Mobile concrete pump

Abstract

The invention relates to a truck-mounted concrete pump (1) with a hydraulically driven concrete pumping device (2), at least one first hydraulic pump (3) provided for the hydraulic drive of the concrete pumping device (2), and a first drive motor (4) provided for the mechanical drive of the at least one first hydraulic pump (3), wherein the first drive motor (4) is an air-cooled electric motor.

Description

The invention relates to a truck-mounted concrete pump with a hydraulically driven concrete pumping device comprising at least one first hydraulic pump, which is provided for the hydraulic drive of the concrete pumping device, and a first drive motor, provided for the mechanical drive of the at least one first hydraulic pump. Such a truck-mounted concrete pump is known, for example, from EP 3 847 321 A1. This truck-mounted concrete pump features a hybrid drive, meaning that at least one hydraulic pump for driving the concrete pumping mechanism can be driven either by an internal combustion engine, which usually also powers the chassis, or by a liquid-cooled electric or synchronous motor. Liquid cooling of an electric motor has several disadvantages, as the housing or interior of the electric motor must be designed to allow the coolant to flow through it via appropriately integrated channels. Furthermore, it is necessary to run coolant lines to a radiator. This radiator must be equipped with a fan driven by an electric or hydraulic motor and mounted on the truck-mounted concrete pump in a location where air can circulate freely through the fan.Due to the already limited space on a truck-mounted concrete pump, the fan is difficult to accommodate and its manufacture is expensive and complex. The object of the invention is therefore to provide an improved truck-mounted concrete pump which, despite the hydraulic pumps being driven by an electric motor, is easy and inexpensive to manufacture. This problem is solved by a truck-mounted concrete pump with the features of claim 1. Because the primary drive motor is an air-cooled electric motor, there is no need for a complex liquid cooling system with cooling channels within the motor, cooling lines to a radiator, and a motor to drive a fan on the radiator. The purchase price of an air-cooled electric motor is comparatively low compared to a liquid-cooled electric motor, and installation is also simple and cost-effective. Advantageous further developments and embodiments of the invention are set out in the dependent claims. It should be noted that the features listed individually in the claims can also be combined with one another in any technologically meaningful way, thus revealing further embodiments of the invention. According to an advantageous embodiment of the invention, a second drive motor is provided for the mechanical drive of at least one second hydraulic pump, which is also intended for the hydraulic drive of the concrete pumping device. The second drive motor for driving a second hydraulic pump for the hydraulic drive of the concrete pumping device has the particular advantage that a further hydraulic pump can be used to drive the concrete pumping device with greater hydraulic power. A particularly preferred embodiment provides that the second drive motor is an internal combustion engine. The drive power of an internal combustion engine, which typically also powers the chassis of a truck-mounted concrete pump, is generally significantly greater than that of an electric motor. By using an internal combustion engine as the second drive motor, the concrete pumping device can be easily and typically with greater power driven by the internal combustion engine when the air-cooled electric motor is unavailable. Furthermore, because the internal combustion engine provides a second hydraulic pump for driving the concrete pumping device, which can, for example, also be driven in conjunction with the first hydraulic pump, a greater overall hydraulic drive power is available when the pump is powered by the internal combustion engine.In contrast, the drive of the concrete pumping device by means of the air-cooled electric motor alone can advantageously be designed with the first hydraulic pump in such a way that, in particular, the hydraulic losses during electric operation are as low as possible. A particularly advantageous embodiment of the invention relates to the fact that the air-cooled electric motor can be driven by the second drive motor as a generator. Because the air-cooled electric motor can be driven by the second drive motor as a generator, electrical power can be generated, making it possible to provide individual systems of the concrete pump assembly with a purely electric drive. In a conventionally designed truck-mounted concrete pump, these systems can only be driven by the combustion engine of the truck chassis. Furthermore, a division / decentralization of the drive structure of the truck-mounted concrete pump is possible, which enables an increase in efficiency or an improvement in the overall efficiency of the truck-mounted concrete pump's drive system.This is particularly advantageous for the electric drive of the concrete pumping system, which typically has a much more limited drive power compared to a drive with an internal combustion engine, in order to achieve a high pumping capacity even with electric drive. A particularly advantageous embodiment of the invention provides for at least one further hydraulic pump, wherein the at least one further hydraulic pump is provided to drive hydraulic actuating elements of an articulated mast of the truck-mounted concrete pump and / or hydraulic actuating elements of a support of the truck-mounted concrete pump and / or a pipe diverter of the truck-mounted concrete pump and / or an agitator of the truck-mounted concrete pump and / or another hydraulic auxiliary unit of the truck-mounted concrete pump, wherein at least one further electric motor is provided for the mechanical drive of the at least one further hydraulic pump.By providing at least one additional electric motor to drive at least one additional hydraulic pump, a particularly high increase in efficiency is possible. This is because, unlike in the prior art, not all hydraulic pumps are always driven by a single electric motor. Instead, individual hydraulic pumps whose power is not required at certain times can be completely switched off or not driven. A hydraulic pump idling still requires a relatively high drive power, as it typically pumps hydraulic oil even when idling, for example, to ensure its own lubrication. An advantageous embodiment of the invention provides that the air-cooled electric motor, driven as a generator by the second drive motor, supplies power to at least one further electric motor. By having the air-cooled electric motor, operating as a generator, supply power to at least one