CN114873487A

CN114873487A - Mobile crane with electric drive

Info

Publication number: CN114873487A
Application number: CN202210116481.7A
Authority: CN
Inventors: R·博纳克
Original assignee: Liebherr Werk Ehingen GmbH
Current assignee: Liebherr Werk Ehingen GmbH
Priority date: 2021-02-05
Filing date: 2022-02-07
Publication date: 2022-08-09
Also published as: DE102021102706A1; JP2022120790A

Abstract

The invention relates to a mobile crane comprising a drivable undercarriage, a superstructure rotatably supported on the undercarriage, and an electric motor for driving the mobile crane, wherein the superstructure comprises a jib system having a jib pivotable about a horizontal axis and a superstructure ballast having at least one ballast stack. The ballast stack comprises one or more ballast elements, which are formed in particular as ballast plates. According to the invention, the electrical energy for driving the electric motor may be provided by at least one energy generating module, which may be attached to the ballast pile.

Description

Mobile crane with electric drive

Technical Field

The present invention relates to a mobile crane.

Background

Mobile cranes typically have a base frame and a superstructure rotatably supported on the base frame, the superstructure having a boom and a superstructure ballast. The energy required for driving a crane or for operating a mobile crane of a separate crane function, for example, is usually supplied via one or more internal combustion engines. Typically, they are diesel engines which are typically arranged within the frame structure of the superstructure.

Because of the environmental and health concerns associated with conventional internal combustion engines, there is a need to use alternative, more environmentally friendly driving methods.

One challenge in finding alternative drive forms is that diesel engines, as conventional and proven drive forms, have many advantages that alternative drive forms cannot easily achieve. For example, diesel fuel has a high energy density, is liquid during normal storage under normal ambient conditions, and is very volatile. Storage does not require the provision of special temperatures or any other complicated conditions in the normal field of use. Suitable methods for safe operation under extreme conditions (especially at low temperatures) are known and have been tried and tested. Furthermore, the fuel is easy to store; the technology in this respect is mature. As such, it is easy to transport, for example in pipes and hoses, where pumps can be used. These aspects naturally also apply to other internal combustion engines, of which gasoline engines are the first to come.

However, the conventional internal combustion engine as a crane drive has many other disadvantages in addition to the environmental factors already explained. For example, combustion drives require complex and space-intensive systems for emissions control. The media used for emission control also place demands on storage and supply to some extent. Further measures must be taken in areas subject to the risk of explosion, since the components of the engine can become very hot in operation. If the internal combustion engine draws in special gases, additional measures must be taken in order to be able to stop the engine again.

Electric motor drives represent an environmentally friendly alternative to conventional internal combustion engines. However, the energy sources available for generating the electrical power required by the electric motor have a significantly lower energy density than the fuels for the internal combustion engine and require space-and weight-intensive storage devices and additional measures to control the safety risks.

Disclosure of Invention

Against this background, the basic object of the invention is to equip a mobile crane of the type initially referred to with an alternative drive which overcomes the above-mentioned disadvantages.

According to the invention, this object is achieved by the device of the invention. Advantageous embodiments of the invention emerge from the dependent claims and the following description.

Thus, according to the invention, a mobile crane, for example a crawler crane with a gantry, is provided, comprising a drivable undercarriage, a superstructure rotatably supported on the undercarriage, and an electric motor for driving the mobile crane, wherein the superstructure comprises a boom system with a boom pivotable about a horizontal axis and two superstructure ballast elements with at least one ballast pile. The ballast stack comprises one or more ballast elements, which are formed in particular as ballast plates. According to the invention, the electrical energy for driving the electric motor may be provided by at least one energy generating module, which may be attached to the ballast pile.

Since the energy generating module is integrated in the superstructure ballast according to the invention, its weight can be simultaneously used as ballast, thus producing a space-and weight-related synergistic effect. In addition, especially in the area of superstructure ballast, there is often sufficient space that can be occupied by the energy generating module without affecting the movement of the crane. In particular, for larger mobile cranes, very high ballast stacks are sometimes used, the height and thus the weight of which can be adapted to the respective crane deployment. Thus, the ballast pile or piles of superstructure ballasts are generally not limited to at least one direction (particularly in the direction of its height, but often also in a rearward and/or forward direction). In addition, the energy generating module can be secured with existing mature connection and securing systems of ballast elements.

