Track-type construction machine

Abstract

A track-mounted railway construction machine (1, 40) is described, comprising a machine frame (23) movable on rail bogies (8) with electric travel drives (27), a current collector system (38, 37, 42, 36, 35) for collecting power from an overhead line network (39), and optionally a direct current intermediate circuit (48). In order to create advantageous design and operating conditions, it is proposed that an electric machine (30) be provided which can be operated both as an electric motor and as an electric generator, which on the one hand is drive-connected to an internal combustion engine (10) via a first clutch (K1) and on the other hand is drive-connected to at least one hydraulic pump (20) for operating hydraulically driven work units (2, 4, 41) via a second clutch (K2).

Description

[0001] The invention relates to a track-mounted railway construction machine comprising a machine frame movable on rail chassis with electric traction drives, optionally a driver's cab, a current collector system for drawing current from an overhead line network and optionally a DC intermediate circuit and at least one hydraulic pump for operating hydraulically driven working units.

[0002] One such track-mounted track construction machine is shown, for example, in EP4230463A1. Track construction machines are built and used for the construction, reconstruction, and maintenance of tracks, the track bed, and overhead lines. Most track construction machines are built with a diesel-hydraulic or diesel-mechanical drive system. A diesel engine drives a hydrodynamic transmission with multiple outputs. On the one hand, the axle drives are driven directly from the transmission via cardan shafts; on the other hand, hydraulic pumps are connected to the transmission outputs, operating a hydraulic circuit. This hydraulic circuit also powers hydrostatic axle drives for moving the machine and supplies the working components.Working units can include tamping units, lifting and straightening units, drive motors for cleaning chains, hydraulic cylinders for positioning conveyor chains, drives for conveyor belts or lifting platforms, tensioning drums for winding or unwinding guide wires, plows and others.

[0003] In the fight against climate change, the international community, and the European Union in particular, is making great efforts to reduce CO2 emissions. A sustainable solution for environmentally friendly and low-CO2 energy supply for newly constructed buildings is therefore highly desirable.

[0004] The following state-of-the-art options are available. If a country has a high proportion of electrified lines, the energy for operating the machines can be supplied via the overhead lines. This requires the installation of a pantograph, a high-voltage transformer, and subsequent rectification of the alternating current using, for example, a four-quadrant converter. The generated direct current can then be used to produce three-phase alternating current for operating the electric motors via traction inverters. Inverters can also be used to generate auxiliary voltages for operating other devices such as computers, air compressors, air conditioners, lighting, valves, control systems, etc.

[0005] For non-electrified lines or construction sites where switching off the overhead line is necessary, the standard power supply for railway construction machinery is insufficient. Additional electrical batteries and supercapacitors could provide short-term energy for these periods. Their use is generally advantageous because they compensate for voltage spikes during significant power fluctuations, such as those experienced by tamping machines that move cyclically from sleeper to sleeper. However, shifts for track construction machinery typically last eight hours. Often, on larger construction sites, several shifts run consecutively. Therefore, batteries can only provide power to railway construction machinery for shorter periods, serving merely as a temporary bridge during power outages.On non-electrified routes, diesel engines with downstream electric generators, i.e. diesel-electric drives, are therefore a possible supplement to the energy supply via overhead lines.

[0006] A railway construction machine with a diesel-electric drive concept is known from AT517558, in which an internal combustion engine with a drive shaft is mechanically connected via a gearbox to both electric generators and hydraulic pumps. This enables the electrical supply of the drives. In diesel engine operation, there is a slight saving in fossil energy, which results primarily from the better efficiency of electric drives.

[0007] WO2017 / 050414 discloses a similar machine with a diesel engine that can be coupled to a transfer case via a clutch. Hydraulic pumps for supplying a hydraulic system, an electric motor, and a generator are connected to the transfer case. When power is supplied from the overhead line, the diesel engine is disengaged from the transfer case, and the electric motor and generator are coupled to the transfer case. A disadvantage of this solution is that both an electric motor and an electric generator are required. In addition to the cost, the large installation space required and the increased weight are also disadvantages.

[0008] A lightweight and compact hybrid drive system for rail vehicles is known from DE 10 2018 124 887 A1. This drive system makes it possible to replace a gearbox and a starting clutch with two clutches that are not used for starting, and which can therefore be designed much more simply and compactly. Thus, the gearbox and starting clutch previously considered necessary in internal combustion engines can be dispensed with.