further electric motor, an energy-efficient, decentralized drive is enabled when operating the truck-mounted concrete pump with the combustion engine, without requiring an additional power supply for the further electric motor, such as a construction site power supply or a battery carried on the truck-mounted concrete pump. A particularly advantageous embodiment is one in which the first drive motor is a synchronous motor. Synchronous motors have a high power density and can therefore be easily installed on a truck-mounted concrete pump, even with air cooling. An advantageous design provides that the truck-mounted concrete pump has an air guide housing for directing cooling air around the first drive motor. This air guide housing allows the cooling air from the air cooling system to be directed directly over the surface of the drive motor for optimal cooling, thus dissipating its heat very efficiently. According to a preferred embodiment of the invention, the truck-mounted concrete pump has an air duct that directs cooling air to the first drive motor, particularly into the air duct housing. The hydraulic pumps of a truck-mounted concrete pump are typically mounted between the longitudinal beams of the truck chassis or the supports of the concrete pump superstructure, i.e., relatively close to the ground. The air-cooled electric motor is preferably arranged directly on the drive shaft of a hydraulic pump or at least in the immediate vicinity of the hydraulic pump. Because air cooling generates a relatively strong airflow, there is a risk that many particles in the form of dust and similar substances will be drawn in, which can then be deposited on the components of the air cooling system and the surface of the drive motor, thus reducing the cooling capacity.For example, an air duct can be used to draw in cooling air at a greater height above the ground, thus significantly reducing the risk of contamination of the air cooling system by contaminated air. A particularly advantageous embodiment includes an air filter for cleaning the cooling air. An air filter for cleaning the cooling air, either as an alternative or in addition to an air duct, also very effectively prevents contamination or clogging of the air cooling system for the electric motor. A particularly advantageous embodiment of the invention provides that the cooling air is actively cooled by an air conditioning condenser of the truck-mounted concrete pump. The air conditioning condenser cools the intake air, thus improving the cooling performance. On the one hand, this further increases the cooling capacity; on the other hand, this measure can reduce the throughput of cooling air, thereby, for example, reducing the drive power for a fan and / or minimizing contamination of the cooling system by dust particles and the like. A particularly advantageous embodiment of the invention relates to the truck-mounted concrete pump having a motor temperature sensor, wherein the motor temperature sensor detects the temperature of the first drive motor. By detecting the temperature of the first drive motor with a motor temperature sensor, energy-intensive cooling can be avoided as long as the temperature of the first drive motor remains within an acceptable range even without cooling. As long as the air cooling is not in operation, no contamination of the air cooling system occurs. Only when the motor temperature sensor detects a temperature of the first drive motor that necessitates cooling are measures initiated to reduce the temperature of the drive motor. Advantageously, the truck-mounted concrete pump is equipped with an ambient temperature sensor, which measures the temperature of the surrounding air. By monitoring the ambient temperature, the cooling system's output can be adjusted accordingly. At low ambient temperatures, the cooling capacity can be reduced, thus saving energy. A particularly advantageous embodiment of the invention provides that the truck-mounted concrete pump has a climate control system, wherein the climate control system operates the air conditioning condenser with a cooling capacity that depends on the temperature of the first drive motor and / or the ambient air. This measure enables particularly energy-efficient cooling because only as much cooling capacity is generated as is actually required. An advantageous embodiment of the invention provides that the first drive motor has a housing, wherein the truck-mounted concrete pump has a fan wheel driven by a fan motor, the fan wheel conveying cooling air along the housing. By means of a fan motor driving a fan wheel, the generation of the cooling airflow can be switched on and off as required, so that during times of low or no cooling demand from the first drive motor, neither power is required nor noise is generated for cooling. A particularly advantageous embodiment provides that the truck-mounted concrete pump has a fan control system, wherein the fan control system operates the fan motor at a speed dependent on the temperature of the first drive motor and / or the ambient air. By using a fan control system that operates the fan motor at such a temperature-dependent speed, the cooling efficiency can be further improved. An advantageous embodiment provides that the fan wheel and / or the fan motor is / are arranged in the air duct and / or in the air guide housing. This allows the cooling air to be guided very easily and precisely through the air duct to the drive motor or close around / along the first drive motor, in order to use the cooling air as effectively as possible for cooling the first drive motor. According to a preferred embodiment of the invention, the first drive motor has a drive shaft projecting from the housing of the drive motor, with at least one fan wheel arranged on the drive shaft, wherein the at least one fan wheel conveys cooling air along the housing of the first drive motor when the drive shaft rotates. This allows for a simple, cost-effective air cooling system for the first drive motor. A particularly advantageous embodiment provides that a gearbox is arranged between the fan wheel and the at least one hydraulic pump, so that the drive speed at which the drive motor drives the fan wheel differs from the drive speed at which the at least one hydraulic pump is driven. This allows, in particular, the cooling capacity to be adjusted. A hydraulic pump, which can be designed, for example, as an axial piston pump with swivel angle adjustment for regulating the delivery rate, operates particularly effectively at a low speed with a high swivel angle. If the optimal speed for the hydraulic pump is insufficient for cooling the drive motor by a directly mounted fan wheel, the speed of the first drive motor can be easily and permanently increased via a gearbox, preferably a reduction gearbox from the perspective of the first drive motor, to increase the cooling