The advantages of the electric drive of the mobile crane can thus be utilized without having to accept the disadvantages caused by storage and fixing. The electric drive by means of the electric motor and the energy generating module according to the invention can be carried out as an alternative or in addition to the drive via a conventional internal combustion engine.

The electric motor is used to drive the mobile crane. It may involve driving the entire mobile crane via the travelling means of the undercarriage (in particular crawler or wheeled undercarriages) and/or operations or drives involving single or all crane functions such as adjustment of the jib system, actuation of the hoisting winches, powering of the crane control via generators arranged downstream, etc. A hydraulically controlled actuator may be provided to control a hydraulic system of a single or all of the above functions, wherein an electric motor is used to drive the hydraulic system, in particular one or more hydraulic pumps.

However, the energy provided by the energy generating module can also be used for direct electric drive of a single or multiple crane functions in addition to the energy supply of the electric motor.

Since the height of the ballast stack in the superstructure ballast is limited by the height of the overall centre of gravity of the ballast stack, it is advantageous to attach the energy generating module on top of the ballast stack. However, depending on the crane configuration, different kinds of attachment are also conceivable. For example, the energy generating module may also be fastened to the ballast pile at the side, e.g. via a hook connection or under a base plate/ballast rack carrying ballast elements.

The term "module" is used hereinafter as an abbreviation for the name of the energy generating module and/or the box module. Furthermore, the feature that the module can be attached to the ballast stack should also be understood throughout the following such that it can also be attached to a different module (which module attached to the ballast stack can thus be considered to be part of the ballast stack).

In a possible embodiment, it is provided that the ballast stacks and/or the energy generating modules are arranged laterally outside the outer contour of the cantilever system, as viewed from the rear side of the superstructure. This means that the ballast stack and the energy generating module attached thereto are located outside the range of motion of the cantilever system, since the cantilever system in particular is only pivotable (relative to the rotatable superstructure) in the vertical pitch plane, i.e. can only be moved with one degree of freedom. The movement of the jib system or the crane function is not impaired thereby.

The superstructure ballast preferably comprises two ballast stacks arranged on both sides outside the outer contour of the cantilever system. At least one respective energy generating module is preferably attachable to both ballast stacks. A single energy generating module attached to one of the two ballast stacks may be provided. It is also possible to attach an energy generating module to each of the ballast stacks. They may be associated with a respective one or more motors or may power one or more motors together. It is likewise possible to use one of the energy generating modules as a replacement energy source in the event of a failure or failure of another energy generating module. In addition, the weight distribution of the superstructure ballast is more uniform when the module is attached to each of the ballast stacks.

In a further possible embodiment, it is provided that the energy generating module comprises a fuel cell, wherein a fuel tank, in particular a hydrogen tank, is preferably provided to supply the fuel cell with fuel, in particular hydrogen. This may naturally be a stack of interconnected fuel cells. In addition to hydrogen, other fuels may be used, such as methane, butane, or natural gas.

The fuel tank may be arranged in the same energy generating module as the fuel cell. However, it is also possible to provide a fuel tank in the energy generation module, which fuel tank is (also) used to supply fuel cells of different energy generation modules. Another possibility is to house the fuel tank in a separate tank module, which may likewise be attached to the ballast stack or the energy generating module.

In the latter two cases, corresponding cabinet lines must be provided to connect the different modules. Here, it is advantageous if the modules connected by one or more tank lines are arranged adjacent to each other or directly connected to each other. For example, the modules may be stacked on top of each other. It is therefore not necessary to provide elongated hoses or the like, but the modules can have corresponding tank connections at the housing, which can be coupled to one another directly or via short connections. Especially for the storage of hydrogen, the storage should be performed as close as possible to the fuel cell in order to minimize any safety risks. Furthermore, the tank connection is preferably arranged outside the fuel containing module, so that the fuel can be easily refilled. The overall module containing fuel may alternatively be designed to be replaceable with a refill module.