[0009] The invention is based on the objective of creating a particularly compact device of the type described above, requiring few components, which offers the possibilities of a purely fuel-electric drive, an overhead line-supported drive or a combination of fuel-electric energy and overhead line-supported drive both for pure driving operation and for the working operation of the work units.

[0010] The invention solves the stated problem by providing an electric machine that can be operated both as an electric motor and as an electric generator. This machine is connected to an internal combustion engine via a first clutch and to at least one hydraulic pump for operating hydraulically driven working units via a second clutch. The electric machine, which can be operated as both an electric motor and an electric generator, has a continuous shaft with the first clutch connected to its first end and the second clutch connected to its second end. The electric machine is thus an electric motor / generator with an armature shaft equipped with a clutch at both ends.

[0011] The electric machine has a continuous mechanical shaft with mechanical couplings on both ends. One coupling is connected to the diesel engine, preferably without an intermediate gearbox, while the other is connected to a mechanical transfer case or directly to the hydraulic pump(s). Several hydraulic pumps can be flanged to the transfer case, supplying power to the working units of the construction machine. Various operating modes can be selected depending on the position of the couplings (engaged or disengaged).

[0012] This creates a hybrid drive system consisting of an internal combustion engine, particularly a diesel engine, a pantograph system, and an electric machine that can be operated as both an electric motor and an electric generator. The pantograph system draws power from the overhead line. A DC link can be supplied via a transformer and inverter from the overhead line and / or from the electric machine driven by the internal combustion engine. An energy storage device in the form of batteries and / or supercapacitors can be connected to the DC link.

[0013] The electric traction drives are preferably connected to the DC link via traction inverters. Appropriate speed controllers can be provided to control the traction inverters.

[0014] Separating the pure driving operation, for example, for transporting the construction machine to the work site, from the working operation, which includes driving and the operation of working units, is essential for increasing the efficiency of this particular construction machine. The drive train for pure driving operation does not include a transfer case; it is therefore transfer case-free. This avoids power losses that occur in a transfer case.

[0015] The various operating modes that can be implemented with the track-mounted construction machine are illustrated by way of example in the figure description.

[0016] The invention is illustrated in the drawing as an example. It shows Figs. 1 and 2 show known (SdT) track-mounted construction machines in schematic side view, Fig. 3 shows a circuit diagram of a construction machine according to the invention, Fig. 4 shows a first part of a construction machine according to the invention in schematic side view, and Fig. 5 shows a second part of the construction machine according to the invention. Fig. 4 in schematic side view.

[0017] Fig. 1Figure 1 shows, as an example of a known railway construction machine, a track-mounted tamping machine 1, comprising a machine frame 23 movable on rail bogies 8 with electric traction drives, two operator cabs 51, and a work cabin 21. The direction of travel is indicated by C. A hydrodynamic transmission 9 with a pump 20 is driven by an internal combustion engine 10, in particular a diesel engine. The pump 20 generates a hydraulic circuit to which various actuators are connected, such as the lifting / lowering cylinder 18 of the tamping unit, fully hydraulic tamping drives of the tamping unit 4, lifting cylinder 5 of a lifting / aligning unit 2, and a longitudinal displacement cylinder of the unit 19. The machine is equipped with bogies and railway wheelsets 25. To increase the driving force, one of the axles is equipped with a hydrostatic traction motor 16 that acts on the axle gearbox 15.The hydrodynamic transmission drives the axle gearboxes 13 of two wheelsets directly via cardan shafts 26, which are mechanically connected to the transmission. A generator 12, flange-mounted to the diesel engine 10, produces the on-board DC voltage of 24VDC. A battery 11 is connected in parallel to the generator. A DC / AC converter 17 generates 380 / 220VAC, which powers various devices such as computers, monitors, and air conditioners. A control computer 46 controls and regulates the drive systems, brakes, and operating electronics. The drive principle is often the same for ballast leveling machines, overhead line vehicles, track measuring cars, grinding machines, dynamic track stabilizers, and material handling silo units.