capacity.A particularly advantageous embodiment of the invention provides that the at least one hydraulic pump is an axial piston pump with a pivoting swashplate, wherein the pivot angle of the swashplate is adjustable to change the delivery rate by means of a pivot angle control, the pivot angle control being designed to set a pivot angle of the at least one hydraulic pump that depends on the temperature of the first drive motor and / or the ambient air. As mentioned above, an axial piston pump operates most efficiently at a high pivot angle and a relatively low speed. However, the resulting low speed of the drive motor can lead to insufficient cooling of the first drive motor.Therefore, at least in the short term, for example in the case of high power demand leading to a temperature increase of the first drive motor, it can be advantageous to reduce the swivel angle of the axial piston pump and simultaneously increase the drive speed of the first drive motor in order to increase the cooling capacity. A possible short-term reduction in efficiency can be accepted in return. In an advantageous embodiment of the invention, a variable coupling, in particular a viscous coupling, is arranged between the fan wheel and the at least one hydraulic pump, so that the drive speed of the fan wheel is variable relative to the drive speed of the first drive motor. This allows the cooling capacity to be actively controlled, for example, depending on the motor temperature or the ambient air temperature, but passive control of the fan wheel speed is also possible. In the simplest case, for example, a bimetallic spring could actuate the coupling, so that the speed or cooling capacity of the fan wheel increases with rising temperature. In one embodiment of the invention, the fan wheel has fan blades with a variable swivel angle. By changing the swivel angle of the fan blades, the cooling capacity can be adapted to the cooling requirements. The fan blades can be fixed at a low swivel angle when the ambient air temperature is low and at a high swivel angle when the ambient air temperature is high. With appropriate control of the swivel angle of the fan blades, the cooling capacity can, for example, be continuously adjusted to the motor temperature and / or the ambient air temperature. Further features, details, and advantages of the invention will become apparent from the following description and from the drawings, which show exemplary embodiments of the invention. Corresponding objects or elements are provided with the same reference numerals in all figures. The figures show: Fig. 1 truck-mounted concrete pump according to the invention, Fig. 2 air-cooled drive motor in a first hybrid drive concept, Fig. 3 air-cooled drive motor in a variant of the first hybrid drive concept, Fig. 4 spatial representation of the hybrid drive concept of Fig. 3, Fig. 5 air-cooled drive motor in a second hybrid drive concept, Fig. 6 spatial representation of the hybrid drive concept of Fig. 5, Fig. 7 air-cooled drive motor in a third hybrid drive concept, Fig. 8 air-cooled drive motor in a fully electric drive concept, Fig. 9 air cooling of a drive motor according to the invention in a first variant.Fig. 10 Air cooling of a drive motor according to the invention in a second variant, Fig. 11 Air cooling of a drive motor according to the invention in a third variant, Fig. 12 Air cooling of a drive motor according to the invention in a fourth variant, Fig. 13 Air cooling of a drive motor according to the invention in a fifth variant, Fig. 14 Air cooling of a drive motor according to the invention in a sixth variant, Fig. 15 Air cooling of a drive motor according to the invention in a seventh variant, Fig. 16 Air cooling of a drive motor according to the invention in an eighth variant, and Fig. 17 Air cooling of a drive motor according to the invention in a ninth variant. Figure 1, designated by reference numeral 1, shows a truck-mounted concrete pump 1 according to the invention. The truck-mounted concrete pump 1 is mounted on a truck chassis driven by a second drive motor 5, typically an internal combustion engine (see, for example, Figure 11) or an electric motor. The truck-mounted concrete pump 1 has a concrete pumping device 2, for example, a two-cylinder piston pump driven by two hydraulic cylinders. A hydraulically driven pipe diverter 14, for example in the form of an S-pipe or a so-called rock valve, is typically used to switch the concrete flow of the two-cylinder piston pump.Fresh concrete, typically fed from a truck-mounted concrete pump 1 by a concrete mixer truck, is conveyed from the concrete pumping device 2 along the extendable articulated boom 11 via a delivery line (not shown) arranged along the boom segments 10, with an end hose at the top of the boom 11, to a discharge point. The feed hopper 46 is usually located at the rear of the truck-mounted concrete pump 11. An agitator 15, driven by an electric or hydraulic motor, is typically located in the feed hopper 46 to mix the fresh concrete. The boom segments 10 of the articulated boom 11 are typically adjustable relative to each other via hydraulic actuators 10 in the form of hydraulic cylinders or other suitable drives. To ensure the truck-mounted concrete pump 1 is stable when operating with the articulated boom 11 extended, it is equipped with outriggers 13, usually extendable by hydraulic actuators 12, for example, extendable or foldable support beams and outriggers.The invention is also applicable to a truck-mounted concrete pump 1 that does not have a articulated mast 11, so that the concrete is conveyed directly from the concrete pumping device 2 to the place of application via a conveying line laid, for example, on the ground. Figure 2 shows an exemplary drive concept for a truck-mounted concrete pump 1 according to the invention, with a first drive motor 4 designed as an air-cooled electric motor. A first hydraulic pump 3 is provided for the hydraulic drive of a hydraulically driven concrete pumping device 2, and the first drive motor 4 is provided for the mechanical drive of the at least one hydraulic pump 3. The drive concept of a truck-mounted concrete pump 1 in Figure 2 is a hybrid drive concept, meaning that the hydraulic actuators of the articulated boom 11 and the concrete pumping device 2 can be driven either by the first drive motor 4 or by the second drive motor 5 of the truck chassis.In this exemplary illustration, the second drive motor 5 can be mechanically connected to the first and a further hydraulic pump 6 for driving the concrete pumping device 2 and the articulated boom 11 or the support 12 by means of a distribution gearbox 45, for example, a distribution shift gearbox. A second hydraulic pump 6 is arranged at one output of the distribution shift gearbox 46 and can be disconnected from the gearbox 36 via a coupling 36. When the truck-mounted