In a further possible embodiment, it is provided that a battery, in particular a rechargeable battery (for example an accumulator), is provided, by means of which the energy generated by the energy generating module can be stored and/or the electric motor can be supplied with energy. The battery is preferably arranged together with the energy generation device or a power generation device provided for generating energy in the energy generation module. The batteries may likewise be arranged in different energy generating modules or in a separate battery module attachable to the ballast stack or to the energy generating module.

For example, the battery may be charged by an energy generating device provided in the energy generating module, such as a fuel cell. Alternatively or additionally, it may be externally chargeable, wherein a corresponding charging connector can be provided at the energy generating module or the battery module to enable connection of a charging cable.

The battery may be used as a short-term energy storage, for example, to maintain a cool supply of the fuel cell at time lags after shutting down the fuel cell or to meet the energy requirements of the mobile crane at idle (e.g., for lighting, operation of sensors, for control, air conditioning or refrigeration, etc.).

Alternatively or additionally, the battery may also serve as an operation for crane functions (such as those described above) during powering of the electric motor by the energy generating module. Fuel cells therefore typically have a certain set-up time, typically in the range of a few seconds. If the crane operator enters a control command to control the crane or the crane actuator, during this setup time, the movement can already be started due to the energy supply of the battery, wherein the fuel cell is switched on (total connection) or takes over completely after the start-up time.

In a further possible embodiment, it is provided that the energy generating module comprises an internal combustion engine and an electric generator for generating energy for the electric motor, which electric generator can be driven by the internal combustion engine. The energy generating module may be the only energy generating module, or two or more energy generating modules having different driving modes may be provided. For example, one energy generating module may include a fuel cell and another energy generating module may include an internal combustion engine having an electrical generator. A fuel tank is preferably provided to supply fuel (in particular hydrogen, diesel or gasoline) to the internal combustion engine.

The fuel tank is preferably arranged in the energy generation module together with the internal combustion engine. The fuel tank may likewise be arranged in a different energy generating module or in a separate tank module attachable to the ballast pile or to the energy generating module. In the latter two cases, corresponding tank lines must be provided to connect the different modules, the same applies to the fuel tank of the fuel cell.

In a further possible embodiment, it is provided that the energy generating module and/or the tank module and/or the battery module have a connecting device for releasable connection to the ballast element and/or to a different module. The module may be arranged at the top of the ballast stack or within the ballast stack (e.g. just at the bottom or in the middle). The connection means may comprise a protrusion and a groove that engage at the ballast element upon attachment of the module. Furthermore, the connecting means may be lockable, or separate locking means may be provided to reversibly lock the module to the ballast element.

In a further possible embodiment, it is provided that all modules and all ballast elements have the same connecting device and can be stacked on top of one another in any desired sequence. This results in a modular design of the ballast elements and modules, so that they can be flexibly arranged, for example, according to the modular principle. Alternatively or additionally, the cell element and the module may have the same bottom area, e.g. a rectangular bottom area. The ballast stacks combined with one or more modules therefore always have the same transverse dimensions, so that only their height (and their weight) varies depending on the arrangement of the ballast elements and modules.

The ballast element may have a design or shape according to DE 202008006356U 1, the disclosure of which is expressly incorporated herein.

In a further possible embodiment, it is provided that the energy generating module and/or the battery module are connected or can be connected to the electric motor via an electrical line. Furthermore, depending on the interconnection of the modules, the individual modules can be connected to one another via power lines, for example if the cells which can be charged by the fuel cells of the energy generating module are arranged in separate cell modules.

In a further possible embodiment, it is provided that the power line comprises a power cable which can be connected to the energy supply connection of the superstructure and/or the respective module. After removal of the respective module, for example an energy generating module, the power cable can be stowed or stored at or in the module or at the superstructure. Special guiding or holding elements, such as hooks, may be provided at the ballast element to enable the laying of the power cables in a controlled manner so that they do not get in the way.