[0018] Fig. 2Another well-known design of railway construction machines 1, 8. Some railway administrations and customers require axle loads that are significantly below the 22.5 tonnes generally permitted in Europe. This is often difficult to comply with with single-unit railway construction machines. Therefore, to reduce weight, the power supply for the internal combustion engine 10, distribution gearbox 24, hydraulic pumps P, hydraulic tank, and diesel tank is relocated from the main machine 1 to a trailer 40. This trailer is often used to mount additional work units such as a dynamic track stabilizer, a sweeper brush with a steep conveyor belt and silo, a plow attachment, or an intermediate compactor. The 24VDC power supply is also generated on the trailer 40 via an alternator 12 with a battery 11 connected in parallel. A DC / AC converter 17 generates 380 / 220VAC to supply the equipment with mains voltage.Valves, indicators, limit switches, and other electrical components are connected to the 24VDC rail for power supply. A control computer 46 controls and regulates the drive systems, brakes, and working electronics. These machines are often driven hydrostatically. Some axles are equipped with axle gearboxes 13 and 15, which are driven by hydraulic motors 16. As can be seen in the diagram, the two front axles in the working direction C of the machine 1 shown are driven (this is an example, but a common configuration in practice). This means that long hydraulic supply lines must run from the distribution gearbox 24, via the driven pumps P, to the front of the vehicles 1 and 8. This has the disadvantage that the response time of the drives is slowed down by the propagation impulse and the expansion of the hoses.This is particularly disadvantageous when working from threshold to threshold, where a rapid response from the machine is crucial for work performance. Another disadvantage of hydraulic drives is the oil leakage in the event of a malfunction. The travel drives 16 typically operate at pressures up to 350 bar, which means a significant loss of hydraulic oil in the event of a failure.

[0019] Fig. 3Figure 1 shows a circuit diagram of a track-mounted construction machine 1, 40 according to the invention, namely a trailer 40 coupled to the main machine 1, on which the power supply for the construction of a modular hybrid drive is located. The energy for various electric drives 27 is supplied via a DC link 48. The DC link voltages commonly used in the railway industry are typically 750 VDC. According to the invention, current is drawn from an overhead line network (39) via a current collector system (38, 37, 42, 36, 35). The current collector system (38, 37, 42, 36, 35) includes a current collector 38. The voltage is supplied to a high-voltage transformer 36 via a main switch 37. On the secondary side, for example, a 4-quadrant converter 35, which supplies the DC link 48, is constructed. Connected to these are an energy storage device (e.g. lithium-ion polymer battery) 34, and / or a supercapacitor unit 33.The energy storage unit 34 and the supercapacitor unit 33 can provide energy for short-term use. They also serve to buffer rapidly changing load requirements, such as those that occur in tamping machines due to the constant starting, braking, and tamping from threshold to threshold.

[0020] The internal combustion engine 10 is connected to the electric machine 30 via a mechanical / electrical clutch K1. The electric machine 30 has a continuous shaft (indicated by dashed lines) and is connected to a mechanical clutch K2. A mechanical transmission, optionally a transfer case 29, is connected to the clutch K2, which drives hydraulic pumps 20 at its outputs. These hydraulic pumps supply hydraulic lines 47 to working units such as tamping units 4, lifting and aligning units 2, or other hydraulic devices 41.

[0021] By means of a switch S1, the electric machine 30 can either supply the DC link 48 with energy via an inverter 43, or be supplied with energy from the DC link 48 via a rectifier 44 and operated as a motor. Switch S1 can also be used to disconnect the electric machine 30 from the DC link 48.

[0022] The following important operating modes result: Overhead line diesel engine Generator / Motor Clutch K1 Clutch K2 Operating mode 0 0 0 0 0 1. Standstill 1 0 0 0 0 2. DRIVE PROMOTION via overhead line 0 1 1 1 1 3. DIESEL ENGINE OPERATION: Electric generator supplies DC link (driving) and through-drive supplies hydraulic pumps (working unit supply) 1 1 1 1 0 4. COMBINED RIDE: DC intermediate circuit supplied via electric generator and overhead line (steep gradient operation) 1 1 0 1 1 5. COMBINED WORK ENTREPRENEURSHIP: The drive power of the diesel engine and the electric motor overlaps (steep gradient work) 0 1 1 1 0 6. DRIVE PROMOTION via diesel engine 1 0 0 0 1 7. WORK OPERATION SUPERVISION: Electric motor drives gearbox (power supply for working units) and DC intermediate circuit for working operation Overhead line: 0 ... without power 1 ... live Diesel engine: 0 ... not in operation 1 ... in operation Generator / Motor: 0 ... Motor 1 ... Generator Clutch K1: 0 ... disengaged (no power supply via diesel engine) 1 ... engaged (power supply via diesel engine) K2 clutch: 0 ... disengaged (operation not possible) 1 ... engaged (working mode)

[0023] The electric drive units 27 are connected to the DC intermediate circuit 48 by means of traction converters 28.