concrete pump 1 is operated with the second drive motor 5, the coupling 36 is closed, and the second drive motor 5 drives the first hydraulic pump 3, the second hydraulic pump 6, and the further hydraulic pump 7 for the hydraulic drive of the articulated boom 11 and the support 12.Because the second drive motor 5 mechanically drives two hydraulic pumps for the hydraulic drive of the concrete pumping device 2, the comparatively high power output of the second drive motor 5, designed as an internal combustion engine, can be used to drive the concrete pumping device 2. The drive power of the first drive motor 4, designed as an air-cooled electric motor, is generally lower due to the available electrical supply power. Therefore, when the first hydraulic pump 3 and the second hydraulic pump 7 are driven mechanically by the electric motor 4, the clutch 36 is opened, so that the second hydraulic pump 6 is not driven when the truck-mounted concrete pump 1 is driven by the first drive motor 4.This optimizes the efficiency of the electric drive, because the first hydraulic pump 3, designed, for example, as an axial piston pump with a swiveling swashplate, can be operated with a large swivel angle of the swashplate at high efficiency, and the second hydraulic pump 6 does not have to be "carried along" in idle mode. A check valve 39 at the outlet of the second hydraulic pump 6 prevents hydraulic oil from being forced into the second hydraulic pump 6 when the first hydraulic pump 3 is driven. When the second drive motor 5 drives the hydraulic pumps 3, 6, 7 via the gearbox 47, the first drive motor 4, i.e., the air-cooled electric motor 4, is also driven by the second drive motor 5 as a generator.This means that the first drive motor 4, when driven by the second drive motor 5, generates electrical power which, in this exemplary illustration, is used to drive two further electric motors 16 and 17. For example, the second electric motor 16 mechanically drives another hydraulic pump 9 for the hydraulic drive of the agitator 15, and the second electric motor 17 is intended for the hydraulic drive of the pipe diverter 14 by driving another hydraulic pump 8. The advantage of the decentralized drive concept presented here is, for example, that the drive power of the air-cooled electric motor 4 does not need to be excessively high, because not all units of the truck-mounted concrete pump 1 need to be driven by this single electric motor 4. Instead, the drive power of at least one further electric motor 16, 17 can be used to drive additional units.This makes it easier to use a relatively simple air cooling system for the first drive motor 4 instead of a very complex liquid cooling system. It should be noted that the hydraulic pumps 3, 6, 7, 8, 9 required for the hydraulic drive of the truck-mounted concrete pump 1 can be distributed or arranged as desired within the scope of this invention. For example, the additional hydraulic pump 9 for driving the pipe diverter 14 could be replaced by the additional hydraulic pump 7 in this concept. The advantage of this variant would be that when operating the articulated boom 11 or the outrigger 12, only the additional hydraulic pump 7 could be driven by another electric motor 17, so that no other hydraulic pumps would be driven idling during the assembly and disassembly of the truck-mounted concrete pump 1, which can significantly reduce energy consumption and / or increase efficiency.The other electric motors 16 and 17 could, of course, also be designed as air-cooled electric motors. In this exemplary illustration, with the purely electric drive of the truck-mounted concrete pump 1, electrical power is supplied to the electric motors 4, 16, and 17 via a connector 34, which is connected, for example, to an AC construction site power supply. In this exemplary illustration, the AC current received via the connector 34 is routed through an AC / DC converter 38 into a DC intermediate circuit 33. The electric motors 4, 16, and 17 are connected to the DC intermediate circuit 33 via inverters 35. Depending on whether the electric motors 4, 16, and 17 are DC or AC motors, the inverters can be DC / DC or DC / AC converters. Figure 3 shows a variant of the drive concept depicted in Figure 2, which relates in particular to the connection of the first hydraulic pump 3 and the second hydraulic pump 6 to the gearbox 46. In this example, the coupling 36 is not arranged between the gearbox 46 and the second hydraulic pump 6, but rather between the gearbox 46 and the first hydraulic pump 3. This allows the gearbox 46 to be completely decoupled when the first hydraulic pump 3 and the second hydraulic pump 7 are operated with the air-cooled electric motor 4, thus avoiding losses due to the drive of the gearbox 46, which is not actually required in this operating state. Figure 4 shows an exemplary three-dimensional representation of a drive train, as schematically depicted in Figure 3. The bell-shaped air guide housing 19 of the drive motor 4 is clearly visible in Figure 4, in which the fan wheel 28, mounted on the drive shaft 30 of the drive motor 4, is also located. The connections 37a and 37b for the cardan shaft of the truck's drive system on the transmission 46 are also clearly visible in Figure 4. Figure 5 shows another exemplary variant of a hybrid drive concept for a truck-mounted concrete pump 1, in which both the second drive motor 5, designed as an internal combustion engine, and the first drive motor 4, designed as an air-cooled electric motor and also as a generator, can be used to drive the components of the truck-mounted concrete pump 1. The electric or hydraulic drive concept largely corresponds to the drive concept of Figures 2, 3, and 4. In contrast to the concept of Figures 2, 3, and 4, a different transmission 47 is provided, which here, by way of example, has a total of six inputs or outputs, two of which, as with transmission 46, are provided for the connection or drive of the cardan shaft 37a, 37b for the wheel drive of the truck chassis of the truck-mounted concrete pump 1. Transmission 47 has a total of four inputs or outputs.Outputs are provided for connecting hydraulic pumps 3, 7, 6 and the first drive motor 4. The advantage of using a gearbox with six inputs / outputs lies particularly in the reduction of the overall drive train's length, which can then be more easily accommodated in the truck-mounted concrete pump 1, depending on the available space. In this exemplary illustration, the first drive motor 4, designed as an electric motor with generator function, is arranged directly at an input / output of the gearbox 47, with the fan 28, located on the drive shaft 30 of the first drive motor 4, positioned on the side facing away from the gearbox 47. The second hydraulic pump 6, which can be disconnected by means of a coupling 36, is arranged at the opposite input / output of the