Alternatively or additionally, the power line may be arranged at or in a ballast element arranged between the respective module and the superstructure. Thus, the lines may for example be integrated in the ballast elements, so that each ballast element has a line section extending at the outside or inside the ballast element. By connecting the ballast elements, the line sections are preferably conductively connected to one another via special electrical contacts which can be provided at the connection means, so that a conductive connection or power line is established between the module and the superstructure. The lines of the bottommost ballast element are then preferably connected to the superstructure or to electronics provided in the superstructure or directly to the motor. Furthermore, the modules likewise have corresponding contacts for connecting their line section to the line section of the next ballast element.

Alternatively, wireless energy transmission, in particular inductive energy transmission, can also be considered between the individual sections, for example between the energy generating module and the closest ballast element and between the individual ballast elements. The module and the individual (or all) ballast elements may thus have respective transmitting/receiving elements (e.g. antennas or coils) for energy transfer. Thereby keeping the distance to be bridged small and maximizing efficiency.

In a further possible embodiment, it is provided that the energy generation module comprises a power generation unit (for example, a fuel cell or a generator) for supplying power to the electric motor, a control unit for controlling/regulating the supply of power to the electric motor, and preferably an energy store (for example, a battery or a corresponding fuel tank for an internal combustion engine and for a fuel cell) connected to the power generation unit, and/or an air conditioner for cooling, heating and/or ventilation. Furthermore, means for dehumidifying and/or for extracting gases, such as sulfur, can be provided. All these units are integrated in a single module. It only needs to be attached to the ballast stack and connected to the corresponding line (in the simplest case only power cables). The energy supply of the mobile crane can thus be configured and optionally changed in a simple manner.

In a further possible embodiment, it is provided that a hydraulic circuit is provided with a hydraulic pump which can be driven by an electric motor. The travel drive and/or the crane actuators may be controlled via a hydraulic circuit. For example, the hydraulic drives that are usually used can therefore continue to be used in crawler cranes. Retrofitting of the mobile crane would not be necessary, in particular if the electric motor is not integrated in the superstructure, but can be fastened to the superstructure as a drive module. It is only necessary to lay the connection lines accordingly and provide the required connections. Furthermore, the electric motor may be used only for driving one or more hydraulic pumps or may additionally provide a direct power supply for one or more crane functions.

In a further possible embodiment it is provided that the electric motor is arranged within a frame structure of the superstructure or outside the superstructure, in particular in a drive module which is releasably connected to the superstructure.

In a further possible embodiment, at least two electric motors for driving the mobile crane are provided, which can be supplied with energy from a common energy generation module and/or from separate energy generation modules, wherein the electric motors are preferably configured to drive the mobile crane together or by means of one of the electric motors, while the other electric motor is used as a replacement electric motor (backup).

In a further possible embodiment, it is provided that the boom system comprises a boom and/or a guyed frame (Abspannbock) which is pivotable in the pitch plane of the boom. In particular for smaller mobile cranes, the boom can thus be cable-steered pivotably via a cable frame (a-frame) which is supported pivotably about a horizontal pivot axis at the upper structure. Alternatively, in particular for larger mobile cranes, the jib can be cable-steered by a boom which is supported pivotably about a horizontal pivot axis at the upper structure, wherein here too an a-frame can be provided. Thus, all of these components of the cantilever system move in a common pitch plane. The energy generating module is preferably arranged such that it is arranged completely outside the movement region of the cantilever system, such that it does not collide with the cantilever system during its movement.

In a further possible embodiment, it is provided that the energy generating module and/or the ballast element have a container size and are preferably releasably connected to one another by container connection elements. The container size is at least the length of a standard container, but preferably has the floor area or bottom dimensions of a standard container. The weight of a ballast plate having the same container size floor area may be determined depending on its height. Since the modules and ballast plates have the same connections as a commercial standard container, they can be transported with it. Furthermore, they are proven and robust connection means, whereby the assembly or the required configuration of the ballast element and the module can be carried out quickly and simply. The modules may have full standard container dimensions, i.e. length, width and height.

The modules cannot slide due to the container connections between the ballast elements and the modules. Safety-related behavior is more important when the load is interrupted and a large amount of energy is suddenly released. In this case, the module is also held firmly in place. The container connection elements are preferably twist lock connectors so that the ballast elements and the modules can be locked to each other.