[0024] If the construction machine can be powered via an overhead line 39 and the pantograph system 38, 37, 42, 36, 35 is connected to the overhead line, then the DC intermediate circuit 48 is supplied with power from the overhead line. The internal combustion engine 10 and the electric motor 30 are switched off and the clutches K1, K2 are disengaged. The switch S1 is in the neutral position. For short periods, e.g., on inclines, energy can also be supplied via the energy storage devices 33, 34 connected to the DC intermediate circuit 48. Pure electric operation via overhead line is then in effect.

[0025] If no overhead line 39 is present, then in pure fuel-electric driving mode the internal combustion engine 10 runs, the clutch K1 is engaged, and the electric machine 30 operates as a generator. The DC link 48 is supplied with energy via the electric machine 30, the switch S1, and the inverter 43. This powers the electric drive units 27. Pure diesel-electric driving is then in operation. The clutch K2 is disengaged.

[0026] For purely electric operation, the overhead line network 39 is connected to the DC link 48 via the pantograph system 38, 37, 42, 36, 35, with the clutch K1 disengaged when the internal combustion engine 10 is switched off, the electric machine 30 operating in engine mode being connected to the DC link 48 via an inverter 44, and the electric machine 30, with clutch K2 engaged, driving at least one hydraulic pump 20 to operate hydraulically driven working units 2, 4, 41. This is purely electrical operation powered by the overhead line 39 (and / or energy storage-assisted).

[0027] For operation powered solely by the drive power of the internal combustion engine 10, the clutch K1 is engaged, and the electric machine 30, operating in generator mode for power generation, is connected to the DC link 48 via the switch S1 and an inverter 43. With the clutch K2 engaged, the internal combustion engine 10 also drives at least one hydraulic pump 20 for operating hydraulically driven working units.

[0028] In the embodiment according to the invention, the construction machine 1,40 also offers the possibility of pulling work wagons as a towing vehicle, even on steeper inclines. Typically, equipment and materials are transported on loading wagons, and ballast wagons or crew wagons are attached, etc., which are required for track construction work at the construction site.

[0029] Steeper gradients require more power. For this purpose, the tractive force can be increased by combining the power supply from the overhead line 39 and the internal combustion engine 10 via the electric machine 30 operating in generator mode.

[0030] Power can be supplied to the DC intermediate circuit 48 for combined operation on track 3 from the pantograph system 38, 37, 42, 36, 35 and from the internal combustion engine 10, whereby the switching clutch K1 is engaged and the electric machine 30, which operates in generator mode for power generation, is connected to the DC intermediate circuit 48 via an inverter 43 and the switching clutch K2 is disengaged.

[0031] In this combined power supply operation, the DC intermediate circuit is supplied on the one hand via the overhead line system - pantograph 38, circuit breaker 37, transformer 36 and 4-quadrant controller 35 - and additionally via the internal combustion engine, clutch K1 engaged and clutch K2 disengaged, E-generator 30, switch S1 and inverter 43.

[0032] However, even during operation, more power may be required on steep uphill sections. For combined operation on track 3, the power supply to the DC intermediate circuit 48 can be provided on the one hand by the pantograph system 38, 37, 42, 36, 35 and on the other hand by the internal combustion engine 10, with the coupling K1 engaged, the electric machine 30 operating in motor mode connected to the DC intermediate circuit 48 via an inverter, and the internal combustion engine 19 and the electric machine 30, with coupling K2 engaged, jointly drive at least one hydraulic pump 20 to operate hydraulically driven working units 2, 4, 41. In this case as well, the power of the internal combustion engine 10 can be supplemented with energy from the overhead line 39.

[0033] Various auxiliary voltages (such as the 24VDC on-board voltage) can be generated via dedicated AC / DC converters 45. Typical loads 52, such as air conditioners and computers, can be connected and operated via the 380 / 220VAC three-phase network. The machine controls 32 and 46 communicate via dedicated control lines. These lines also allow communication between the driver's cabs and for the coordination of the drives.

[0034] The system boundary 50 between trailer 40 and main machine 1 is in Fig. 3 represented by a dash-dotted line.