gearbox 47 and drives the concrete pumping device 2.The first hydraulic pump 3 for driving the concrete pumping device 2 and the second hydraulic pump 7 for driving the articulated mast 11 or the support 13 are arranged at the two further inputs / outputs of the gearbox 47. The arrangement of the hydraulic pumps 3, 6, and 7 and the first drive motor 4 can be readily varied at the discretion of a person skilled in the art. For example, the preferably detachable second hydraulic pump 6 and the first hydraulic pump 3 could be interchanged, so that the first drive motor 4 can drive the then opposite first hydraulic pump 3 with lower gearbox losses. In this embodiment, the first drive motor 4 is also designed as a generator which, when operating with the combustion engine and driven by the second drive motor 5, generates electrical power for driving at least one further electric motor, in this case two electric motors 17, 18.In this embodiment, the additional electric motor 18 is not coupled to a hydraulic pump, but directly drives other components of the truck-mounted concrete pump 1, such as a high-pressure cleaner, cable reel, hydraulic fan motor, or similar. Alternatively, when using a gearbox 47 with six inputs / outputs, it would also be possible to dispense with the generator function of the first drive motor 4 and, for example, to couple the additional hydraulic pumps 8, 9 to the gearbox 47 in a suitable manner, grouped into smaller hydraulic pump trains. Further couplings inside or outside the gearbox 47, which can be assigned to the individual inputs / outputs of the gearbox 47, can be used to connect / disconnect individual inputs / outputs in order to disconnect hydraulic pumps that are not needed in certain operating situations and consume unnecessary drive energy when idling.Thus, during the assembly and disassembly of the truck-mounted concrete pump 1, i.e., during the extension of the outrigger 13 and the unfolding of the knuckle boom 11, the first and second hydraulic pumps 3, 6 for the drive of the concrete pumping device 2 could be decoupled, especially when driven by the electric motor 4, so that the electric motor 4 does not have to provide any electrical energy for their drive and therefore also requires less energy for its own cooling. In contrast to the electrical concept of the drive system in Fig. 2, the electrical concept of the drive system in Fig. 5 includes two additional energy storage devices 40 and 41. The first energy storage device 40 is, for example, a battery that can store a larger amount of electrical energy to supply, for example, one or all of the electric motors 4, 17, 18 with electrical energy for a certain period of time without necessarily requiring a power connection for the drive of the truck-mounted concrete pump 1. The battery 40 can also be charged, for example, by the first drive motor 4 operating as a generator or by a construction site power supply, for example via the DC circuit 33.The second energy storage device 41, designed for example as a capacitor or so-called supercapacitor, has a comparatively small capacity, but can quickly provide a high electrical power when, for example, an electric motor 4, 17, 18 starts up or during other short power peaks in the system, and recharge itself during periods of lower power demand in order to absorb subsequent power peaks. Fig. 6 shows, particularly in comparison to Fig. 4, very clearly that the design of the gearbox 47 of Fig. 5 enables a significantly more compact design of the drive system. In the drive concept of a truck-mounted concrete pump 1 shown in Fig. 7, with a first drive motor 4 designed as an air-cooled electric motor, the first drive motor 4 can be driven by a second drive motor 5 acting as a generator. In contrast to the drive concepts shown in Figs. 2, 3, 4, 5 to 6, however, no transfer case is required, resulting in a significant reduction in weight and a reduction in the required installation space.Instead of a transfer case, a power take-off (PTO) 44, typically a so-called engine-dependent PTO (known as NMV - Motor-Connected PTO), is used between the truck's drive transmission and the internal combustion engine 5. This PTO is connected via a PTO shaft 49, designed, for example, as a cardan shaft, to the second hydraulic pump 6 and the first hydraulic pump 3 for driving the concrete pumping system 2. The first and second hydraulic pumps 3 and 6, together with the additional hydraulic pump 7 for driving the articulated boom 11 and the outrigger 13, are connected to form a hydraulic pump train. The first drive motor 4 is connected to the three hydraulic pumps 3, 7, and 6.The coupling 36, located between the first and second hydraulic pumps 3, 6, serves to decouple the second hydraulic pump 6 when the first drive motor 4 is used for electric operation, thus preventing unnecessary drag losses. However, when the truck-mounted concrete pump 1 is operated with the second drive motor 5, which is a combustion engine, the coupling 36 is closed, allowing the concrete pumping device 2 to be supplied with the hydraulic power of both hydraulic pumps 3, 6. As in the embodiments shown in Figures 2, 3, 4, 5 to 6, the first drive motor 4, driven by the second drive motor 5, can generate electrical energy which, in the exemplary illustration of Figure 7, is used via the DC link 33 to drive an electric motor 16. This electric motor drives the further hydraulic pumps 8, 9 for driving the pipe diverter 14 and the agitator 9. Figure 7 shows two connector plugs 34 which can be connected, for example, via suitable adapter cables or plugs 42 to construction site power connections 43 with different output capacities. For example, a single construction site power connection with a capacity of 125 amperes can be used, or two construction site power connections with capacities of 63 or 32 amperes can be connected together.The power connections 34 are coupled to a DC circuit 33 via one or more AC / DC converters. In purely electric operation, this circuit supplies electrical energy to the first drive motor 4 and the second electric motor 16 in this exemplary arrangement. The AC / DC converter can, for example, be one or more chargers connected in parallel, so-called on-board chargers (OBCs), which are manufactured in large quantities for use in passenger cars and are relatively inexpensive. The on-board chargers, which typically operate as switched-mode power supplies, also serve as galvanic isolation, thus eliminating the need for large and heavy transformers required for galvanic isolation. Figure 8 shows another embodiment of a truck-mounted concrete pump 1 with a hydraulically driven concrete pumping device 2, at least one first hydraulic pump 3 for the hydraulic drive of the concrete pumping device 2, and a first drive motor 4 for the mechanical drive of the at least one first hydraulic pump 3, wherein the first drive