Drawings

Further features, details and advantages of the invention result from the following description of embodiments with reference to the drawings. Shown in the drawings are:

FIG. 1: a general perspective view of an embodiment of a mobile crane according to the invention;

FIG. 2: a rear view of the mobile lift crane of fig. 1;

FIG. 3: a perspective view of a superstructure ballast of a mobile crane according to a first embodiment;

FIG. 4: a superstructure and a superstructure ballast according to the second embodiment;

FIG. 5: a schematic diagram of an energy generating module according to a first embodiment; and

FIG. 6: schematic diagram of an energy generating module according to a second embodiment.

Detailed Description

Fig. 1 shows an exemplary embodiment of a mobile crane 10 according to the invention in perspective overall view. The mobile crane 10 comprises an undercarriage 12 with two crawler undercarriages 13 and a superstructure 14 which is rotatably supported on the undercarriage 12 about a vertical axis and has a cantilever system and a superstructure ballast 20.

The cantilever system comprises a cantilever 16 (here a main cantilever with adjustable fly-bar) pivotally (or rotatably) connected to the superstructure 14 in an articulated manner and cable-steered via a boom 17 and a cable frame or a-frame 18. The boom 17 and preferably also the a-frame 18 are likewise each pivotably supported about a horizontal axis at the upper structure 14 and pivotable in the same pitch plane. The components of the cantilever system are adjustably connected, in part, via a complex cable system in the plane of the cantilever. Furthermore, at least the boom 16 and the boom 17 are rotatable elements. This means that the pitch plane of these elements remains independent of the other components of the mobile crane 10 over its entire width.

Fig. 2 shows the mobile crane 10 in a rear view, i.e. from the rear side. The superstructure ballast 20 is located in or at the rear region of the superstructure 14 and comprises two

ballast stacks

22, 23 arranged to the pitch plane side of the cantilever system and each comprising a plurality of plate-like ballast elements or ballast plates 24 having a rectangular bottom area. The ballast stacks 22, 23 are arranged here such that they lie completely outside the movement region of the components of the cantilever system. This can be easily identified in the rear view of fig. 2. The a-frame 18 of the boom 17 and the boom 16 have substantially the same width and therefore overall a certain total width. The minimum distance of the ballast stacks 22, 23 is now greater than this total width. In other words, the a-frame 18, boom 17 and boom 16 are free to move without colliding with the ballast stacks 22, 23. The latter does not hinder the movement of the cantilever system.

The ballast stacks 22, 23 are arranged on ballast carriers connected to the rearwardly projecting frame structure of the superstructure 14. A plurality of crane actuators, such as hoisting winches and/or cable winches, are further arranged at the upper structure 14. In the embodiment of fig. 1, the boom 17 is additionally connected to a crane ballast 21 separate from the superstructure 14, however, this is not essential to the invention here.

Since the cantilever system always has only one degree of freedom, the height of the stacked ballast plates 24 is less relevant. In any event, since the superstructure 14 rotates with its cantilever system, space must remain free and rotational movement always occurs with the cantilever system.

According to the invention, the mobile crane 10 is driven via at least one electric motor, which is in turn supplied with energy or power by the energy generating module 30. The energy generating module 30 is stacked on or attached to the stacked ballast plates 24, preferably as a terminal end of the ballast stacks 22, 23. Thus, the energy generating module 30 acts as a normal ballast weight, i.e. it is part of the superstructure ballast 20, so that its spatial extent or height is not important. This also applies to its weight, since it acts as a ballast weight and is in any case required as a counterweight. The energy generating module 30 can naturally also be introduced below the ballast plate 24 or in the middle of the ballast stacks 22, 23. This will shorten the distance to the steel structure of the superstructure 14 in which the motor is accommodated. However, the position of the overall centre of gravity of the superstructure ballast 20 and thus the entire mobile crane 10 will therefore increase.

