] The advantage here is that the high-voltage air conditioning compressor 21 and the high-voltage heater 20 can air-condition the cabin 5 even when the entire drive train (engine, transmission, shafts) is at a standstill, and furthermore, no pollutant emissions are produced when operating a high-voltage heater 20 compared to a fuel-driven auxiliary heater.

[0065] An advantageous method for operating a drive device involves using idling phases during crane operation, when no crane action is taking place, to continue loading the internal combustion engine 8 in order to maintain the exhaust gas temperature above a certain temperature threshold. This improves exhaust aftertreatment and results in lower overall emissions. Once the energy storage device 26 is full or has exceeded a certain charge level, the internal combustion engine 8 can be switched off, and crane operation can continue using the electric motor 22 in conjunction with the energy storage device. Furthermore, stopping the internal combustion engine 8 eliminates noise emissions from the engine, thus reducing idling time.

[0066] Furthermore, the drive device can advantageously be used to mitigate or completely eliminate the interruptions in traction that occur during gear changes in the internal combustion engine's transmission. For gear changes, the power flow from the internal combustion engine 8 to the wheels 7 must be briefly interrupted; however, the application of a corresponding force by the electric motor 22 in motor mode mitigates this interruption in traction.

[0067] Furthermore, it is advantageous that the crane retains full functionality even in the event of a fault in the high-voltage system, since operation using the internal combustion engine and the corresponding mechanical shafts (when the first clutch K1 and the second clutch K2 are engaged) is still possible if the electric motor 22 fails. This is not necessarily the case when using a high-voltage generator on the diesel engine and an electric motor to drive the hydraulic pump, as the internal combustion engine 8 then no longer needs a mechanical connection to the hydraulic pump. Reference symbol list:

[0068] Mobile crane 1 Undercarriage 2 Superstructure 3 Driver's cab 4 Cab 5 Axles 6 Wheels 7 Internal combustion engine 8 Powershift transmission 9 Starter 10 Vehicle battery 11 On-board electrical system 12 Alternator 13 Transfer case 14 Hydraulic pumps 15 External power supply 16 Contactors 17 Rectifier 18 DC intermediate circuit 19 High-voltage heater 20 High-voltage air conditioning compressor 21 High-voltage electric motor 22 Inverter 23 DC / DC converter 24 High-voltage generator 25 High-voltage battery 26 Shaft 27 AC contactor 28 High-voltage distribution box 29 Coupling K1 Coupling K2 Steering pump 100 Heat pump 101 High-voltage heater 102

Claims

1. A drive device for a mobile crane, comprising: an internal combustion engine for outputting power, an electric machine for outputting power in its motor mode and / or for generating power in its generator mode, and a transfer case for selectively distributing power output to the transfer case to a drive mechanism for moving the mobile crane and to a pump assembly for performing crane operation, wherein the internal combustion engine interacts with an input shaft of the transfer case, the input shaft interacts with the drive mechanism, the electric machine interacts with an intermediate shaft of the transfer case, and the pump assembly interacts with an output shaft of the transfer case, characterized bya first clutch disposed between the input shaft and the intermediate shaft for coupling or disengaging the input shaft and the intermediate shaft as needed, and a second clutch disposed between the intermediate shaft and the output shaft for coupling or disengaging the intermediate shaft and the output shaft as needed.

2. Drive device according to the preceding claim 1, further comprising an energy storage device connected to the electric machine to store energy from the electric machine in the generator mode or to supply energy to the electric machine in the motor mode.

3. Drive device according to one of the preceding claims, further comprising at least one secondary consumer, in particular a heating element for tempering a cabin and / or driver's cab of the mobile crane and / or a compressor of an air conditioning system for tempering a cabin of the mobile crane, and / or a heat pump for tempering an energy storage device and / or a heating element for tempering an energy storage device, wherein the at least one secondary consumer is preferably connected to the electrical machine in an intermediate circuit for supplying energy.

4. Drive device according to the preceding claim 3, wherein the intermediate circuit has a connection option to an external power supply.

5. Drive device according to one of the preceding claims 3 or 4, wherein the intermediate circuit is connected to the electrical machine via at least one contactor and / or an inverter.

6. Drive device according to one of the preceding claims 3 to 5, wherein an on-board network, in particular a 12 V or 24 V on-board network, is connected to the intermediate circuit via a DC-DC converter.

7. Drive device according to one of the preceding claims, further comprising a manual transmission for switching different gears, which is arranged between the input shaft of the transfer case and an engine output shaft of the internal combustion engine, wherein the output of the manual transmission cooperates with the input shaft of the transfer case or is this.

8. Drive device according to one of the preceding claims, wherein the electric machine is a high-voltage electric motor.

9. Drive device according to one of the preceding claims, wherein when the first clutch is closed and the second clutch is open, the transfer case is designed to supply power from the internal combustion engine to the drive mechanism, which power can be used to move the mobile crane.

10. Drive device according to the preceding claim 9, wherein when the first clutch is closed and the second clutch is open, the transfer case is designed to establish a force-locking connection with the electric machine so that the electric machine can generate energy in a generator mode or support the power of the internal combustion engine in a motor mode.

11. Drive device according to one of the preceding claims, wherein when the second clutch is closed, the transfer case is designed to decouple the drive mechanism from the input shaft by means of a third clutch to ensure that crane operation is only possible when the mobile crane is stationary.

12. Mobile crane with a drive device according to one of the preceding claims, preferably wherein the mobile crane is a large mobile crane with a load moment of at least 400 kNm.

13. Method for operating a drive device according to one of the preceding claims 1 to 11 or a mobile crane according to the preceding claim 12.

14. The method according to claim 12, further developed with the features of claim 7, wherein during a gear shift in the manual transmission, motor operation of the electric machine is carried out in order to reduce an interruption in traction caused by the gear shift.

15. The method according to claim 12 or 13, wherein in an idling phase of crane operation the internal combustion engine is nevertheless loaded by a generator mode of the electric machine in order to keep the exhaust gas temperature at a predetermined level, preferably in order to carry out exhaust gas aftertreatment with high efficiency and / or to switch off the internal combustion engine after full charging or when a desired charge state of the energy storage device is reached and to continue the crane operation via the energy storage device in order to end the noise or exhaust emissions arising during operation of the internal combustion engine.

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