motor 4 is an air-cooled electric motor. The drive concept of Figure 8 is a purely electric drive; that is, in contrast to the concepts of Figures 2, 3, 4, 5, 6 to 7, no second drive motor 5 designed as an internal combustion engine is provided. The electric motors 4, 16 of this exemplary drive concept obtain electrical energy either from a battery 40 or from a construction site power supply 43.The accumulator 40 can be, for example, a smaller accumulator 40 from the superstructure of the truck-mounted concrete pump 1, which provides sufficient energy for the setup phase. The accumulator 40 can also be the traction battery of the truck chassis on which the concrete pump superstructure is mounted, which may provide sufficient energy to drive the concrete pumping device 2 for supplying concrete to smaller construction sites. Of course, several accumulators 40 can also be used. It is also possible to supply one or more additional electric motors 16, 17, preferably directly from the traction battery of the truck chassis, and, for example, to supply the electric motor 4, preferably from a construction site power supply.In order to enable the electrical assembly and disassembly of the truck-mounted concrete pump 1 without a site power connection, the hydraulic pump 7 would then preferably be driven by another electric motor 16,17 and the first drive motor 4 for the drive of the concrete pumping device would be coupled to the first hydraulic pump 3. In the exemplary drive concepts shown in Figures 2, 3, 4, 5, 6, 7 to 8, a first drive motor 4 is provided, which is designed for the mechanical drive of the at least one first hydraulic pump 3, wherein the first drive motor 4 is an air-cooled electric motor. In these drive concepts, a fan wheel 28 is arranged on the drive shaft 30 of the first drive motor 4, which projects from the housing 26, and is fixedly connected to it, so that the fan wheel 28 is always driven at the speed of the electric motor 4. This means that the cooling capacity of the air cooling is directly dependent on the speed of the electric motor 4. Such cooling is sufficient in cases where the speed of the electric motor 4 is mostly in the higher range. However, drive situations are also conceivable in which the electric motor 4 delivers high drive power at a low speed.In these cases, the cooling capacity may be insufficient, necessitating technical measures to improve it. Furthermore, the electric motor 4 is often located in the lower section of the truck-mounted concrete pump 1, for example, between the longitudinal beams of the truck chassis or the pump body. This can lead to contamination by dust, sand, and similar materials, reducing or even completely blocking the cooling effect. Additionally, the fan wheel 28 increases the required installation space for the electric motor 4, which can be disadvantageous in confined spaces. Therefore, in conjunction with Figures 9, 10, 11, 12, 13, 14, 15, 16 to 17, various measures are proposed to reduce or completely eliminate the aforementioned problems associated with air cooling.The variants shown can all be combined in a technically sensible way with the drive concepts of Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7 to Fig. 8, and the variants presented in conjunction with Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15, Fig. 16 to Fig. 17 can also be combined with each other in a technically sensible way and adapted to the drive conditions. In the air-cooled electric motor 4 of Fig. 9, the fan wheel 28 is arranged on the drive shaft 30 of the electric motor 4 and is driven at the speed of the electric motor 4. To increase the cooling capacity, a reduction gear 31a is arranged between the electric motor 4 and the first hydraulic pump 3 driven by it, increasing the speed of the electric motor 4 relative to the speed of the first hydraulic pump 3. This also increases the speed of the fan wheel 28 and correspondingly increases the cooling capacity. In contrast, the air-cooled electric motor 4 in Fig. 10 incorporates a transmission 31b between the drive shaft 30 and the fan wheel 28, which increases the rotational speed of the fan wheel 28 relative to the rotational speed of the drive shaft 30 of the electric motor 4. This measure also significantly increases the cooling capacity. Compared to the variant in Fig. 9, the transmission 31b can, for example, be dimensioned somewhat less robustly because the drive power required for the fan wheel 28 is typically considerably lower than the drive power required by the first hydraulic pump 3. In the air cooling system shown in Fig. 11, the fan wheel 28 is not arranged on the drive shaft 30 of the electric motor 4, but is driven by a separate fan motor 27, which can be, for example, an electric or hydraulic motor. The motor speed of the fan motor 27 can be fixed or can be adjusted, for example, to the cooling requirements of the electric motor 4. For example, a motor temperature sensor 24 can be arranged on the housing 26 of the electric motor 4 or inside it, for example, on the motor winding, and report the motor temperature to a control unit 29, which adjusts the speed or power of the fan motor 27 to the cooling requirements of the electric motor 4.Alternatively or additionally, the power or speed of the fan motor 27 can be linked to the current power consumption of the electric motor 4, so that the cooling capacity is automatically increased as soon as the power consumption of the electric motor 4 increases. The cooling concept shown in Fig. 12 provides for varying the delivery rate of the first hydraulic pump 3 depending on the cooling capacity requirement of the electric motor 4. Typically, a hydraulic pump, especially an axial piston pump with a controllable or pivoting swashplate for adjusting the delivery rate, operates most efficiently, i.e., with a high efficiency, when the pivot angle of the swashplate is set as large as possible, meaning the delivery rate per revolution is as high as possible. However, this leads to a relatively low rotational speed of the electric motor 4 and thus also to a low cooling capacity of the air cooling system, particularly if the fan wheel 28 is arranged directly on the drive shaft 30 of the electric motor 4.To nevertheless achieve an increase in speed to increase cooling capacity, the delivery rate of the hydraulic pump 3 per revolution can be reduced, for example by decreasing the swivel angle of the swashplate of an axial piston hydraulic pump, and simultaneously the speed of the electric motor 4 can be increased. This results in the cooling capacity remaining constant with a constant delivery rate of the first hydraulic pump 3. The advantage here lies in the relatively simple design, as the control system of the first hydraulic pump 3, which is already typically present, can easily be integrated into the control of the cooling capacity. It should, of