Fig. 3 shows a first embodiment of a superstructure ballast 20 with two transverse ballast stacks 22, 23, where an energy generating module 30 is provided, wherein one respective module 30 is arranged on one of the ballast stacks 22, 23. In the embodiment shown here, one or more electric motors are arranged in the frame structure of the superstructure 14 and are connected to the respective modules 30 via not shown power lines, such as power cables. Due to the arrangement of the energy generating module 30, the path along which the electrical energy must cover the lines is very short. This is very simply possible, for example, with each module 30 via a power cable extending over the plug-in connection between the energy generating module 30 and the steel structure of the superstructure 14. The line loss is small. Depending on the space requirements, the power cable can be stored in the energy generating module 30 during transport or in the steel structure. Alternatively, it can be transported separately.

An alternative embodiment is shown in fig. 4, where here the one or more electric motors are not arranged within the frame structure of the superstructure 14, but in a drive module 31 which can be fastened laterally outside the superstructure 14. The drive module 31 may also contain secondary parts of the electric motor, such as cooling means.

In all of the embodiments shown herein, the ballast plates 24 have a floor area of standard container size. The energy generating modules 30 have the same footprint and are preferably sized with a corresponding height that is entirely in accordance with standard container dimensions. The energy generating module 30 can thus be transported with a commercial container. The height of ballast plates 24 may be dimensioned such that a certain number of ballast elements 24 stacked on top of each other results in a height of energy generating module 30.

All of the ballast plates 24 and energy generating modules 30 preferably have standardized container connector means or connection means and can thus be connected and locked to each other in a known manner. Ballast stacks 22, 23 can thus be simply and quickly configured or assembled with a certain number of ballast elements 24 and modules 30 and in a certain arrangement (energy generating module 30 on top, bottom or in the middle of ballast stacks 22, 23). Energy generating module 30 and ballast plates 24 cannot slide due to the connecting means, in particular twist lock containers commonly used with standard containers and thus are reliably fixed to

ballast stacks

22, 23.

Two different embodiments of energy generating module 30 are shown in fig. 5 and 6, schematically illustrating their internal structure. The energy generating module 30 according to fig. 5 has a power generation device 32, by means of which power can be generated and can be used by an electric motor. The power generation device may be a fuel cell (or one or more fuel cell stacks) that generates power by supplying fuel such as hydrogen. Alternatively, the power generation means 32 may comprise an internal combustion engine with a generator connected downstream.

In addition to the power generation device 32, a battery 34 is provided, which can preferably be charged via a charging connector at the housing of the energy generation module 30. The battery 34 may specifically store the energy generated by the power generation device 32 and provide it to the motor as needed (e.g., during the setup time of the fuel cell or after it is shut down to maintain the power supply). However, the connection between the power generation device 32 and the battery 34 is not absolutely necessary.

Energy generation module 30 also includes a control unit 36 by which the energy generated by power generation device 32 and/or stored in battery 34 may be controlled and/or regulated to be provided to the motor. Power electronics may be provided herein. All of these components are combined together in energy generating module 30. The power supply of the power generation device 32 (with the respective fuel in the case of a fuel cell and in the case of an internal combustion engine) takes place via a tank which is arranged outside the energy generation module 30, not shown here, and can be arranged in a tank module arranged at/in the ballast stacks 22, 23.

The box module preferably has the same dimensions and connections as the energy generating module 30. Ideally, the energy generating module 30 and the one or more box modules are directly connected or arranged adjacent to each other to avoid long and interfering respective fuel lines. The corresponding box connector may thus be provided at the container lid of the module 30, which may be interconnected directly or via short wires.

It is also conceivable that each of the two modules 30 on one

respective ballast stack

22, 23. In this case, one module 30 can be designed as an energy generating module, while one module 30 can be designed as a fuel storage module. In this case, both are connected via respective lines.

In an alternative embodiment shown in fig. 6, a tank 38 for supplying power to the power generation device 32 is likewise integrated in the energy generation module 30. In addition, however, one or more tank modules may be provided to increase the total capacity of available fuel/fuel.

Alternatively, the controls or power electronics for controlling/regulating the power supply of the electric motor may also be accommodated in a separate control module which may also be attached to the ballast stacks 22, 23. Similarly, the battery 34 (or additional batteries) may be disposed in a separate battery module.