[0035] Fig. 4Figure 1 schematically shows the trailer 40, which carries the power supply and is coupled to the main machine 1 (working machine). The trailer 40 comprises a driver's cab 51 with an exterior door 22, a machine control unit 32, and runs on rail bogies 8. The rail bogies 8 are driven by electric traction drives 27 and axle drives 13. The trailer 40 rests on the rail bogies 8, which run on the railway tracks 3, via the vehicle frame 23. The DC link 48 is supplied via the pantograph 38, the circuit breaker 37, the high-voltage transformer 36, and the 4-quadrant controller 35. The voltage of the DC rail 48 is also buffered by energy storage devices 34 and / or supercapacitors 33. The traction drives 27 are supplied and controlled via traction converters 28. The vehicle 40 carries, in addition to the internal combustion engine 10, an electric machine 30 that can be operated both as an electric motor and as an electric generator.The electric machine 30 has a continuous shaft. Clutches K1 and K2 are located on both sides of the shaft. These connect the electric machine 30 to the internal combustion engine 10 on one side and to the distribution gearbox 29 on the other. Hydraulic pumps 20 are flanged to the gearbox and supply the machine's working units via hydraulic lines 47. An inverter 31 generates 380 / 220 VAC to power various devices such as heaters, fans, or air conditioners. The DC bus 48, the hydraulic lines 47, and the AC bus 49 are routed from the trailer 40 to the main machine 1.

[0036] Fig. 5Figure 1 schematically shows the coupling of trailer 40 with the main machine 1. The DC intermediate circuit 48, the AC busbar 49, and the hydraulic lines 47 lead from trailer 40 to the main machine 1. The machine's frame 23 rests on rail bogies 8. The front rail bogie 8 is driven by electric traction drives 27. The electric traction drives 27 drive the axles via axle gearboxes 13. A tamping machine is shown as an example of a track maintenance machine 1. This machine has tamping units 4 and a lifting and aligning unit 2. These units are hydraulically driven via the hydraulic supply 47. The tamping unit 4 has fully hydraulic tamping drives and a lifting / lowering cylinder 18. The lifting / aligning unit 2 has a lifting cylinder 5 or a longitudinal displacement cylinder 19. The lifting / aligning unit 2 also has a roller clamp 6, a lifting hook 7, and an alignment roller 14.Machine 1 has an electronic control unit 46 that regulates and controls the work processes as well as the coordination with the trailer 40. Various required DC voltages VDCi are generated via a converter 45. The traction converters 28 control the drive units 27. Machine 1 has a driver's cab 51. For operation, the machine has a tamping cab 21. The machine operates in direction C.

[0037] Of course, the entire supply section (concerning fuel and overhead line supply) can also be built on a single-unit construction machine if weight and space requirements allow.

Claims

1. Rail-drivable track construction machine (1, 40), comprising a machine frame (23) drivable on rail running gears (8) with electric travel drives (27), optionally a driver's cab (51), a current collector system (38, 37, 42, 36, 35) for taking current from an overhead line network (39) and optionally a DC intermediate circuit (48) and at least one hydraulic pump (20) for operating hydraulically driven working aggregates (2, 4, 41), characterized in that an electrical machine (30) operable both as electric motor and also as electric generator is provided, which, on the one hand, is drive-connected to an internal combustion engine (10) via a first shift clutch (K1) and which, on the other hand, is drive-connected to the at least one hydraulic pump (20) for operating the hydraulically driven working aggregates (2, 4, 41) via a second shift clutch (K2).

2. Rail-drivable construction machine (1, 40) according to claim 1, characterized in that the electrical machine (30) operable both as an electric motor as well as an electric generator has a continuous shaft, to whose first end the first shift clutch (K1) is connected and to whose second end the second shift clutch (K2) is connected.

3. Rail-drivable construction machine (1, 40) according to claim 1 or 2, characterized in that the electric travel drives (27) are connected by means of traction inverters (28) to the DC intermediate circuit (48).

4. Rail-drivable construction machine (1, 40) according to one of the claims 1 to 3, characterized in that the current collector system (38, 37, 42, 36, 35) connectable to an overhead line network (39) is connected to the DC intermediate circuit (48) for a purely electric travel operation on the track (3), and the internal combustion engine (10) and the electrical machine (30) are switched off and the shift clutches (K1, K2) are preferably disengaged.