course, be noted that the electric motor 4, as shown in the drive concepts of Figs. 2, 3, 4, 5, 6, 7 to 8, must be connected to the electric motor 4.Figure 8 shows that, under certain circumstances, an additional hydraulic pump 7 or, depending on the drive concept, further hydraulic pumps 8, 9 can be driven, which must be taken into account when adjusting the motor speed. The speed control of the electric motor 4 presented here can also be linked, for example, to the current motor temperature and / or to the power consumption of the electric motor 4 and / or, for example, to the ambient air temperature. In the cooling concept of Fig. 13, the problem of contamination of the cooling system by aspirated foreign particles, for example dust and sand, is solved by an air duct 21, through which the ambient air for cooling the electric motor 4 is drawn in from an area further above the ground and directed to the air guide housing 19 of the electric motor 4. A further improvement regarding the intake of foreign particles can be achieved by using an air filter 22, which, as shown by way of example in Fig. 14, is arranged at the inlet-side end of the air duct 21. A very effective increase in cooling capacity can also be achieved by using an air conditioning condenser 23 or an air conditioning system, which cools the cooling air 20 drawn in by the fan wheel 28 before it is directed to the electric motor 4 for its cooling. The cooling capacity of the air conditioning condenser 23 or of the air conditioning system can be controlled via a climate control unit 25, which receives data from, for example, an engine temperature sensor 24 and / or an ambient temperature sensor 45 and controls the cooling capacity of the air conditioning condenser 23 on the basis of this data. Figure 16 shows an example of a way to reduce the installation length of an air-cooled electric motor 4. The fan wheel 28 is not located on the drive shaft 30 of the electric motor 4, but rather in the upper part of an air duct 21, where it is driven by a separate fan motor 27. The air duct 21 is designed and arranged such that the cooling airflow 20 from the air duct 21 strikes the electric motor 4 from behind, for example, on the side facing away from the output side, and is then guided around the housing 26 of the electric motor 4 by the air guide housing 19 to dissipate heat from the surface of the electric motor 4. Fig. 17 shows a variant of the cooling air 20 or cooling airflow 20, in which the cooling airflow 20 is directed not longitudinally, but transversely to the housing of the electric motor 4. For this purpose, the cooling air duct 21 is directed laterally from above onto the electric motor 3 and the air guide housing 19. This offers the particular advantage that hydraulic pumps could be arranged on both sides of the drive shaft 30 of the electric motor 4, for example, the first hydraulic pump 3 on one side and the second hydraulic pump 7 and / or further hydraulic pumps 8, 9 on the other side without obstructing the cooling airflow 2. Alternatively, for example, the first hydraulic pump 3 and the second hydraulic pump 6 could be arranged on one side of the electric motor 4, with the second hydraulic pump 6 being able to be decoupled via a coupling 36 during electric operation. In the air cooling of Fig.17 is the fan wheel 28, driven by a separate fan motor 27, arranged in an air duct 21, as in Fig. 16, through which the cooling air 20 is directed to the electric motor 4. In another embodiment of the cooling system for the first drive motor 4, the fan wheel 28 could be mechanically coupled or connected to the drive shaft 30 of the drive motor 4 via a variable coupling (not shown separately in the figures), in particular a viscous coupling or similar device, so that the rotational speed of the fan wheel 28 is variable relative to the rotational speed of the first drive motor 4. As long as the first drive motor 4 does not require cooling, the fan wheel 28 can be decoupled from the drive shaft 30 by means of the viscous coupling, so that no energy is wasted on cooling the first drive motor 4. The viscous coupling can, for example, also be controlled by a controller to regulate the rotational speed of the fan wheel 28 depending on the motor temperature and / or the ambient air temperature.Alternatively or additionally to a viscous coupling, the blades of the fan wheel 28 could, for example, be pivoted so that no or only a small cooling airflow 20 is generated when cooling requirements are low. A high cooling airflow can be generated when needed by adjusting the blades of the fan wheel 28. The fan wheel 28 can have very different shapes, adapted to the respective installation or drive situation. The crucial point is that it generates a flow of cooling air, which dissipates heat from the surface or housing 26 of the first drive motor 4 or, depending on the design of the first drive motor 4, from its interior. Thus, the fan wheel 28 can, for example, be a radial or axial fan, in the form of a ventilator or propeller, or similar designs. The air cooling of the first drive motor 4 can also be achieved with a plurality of fan wheels 28. For example, a first fan wheel 28 arranged on the drive shaft 30 of the first drive motor 4, which ensures continuous base cooling during operation of the first drive motor 28, can be combined with a second fan wheel 28 driven by a fan motor 27. The fan motor 27 is only activated during periods of increased cooling demand and, if necessary, is controlled by the motor and / or ambient temperature as described above. Cooling with a fan wheel 28 driven by a fan motor 27 can also remain active when the first drive motor 4 is not in operation, for example, to cool the first drive motor 4 before it is restarted. Reference symbol list 1 Truck-mounted concrete pump 2 Concrete pumping device 3 First hydraulic pump 4 First drive motor (electric motor / generator) 5 Second drive motor (internal combustion engine) 6 Second hydraulic pump 7 Additional hydraulic pump (mast pump / support pump) 8 Additional hydraulic pump (pipe diverter pump) 9 Additional hydraulic pump (agitator pump) 10 Hydraulic actuators (articulated mast) 11 Articulated mast 12 Additional hydraulic actuators (support) 13 Support 14 Pipe diverter 15 Agitator 16 Additional electric motor 17 Additional electric motor 18 Additional electric motor 19 Air guide housing 20 Cooling air 21 Air duct 22 Air filter 23 Air conditioning condenser 24 Motor temperature sensor 25 Air conditioning control 26 Housing (first drive motor) 27 Fan motor 28 Fan wheel 29 Fan control 30 Drive shaft 31 Gearbox 32 Swivel angle control 33 Internal combustion engine 34 Connector plug 35 Motor control 36 Clutch 37 Cardan shaft 38 AC / DC converter 39 Check valve 40 First energy storage device (accumulator) 41 Second energy storage device(Capacitor) 42 Adapter 43 Construction site power supply 44 Gearbox auxiliary drive (PTO) 45 Ambient temperature sensor 46 Transfer case with four inputs / outputs 47 Transfer case with six inputs / outputs QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature EP 3 847 321 A1