However, all basic components of the energy generation module 30, such as the energy storage/battery 34, the energy generation module 32, and optional secondary elements, such as cooling of the fuel cell via fans, temperature control, dehumidification, units for extracting sulfur, etc., are contained in a single enclosure/container. The total energy generation module 30 may be considered a power supply that operates as a power source at a defined maximum level and for an infinite duration.

The mobile crane 10 according to the invention preferably has at least one energy generating module 30 with a fuel cell, wherein further energy generating modules 30 can be provided, which can likewise comprise a fuel cell and/or an internal combustion engine with a generator. At least two motors are advantageously provided. There is redundancy and emergency operation can be maintained in general.

The housing of the module (i.e., energy generating module 30, box module, and/or battery module) may be a standard shipping container. Due to the free height, it is also possible for a plurality of modules to be stacked on top of one another.

In the case of mobile cranes, which are usually driven via an internal combustion engine, the power they permanently supply is not required at all most of the time. Internal combustion engines are most often operated in idle mode. By using the solution according to the invention with an energy generating module 30 of fuel cells, it or at least a number of interconnected fuel cells can be shut down when it/they are not needed. There is a great potential for energy savings.

Controller 36 may take over power management. Short term energy storage (e.g., battery 34 or a separate battery module) may also be integrated in the power management. Hysteresis for cooling the fuel cell, energy requirements of the mobile crane 10 at idle, such as lighting, operation of sensors, for control, air conditioning, etc., can be taken into account in this respect. Short term energy storages are also conceivable, which can directly control the crane function (without any detour via the electric motor).

The fuel cell has a start-up time. Typically this amounts to a few seconds (e.g., about 5 seconds). If the crane operator enters a request for a crane actuator, the movement may already have begun at this point. This can optionally also be a summation circuit of electrical energy from already operating fuel cells and short-term energy storages.

The mobile crane can be provided or configured in different drive modes. The selectable drive modes may be conventional and/or electric. The energy generating module 30 (and possibly other modules) can be attached to the ballast stacks 22, 23 without problems, as well as an electrical connection to the electric motor.

The water produced during the use of the fuel cell is absolutely pure. It is therefore conceivable to let it evaporate at the deployment site. It may also be performed on the floor of the deployment site. The function of the mobile crane 10 is similar to that of known cranes having conventional drives. In particular, there is therefore no cable connecting the mobile crane 10 to the main power supply of the deployment site.

The tanks for the respective fuels are preferably cylindrical, to better withstand pressures of typically several hundred bar (for example around 700 bar).

The possible space requirement of the fuel cell is observed or estimated. Diesel oil tankThe energy contained in (a) is considered to be 1. If this energy is stored in a battery, about 25 times the space (volume) is required. For hydrogen, about 16 times the space must be provided. Energy generating module 30 may be a 20 foot container with an internal dimension of 5.898x2.352x2.390m ³ ＝33.1m ³ . However, for a cylindrical bin to be accommodated in such a container, only about 22m ³ This corresponds to a maximum of 22,000l of diesel, i.e. 22,000 l/16-1,377 l. Three modules are therefore also conceivable, one of which forms the energy generating module 30 and two of which form a box module.

If the tank module is attached or introduced on top of the ballast stacks 22, 23, a fast refuelling is also possible via replacement of the total tank module. Connections may be designed using known and tested components.

List of reference numerals:

10 mobile crane

12 underframe

14 superstructure

16 cantilever

17 boom

18 dragline frame

20 superstructure ballast

21 crane ballast

22 ballast pile

23 ballast pile

24 ballast element

30 energy generating module

31 drive module

32 power generation unit

34 cell

36 control unit

38 boxes.

Claims

1. Mobile crane (10) having a drivable undercarriage (12), a superstructure (14) rotatably supported on the undercarriage (14) and an electric motor for driving the mobile crane (10), wherein the superstructure (14) comprises a jib system having a jib (16) pivotable about a horizontal axis and a superstructure ballast (20), the superstructure ballast (20) having at least one ballast stack (22, 23) consisting of one or more ballast elements (24),

the characteristics of the utility model are that,

the electrical energy for driving the electric motor can be provided by at least one energy generating module (30) attachable to the ballast stacks (22, 23).