5. Rail-drivable construction machine (1, 40) according to one of the claims 1 to 3, characterized in that for a travel only operation on the track (3) only with the drive power of the internal combustion engine (10), the shift clutch (K1) is engaged, the shift clutch (K2) is disengaged, and the electrical machine (30) operating for power generation in generator operation is connected to the DC intermediate circuit (48) via an inverter (43).

6. Rail-drivable construction machine (1, 40) according to one of the claims 1 to 3, characterized in that for an exclusively electric work operation the current collector system (38, 37, 42, 36, 35) connectable to an overhead line network (39) is connected to the DC intermediate circuit (48), wherein the shift clutch (K1) is disengaged with the internal combustion engine (10) switched off, wherein the electrical machine (30) operating in motor operation is connected to the DC intermediate circuit (48) via an inverter, and wherein the electrical machine (30), with the shift clutch (K2) engaged, drives the at least one hydraulic pump (20) for operating hydraulically driven working aggregates (2, 4, 41).

7. Rail-drivable construction machine (1, 40) according to one of the claims 1 to 3, characterized in that for a work operation only with the drive power of the internal combustion engine (10) the shift clutch (K1) is engaged, the electrical machine (30) operating for power generation in generator operation is connected to the DC intermediate circuit (48) via an inverter (43), and that the internal combustion engine (10), with the shift clutch (K2) engaged, drives the at least one hydraulic pump (20) for operating hydraulically driven working aggregates (2, 4, 41).

8. Rail-drivable construction machine (1, 40) according to one of the claims 1 to 3, characterized in that the power supply to the DC intermediate circuit (48) for a combined travel operation on the track (3) is provided on the one hand from the current collector system (38, 37, 42, 36, 35) and on the other hand from the internal combustion engine (10), wherein the shift clutch (K1) is engaged and the electrical machine (30) operating for power generation in generator operation is connected to the DC intermediate circuit (48) via an inverter (43) and the shift clutch (K2) is disengaged.

9. Rail-drivable construction machine (1, 40) according to one of the claims 1 to 3, characterized in that the power supply to the DC intermediate circuit (48) for a combined work operation on the track (3) is provided on the one hand from the current collector system (38, 37, 42, 36, 35) and on the other hand from the internal combustion engine (10), wherein the shift clutch (K1) is engaged, the electrical machine (30) operating in motor operation is connected to the DC intermediate circuit (48) via an inverter, and wherein the internal combustion engine (19) and the electrical machine (30), with the shift clutch (K2) engaged, jointly drive the at least one hydraulic pump (20) for operating hydraulically driven working aggregates (2, 4, 41).

10. Rail-drivable construction machine (1, 40) according to one of the claims 1 to 3, characterized in that at least one energy storage device (33, 34) is connected to the DC intermediate circuit (48) and that, for a travel operation on the track (3) exclusively with the drive power of the energy storage device (33, 34), the internal combustion engine (10) and the electrical machine (30) are switched off and the shift clutches (K1, K2) are preferably disengaged.

11. Rail-drivable construction machine (1, 40) according to one of the claims 1 to 3, characterized in that for a work operation exclusively with the drive power of an energy storage device (33, 34) connected to the DC intermediate circuit (48), the internal combustion engine (10) is switched off, the shift clutch (K1) is disengaged, the electrical machine (30) operating for power generation in generator operation is connected to the DC intermediate circuit (48) via an inverter (43), the shift clutch (K2) is engaged, and the electrical machine (30) drives at least one hydraulic pump (20) for operating hydraulically driven working aggregates (2, 4, 41).

12. Rail-drivable construction machine (1, 40) according to one of the claims 1 to 3, characterized in that for charging an energy storage device (33, 34) connected to the DC intermediate circuit (48) by means of the current collector system (38, 37, 42, 36, 35) the internal combustion engine (10) and the electrical machine are switched off and the shift clutches (K1, K2) are preferably disengaged.

13. Rail-drivable construction machine (1, 40) according to one of the claims 1 to 3, characterized in that for charging an energy storage device (33, 34) connected to the DC intermediate circuit (48) with the internal combustion engine (10) via the DC intermediate circuit (48), the shift clutch (K1) is engaged, the shift clutch (K2) is disengaged, and the electrical machine (30) operating for power generation in generator operation is connected to the DC intermediate circuit (48) via an inverter (43).

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