[0002]

Claims

Truck-mounted concrete pump (1) comprising a hydraulically driven concrete pumping device (2), at least one first hydraulic pump (3) which is provided for the hydraulic drive of the concrete pumping device (2), and a first drive motor (4) provided for the mechanical drive of the at least one first hydraulic pump (3), characterized in that the first drive motor (4) is an air-cooled electric motor. Truck-mounted concrete pump (1) according to claim 1, characterized by a second drive motor (5), provided for the mechanical drive of at least one second hydraulic pump (6), which is also provided for the hydraulic drive of the concrete pumping device (2). Truck-mounted concrete pump (1) according to claim 2, characterized in that the second drive motor (5) is an internal combustion engine. Truck-mounted concrete pump (1) according to claim 2 or 3, characterized in that the air-cooled electric motor (4) can be driven by the second drive motor (5) as a generator. A truck-mounted concrete pump (1) according to one of the preceding claims, characterized by at least one further hydraulic pump (7, 8, 9), wherein the at least one further hydraulic pump (7, 8, 9) is provided to drive hydraulic actuating elements (10) of an articulated boom (11) of the truck-mounted concrete pump (1) and / or hydraulic actuating elements (12) of a support (13) of the truck-mounted concrete pump (1) and / or a pipe diverter (14) of the truck-mounted concrete pump (1) and / or an agitator (15) of the truck-mounted concrete pump (1) and / or another hydraulic auxiliary unit of the truck-mounted concrete pump (1), wherein at least one further electric motor (16, 17, 18) is provided for the mechanical drive of the at least one further hydraulic pump (7, 8, 9). Truck-mounted concrete pump (1) according to claims 4 and 5, characterized in that the air-cooled electric motor (4) driven by the second drive motor (5) as a generator supplies the at least one further electric motor (16, 17, 18) with current. Truck-mounted concrete pump (1) according to one of the preceding claims, characterized in that the first drive motor (4) is a synchronous motor. truck-mounted concrete pump (1) according to one of the preceding claims, characterized in that the truck-mounted concrete pump (1) has an air guide housing (19) for guiding cooling air (20) around the first drive motor (4). truck-mounted concrete pump (1) according to one of the preceding claims, characterized in that the truck-mounted concrete pump (1) has an air duct (21) which directs cooling air (20) to the first drive motor (4), in particular into the air guide housing (19). Truck-mounted concrete pump (1) according to one of the preceding claims, characterized in that an air filter (22) is provided for cleaning the cooling air (20). Truck-mounted concrete pump (1) according to one of claims 8 to 10, characterized in that the cooling air (20) is actively cooled by an air conditioning condenser (23) of the truck-mounted concrete pump (1). truck-mounted concrete pump (1) according to one of the preceding claims, characterized in that the truck-mounted concrete pump (1) has a motor temperature sensor (24) wherein the motor temperature sensor (24) detects the temperature of the first drive motor (4). Truck-mounted concrete pump (1) according to one of the preceding claims, characterized in that the truck-mounted concrete pump (1) has an ambient temperature sensor (45), wherein the ambient temperature sensor (45) detects the temperature of the ambient air of the truck-mounted concrete pump (1). Truck-mounted concrete pump (1) according to claim 11 and claim 12 and / or 13, characterized in that the truck-mounted concrete pump (1) has a climate control unit (25), wherein the climate control unit (25) operates the climate condenser (23) with a cooling capacity that depends on the motor temperature of the first drive motor (4) and / or the temperature of the ambient air. A truck-mounted concrete pump (1) according to one of the preceding claims, characterized in that the first drive motor (4) has a housing (26), wherein the truck-mounted concrete pump (1) has a fan wheel (28) driven by a fan motor (27), wherein the fan wheel (28) conveys cooling air (20) along the housing (26). Truck-mounted concrete pump (1) according to claim 12 and / or 13 and claim 15, characterized in that the truck-mounted concrete pump (1) has a fan control (29), wherein the fan control (29) controls the fan motor (27) with a speed dependent on the temperature of the first drive motor (4) and / or the temperature of the ambient air. Truck-mounted concrete pump (1) according to one of claims 8 to 10 and claim 15 or 16, characterized in that the fan wheel (28) and / or the fan motor (27) is / are arranged in the air duct (21) and / or in the air guide housing (19). A truck-mounted concrete pump (1) according to one of the preceding claims, characterized in that the first drive motor (4) has a drive shaft (30) projecting from the housing (26) of the drive motor (4), wherein at least one fan wheel (28) is arranged on the drive shaft (30), wherein the at least one fan wheel (28) conveys cooling air (20) along the housing (26) when the drive shaft (30) is rotated. Truck-mounted concrete pump (1) according to claim 18, characterized in that a gearbox (31) is arranged between the fan wheel (28) and the at least one hydraulic pump (3, 6), such that the drive speed at which the first drive motor (4) drives the fan wheel (28) differs from the drive speed at which the at least one hydraulic pump (3) is driven. Truck-mounted concrete pump (1) according to claim 18, characterized in that a variable coupling, in particular a viscous coupling, is arranged between the fan wheel (28) and the at least one hydraulic pump (3, 6), so that the drive speed of the fan wheel (28) is variable relative to the drive speed of the first drive motor (4). Truck-mounted concrete pump (1) according to one of claims 15 to 20, characterized in that the fan wheel (28) has fan blades with a variable swivel angle. Truck-mounted concrete pump (1) according to one of claims 1 to 11 or 14 to 21 and claim 12 and / or claim 13, characterized in that the at least one hydraulic pump (3) is an axial piston pump with a pivoting swashplate, wherein the pivot angle of the swashplate is adjustable for varying the delivery rate by means of a pivot angle control (32), wherein the pivot angle control (32) is provided to set a pivot angle in the at least one first hydraulic pump (3) that depends on the temperature of the first drive motor (4) and / or the temperature of the ambient air.

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