2. Mobile crane (10) according to claim 1, characterized in that the ballast stacks (22, 23) and/or the energy generating module (30) are arranged laterally outside the outer contour of the cantilever system, seen in the direction of the rear side of the superstructure, wherein the superstructure ballast (20) preferably comprises two ballast stacks (22, 23) arranged on both sides outside the outer contour of the cantilever system.

3. Mobile crane (10) according to claim 1 or 2, characterized in that the energy generating module (30) comprises a fuel cell, wherein preferably a fuel cell tank (38) is provided to supply the fuel cell with fuel, in particular with hydrogen, which is arranged in the same or another energy generating module (30) or in a tank module attachable to the ballast stacks (22, 23).

4. Mobile crane (10) according to one of the preceding claims, characterized in that a battery (34), in particular a rechargeable battery, is provided, by means of which the energy generated by the energy generating module can be supplied and/or the electric motor can be supplied with energy, wherein the battery (34) is preferably arranged in the same or another energy generating module or in a battery module which can be attached to the ballast stack.

5. Mobile crane (10) according to any one of the preceding claims, characterized in that an energy generating module comprises an internal combustion engine and an electric generator drivable by the internal combustion engine for generating energy for the electric motor, wherein preferably a fuel tank (38) is provided for supplying fuel to the internal combustion engine, which fuel tank is arranged in the same or another energy generating module or in a tank module attachable to the ballast pile.

6. Mobile crane (10) according to one of the preceding claims, characterized in that the energy generating module (30) and/or box module and/or battery module has a connection device for releasable connection to a ballast element (24) and/or another module and can preferably be arranged on top of the ballast stacks (22, 23) or within the ballast stacks (22, 23).

7. Mobile crane (10) according to claim 6, characterized in that all modules and all ballast elements (24) have the same connecting means and can be stacked on top of each other in any desired order; and/or all modules and all ballast elements have the same floor area.

8. The mobile crane (10) according to one of the preceding claims, characterized in that the energy generating module (30) and/or the battery module (34) are connected or connectable to the electric motor via an electric line.

9. Mobile crane (10) according to claim 8, characterized in that the power line comprises a power cable connectable to an energy supply connection of the superstructure (14) and/or the respective module (30); and/or the electrical lines are arranged at or in the ballast element (24) arranged between the respective module (30) and the superstructure (14), wherein the line sections of the individual ballast elements (24) are conductively connectable to one another, preferably by means of electrical contacts.

10. Mobile crane (10) according to any one of the preceding claims, characterized in that the energy generating module (30) comprises an electricity generating unit (32) for supplying the electric motor, a control unit (36) for controlling/regulating the supply of the electric motor, and preferably an energy storage (34, 38) connected to the electricity generating unit (32) and/or an A/C system for cooling, heating and/or ventilation.

11. Mobile crane (10) according to one of the preceding claims, characterized in that a hydraulic circuit is provided with a hydraulic pump which can be driven by the electric motor.

12. Mobile crane (10) according to any one of the preceding claims, characterized in that the electric motor is arranged within the frame structure of the superstructure (14) or outside the superstructure (14), in particular in a drive module (31) releasably connected to the superstructure (14).

13. Mobile crane (10) according to one of the preceding claims, characterized in that at least two electric motors for driving the mobile crane (10) are provided, which can be supplied with energy from a common energy generating module and/or from respective individual energy generating modules (30), wherein the electric motors are preferably configured to drive the mobile crane (10) together or by one of the electric motors driving the mobile crane (10) and the other electric motor serving as a replacement electric motor.

14. Mobile crane (10) according to any one of the preceding claims, characterized in that the cantilever system comprises a boom (17) and/or a cable frame (18) pivotable in the pitch plane of the cantilever (16), wherein the energy generating module (30) is preferably arranged such that it is completely arranged outside the movement area of the cantilever system.

15. Mobile crane (10) according to one of the preceding claims, characterized in that the energy generating module (30) and/or the ballast element (24) have a container size and are preferably releasably connected to each other by container connection means, in particular twist lock connectors.